Editing Abdominal obesity (section)

== Diagnosis ==
[[File:Obesity-waist circumference.svg|thumb|190px|Silhouettes and waist circumferences representing normal, overweight, and obese]]
There are various ways of measuring abdominal obesity including:
*Absolute waist circumference (>{{convert|102|cm|in|abbr=on}} in men and >{{convert|88|cm|in|abbr=on}} in women)<ref name="ATP3pii17" />
*[[Waist–hip ratio]] (the circumference of the waist divided by that of the hips of >0.9 for men and >0.85 for women)<ref name=Yusuf2004/>
*[[Waist-to-stature ratio|Waist-stature ratio]] (waist circumference divided by their height, >0.5 for adults under 40 and >0.6 for adults over 50)
*[[Sagittal Abdominal Diameter]]<ref name=pmid17041127>{{cite journal | vauthors = Iribarren C, Darbinian JA, Lo JC, Fireman BH, Go AS | title = Value of the sagittal abdominal diameter in coronary heart disease risk assessment: cohort study in a large, multiethnic population | journal = American Journal of Epidemiology | volume = 164 | issue = 12 | pages = 1150–9 | date = December 2006 | pmid = 17041127 | doi = 10.1093/aje/kwj341 | doi-access = free }}</ref>

[[File:Excess abdominal fat.jpg|alt=|thumb|Overweight teenage boy holding his excess abdominal fat]]
In those with a [[body mass index]] (BMI) under 35, intra-abdominal body fat is related to negative health outcomes independent of total body fat.<ref name=HSTAT>{{cite book|author=U.S. Preventive Services Task Force Evidence Syntheses|title=HSTAT: Guide to Clinical Preventive Services, 3rd Edition: Recommendations and Systematic Evidence Reviews, Guide to Community Preventive Services|year=2000|url=https://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=hstat3.section.36199|access-date=2017-08-29|archive-date=2009-07-04|archive-url=https://web.archive.org/web/20090704131837/http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=hstat3.section.36199|url-status=dead}}</ref> Intra-abdominal or [[Adipose tissue#Visceral fat|visceral fat]] has a particularly strong correlation with [[cardiovascular disease]].<ref name=Yusuf2004>{{cite journal | vauthors = Yusuf S, Hawken S, Ounpuu S, Dans T, Avezum A, Lanas F, McQueen M, Budaj A, Pais P, Varigos J, Lisheng L | display-authors = 6 | title = Effect of potentially modifiable risk factors associated with myocardial infarction in 52 countries (the INTERHEART study): case-control study | journal = Lancet | volume = 364 | issue = 9438 | pages = 937–52 | year = 2004 | pmid = 15364185 | doi = 10.1016/S0140-6736(04)17018-9 | hdl-access = free | s2cid = 30811593 | hdl = 10983/21615 }}</ref>

