Abdominal obesity
Encyclopedia
Abdominal obesity, colloquially known as belly fat or clinically
as central obesity, is the accumulation of abdominal fat resulting in an increase in waist size. There is a strong correlation between central obesity
and cardiovascular disease
.
Visceral fat, also known as organ fat or intra-abdominal fat, is located inside the peritoneal cavity
, packed in between internal organs and torso, as opposed to subcutaneous fat which is found underneath the skin
, and intramuscular fat
which is found interspersed in skeletal muscle
. Visceral fat is composed of several adipose depots including mesenteric, epididymal
white adipose tissue
(EWAT) and perirenal fat. An excess of visceral fat is known as central obesity, the "pot belly" or "beer belly" effect, in which the abdomen protrudes excessively. This body type is also known as "apple shaped", as opposed to "pear shaped", in which fat is deposited on the hips and buttocks.
and environment
. There is a growing consensus that, in humans, central obesity is related to the excessive consumption of fructose
. Other environmental factors, such as maternal smoking, estrogenic compounds in the diet and endocrine-disrupting chemicals may be important also.
Hypercortisolism, such as in Cushing's syndrome
also leads to central obesity. Many prescription drugs, such as dexamethasone and other steroids, can also have side effects resulting in central obesity
, especially in the presence of elevated insulin levels.
Because fat in the midsection contains the greatest amount of cortisol receptors, fat is created and stored in the midsection, specifically in fat cell deposits deep in the abdomen.
includes distinguishing central obesity from ascites
and intestinal bloating
. In the cohort
of 15,000 people participating in the National Health and Nutrition Examination Survey
(NHANES III), waist circumference explained obesity-related health risk better than the body mass index
(or BMI) when metabolic syndrome
was taken as an outcome measure
and this difference was statistically significant. In other words, excessive waist circumference appears to be more of a risk factor for metabolic syndrome than BMI
. Another measure of central obesity which has shown superiority to BMI in predicting cardiovascular disease risk is the Index of Central Obesity (waist-to-height ratio - WHtR), where a ratio of >=0.5 (i.e. a waist circumference at least half of the individual's height) is predictive of increased risk.
An increasing acceptance of the importance of central obesity
within the medical profession as an indicator of health risk has led to new developments in obesity diagnosis such as the Body Volume Index
, which measures central obesity
by measuring a person’s body shape and their weight distribution.
. The National Cholesterol Education Program
Adult Treatment Panel III suggested cut off of 102 cm and 88 cm for males and females as a marker of central obesity. The same was used in defining metabolic syndrome
. Misra et al. suggested that these cutoffs are not applicable among Indians and the cutoffs be lowered to 90 cm and 80 cm for males and females. Various race specific cutoffs were suggested by different groups. The International Diabetes Federation
defined central obesity based on these various race and gender specific cutoffs. The other limitation of waist circumference is that it can not be applied in children.
Parikh et al looked at the average heights of various races and suggested that by using ICO various race- and gender-specific cutoffs of waist circumference can be discarded. An ICO cutoff of more than 0.5 is suggested as a criteria to define central obesity. Parikh et al further tested a modified definition of of metabolic syndrome
in which waist circumference was replaced with ICO in the National Health and Nutrition Examination Survey
(NHANES) database and found the modified definition to be more specific and sensitive.
This parameter has been used in the study of metabolic syndrome
and cardiovascular disease
.
is based upon the principle that excess abdominal weight, measured by part volume as a percentage of total volume, constitutes a greater health risk. Recent validation has concluded that total and regional body volume estimates correlate positively and significantly with biomarkers of cardio-vascular risk and BVI
calculations correlate significantly with all biomarkers of cardio-vascular risk.
, hypertension
, insulin resistance
, and Diabetes Mellitus Type 2
(see below). Belly fat is a symptom of metabolic syndrome, and is an indicator used in the diagnosis of that disorder.
Central obesity can be a feature of lipodystrophies
, a group of diseases which is either inherited
, or due to secondary causes (often protease inhibitor
s, a group of medication
s against AIDS
). Central obesity is a symptom of Cushing's syndrome
and is also common in patients with polycystic ovary syndrome
(PCOS). Central obesity is associated with glucose intolerance and dyslipidemia
.
. Central obesity is known to predispose individuals for insulin resistance. Abdominal fat is especially active hormonally, secreting a group of hormones called adipokine
s that may possibly impair glucose tolerance
.
Insulin resistance
is a major feature of Diabetes Mellitus Type 2
(T2DM), and central obesity is correlated with both insulin resistance and T2DM itself. Increased adiposity (obesity) raises serum resistin levels, which in turn directly correlate to insulin resistance. Studies have also confirmed a direct correlation between resistin levels and T2DM. And it is waistline adipose tissue (central obesity) which seems to be the foremost type of fat deposits contributing to rising levels of serum resistin. Conversely, serum resistin levels have been found to decline with decreased adiposity following medical treatment.
examining over 700 adults found evidence to suggest higher volumes of visceral fat, regardless of overall weight, were associated with smaller brain volumes and increased risk of dementia
.
