Cadaver-assessed validity of anthropometric indicators of adipose tissue distribution

BMI-specific waist circumference is better than skinfolds for health-risk determination in the general population

Distribution of fat is important when considering health risk; however, the value added from skinfold measurements (SKF) when using body mass index (BMI) refined by waist circumference (WC) is not well understood. The purpose of this study was to assess the utility of SKF compared with WC in determination of health risk in the general population. Data from the Canadian Health Measures Survey (cycles 1 and 2; N = 5217) were used. Health outcomes included directly measured blood pressure, cholesterol, glycated haemoglobin, lung function, self-reported health, and chronic conditions. Technical errors of measurements (TEM), sensitivity, and specificity analysis and linear regressions were conducted. Data indicated that TEM for SKF was above the acceptable 5% in most age and sex categories. Sensitivity and specificity of chronic conditions was not improved with the inclusion of SKF in models containing WC (in those aged 45-69 years) and SKF did not explain any additional variance in regression models containing WC. Health outcomes for those in the normal weight and overweight BMI category were significantly worse in those classified as high risk based on WC, whereas SKF did not consistently discriminate risk. In conclusion, evidence-based WC cut-points were shown to identify health risk, particularly in normal weight and overweight individuals. Thus, BMI refined by WC appears to be more appropriate than SKF for assessment of body composition when determining health risk in the general population.

Use of anthropometry for the prediction of regional body tissue distribution in adults: benefits and limitations in clinical practice

Regional body composition changes with aging. Some of the changes in composition are considered major risk factors for developing obesity related chronic diseases which in turn may lead to increased mortality in adults. The role of anthropometry is well recognized in the screening, diagnosis and follow-up of adults for risk classification, regardless of age. Regional body composition is influenced by a number of intrinsic and extrinsic factors. Therapeutic measures recommended to lower cardiovascular disease risk include lifestyle changes. The aim of this review is to systematically summarize studies that assessed the relationships between anthropometry and regional body composition. The potential benefits and limitations of anthropometry for use in clinical practice are presented and suggestions for future research given.

Hypertriglyceridemic waist and newly-diagnosed diabetes among remote-dwelling Indigenous Australians

AIMS

Hypertriglyceridemic waist (HTgW) is predictive of cardiovascular disease. The HTgW relationship with diabetes is little studied.

METHODS

This study analysed data from diabetes and cardiovascular risk factor screening programmes in remote Indigenous Australian settlements. Elevated waist girth (EW) was defined as ≥90 cm for men (n = 1134) or ≥80 cm for women (n = 1313). Hypertriglyceridemia (ETg) was defined as ≥1.7 mmol/L. Diabetes was defined as fasting plasma glucose ≥7.0 mmol/L. Body mass index (BMI) was categorised as <22, 22-24.9 and >25.0 kg/m(2). Logistic regression was used to analyse the odds of newly-diagnosed diabetes for individuals with either HTgW, ETg or EW, relative to individuals with values below cut-offs.

RESULTS

The prevalence of HTgW was 33.2% for men and 34.8% for women. Accounting for age-group and gender, newly-diagnosed diabetes was associated (odds ratio (OR) (95% confidence interval)) with HTgW: 9.6 (6.6, 13.8). The relationship remained strong after accounting for the covariates BMI and smoking (OR = 4.9 (2.7, 8.8)). In BMI-stratified analyses the strongest odds were observed for the lowest category (<22 kg/m(2): OR = 12.9 (4.0, 41.7)).

CONCLUSIONS

HTgW has a high prevalence and is associated with newly-diagnosed diabetes in Indigenous people, particularly those with BMI <22 kg/m(2), whom clinicians might not normally consider for screening.

Cross-sectional content analysis of clinically applied circumferences

BACKGROUND

The contours of a human body are determined by the volumes of the underlying tissues [adipose tissue (AT), muscle, bone and viscera]. Conceptually, they are assumed to be used as a concentric set of cylinders. Determination of these clinically applied circumferences in terms of relative tissue proportions has led to conflicting results. As it remains unclear what a circumference really measures or represents and how it relates to body composition (BC), the aim of this study was to determine the content of the circumferences and whether these perimeters can be used to assess segmental or whole body tissue components.

DESIGN

Subsequent to an anthropometric protocol, the five white Caucasian cadavers were fractionated into slices of 3 cm and segmental and whole BC was determined at the anatomical tissue-system level by direct dissection.

RESULTS

Only two circumferences correlated significantly with their dominating component [upper arm circumference (r = 0·98; P < 0·01) and waist circumference (WC) (r = 0·90; P < 0·05) with AT]. Two circumferences were related to a segmental tissue component [WC (r = 1·00; P < 0·001) with muscle mass of the trunk and wrist circumference (WrC) (r = 0·90; P < 0·05) with bone mass of the upper limb]. Two circumferences were related to a whole body tissue component [chest circumference (r = 0·90; P < 0·05) with whole body AT mass and WrC (r = 0·90; P < 0·05) with whole body bone mass].