BMI and waist measurements are well recognized ways to characterize obesity. However, waist measurements are not as accurate as BMI measurements. Waist measurement (''e.g.'', for [[Body fat percentage|BFP]] standard) is more prone to errors than measuring height and weight (''e.g.'', for [[Body mass index|BMI]] standard). BMI will illustrate the best estimate of one's total body fatness, while waist measurement gives an estimate of visceral fat and risk of obesity-related disease.<ref>Abdominal obesity and your health. (2006). Retrieved from http://www.health.harvard.edu/fhg/updates/abdominal-obesity-and-your-health.shtml {{Webarchive|url=https://web.archive.org/web/20130315182221/http://www.health.harvard.edu/fhg/updates/abdominal-obesity-and-your-health.shtml|date=2013-03-15}}</ref> It is recommended to use both methods of measurements.<ref>{{cite web |title=Abdominal obesity and your health |url=http://www.health.harvard.edu/fhg/updates/abdominal-obesity-and-your-health.shtml |url-status=dead |archive-url=https://web.archive.org/web/20130315182221/http://www.health.harvard.edu/fhg/updates/abdominal-obesity-and-your-health.shtml |archive-date=2013-03-15 |access-date=2013-01-05 |publisher=Health.harvard.edu}}</ref>
[[File:Centrally Obese Man.jpg|thumb|A man with abdominal obesity]]
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 {{convert|102|cm|in}} in men and {{convert|88|cm|in}} in women and the [[waist–hip ratio]] (>0.9 for men and >0.85 for women)<ref name=Yusuf2004/> are both used as measures of central obesity. A [[differential diagnosis]] includes distinguishing central obesity from [[ascites]] and intestinal [[bloating]]. In the [[cohort (statistics)|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 BMI when [[metabolic syndrome]] was taken as an [[Clinical endpoint|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 [[body mass index|BMI]].<ref>{{cite journal | vauthors = Smith SC, Haslam D | title = Abdominal obesity, waist circumference and cardio-metabolic risk: awareness among primary care physicians, the general population and patients at risk--the Shape of the Nations survey | journal = Current Medical Research and Opinion | volume = 23 | issue = 1 | pages = 29–47 | date = January 2007 | pmid = 17261236 | doi = 10.1185/030079906X159489 | s2cid = 11796524 }}</ref> 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.<ref>{{cite journal | vauthors = Knowles KM, Paiva LL, Sanchez SE, Revilla L, Lopez T, Yasuda MB, Yanez ND, Gelaye B, Williams MA | display-authors = 6 | title = Waist Circumference, Body Mass Index, and Other Measures of Adiposity in Predicting Cardiovascular Disease Risk Factors among Peruvian Adults | journal = International Journal of Hypertension | volume = 2011 | pages = 931402 | date = January 2011 | pmid = 21331161 | pmc = 3034939 | doi = 10.4061/2011/931402 | doi-access = free }}</ref>
Another diagnosis of obesity is the analysis of intra-abdominal fat having the most risk to one's personal health. The increased amount of fat in this region relates to the higher levels of [[plasma lipid]] and [[lipoproteins]] as per studies mentioned by [[Eric Poehlman]] (1998) review.<ref name="Poehlman1998" />
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 effect of abdominal adiposity occurs not just in those who are obese, but also affects people who are non-obese and it also contributes to insulin sensitivity.

=== 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<ref name=pmid20450297>{{cite journal | vauthors = Méthot J, Houle J, Poirier P | title = Obesity: how to define central adiposity? | journal = Expert Review of Cardiovascular Therapy | volume = 8 | issue = 5 | pages = 639–44 | date = May 2010 | pmid = 20450297 | doi = 10.1586/erc.10.38 | s2cid = 31913449 }}</ref> as a better substitute to the widely used waist circumference in defining [[metabolic syndrome]].<ref name=pmid19558273>{{cite journal | vauthors = Parikh RM, Joshi SR, Pandia K | title = Index of central obesity is better than waist circumference in defining metabolic syndrome | journal = Metabolic Syndrome and Related Disorders | volume = 7 | issue = 6 | pages = 525–7 | date = December 2009 | pmid = 19558273 | doi = 10.1089/met.2008.0102 }}</ref> The [[National Cholesterol Education Program]] Adult Treatment Panel III suggested cutoff of {{convert|102|cm|in|abbr=on}} and {{convert|88|cm|in|abbr=on}} for males and females as a marker of central obesity.<ref name=ATP3pii17>{{cite book |title=Third Report of the Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (ATP III Final Report) |publisher=[[National Institutes of Health]] |year=2002 |url=http://www.nhlbi.nih.gov/guidelines/cholesterol/atp3_rpt.htm |author=National Cholesterol Education Program |page=II–17 |author-link=National Cholesterol Education Program |access-date=2011-05-14 |archive-url=https://web.archive.org/web/20050524010904/http://www.nhlbi.nih.gov/guidelines/cholesterol/atp3_rpt.htm |archive-date=2005-05-24 |url-status=dead }}</ref> The same was used in defining [[metabolic syndrome]].<ref name=ATP3pii27>{{cite book |title=Third Report of the Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (ATP III Final Report) |publisher=[[National Institutes of Health]] |year=2002 |url=http://www.nhlbi.nih.gov/guidelines/cholesterol/atp3_rpt.htm |author=National Cholesterol Education Program |page=II–27 |author-link=National Cholesterol Education Program |access-date=2011-05-14 |archive-url=https://web.archive.org/web/20050524010904/http://www.nhlbi.nih.gov/guidelines/cholesterol/atp3_rpt.htm |archive-date=2005-05-24 |url-status=dead }}</ref> Misra et al. suggested that these cutoffs are not applicable among Indians and the cutoffs be lowered to {{convert|90|cm|in|abbr=on}} and {{convert|80|cm|in|abbr=on}} for males and females.<ref name=pmid20156066>{{cite journal | vauthors = Misra A, Wasir JS, Vikram NK, Pandey RM, Kumar P | title = Cutoffs of abdominal adipose tissue compartments as measured by magnetic resonance imaging for detection of cardiovascular risk factors in apparently healthy adult Asian Indians in North India | journal = Metabolic Syndrome and Related Disorders | volume = 8 | issue = 3 | pages = 243–7 | date = June 2010 | pmid = 20156066 | doi = 10.1089/met.2009.0046 }}</ref> Various race specific cutoffs were suggested by different groups.<ref>{{Cite web|website=hsph.harvard.edu|date=2012-10-21|title=Abdominal Obesity Measurement Guidelines for Different Ethnic Groups|url=https://www.hsph.harvard.edu/obesity-prevention-source/waist-circumference-guidelines-for-different-ethnic-groups/|access-date=2021-03-31|department=Obesity Prevention Source|language=en-us}}</ref> The [[International Diabetes Federation]] defined central obesity based on these various race and gender specific cutoffs.<ref name=Alberti2005>{{cite journal | vauthors = Alberti KG, Zimmet P, Shaw J | title = The metabolic syndrome--a new worldwide definition | journal = Lancet | volume = 366 | issue = 9491 | pages = 1059–62 | year = 2005 | pmid = 16182882 | doi = 10.1016/S0140-6736(05)67402-8 | s2cid = 30586927 }}</ref> The other limitation of waist circumference is that it the measurement procedure has not been standardized and in children there are no, or few, comparison standards or reference data.<ref>{{Cite web|website=hsph.harvard.edu|date=2012-10-21|title=Measuring Obesity|url=https://www.hsph.harvard.edu/obesity-prevention-source/obesity-definition/how-to-measure-body-fatness/|access-date=2021-03-31|department=Obesity Prevention Source|language=en-us}}</ref>