In those with a BMI under 35, intra-abdominal body fat is related to negative health outcomes independent of total body fat. Intra-abdominal or visceral fat has a particularly strong correlation with cardiovascular disease
.
causes fat to be stored in the buttocks
, thighs, and hips
in women. Men are more likely to have fat stored in the belly due to sex hormone differences
. When women reach menopause
and the estrogen produced by ovaries declines, fat migrates from their buttocks, hips and thighs to their waists; later fat is stored in the belly
.
or sibutramine
, although the latter has been associated with increased cardiovascular events and strokes and has been withdrawn from the market in the United States
, the UK, the EU, Australia
, Canada
, Hong Kong
, Thailand
and Mexico
.
In the presence of diabetes mellitus type 2
, the physician might instead prescribe metformin
and thiazolidinedione
s (rosiglitazone
or pioglitazone
) as anti-diabetic drug
s rather than sulfonylurea
derivatives. Thiazolidinediones may cause slight weight gain but decrease "pathologic" abdominal fat (visceral fat), and therefore may be prescribed for diabetics with central obesity.
Low fat diets may not be an effective long term intervention for obesity: as Bacon and Aphramor wrote, "The majority of individuals regain virtually all of the weight that was lost during treatment.". The Women's Health Initiative ("the largest and longest randomized, controlled dietary intervention clinical trial") found that long-term dietary intervention increased the waist circumference of both the intervention group and the control group, though the increase was smaller for the intervention group. The conclusion was that mean weight decreased significantly in the intervention group from baseline to year 1 by 2.2 kg (P<.001) and was 2.2 kg less than the control group change from baseline at year 1. This difference from baseline between control and intervention groups diminished over time, but a significant difference in weight was maintained through year 9, the end of the study.
(that is, exercising a specific muscle or location of the body) most effectively burns fat at the desired location, but this is not the case. Spot exercise is beneficial for building specific muscles, but it has little effect, if any, on fat in that area of the body, or on the body's distribution of body fat. The same logic applies to sit-ups and belly fat. Sit-ups
, crunches
and other abdominal exercises are useful in building the abdominal muscles, but they have little effect, if any, on the adipose tissue
located there.
drinking. However, there is little scientific evidence that beer drinkers are more prone to abdominal obesity, despite it being known colloquially as "beer belly", "beer gut", or "beer pot". One of the few studies conducted on the subject did not find that beer drinkers are more prone to abdominal obesity than nondrinkers or drinkers of wine or spirits. Chronic alcoholism can lead to cirrhosis
, symptoms of which include gynecomastia
(enlarged breasts) and ascites
(abdominal fluid). These symptoms can suggest the appearance of central obesity.
"Love handles" and "spare tyre" (or "spare tire") are colloquial terms for deposits of fat
around a person's midsection, especially visible on the sides over the abdominal external oblique muscle
. Love handles are visible deposits on each side of the abdomen or lower back (that a hypothetical lover might grab to pull the subject into an embrace); a spare tire appears to encircle the abdomen (thus resembling an automobile tire).
"Muffin top
" is a term used for a person whose midsection spills over the waistline of his or her trousers in a manner that resembles the top of a muffin
spilling over its baking pan.
"Pot belly" is another colloquial term used to describe a person who has an excessive amount of abdominal fat. This is especially pronounced and visible over clothing.
Medical terminology
Medical terminology is a vocabulary for accurately describing the human body and associated components, conditions, processes and process in a science-based manner. Some examples are: R.I.C.E., trapezius, and latissimus dorsi. It is to be used in the medical and nursing fields...
as central obesity, is the accumulation of abdominal fat resulting in an increase in waist size. There is a strong correlation between central obesity
Obesity
Obesity is a medical condition in which excess body fat has accumulated to the extent that it may have an adverse effect on health, leading to reduced life expectancy and/or increased health problems...
and cardiovascular disease
Cardiovascular disease
Heart disease or cardiovascular disease are the class of diseases that involve the heart or blood vessels . While the term technically refers to any disease that affects the cardiovascular system , it is usually used to refer to those related to atherosclerosis...
.
Visceral fat, also known as organ fat or intra-abdominal fat, is located inside the peritoneal cavity
Peritoneal cavity
The peritoneal cavity is a potential space between the parietal peritoneum and visceral peritoneum, that is, the two membranes that separate the organs in the abdominal cavity from the abdominal wall...
, packed in between internal organs and torso, as opposed to subcutaneous fat which is found underneath the skin
Skin
-Dermis:The dermis is the layer of skin beneath the epidermis that consists of connective tissue and cushions the body from stress and strain. The dermis is tightly connected to the epidermis by a basement membrane. It also harbors many Mechanoreceptors that provide the sense of touch and heat...
