BMI, fat and muscle differences in urban women of five ethnicities from two countries

A Systematic Review on the Association between Lipid Accumulation Product Index and Type 2 Diabetes Mellitus

Introduction

Excess fat accumulation contributes to the development of type 2 diabetes mellitus (T2DM). Lipid accumulation product (LAP) is an index computed from waist circumference and triglycerides, which represents increased lipotoxicity. We aim to study the relationship of LAP index and T2DM and its utility as a predictor for T2DM development.

Methodology

A literature search in PubMed and Cochrane database was performed to retrieve and review studies reporting the association between LAP and T2DM.

Results

Two cross-sectional studies from Japan and the United States, and one cohort study from Iran were obtained. A high LAP was associated with a higher risk of T2DM [odds ratio (OR) 19.1, 95% confidence interval (CI) (6.6-55.5) for women; and OR 7.4, 95% CI (5.1-10.8) for men].

Conclusion

LAP was strongly associated with T2DM. Its utility in predicting the development of T2DM needs to be confirmed.

Prognostic Impact of Low Skeletal Muscle Mass on Major Adverse Cardiovascular Events in Coronary Artery Disease: A Propensity Score-Matched Analysis of a Single Center All-Comer Cohort

The impact of sarcopenia on atherosclerotic cardiovascular disease remains unclear. We aimed to investigate the prognostic impact of sarcopenia on coronary artery disease (CAD). A total of 475 patients with CAD who underwent successful percutaneous coronary intervention (PCI) and computed tomography (CT) were enrolled. The cross-sectional area of skeletal muscle at the first lumbar (L1) vertebral level was measured, and sex-specific cut-off values of L1 skeletal muscle index (L1 SMI; male <31.00 cm2/m2, female <25.00 cm2/m2) were obtained. The primary outcome was 3-year all-cause mortality and the secondary outcome was 3-year major adverse cardiovascular events (MACEs). Low L1 SMI was present in 141 (29.7%) of 475 patients. The incidence of all-cause mortality (23.7% vs. 5.9%, p < 0.001) and MACEs (39.6% vs. 11.8%, p < 0.001) was significantly higher in patients with low L1 SMI than in those with high L1 SMI. In multivariate analysis, low L1 SMI was an independent predictor of higher risk of all-cause mortality (hazard ratio (HR): 4.07; 95% confidence interval (CI): 1.95-8.45; p < 0.001) and MACEs (HR: 3.76; 95% CI: 2.27-6.23; p < 0.001). These findings remained consistent after propensity score-matched analysis with 91 patient pairs (C-statistic = 0.848). CT-diagnosed low skeletal muscle mass is a powerful predictor of adverse outcomes in patients with CAD undergoing PCI.

A Global Comparison of Anatomic Risk Factors and Their Relationship to Obstructive Sleep Apnea Severity in Clinical Samples

STUDY OBJECTIVES

Obstructive sleep apnea (OSA) is a global health issue and is associated with obesity and oropharyngeal crowding. Global data are limited on the effect of ethnicity and sex on these relationships. We compare associations between the apnea-hypopnea index (AHI) and these risk factors across ethnicities and sexes within sleep clinics.

METHODS

This is a cross-sectional, multicenter study of patients with OSA from eight sleep centers representing the Sleep Apnea Global Interdisciplinary Consortium (SAGIC). Four distinct ethnic groups were analyzed, using a structured questionnaire: Caucasians (Australia, Iceland, Germany, United States), African Americans (United States), Asians (Taiwan), and South Americans (Brazil). Regression analyses and interaction tests were used to assess ethnic and sex differences in relationships between AHI and anthropometric measures (body mass index [BMI], neck circumference, waist circumference) or Mallampati score.

RESULTS

Analyses included 1,585 individuals from four ethnic groups: Caucasian (60.6%), African American (17.5%), Asian (13.1%), and South American (8.9%). BMI was most strongly associated with AHI in South Americans (7.8% increase in AHI per 1 kg/m² increase in BMI; P < .0001) and most weakly in African Americans (1.9% increase in AHI per 1 kg/m² increase in BMI; P = .002). In Caucasians and South Americans, associations were stronger in males than females. Mallampati score differed between ethnicities but did not influence AHI differently across groups.

CONCLUSIONS

We demonstrate ethnic and sex variations in associations between obesity and OSA. For similar BMI increases, South American patients show greatest AHI increases compared to African Americans. Findings highlight the importance of considering ethnicity and sex in clinical assessments of OSA risk.