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.<ref name=pmid19558273/> An ICO cutoff of 0.53 was suggested as a criterion to define central obesity. Parikh ''et al.'' further tested a modified definition 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.<ref name=pmid19558273/>

This parameter has been used in the study of [[metabolic syndrome]]<ref name=pmid18700281>{{cite journal | vauthors = Joshi PP | title = Is waist to height ratio a better and more practical measure of obesity to assess cardiovascular or diabetes risk in indians? | journal = The Journal of the Association of Physicians of India | volume = 56 | pages = 202–3; author reply 203–4 | date = March 2008 | pmid = 18700281 | url = http://www.japi.org/march2008/Corr2.htm | access-date = 2011-06-04 | archive-date = 2017-10-11 | archive-url = https://web.archive.org/web/20171011175412/http://www.japi.org/march2008/Corr2.htm | url-status = dead }}</ref><ref name=veigas2011>{{cite journal | vauthors = Veigas NM, Dharmalingam, Marcus SR |year=2011 |title=Oxidative Stress in Obesity and Metabolic Syndrome in Asian Indians |journal=Journal of Medical Biochemistry |volume=30 |issue=2 |pages=115–20 |doi=10.2478/v10011-011-0006-6|doi-access=free }}</ref> and [[cardiovascular disease]].<ref name=pmid18051732>{{cite journal | vauthors = Gupta R, Rastogi P, Sarna M, Gupta VP, Sharma SK, Kothari K | title = Body-mass index, waist-size, waist–hip ratio and cardiovascular risk factors in urban {{sic|nolink=y|reason=error in source|subejcts}} | journal = The Journal of the Association of Physicians of India | volume = 55 | pages = 621–7 | date = September 2007 | pmid = 18051732 | url = http://www.japi.org/september2007/O-621.htm | access-date = 2011-06-04 | archive-date = 2017-10-12 | archive-url = https://web.archive.org/web/20171012204029/http://www.japi.org/september2007/O-621.htm | url-status = dead }}</ref>

Central obesity in individuals with normal BMI is referred to as [[normal weight obesity]].

=== Sex differences ===
There are sex-dependent differences in regional fat distribution.