, and intramuscular fat
Intramuscular fat
Intramuscular fat or Intramuscular triglycerides is located throughout skeletal muscle and is responsible for the marbling seen in certain cuts of beef. In humans, excess accumulation of intramuscular fat is associated with insulin resistance and type 2 diabetes...
which is found interspersed in skeletal muscle
Skeletal muscle
Skeletal muscle is a form of striated muscle tissue existing under control of the somatic nervous system- i.e. it is voluntarily controlled. It is one of three major muscle types, the others being cardiac and smooth muscle...
. Visceral fat is composed of several adipose depots including mesenteric, epididymal
Epididymis
The epididymis is part of the male reproductive system and is present in all male amniotes. It is a narrow, tightly-coiled tube connecting the efferent ducts from the rear of each testicle to its vas deferens. A similar, but probably non-homologous, structure is found in cartilaginous...
white adipose tissue
Adipose tissue
In histology, adipose tissue or body fat or fat depot or just fat is loose connective tissue composed of adipocytes. It is technically composed of roughly only 80% fat; fat in its solitary state exists in the liver and muscles. Adipose tissue is derived from lipoblasts...
(EWAT) and perirenal fat. An excess of visceral fat is known as central obesity, the "pot belly" or "beer belly" effect, in which the abdomen protrudes excessively. This body type is also known as "apple shaped", as opposed to "pear shaped", in which fat is deposited on the hips and buttocks.
Causes
The immediate cause of obesity is net energy imbalance — the organism consumes more usable calories than it expends, wastes, or discards via elimination. The fundamental cause of obesity is not well understood, but is presumably a combination of the organism's genesGenetics
Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....
and environment
Environment (biophysical)
The biophysical environment is the combined modeling of the physical environment and the biological life forms within the environment, and includes all variables, parameters as well as conditions and modes inside the Earth's biosphere. The biophysical environment can be divided into two categories:...
. There is a growing consensus that, in humans, central obesity is related to the excessive consumption of fructose
Fructose
Fructose, or fruit sugar, is a simple monosaccharide found in many plants. It is one of the three dietary monosaccharides, along with glucose and galactose, that are absorbed directly into the bloodstream during digestion. Fructose was discovered by French chemist Augustin-Pierre Dubrunfaut in 1847...
. Other environmental factors, such as maternal smoking, estrogenic compounds in the diet and endocrine-disrupting chemicals may be important also.
Hypercortisolism, such as in Cushing's syndrome
Cushing's syndrome
Cushing's syndrome is a hormone disorder caused by high levels of cortisol in the blood. This can be caused by taking glucocorticoid drugs, or by tumors that produce cortisol or adrenocorticotropic hormone or CRH...
also leads to central obesity. Many prescription drugs, such as dexamethasone and other steroids, can also have side effects resulting in central obesity
Central obesity
Abdominal obesity, colloquially known as belly fat or clinically as central obesity, is the accumulation of abdominal fat resulting in an increase in waist size...
, especially in the presence of elevated insulin levels.
Because fat in the midsection contains the greatest amount of cortisol receptors, fat is created and stored in the midsection, specifically in fat cell deposits deep in the abdomen.
Diagnosis
While central obesity can be obvious just by looking at the naked body (see the picture), the severity of central obesity is determined by taking waist and hip measurements. The absolute waist circumference (>102 centimetres (40.2 in) in men and >88 centimetres (34.6 in) in women) and the waist-hip ratio (>0.9 for men and >0.85 for women) are both used as measures of central obesity. A differential diagnosisDifferential diagnosis
A differential diagnosis is a systematic diagnostic method used to identify the presence of an entity where multiple alternatives are possible , and may also refer to any of the included candidate alternatives A differential diagnosis (sometimes abbreviated DDx, ddx, DD, D/Dx, or ΔΔ) is a...
includes distinguishing central obesity from ascites
Ascites
Ascites is a gastroenterological term for an accumulation of fluid in the peritoneal cavity.The medical condition is also known as peritoneal cavity fluid, peritoneal fluid excess, hydroperitoneum or more archaically as abdominal dropsy. Although most commonly due to cirrhosis and severe liver...
and intestinal bloating
Bloating
Bloating is any abnormal general swelling, or increase in diameter of the abdominal area. As a symptom, the patient feels a full and tight abdomen, which may cause abdominal pain sometimes accompanied by increased borborygmus or more seriously the total lack of borborygmus.-Symptoms:The most common...
. In the cohort
Cohort (statistics)
In statistics and demography, a cohort is a group of subjects who have shared a particular time together during a particular time span . Cohorts may be tracked over extended periods in a cohort study. The cohort can be modified by censoring, i.e...
of 15,000 people participating in the National Health and Nutrition Examination Survey
National Health and Nutrition Examination Survey
The National Health and Nutrition Examination Survey is a survey research program conducted by the National Center for Health Statistics to asses the health and nutritional status of adults and children in the United States, and to track changes over time. The survey combines interviews and...