Prediction of maximal oxygen consumption using the Young Men's Christian Association-step test in Korean adults

PURPOSE

To develop accurate and practical prediction models of maximal oxygen consumption (VO₂max) using the Young Men's Christian Association (YMCA)-step test in South Korean adults.

METHODS

In total, 568 adults (20-66 years) were included in this study. To develop and cross-validate prediction models of VO₂max, the total sample was divided into 80% training and 20% testing using a simple random sampling method. VO₂max was measured using the maximal-graded exercise treadmill test. Sex, age, 1-min recovery heart rate, body weight, and height were measured as potential predictors. Each test was conducted within a 2- to 3-day interval, ensuring sufficient rest. Preliminary prediction models were developed from training datasets, which were cross-validated using regression analyses and/or repeated-measures analysis of variance. The accuracy of prediction models was evaluated using R², standard error of estimate (SEE), and mean difference (MD) against a criterion-measured VO₂max.

RESULTS

The average age and VO₂max were 43.5 ± 12.9 years and 39.1 ± 7.5 ml/kg/min, respectively. For model development, three practical models with acceptable accuracy were developed (R² = 0.56-0.61; SEE = 4.74-5.01). For model cross-validation, significant relationships between the criterion-measured and predicted VO₂max were observed in all three models (R² = 0.56-0.61; SEE = 4.62-4.88). The difference between criterion-measured and predicted VO₂max was not significant in the models (MD =- 0.03 to - 0.14).

CONCLUSIONS

The prediction models included 3-5 variables as significant predictors of VO₂max and had acceptable accuracy in a large sample of South Korean adults. The selected models provide a simple and practical method to estimate VO₂max using the YMCA-step test for South Korean adults.

Ethnic differences in regional adipose tissue oestrogen receptor gene expression

Studies have shown ethnic differences in body fat distribution, characterised by greater peripheral and less central fat accumulation in black compared to white South African (SA) women. As sex hormones play an important role in body fat distribution, our study aimed to determine whether differences in body fat distribution between black and white SA women were associated with subcutaneous adipose tissue (SAT) expression of oestrogen receptors (ERA and ERB) and aromatase (CYP19A1). Body fat distribution (DXA and CT) and ERA, ERB and CYP19A1 expression in abdominal and gluteal SAT were measured in 26 black and 22 white SA women. Abdominal SAT ERA and ERB did not differ by ethnicity or BMI. Gluteal ERA was higher (1.08 ± 0.06 vs 0.99 ± 0.05, P < 0.001) and ERB was lower (0.99 ± 0.06 vs 1.10 ± 0.07, P < 0.001) in black vs white SA women. CYP19A1 increased with obesity in all depots (P < 0.001). In both black and white SA women, gluteal ERA was associated with lower central fat mass (FM) and greater gynoid FM (P < 0.05), while the inverse association was shown for CYP19A1 in all depots (P < 0.01). In conclusion, ethnic differences in gluteal ERA expression were associated with differences in body fat distribution previously reported between black and white SA women.

Adjusting for BMI in analyses of volumetric mammographic density and breast cancer risk

BACKGROUND

Fully automated assessment of mammographic density (MD), a biomarker of breast cancer risk, is being increasingly performed in screening settings. However, data on body mass index (BMI), a confounder of the MD-risk association, are not routinely collected at screening. We investigated whether the amount of fat in the breast, as captured by the amount of mammographic non-dense tissue seen on the mammographic image, can be used as a proxy for BMI when data on the latter are unavailable.

METHODS

Data from a UK case control study (numbers of cases/controls: 414/685) and a Norwegian cohort study (numbers of cases/non-cases: 657/61059), both with volumetric MD measurements (dense volume (DV), non-dense volume (NDV) and percent density (%MD)) from screening-age women, were analysed. BMI (self-reported) and NDV were taken as measures of adiposity. Correlations between BMI and NDV, %MD and DV were examined after log-transformation and adjustment for age, menopausal status and parity. Logistic regression models were fitted to the UK study, and Cox regression models to the Norwegian study, to assess associations between MD and breast cancer risk, expressed as odds/hazard ratios per adjusted standard deviation (OPERA). Adjustments were first made for standard risk factors except BMI (minimally adjusted models) and then also for BMI or NDV. OPERA pooled relative risks (RRs) were estimated by fixed-effect models, and between-study heterogeneity was assessed by the I2 statistics.