Males are more susceptible to upper-body fat accumulation, most likely in the belly, due to sex hormone differences.<ref>{{cite journal |vauthors=Elbers JM, Asscheman H, Seidell JC, Gooren LJ |date=February 1999 |title=Effects of sex steroid hormones on regional fat depots as assessed by magnetic resonance imaging in transsexuals |journal=The American Journal of Physiology |volume=276 |issue=2 |pages=E317-25 |doi=10.1152/ajpendo.1999.276.2.E317 |pmid=9950792}}</ref> When comparing the body fat of men and women it is seen that men have close to twice the visceral fat as that of pre-menopausal women.<ref>{{cite journal |vauthors=Lemieux S, Prud'homme D, Bouchard C, Tremblay A, Després JP |date=October 1993 |title=Sex differences in the relation of visceral adipose tissue accumulation to total body fatness |journal=The American Journal of Clinical Nutrition |volume=58 |issue=4 |pages=463–7 |doi=10.1093/ajcn/58.4.463 |pmid=8379501|doi-access=free }}</ref><ref>{{cite journal |vauthors=Carey DG, Campbell LV, Chisholm DJ |year=1996 |title=Is visceral fat (intra-abdominal and hepatic) a major determinant of gender differences in insulin resistance and dyslipidaemia? |journal=Diabetes |volume=45 |page=110A}}</ref>

In women, [[estrogen]] is believed to cause fat to be stored in the [[buttocks]], [[thighs]], and [[hips]].<ref>{{cite journal | vauthors = Andersen BL, Legrand J | title = Body Image for Women: Conceptualization, Assessment, and a Test of its Importance to Sexual Dysfunction and Medical Illness | journal = Journal of Sex Research | volume = 28 | issue = 3 | pages = 457–477 | year = 1991 | pmid = 21451731 | pmc = 3065017 | doi = 10.1080/00224499109551619 }}</ref> When women reach [[menopause]] and the estrogen produced by [[ovaries]] declines, fat at their buttocks, hips, and thighs decreases while fat at their belly increases.<ref>{{cite web |url=http://health.yahoo.com/topic/nutrition/overview/article/womens-health/26287 |archive-url=https://web.archive.org/web/20071024193506/http://health.yahoo.com/topic/nutrition/overview/article/womens-health/26287|archive-date=October 24, 2007 |work=Yahoo! Health |title=A Matter of Fat |first=Michelle |last=Andrews |date=2006-12-01}}</ref><ref>{{cite web |url=http://www.health.harvard.edu/newsweek/Abdominal-fat-and-what-to-do-about-it.htm |title=Abdominal fat and what to do about it. Visceral fat more of a health concern than subcutaneous fat |publisher=Harvard Health Publications |access-date=2013-01-05 |archive-url=https://web.archive.org/web/20110928081252/http://www.health.harvard.edu/newsweek/Abdominal-fat-and-what-to-do-about-it.htm |archive-date=2011-09-28 |url-status=dead }}</ref>

50% of men and 70% of women in the [[United States]] between the ages of 50 and 79 years now{{when|date=July 2024}} exceed the waist circumference threshold for central obesity.<ref>{{cite journal |vauthors=Li C, Ford ES, McGuire LC, Mokdad AH |title=Increasing trends in waist circumference and abdominal obesity among US adults |journal=Obesity |year=2007 |volume=15 |issue=1 |pages=216–224|doi=10.1038/oby.2007.505 |pmid=17228050 }}</ref>

Central obesity is positively associated with [[coronary heart disease]] risk in women and men. It has been hypothesized that the sex differences in fat distribution may explain the sex difference in coronary heart disease risk.<ref>{{cite journal |vauthors=Wingard DL |date=May 1990 |title=Sex differences and coronary heart disease. A case of comparing apples and pears? |journal=Circulation |volume=81 |issue=5 |pages=1710–2 |doi=10.1161/01.cir.81.5.1710 |pmid=2331775 |doi-access=free}}</ref> Even with the differences, at any given level of central obesity measured as waist circumference or waist to hip ratio, coronary artery disease rates are identical in men and women.<ref>{{cite journal | vauthors = Barrett-Connor E | title = Sex differences in coronary heart disease. Why are women so superior? The 1995 Ancel Keys Lecture | journal = Circulation | volume = 95 | issue = 1 | pages = 252–64 | date = January 1997 | pmid = 8994444 | doi = 10.1161/01.cir.95.1.252 }}</ref>