(NHANES III), waist circumference explained obesity-related health risk better than the body mass index
Body mass index
The body mass index , or Quetelet index, is a heuristic proxy for human body fat based on an individual's weight and height. BMI does not actually measure the percentage of body fat. It was invented between 1830 and 1850 by the Belgian polymath Adolphe Quetelet during the course of developing...
(or BMI) when metabolic syndrome
Metabolic syndrome
Metabolic syndrome is a combination of medical disorders that, when occurring together, increase the risk of developing cardiovascular disease and diabetes. It affects one in five people in the United States and prevalence increases with age...
was taken as an outcome measure
Clinical endpoint
In a clinical research trial, a clinical endpoint generally refers to occurrence of a disease, symptom, sign or laboratory abnormality that constitutes one of the target outcomes of the trial, but may also refer to any such disease or sign that strongly motivates the withdrawal of that individual...
and this difference was statistically significant. In other words, excessive waist circumference appears to be more of a risk factor for metabolic syndrome than BMI
Body mass index
The body mass index , or Quetelet index, is a heuristic proxy for human body fat based on an individual's weight and height. BMI does not actually measure the percentage of body fat. It was invented between 1830 and 1850 by the Belgian polymath Adolphe Quetelet during the course of developing...
. Another measure of central obesity which has shown superiority to BMI in predicting cardiovascular disease risk is the Index of Central Obesity (waist-to-height ratio - WHtR), where a ratio of >=0.5 (i.e. a waist circumference at least half of the individual's height) is predictive of increased risk.
An increasing acceptance of the importance of central obesity
Central obesity
Abdominal obesity, colloquially known as belly fat or clinically as central obesity, is the accumulation of abdominal fat resulting in an increase in waist size...
within the medical profession as an indicator of health risk has led to new developments in obesity diagnosis such as the Body Volume Index
Body volume index
The Body Volume Index is a new measurement for human obesity that has been proposed as an alternative to the Body Mass Index .BMI is based on a measurement of total mass, irrespective of the location of the mass, but BVI looks at the relationship between mass and volume distribution...
, which measures central obesity
Central obesity
Abdominal obesity, colloquially known as belly fat or clinically as central obesity, is the accumulation of abdominal fat resulting in an increase in waist size...
by measuring a person’s body shape and their weight distribution.
Index of Central Obesity
Index of Central Obesity (ICO) is the ratio of waist circumference and height first proposed by a Parikh et al in 2007 as a better substitute to the widely-used waist circumference in defining metabolic syndromeMetabolic syndrome
Metabolic syndrome is a combination of medical disorders that, when occurring together, increase the risk of developing cardiovascular disease and diabetes. It affects one in five people in the United States and prevalence increases with age...
. The National Cholesterol Education Program
National Cholesterol Education Program
The National Cholesterol Education Program is a program managed by the National Heart, Lung and Blood Institute, a division of the National Institutes of Health. Its goal is to reduce increased cardiovascular disease rates due to hypercholesterolemia in the United States of America...
Adult Treatment Panel III suggested cut off of 102 cm and 88 cm for males and females as a marker of central obesity. The same was used in defining metabolic syndrome
Metabolic syndrome
Metabolic syndrome is a combination of medical disorders that, when occurring together, increase the risk of developing cardiovascular disease and diabetes. It affects one in five people in the United States and prevalence increases with age...
. Misra et al. suggested that these cutoffs are not applicable among Indians and the cutoffs be lowered to 90 cm and 80 cm for males and females. Various race specific cutoffs were suggested by different groups. The International Diabetes Federation
International Diabetes Federation
The International Diabetes Federation is a worldwide alliance of some 200 diabetes associations in more than 160 countries, who have come together to enhance the lives of people with diabetes everywhere. For over 50 years, IDF has been at the vanguard of global diabetes advocacy...
defined central obesity based on these various race and gender specific cutoffs. The other limitation of waist circumference is that it can not be applied in children.
Parikh et al looked at the average heights of various races and suggested that by using ICO various race- and gender-specific cutoffs of waist circumference can be discarded. An ICO cutoff of more than 0.5 is suggested as a criteria to define central obesity. Parikh et al further tested a modified definition of of metabolic syndrome
Metabolic syndrome
Metabolic syndrome is a combination of medical disorders that, when occurring together, increase the risk of developing cardiovascular disease and diabetes. It affects one in five people in the United States and prevalence increases with age...
in which waist circumference was replaced with ICO in the National Health and Nutrition Examination Survey
National Health and Nutrition Examination Survey
The National Health and Nutrition Examination Survey is a survey research program conducted by the National Center for Health Statistics to asses the health and nutritional status of adults and children in the United States, and to track changes over time. The survey combines interviews and...
(NHANES) database and found the modified definition to be more specific and sensitive.