RESULTS

BMI was positively correlated with NDV (adjusted r = 0.74 in the UK study and r = 0.72 in the Norwegian study) and with DV (r = 0.33 and r = 0.25, respectively). Both %MD and DV were positively associated with breast cancer risk in minimally adjusted models (pooled OPERA RR (95% confidence interval): 1.34 (1.25, 1.43) and 1.46 (1.36, 1.56), respectively; I2 = 0%, P >0.48 for both). Further adjustment for BMI or NDV strengthened the %MD-risk association (1.51 (1.41, 1.61); I2 = 0%, P = 0.33 and 1.51 (1.41, 1.61); I2 = 0%, P = 0.32, respectively). Adjusting for BMI or NDV marginally affected the magnitude of the DV-risk association (1.44 (1.34, 1.54); I2 = 0%, P = 0.87 and 1.49 (1.40, 1.60); I2 = 0%, P = 0.36, respectively).

CONCLUSIONS

When volumetric MD-breast cancer risk associations are investigated, NDV can be used as a measure of adiposity when BMI data are unavailable.

Association between skeletal muscle mass to visceral fat area ratio and arterial stiffness in Chinese patients with type 2 diabetes mellitus

BACKGROUND

The skeletal muscle mass-to-visceral fat area ratio (SVR) has been linked to arterial stiffness in non-diabetic adults. We examined the association between the SVR and arterial stiffness in patients with type 2 diabetes mellitus (T2DM).

METHODS

Patients with type 2 diabetes mellitus (252 men and 171 women) aged 40-75 years were enrolled and divided into three groups according to SVR tertiles. Arterial stiffness was measured as brachial-ankle pulse wave velocity (baPWV), with baPWV> 1800 mm/s defined as high. Spearman's partial correlation was used to adjust confounding factors. The odds ratio for high baPWV was determined by multiple logistic regression analyses, and receiver-operating characteristic analysis was conducted.

RESULTS

SVR was associated with baPWV in Chinese patients with T2DM (Spearman's partial correlation = - 0.129, P < 0.01). SVR was found to be significantly associated with baPWV on multiple logistic regression analysis. Patients in the lower SVR tertiles had a higher OR than did those in the higher SVR tertiles, after adjusting for multiple covariates (Q1: OR = 4.33 in men and 4.66 in women; Q3: OR = 1). The area under the curve for SVR was significantly greater than that for appendicular skeletal muscle (ASM), ASM/height², and visceral fat area (VAF) for identifying high baPWV (0.747 in men and 0.710 in women). The optimal cutoffs values of SVR for detecting high baPWV were 191.7 g/cm² for men and 157.3 g/cm² for women.

CONCLUSIONS

SVR has an independent, negative association with arterial stiffness, and is a better risk-assessment tool than ASM, ASM/height², and VFA in clinical practice to identify patients with type 2 diabetes at high cardiovascular risk.

The association between high-sensitivity C-reactive protein and metabolic risk factors in black and white South African women: a cross-sectional study

Background

High-sensitivity C-reactive protein (hsCRP) is associated with metabolic risk, however it is unclear whether the relationship is confounded by racial/ethnic differences in socioeconomic status (SES), lifestyle factors or central adiposity. The aims of the study was, (1) to investigate whether hsCRP levels differ by race/ethnicity; (2) to examine the race/ethnic-specific associations between hsCRP, HOMA-IR and serum lipids [total cholesterol (TC), triglycerides (TG), high-density lipoproteins (HDL-C) and low-density lipoproteins (LDL-C)]; and (3) to determine whether race/ethnic-specific associations are explained by SES, lifestyle factors or waist circumference (WC).

Methods

The convenience sample comprised 195 black and 153 white apparently health women, aged 18-45 years. SES (education, assets and housing density) and lifestyle factors (alcohol use, physical activity and contraceptive use) were collected by questionnaire. Weight, height and WC were measured, and fasting blood samples collected for hsCRP, glucose, insulin, and lipids.

Results

Black women had higher age- and BMI-adjusted hsCRP levels than white women (p = 0.047). hsCRP was associated with HOMA-IR (p < 0.001), TG (p < 0.001), TC (p < 0.05), HDL-C (p < 0.05), and LDL-C (p < 0.05), independent of age and race/ethnicity. The association between hsCRP and lipids differed by race/ethnicity, such that hsCRP was positively associated with TG and LDL-C in white women, and inversely associated with HDL-C in black women. Higher hsCRP was also associated with higher TC in white women and lower TC in black women. Furthermore, when adjusting for SES and lifestyle factors, the associations between hsCRP, and TC and TG, remained, however the associations between hsCRP, and HDL-C and LDL-C, were no longer significant.

