Waist circumference as the best predictor of noninsulin dependent diabetes mellitus (NIDDM) compared to body mass index, waist/hip ratio and other anthropometric measurements in Mexican Americans--a 7-year prospective study

Techniques of body composition assessment: a review of laboratory and field methods

Body composition is one of the major health-related components of fitness. Thus, it is important for health and fitness professionals to have a general understanding of the most commonly used techniques for assessing body composition. This review presents the developmental background and underlying principles and theory of four laboratory (hydrodensitometry, air displacement plethysmography, isotope dilution, and dual-energy x-ray absorptiometry) and four field (bioelectrical impedance analysis, near-infrared interactance, skinfolds, and anthropometry) methods of body composition assessment. In addition to a description of the methods, the validity, and reliability, strengths, and limitations of each measurement tool are examined. Highlights of the laboratory methods include the relatively new Bod Pod air displacement device, which is a promising assessment tool more convenient than hydrodensitometry but still lacking substantial validity testing and the ability of dual-energy x-ray absorptiometry to measure regional composition making it an attractive method for clinicians. Advancements in segmental and multifrequency bioelectrical impedance for compartmental analysis have enhanced the value of this field method, but research continues to show that commercially available near-infrared interactance units are invalid. With this knowledge, the clinician and researcher should be able to make an informed decision regarding the most appropriate measurement device for their body composition assessments.

Studies of body composition and fat distribution in HIV-infected and control subjects

OBJECTIVE

Recent studies have documented alterations in body fat distribution that have been associated with protease inhibitor therapy. We compared body composition, including measurements of fat distribution, in 96 HIV-infected subjects studied since January 1996 (current HIV), subjects seen prior to January 1996 (previous HIV), and healthy controls.

DESIGN

Retrospective cross-sectional studies of subjects matched by gender, race, age, and height.

METHODS

Body weight, height, body cell mass by whole-body counting of 40K plus fat, fat-free mass, and body fat distribution by anthropometry were measured.

RESULTS

Current HIV men weighed more (p = .025) and had more body cell mass than previous HIV men, but less than controls (p < .001). In women, the between group differences in fat were greater than the differences in body cell mass. Current and previous HIV study subjects had lower indices of subcutaneous and higher indices of visceral fat than controls. In current HIV subjects, body fat distribution was significantly associated with log plasma HIV RNA content but not with antiretroviral or protease inhibitor usage, nor with CD4+ lymphocyte counts. In 7 of 9 current HIV subjects studied, 24-hour urinary free cortisol excretion was abnormally high.

CONCLUSIONS

Alterations in body fat distribution are a characteristic feature in HIV infection. The occurrence of increased visceral fat content and decreased subcutaneous fat content preceded the era of combination antiretroviral therapy. The alteration in fat distribution may be affected by plasma HIV RNA content rather than antiretroviral or protease-inhibitor therapy. The body composition alterations might be associated with endogenous hypercortisolism.

Relation of circumferences and skinfold thicknesses to lipid and insulin concentrations in children and adolescents: the Bogalusa Heart Study

BACKGROUND

Although body fat patterning has been related to adverse health outcomes in adults, its importance in children and adolescents is less certain.

OBJECTIVE

We examined the relation of circumference (waist and hip) and skinfold-thickness (subscapular and triceps) measurements to lipid and insulin concentrations among 2996 children and adolescents aged 5-17 y.

DESIGN

This was a community-based, cross-sectional study conducted in 1992-1994.

RESULTS

A central or abdominal distribution of body fat was related to adverse concentrations of triacylglycerol, LDL cholesterol, HDL cholesterol, and insulin; these associations were independent of race, sex, age, weight, and height. These associations were observed whether fat patterning was characterized by using 1) waist circumference alone (after adjustment for weight and height), 2) waist-to-hip ratio, or 3) principal components analysis. Compared with a child at the 10th percentile of waist circumference, a child at the 90th percentile was estimated to have, on average, higher concentrations of LDL cholesterol (0.17 mmol/L), triacylglycerol (0.11 mmol/L), and insulin (6 pmol/L) and lower concentrations of HDL cholesterol (-0.07 mmol/L). These differences, which were independent of weight and height, were significant at the 0.001 level and were consistent across race-sex groups.

CONCLUSIONS

These findings emphasize the importance of obtaining information on body fat distribution, waist circumference in particular, in children. Waist circumference, which is relatively easy to measure, may help to identify children likely to have adverse concentrations of lipids and insulin.

Genetic and behavioral determinants of waist-hip ratio and waist circumference in women twins

OBJECTIVES

This study examines genetic and behavioral determinants of waist-hip ratio (WHR) and waist circumference among women twins.

RESEARCH METHODS AND PROCEDURES

Six hundred eighty participants from the second examination of the Kaiser-Permanente Women Twins Study (1989 to 1990) were included. Women ranged in age from 31 to 90 years, and included 59% monozygotic and 41% dizygotic twins. Heritabilities of WHR and waist circumference were estimated (range=0 to 1) using three different statistical methods. Linear regression models that adjusted for the lack of independence within twin pairs were used to assess associations between behavioral variables, WHR, and waist circumference.

RESULTS

Age and body mass index-adjusted heritability estimates ranged from 0.36 to 0.61 for WHR and 0.72 to 0.82 for waist circumference. When considered individually, after adjusting for age and body mass index, all behavioral characteristics, except calorie-adjusted fat intake, were significantly (p<0. 10) associated with waist circumference and WHR. Greater central adiposity was associated with lower education, higher alcohol consumption, lower physical activity, current cigarette smoking, higher parity, and postmenopausal status without hormone replacement therapy. In multivariate models, these associations persisted, except neither educational attainment nor alcohol intake was significantly associated with waist circumference. In longitudinal analyses, both measures were positively associated with current or recent-past smoking; infrequent or inconsistent physical activity; and long-term, daily consumption of alcohol.

DISCUSSION

These cross-sectional and longitudinal associations are consistent with genetic and behavioral predictors of waist circumference and WHR. Whereas the evidence for genetic influences is stronger for waist circumference, both body fat measures may be similarly influenced by the behavioral factors considered.

Visceral obesity and the risk of ischaemic heart disease: insights from the Québec Cardiovascular Study

There is no doubt that visceral obesity increases the susceptibility to IHD, emphasizing the need to consider this condition in the risk management of IHD. The use of CT or MRI as clinical tools to assess visceral adipose tissue accumulation does not appear to be justified, however, mostly because of the costs of the procedures and the limited availability of the necessary apparatus. The waist:hip ratio has been used extensively as an indicator of body fat distribution. However, it has been shown that the waist:hip ratio is less accurate than the waist circumference alone or the sagittal diameter in predicting visceral adipose tissue accumulation, particularly when monitoring changes in visceral adipose tissue mass over time.79 Also, the prediction of visceral adipose tissue levels by the waist circumference alone, as opposed to the waist:hip ratio, does not appear to be affected by gender or by the degree of obesity.80 For these reasons we have proposed that the waist circumference should be systematically measured in managing the risk of IHD. It is a simple and inexpensive measurement to perform, while providing potentially critical information on the risk profile of both men and women.80 We believe that identification of viscerally obese patients, a high-risk population for IHD, should be considered as a critical step in the risk management of IHD.