This parameter has been used in the study of metabolic syndrome
Metabolic syndrome
Metabolic syndrome is a combination of medical disorders that, when occurring together, increase the risk of developing cardiovascular disease and diabetes. It affects one in five people in the United States and prevalence increases with age...
and cardiovascular disease
Cardiovascular disease
Heart disease or cardiovascular disease are the class of diseases that involve the heart or blood vessels . While the term technically refers to any disease that affects the cardiovascular system , it is usually used to refer to those related to atherosclerosis...
.
Body Volume Index
BVIBody volume index
The Body Volume Index is a new measurement for human obesity that has been proposed as an alternative to the Body Mass Index .BMI is based on a measurement of total mass, irrespective of the location of the mass, but BVI looks at the relationship between mass and volume distribution...
is based upon the principle that excess abdominal weight, measured by part volume as a percentage of total volume, constitutes a greater health risk. Recent validation has concluded that total and regional body volume estimates correlate positively and significantly with biomarkers of cardio-vascular risk and BVI
Body volume index
The Body Volume Index is a new measurement for human obesity that has been proposed as an alternative to the Body Mass Index .BMI is based on a measurement of total mass, irrespective of the location of the mass, but BVI looks at the relationship between mass and volume distribution...
calculations correlate significantly with all biomarkers of cardio-vascular risk.
Health risks
Central obesity is associated with a statistically higher risk of heart diseaseHeart disease
Heart disease, cardiac disease or cardiopathy is an umbrella term for a variety of diseases affecting the heart. , it is the leading cause of death in the United States, England, Canada and Wales, accounting for 25.4% of the total deaths in the United States.-Types:-Coronary heart disease:Coronary...
, hypertension
Hypertension
Hypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...
, insulin resistance
Insulin resistance
Insulin resistance is a physiological condition where the natural hormone insulin becomes less effective at lowering blood sugars. The resulting increase in blood glucose may raise levels outside the normal range and cause adverse health effects, depending on dietary conditions. Certain cell types...
, and Diabetes Mellitus Type 2
Diabetes mellitus type 2
Diabetes mellitus type 2formerly non-insulin-dependent diabetes mellitus or adult-onset diabetesis a metabolic disorder that is characterized by high blood glucose in the context of insulin resistance and relative insulin deficiency. Diabetes is often initially managed by increasing exercise and...
(see below). Belly fat is a symptom of metabolic syndrome, and is an indicator used in the diagnosis of that disorder.
Central obesity can be a feature of lipodystrophies
Lipodystrophy
Lipodystrophy is a medical condition characterized by abnormal or degenerative conditions of the body's adipose tissue. A more specific term, lipoatrophy is used when describing the loss of fat from one area...
, a group of diseases which is either inherited
Genetic disorder
A genetic disorder is an illness caused by abnormalities in genes or chromosomes, especially a condition that is present from before birth. Most genetic disorders are quite rare and affect one person in every several thousands or millions....
, or due to secondary causes (often protease inhibitor
Protease inhibitor (pharmacology)
Protease inhibitors are a class of drugs used to treat or prevent infection by viruses, including HIV and Hepatitis C. PIs prevent viral replication by inhibiting the activity of proteases, e.g.HIV-1 protease, enzymes used by the viruses to cleave nascent proteins for final assembly of new...
s, a group of medication
Medication
A pharmaceutical drug, also referred to as medicine, medication or medicament, can be loosely defined as any chemical substance intended for use in the medical diagnosis, cure, treatment, or prevention of disease.- Classification :...
s against AIDS
AIDS
Acquired immune deficiency syndrome or acquired immunodeficiency syndrome is a disease of the human immune system caused by the human immunodeficiency virus...
). Central obesity is a symptom of Cushing's syndrome
Cushing's syndrome
Cushing's syndrome is a hormone disorder caused by high levels of cortisol in the blood. This can be caused by taking glucocorticoid drugs, or by tumors that produce cortisol or adrenocorticotropic hormone or CRH...
and is also common in patients with polycystic ovary syndrome
Polycystic ovary syndrome
Polycystic ovary syndrome is one of the most common female endocrine disorders. PCOS is a complex, heterogeneous disorder of uncertain aetiology, but there is strong evidence that it can to a large degree be classified as a genetic disease....
(PCOS). Central obesity is associated with glucose intolerance and dyslipidemia
Dyslipidemia
Dyslipidemia or dyslipidaemia is an abnormal amount of lipids in the blood. In developed countries, most dyslipidemias are hyperlipidemias; that is, an elevation of lipids in the blood, often due to diet and lifestyle. The prolonged elevation of insulin levels can lead to dyslipidemia...
.
Relationship with diabetes
There are numerous theories as to the exact cause and mechanism in Type 2 DiabetesDiabetes mellitus type 2
Diabetes mellitus type 2formerly non-insulin-dependent diabetes mellitus or adult-onset diabetesis a metabolic disorder that is characterized by high blood glucose in the context of insulin resistance and relative insulin deficiency. Diabetes is often initially managed by increasing exercise and...