Conclusion

Although circulating hsCRP may identify individuals at increased metabolic risk, the heterogeneity in these associations between racial/ethnic groups highlights the need for prospective studies investigating the role of hsCRP for risk prediction in different populations.

Different adiposity indices and their association with blood pressure and hypertension in middle-aged urban black South African men and women: findings from the AWI-GEN South African Soweto Site

Background

To report associations between different adiposity indices [anthropometric and dual-energy X-ray absorptiometry (DXA) measures] and blood pressure (BP) and hypertension in urban black South African adults.

Methods

Anthropometric and DXA whole body measures were performed on 1026 men and 982 women. Participants were classified as being hypertensive if they had a systolic BP (SBP) ≥ 140 mmHg and/or diastolic (DBP) ≥ 90 mmHg. Within each gender the relationship of adiposity with BP and hypertension risk was assessed using linear and logistic regression models respectively. Bivariate models were computed for each body composition variable. Furthermore, we computed a multiple regression model to illustrates how body composition parameters are associated with the outcome variables independent of each other.

Results

The males were significantly taller and had a higher fat free soft tissue mass (FFSTM), DBP and socio-economic status, and were more likely to use tobacco and be hypertensive (48.0% vs. 38.8%). The females had higher body mass index (BMI), waist circumference (WC), fat mass (FM), subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT), FM/FFSTM ratio and body fat % than males. All body composition parameters were positively associated with hypertension. In both males and females, the FM/FFSTM ratio associated the strongest with hypertension illustrating the following odds ratios [males: 70.37 (18.47, 268.16) p ≤ 0.001; females 2.48 (0.86,7.21) p = 0.09]. The multiple regression model, indicated that the VAT and WC significantly associated with both SBP and DBP in the men and women respectively, whilst WC was the only significant predictor for hypertension.

Conclusions

All body composition parameters were associated with hypertension and FM/FFSTM ratio showed the strongest relationship. It was reassuring that WC remains a useful measure of central adiposity that can be used as a risk indicator for hypertension if more sophisticated measures are not available. Furthermore, our data in part, implies that reducing abdominal adiposity in aging adults could contribute to reducing the risk of elevated blood pressure and hypertension.

Electronic supplementary material

The online version of this article (10.1186/s12889-018-5443-4) contains supplementary material, which is available to authorized users.

An Exercise Intervention to Unravel the Mechanisms Underlying Insulin Resistance in a Cohort of Black South African Women: Protocol for a Randomized Controlled Trial and Baseline Characteristics of Participants

Background

The pathogenesis of type 2 diabetes (T2D) in black African women is complex and differs from that in their white counterparts. However, earlier studies have been cross-sectional and provide little insight into the causal pathways. Exercise training is consistently used as a model to examine the mechanisms underlying insulin resistance and risk for T2D.

Objective

The objective of the study was to examine the mechanisms underlying the changes in insulin sensitivity and secretion in response to a 12-week exercise intervention in obese black South African (SA) women.

Methods

A total of 45 obese (body mass index, BMI: 30-40 kg/m²) black SA women were randomized into a control (n=22) or experimental (exercise; n=23) group. The exercise group completed 12 weeks of supervised combined aerobic and resistance training (40-60 min, 4 days/week), while the control group maintained their typical physical activity patterns, and both groups were requested not to change their dietary patterns. Before and following the 12-week intervention period, insulin sensitivity and secretion (frequently sampled intravenous glucose tolerance test) and its primary and secondary determinants were measured. Dietary intake, sleep quality and quantity, physical activity, and sedentary behaviors were measured every 4 weeks.

Results

The final sample included 20 exercise and 15 control participants. Baseline sociodemographics, cardiorespiratory fitness, anthropometry, cardiometabolic risk factors, physical activity, and diet did not differ between the groups (P>.05).

Conclusions

The study describes a research protocol for an exercise intervention to understand the mechanisms underlying insulin sensitivity and secretion in obese black SA women and aims to identify causal pathways underlying the high prevalence of insulin resistance and risk for T2D in black SA women, targeting specific areas for therapeutic intervention.