CONCLUSION

The clinically applied circumferences do not measure what they pretend to measure. Of all the studied circumferences, only 2 circumferences (WC and WrC) can be used to assess segmental or whole body tissue components.

Direct relationship of body mass index and waist circumference with body tissue distribution in elderly persons

OBJECTIVES

To explore the relationship of BMI and WC with muscle/adipose tissue mass ratios and with trunk adipose tissue distribution, based on an anatomical 5-compartment model, by dissection of cadavers of elderly persons.

DESIGN

Cross-sectional explorative study.

SETTING

Brussels Cadaver Analysis Study.

PARTICIPANTS

Cadavers of twenty-nine white Caucasian elderly persons (17 females and 12 males, aged 78.1±6.9 years).

MEASUREMENTS

Whole body and trunk composition were determined at the anatomical tissue-system level by direct dissection.

RESULTS

BMI and WC were significantly and positively related to absolute tissue masses in both sexes. Muscle tissue mass, adipose tissue mass and trunk internal adipose tissue mass correlated better with BMI (r-values between 0.68 and 0.89) than with WC (r-values between 0.49 and 0.71). BMI was significantly and inversely related with various muscle/adipose tissue ratios in both sexes (r-values between -0.54 and -0.68). WC correlated with muscle/adipose tissue ratios in females only (r-values between -0.55 and -0.64). BMI was also significantly related to trunk adipose tissue distribution in elderly females, but not in males. When comparing individual tissue proportions within and between adjacent BMI-classifications or WC categories, body composition varied considerably.

CONCLUSION

Our results show that BMI and WC are significantly related with adipose tissue mass and with several ratios of muscle to adipose tissue in elderly subjects. However, cautious clinical interpretation is warranted since important differences in tissue mass proportions were found in subjects with similar BMI and/or WC values.

Effects of a 1-year randomized controlled trial of resistance training on lower limb bone and muscle structure and function in older men

SUMMARY

A 1-year randomized controlled trial of resistance training compared with a control group was undertaken in 143 men aged 55-80 years. Although hip bone mineral density, lean body mass, and function increased in both groups, lean body mass and function but not bone density increased more in the resistance group.

INTRODUCTION

Previous studies have demonstrated a positive effect of resistance training on bone mineral density (BMD) in postmenopausal women, but the effect in men is unclear. The aim was to examine the effect of a 1-year resistance training program on bone and lean body mass in 143 men aged 55-80 years, randomized to either resistance training or active control.

METHODS

Resistance exercises were selected to provide loading at the hips. Measurements were taken at 0, 6, and 12 months for BMD (whole body, hip, and spine), lean body mass, strength, and functional fitness.

RESULTS

The intervention showed a significant increase in total hip BMD for both groups at 12 months (active control, 1,014-1,050 mg/cm(2); resistance, 1,045-1,054 mg/cm(2), p < 0.05) with no increased effect of resistance training compared to active control. However, compared to the active control group, the resistance group increased their lean body mass (active control, 0.1 +/- 2.1%; resistance, 1.5 +/- 2.7%, p < 0.05), fitness (active control, 4.6 +/- 11.1%; resistance, 13.0 +/- 13.4%, p < 0.05), and lower limb muscle strength (active control, 14.3 +/- 16.8%; resistance, 39.4 +/- 30.87%, p < 0.05).

CONCLUSIONS

In contrast to previous findings in older women, in older men, a resistance training program does not increase hip bone mass more than walking 30 min three times a week.

Desaturation patterns detected by oximetry in a large population of athletes

Optimal exercise performance in well trained athletes can be affected by arterial oxygen saturation failure. Noninvasive detection of this phenomenon when performing a routine ergometric test can be a valuable tool for subsequent planning of the athlete's training recovery, and nutrition. Oximetry has been used to this end. The authors studied 339 athletes performing a similar exercise trial under well controlled environmental conditions. Maximum speed, oxygen uptake, and heart rate levels were simultaneously measured. From the obtained data, six patterns were found: (a) athletes in whom oxygen saturation is constant (> or = 95%) during test execution; (b) athletes displaying a progressive desaturation with incremental exercise intensities; (c) athletes presenting a transient desaturation in the anaerobic threshold region; (d) athletes starting with a mild-to-moderate desaturation at the beginning of the test, but reaching normal saturation values at the end; (e) athletes displaying mild-to-moderate desaturation levels throughout the whole test; and (f) athletes displaying a transient desaturation in the anaerobic threshold region and a new desaturation at the end of the test. In conclusion, it is believed that establishment of desaturation patterns by validated oximetry could be a first approach to evaluate the adaptation of the cardiorespiratory system to exercise intensity, helping to improve results.