. Central obesity is known to predispose individuals for insulin resistance. Abdominal fat is especially active hormonally, secreting a group of hormones called adipokine
Adipokine
The adipokines or adipocytokines are cytokines secreted by adipose tissue.Members include:* chemerin* interleukin-6...
s that may possibly impair glucose tolerance
Impaired glucose tolerance
Impaired glucose tolerance is a pre-diabetic state of dysglycemia that is associated with insulin resistance and increased risk of cardiovascular pathology. IGT may precede type 2 diabetes mellitus by many years...
.
Insulin resistance
Insulin resistance
Insulin resistance is a physiological condition where the natural hormone insulin becomes less effective at lowering blood sugars. The resulting increase in blood glucose may raise levels outside the normal range and cause adverse health effects, depending on dietary conditions. Certain cell types...
is a major feature of Diabetes Mellitus Type 2
Diabetes mellitus type 2
Diabetes mellitus type 2formerly non-insulin-dependent diabetes mellitus or adult-onset diabetesis a metabolic disorder that is characterized by high blood glucose in the context of insulin resistance and relative insulin deficiency. Diabetes is often initially managed by increasing exercise and...
(T2DM), and central obesity is correlated with both insulin resistance and T2DM itself. Increased adiposity (obesity) raises serum resistin levels, which in turn directly correlate to insulin resistance. Studies have also confirmed a direct correlation between resistin levels and T2DM. And it is waistline adipose tissue (central obesity) which seems to be the foremost type of fat deposits contributing to rising levels of serum resistin. Conversely, serum resistin levels have been found to decline with decreased adiposity following medical treatment.
Relationship with Alzheimer's Disease
A US study reported in May 2010 Annals of NeurologyAnnals of Neurology
Annals of Neurology is a peer-reviewed medical journal covering neurology....
examining over 700 adults found evidence to suggest higher volumes of visceral fat, regardless of overall weight, were associated with smaller brain volumes and increased risk of dementia
Dementia
Dementia is a serious loss of cognitive ability in a previously unimpaired person, beyond what might be expected from normal aging...
.
Measurement
There are various ways of measuring abdominal obesity including:- Absolute waist circumference (>102 cm in men and >88 cm in women)
- Waist–hip ratio (the circumference of the waist divided by that of the hips of >0.9 for men and >0.85 for women)
- Index of Central Obesity
- Sagittal Abdominal DiameterSagittal Abdominal DiameterSagittal Abdominal Diameter is a measure of visceral obesity, the amount of fat in the gut region. SAD is the distance from the small of the back to the upper abdomen at the point midway between the top of the pelvis and the bottom of the ribs, measured while standing...
In those with a BMI under 35, intra-abdominal body fat is related to negative health outcomes independent of total body fat. Intra-abdominal or visceral fat has a particularly strong correlation with cardiovascular disease
Cardiovascular disease
Heart disease or cardiovascular disease are the class of diseases that involve the heart or blood vessels . While the term technically refers to any disease that affects the cardiovascular system , it is usually used to refer to those related to atherosclerosis...
.
Sex differences
Female sex hormoneEstrogen
Estrogens , oestrogens , or œstrogens, are a group of compounds named for their importance in the estrous cycle of humans and other animals. They are the primary female sex hormones. Natural estrogens are steroid hormones, while some synthetic ones are non-steroidal...
causes fat to be stored in the buttocks
Buttocks
The buttocks are two rounded portions of the anatomy, located on the posterior of the pelvic region of apes and humans, and many other bipeds or quadrupeds, and comprise a layer of fat superimposed on the gluteus maximus and gluteus medius muscles. Physiologically, the buttocks enable weight to...
, thighs, and hips
Hip (anatomy)
In vertebrate anatomy, hip refer to either an anatomical region or a joint.The hip region is located lateral to the gluteal region , inferior to the iliac crest, and overlying the greater trochanter of the femur, or "thigh bone"...
in women. Men are more likely to have fat stored in the belly due to sex hormone differences
Sex differences in humans
A sex difference is a distinction of biological and/or physiological characteristics associated with either males or females of a species. These can be of several types, including direct and indirect. Direct being the direct result of differences prescribed by the Y-chromosome, and indirect being...
. When women reach menopause
Menopause
Menopause is a term used to describe the permanent cessation of the primary functions of the human ovaries: the ripening and release of ova and the release of hormones that cause both the creation of the uterine lining and the subsequent shedding of the uterine lining...
and the estrogen produced by ovaries declines, fat migrates from their buttocks, hips and thighs to their waists; later fat is stored in the belly
Abdomen
In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...
.