Trial Registration

Pan African Clinical Trial Registry PACTR201711002789113; http://www.pactr.org/ATMWeb/ appmanager/atm/atmregistry?_nfpb=true&_pageLabel=portals_app_atmregistry_portal_page_13 (Archived by WebCite at http://www.webcitation.org/6xLEFqKr0)

Management of obesity after spinal cord injury: a systematic review

CONTEXT

Individuals with chronic spinal cord injury (SCI) are susceptible to central and visceral obesity and it's metabolic consequences; consensus based guidelines for obesity management after SCI have not yet been stablished.

OBJECTIVES

To identify and compare effective means of obesity management among SCI individuals.

METHODS

This systematic review included English and non-English articles, published prior to April 2017 found in the PubMed/Medline, Embase, CINAHL Psychinfo and Cochrane databases. Studies evaluating any obesity management strategy, alone or in combination, including: diet therapy, voluntary and involuntary exercise such as neuro-muscular electric stimulation (NMES), pharmacotherapy, and surgery, among individuals with chronic SCI were included. Outcomes of interest were reductions in waist circumference, body weight (BW), body mass index (BMI) and total fat mass (TFM) and increases in total lean body mass (TLBM) from baseline. From 3,553 retrieved titles and abstracts, 34 articles underwent full text review and 23 articles were selected for data abstraction. Articles describing weight loss due to inflammation, cancer or B12 deficiency were excluded. The Downs and Black reported poor to moderate quality of the studies.

RESULTS

Bariatric surgery produced the greatest permanent weight reduction and BMI correction followed by combinations of physical exercise and diet therapy. Generally, NMES and pharmacotherapy improved TLBM and reduced TFM but not weight.

CONCLUSIONS

The greatest weight reduction and BMI correction was produced by bariatric surgery, followed by a combination of physical exercise and diet therapy. NMES and pharmacologic treatment did not reduce weight or TFM but increased in TLBM.

Reference Ranges Using Bioimpedance for Detection of Lymphedema in Chinese Women

BACKGROUND

Bioimpedance is a commonly used technique for detection of early lymphedema. The thresholds used for detection are based on impedance measurements obtained in Western populations. It is unknown whether these thresholds are applicable to a Chinese population.

METHODS AND RESULTS

Impedance measurements were obtained for both arms in 391 women, ranging in age from 20 to 84 years, using a standardized protocol. Frequency distributions of interlimb impedance arm ratios for both dominant:non-dominant and non-dominant:dominant were used to determine thresholds at two and three standard deviations (SDs) above the mean. Absolute impedance was significantly higher in the youngest group (20-39 years) compared to other age groups. However, there was no significant effect of age on impedance ratios. Similarly, there was no significant difference between impedance ratios determined in this study and those from recent studies in the Australia and the United States, which used similar protocols. New two and three SDs above the mean thresholds, using a weighted average from the pooled data of these studies are 1.108 and 1.153 for use when the dominant limb is at-risk and 1.072 and 1.116 when the non-dominant limb is at-risk.

CONCLUSION

There was no effect of ethnicity on impedance ratios. Consequently, the proposed pooled thresholds can be used, irrespective of ethnicity.

Agreement between specific measures of adiposity and associations with high blood pressure in black South African women

OBJECTIVES

To derive percentage body fat (%BF) cut-points according to body mass index (BMI) categories for adult black South African women and to investigate the agreement between adiposity classifications according to WHO BMI and %BF cut-points. The secondary aim was to determine the association between these different adiposity measures and high blood pressure.

METHODS

Black women aged 29-65 years (n = 435) from Ikageng, South Africa, were included in this cross-sectional study. Socio-demographic and anthropometric data were collected (weight, height and BMI). %BF using dual-energy X-ray absorptiometry and blood pressure were measured.

RESULTS

There was significant agreement between three %BF categories: low/normal (<35.8% age 29-49 years; or <38% age 50-65 years), overweight range (35.8-40.7% age 29-49 years; or 38-42.1% age 50-65 years) and obese (≥40.7% age 29-49 years; or ≥42.1% age 50-65 years) and three BMI categories: low/normal (<25 kg/m² ), overweight range (25-29.9 kg/m² ) and obese (≥30kg/m² ); (κ = 0.62, P < .0001). Despite statistically significant agreement between groups, more than half of overweight individuals were misclassified as having either a normal (30.2%) or obese %BF (25.5%). %BF misclassification was low in the low/normal and obese BMI ranges. After adjustment for confounders, obesity (BMI ≥ 30kg/m² ), as well as high %BF were significantly associated with high blood pressure (OR = 1.75, 95% CI 1.09-2.81 versus OR = 1.92, 95% CI 1.15-3.23, respectively).