Prevention and treatments
A permanent routine of exercise, eating healthier and consuming the same number or fewer calories than one expends will prevent and help fight obesity. Adjunctive therapies which may be prescribed by a physician are orlistatOrlistat
Orlistat , also known as tetrahydrolipstatin, is a drug designed to treat obesity. Its primary function is preventing the absorption of fats from the human diet, thereby reducing caloric intake...
or sibutramine
Sibutramine
Sibutramine is an oral anorexiant. Until 2010 it was marketed and prescribed as an adjunct in the treatment of exogenous obesity along with diet and exercise...
, although the latter has been associated with increased cardiovascular events and strokes and has been withdrawn from the market in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, the UK, the EU, Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
, Hong Kong
Hong Kong
Hong Kong is one of two Special Administrative Regions of the People's Republic of China , the other being Macau. A city-state situated on China's south coast and enclosed by the Pearl River Delta and South China Sea, it is renowned for its expansive skyline and deep natural harbour...
, Thailand
Thailand
Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...
and Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
.
In the presence of diabetes mellitus type 2
Diabetes mellitus
Diabetes mellitus, often simply referred to as diabetes, is a group of metabolic diseases in which a person has high blood sugar, either because the body does not produce enough insulin, or because cells do not respond to the insulin that is produced...
, the physician might instead prescribe metformin
Metformin
Metformin is an oral antidiabetic drug in the biguanide class. It is the first-line drug of choice for the treatment of type 2 diabetes, in particular, in overweight and obese people and those with normal kidney function. Its use in gestational diabetes has been limited by safety concerns...
and thiazolidinedione
Thiazolidinedione
The thiazolidinediones , also known as glitazones, are a class of medications used in the treatment of diabetes mellitus type 2. They were introduced in the late 1990s.- Mechanism of action :...
s (rosiglitazone
Rosiglitazone
Rosiglitazone is an antidiabetic drug in the thiazolidinedione class of drugs. It works as an insulin sensitizer, by binding to the PPAR receptors in fat cells and making the cells more responsive to insulin...
or pioglitazone
Pioglitazone
Pioglitazone is a prescription drug of the class thiazolidinedione with hypoglycemic action.Pioglitazone is marketed as trademarks Actos in the USA, Canada, the UK and Germany, Glustin in Europe,"Glizone" and "Pioz" in India by Zydus CND and USV respectively and Zactos in Mexico by Takeda...
) as anti-diabetic drug
Anti-diabetic drug
Anti-diabetic medications treat diabetes mellitus by lowering glucose levels in the blood. With the exceptions of insulin, exenatide, and pramlintide, all are administered orally and are thus also called oral hypoglycemic agents or oral antihyperglycemic agents...
s rather than sulfonylurea
Sulfonylurea
Sulfonylurea derivatives are a class of antidiabetic drugs that are used in the management of diabetes mellitus type 2. They act by increasing insulin release from the beta cells in the pancreas.-First generation:* Carbutamide...
derivatives. Thiazolidinediones may cause slight weight gain but decrease "pathologic" abdominal fat (visceral fat), and therefore may be prescribed for diabetics with central obesity.
Low fat diets may not be an effective long term intervention for obesity: as Bacon and Aphramor wrote, "The majority of individuals regain virtually all of the weight that was lost during treatment.". The Women's Health Initiative ("the largest and longest randomized, controlled dietary intervention clinical trial") found that long-term dietary intervention increased the waist circumference of both the intervention group and the control group, though the increase was smaller for the intervention group. The conclusion was that mean weight decreased significantly in the intervention group from baseline to year 1 by 2.2 kg (P<.001) and was 2.2 kg less than the control group change from baseline at year 1. This difference from baseline between control and intervention groups diminished over time, but a significant difference in weight was maintained through year 9, the end of the study.
Sit-ups myth
There is a common misconception that spot exerciseSpot reduction
Spot reduction refers to the belief, long viewed as a myth, that fat can be targeted for reduction from a specific area of the body. There is a common view, although many people believe that view is misguided, that it is possible to achieve spot reduction through exercise of specific muscles in...
(that is, exercising a specific muscle or location of the body) most effectively burns fat at the desired location, but this is not the case. Spot exercise is beneficial for building specific muscles, but it has little effect, if any, on fat in that area of the body, or on the body's distribution of body fat. The same logic applies to sit-ups and belly fat. Sit-ups
Sit-up (exercise)
The sit-up is a strength training exercise commonly performed with the aim of strengthening the hip flexors and abdominal muscles. It begins with lying with the back on the floor, typically with the arms across the chest or hands behind the head and the knees bent in an attempt to reduce stress on...
, crunches
Crunch (exercise)
The crunch is one of the most common abdominal exercises. It primarily works the rectus abdominis muscle.-Form:A crunch begins with lying face up on the floor with knees bent. The movement begins by curling the shoulders towards the pelvis. The hands can be behind or beside the neck or crossed over...
and other abdominal exercises are useful in building the abdominal muscles, but they have little effect, if any, on the adipose tissue
Adipose tissue
In histology, adipose tissue or body fat or fat depot or just fat is loose connective tissue composed of adipocytes. It is technically composed of roughly only 80% fat; fat in its solitary state exists in the liver and muscles. Adipose tissue is derived from lipoblasts...
located there.
Slang terms
Several colloquial terms used to refer to central obesity, and to people who have it, refer to beerBeer
Beer is the world's most widely consumed andprobably oldest alcoholic beverage; it is the third most popular drink overall, after water and tea. It is produced by the brewing and fermentation of sugars, mainly derived from malted cereal grains, most commonly malted barley and malted wheat...
drinking. However, there is little scientific evidence that beer drinkers are more prone to abdominal obesity, despite it being known colloquially as "beer belly", "beer gut", or "beer pot". One of the few studies conducted on the subject did not find that beer drinkers are more prone to abdominal obesity than nondrinkers or drinkers of wine or spirits. Chronic alcoholism can lead to cirrhosis
Cirrhosis
Cirrhosis is a consequence of chronic liver disease characterized by replacement of liver tissue by fibrosis, scar tissue and regenerative nodules , leading to loss of liver function...
, symptoms of which include gynecomastia
Gynecomastia
Gynecomastia or Gynaecomastia, , is the abnormal development of large mammary glands in males resulting in breast enlargement. The term comes from the Greek γυνή gyné meaning "woman" and μαστός mastós meaning "breast"...
(enlarged breasts) and ascites
Ascites
Ascites is a gastroenterological term for an accumulation of fluid in the peritoneal cavity.The medical condition is also known as peritoneal cavity fluid, peritoneal fluid excess, hydroperitoneum or more archaically as abdominal dropsy. Although most commonly due to cirrhosis and severe liver...
(abdominal fluid). These symptoms can suggest the appearance of central obesity.
"Love handles" and "spare tyre" (or "spare tire") are colloquial terms for deposits of fat
Adipose tissue
In histology, adipose tissue or body fat or fat depot or just fat is loose connective tissue composed of adipocytes. It is technically composed of roughly only 80% fat; fat in its solitary state exists in the liver and muscles. Adipose tissue is derived from lipoblasts...
around a person's midsection, especially visible on the sides over the abdominal external oblique muscle
Abdominal external oblique muscle
The external oblique muscle is the largest and the most superficial of the three flat muscles of the lateral anterior abdomen.-Structure:...
. Love handles are visible deposits on each side of the abdomen or lower back (that a hypothetical lover might grab to pull the subject into an embrace); a spare tire appears to encircle the abdomen (thus resembling an automobile tire).
"Muffin top
Muffin top
"Muffin-top" is a generally pejorative slang term used to describe the phenomenon of overhanging flesh when it spills over the waistline of pants or skirts in a manner that resembles the top of a muffin spilling over its paper casing.- Origin :...
" is a term used for a person whose midsection spills over the waistline of his or her trousers in a manner that resembles the top of a muffin
Muffin
A muffin is an American English name for a type of quick bread that is baked in small portions. Many forms are somewhat like small cakes or cupcakes in shape, although they usually are not as sweet as cupcakes and generally lack frosting. Savory varieties, such as cornbread muffins, also exist...
spilling over its baking pan.
"Pot belly" is another colloquial term used to describe a person who has an excessive amount of abdominal fat. This is especially pronounced and visible over clothing.
See also
- BariatricsBariatricsBariatrics is the branch of medicine that deals with the causes, prevention, and treatment of obesity. The term bariatrics was created around 1965, from the Greek root bar- , suffix -iatr , and suffix -ic...
, the branch of medicine that deals with the causes, prevention, and treatment of obesity - Sagittal Abdominal Diameter (SAD)Sagittal Abdominal DiameterSagittal Abdominal Diameter is a measure of visceral obesity, the amount of fat in the gut region. SAD is the distance from the small of the back to the upper abdomen at the point midway between the top of the pelvis and the bottom of the ribs, measured while standing...
, a measure of Visceral Obesity - SteatosisSteatosisIn cellular pathology, steatosis is the process describing the abnormal retention of lipids within a cell. It reflects an impairment of the normal processes of synthesis and elimination of triglyceride fat. Excess lipid accumulates in vesicles that displace the cytoplasm...
, also called fatty change, fatty degeneration or adipose degeneration - LipoatrophyLipoatrophyLipoatrophy is the term describing the localized loss of fat tissue. This may occur as a result of subcutanous injections of insulin in the treatment of diabetes, from the use of human growth hormone or from subcutanous injections of Copaxone used for the treatment of multiple sclerosis. In the...
, the term describing the localized loss of fat tissue - LipodystrophyLipodystrophyLipodystrophy is a medical condition characterized by abnormal or degenerative conditions of the body's adipose tissue. A more specific term, lipoatrophy is used when describing the loss of fat from one area...
, a medical condition characterized by abnormal or degenerative conditions of the body's adipose tissue.