CONCLUSION

Despite significant agreement between BMI and %BF categories, considerable misclassification occurred in the overweight range. Participants with excessive %BF had a greater odds of high blood pressure than those in the highest BMI category.

Visceral Adiposity Is an Independent Determinant of Hypercoagulability as Measured by Thrombin Generation in Morbid Obesity

Introduction  Increased visceral adipose tissue (VAT) has been shown to be associated with the development of insulin resistance, type 2 diabetes, stroke, and ischemic heart disease. It remains unknown whether fat distribution impacts on coagulation markers and/or the risk of venous thrombosis. This study evaluates markers of hypercoagulability in class III obesity (body mass index [BMI] >40 kg/m 2 ) compared with nonobese controls. We further investigated whether hypercoagulability was influenced by VAT, metabolic syndrome, and metabolic markers, including adiponectin. Patients and Methods  Ninety patients were recruited from the obesity clinic at King's College Hospital from November 2009 to December 2011. The inclusion criteria were class III obesity (BMI ≥40 kg/m 2 ) and age 18 to 65 years. A control group (healthy ambulatory participants, with a BMI < 30 kg/m 2 ) was recruited from volunteers responding to advertisement. Abdominal VAT and subcutaneous adipose tissue surface areas were determined by evaluation of a single-slice CT at spinal vertebra L4. Results  Thrombin generation revealed a significantly increased peak and endogenous thrombin potential in patients compared with controls. Lag time and time to peak (ttP) were also significantly prolonged in patients. VAT was found to have the strongest association with thrombin generation parameters: lag time (β = 0.378; p  < 0.001), peak thrombin (0.378; p  = 0.04), and ttP (β = 0.373; p  = 0.001). BMI was found to be a predictor for lag time only (β = 0.313; p  = 0.003). SAT was not associated with any of the thrombin generation parameters (data not shown). VAT was found to be an independent determinant of peak thrombin, lag time, and ttP. The study suggests not only fat mass but also fat distribution, particularly visceral adiposity, mediates hypercoagulability in obesity.

Obesity indices predict hypertension among indigenous adults in Krau Wildlife Reserve, Peninsular Malaysia

BACKGROUND

The disease burden of indigenous peoples has been augmented by the rising prevalence of obesity and hypertension in this population. This study assessed the ability of obesity indices to predict hypertension among indigenous adults of Peninsular Malaysia.

METHODS

In this cross-sectional study, 482 adults (223 men, 259 women) aged ≥18 years old were measured for body mass index (BMI), waist circumference (WC), waist-height ratio (WHtR), waist-hip ratio (WHR), and blood pressure. Receiver operating characteristic (ROC) analysis was used to determine the predictive ability of obesity indices for hypertension in men and women. Gender-specific logistic regression analyses were done to examine the association between obesity, defined by BMI, WC, WHtR and WHR, and hypertension.

RESULTS

Prevalence of hypertension was 25.5%. Overall, WHtR was the best predictor of the presence of hypertension, in both men and women. The optimal WHtR cut-off values for hypertension were 0.45 and 0.52 in men and women, respectively. Obese adults with WHtR ≥0.5 had about two times increased odds of having hypertension compared to non-obese adults.

CONCLUSIONS

WHtR may serve as a simple and inexpensive screening tool to identify individuals with hypertension in this relatively difficult to reach population.

Type 2 diabetes mellitus in African women

Compared to global estimates, Sub-Saharan Africa (SSA) has the highest projected rates of increase in type 2 diabetes (T2D) over the next 25years. This is attributed to the ageing population, increasing urbanisation and the associated lifestyle changes. Although the prevalence does not differ by gender, deaths attributable to T2D in SSA are greater in women, likely due to differences in beliefs and access to care. Women in SSA also have greater risk factor burden for T2D than men, in particular obesity, which is explained in part by sociocultural factors. The pathogenesis of diabetes differs between African and Caucasian women, with implications for risk assessment. African women are more insulin resistant than their Caucasian counterparts, despite a more 'favourable' body fat distribution. Notably, women in SSA face the dual burden of T2D and HIV/AIDS. HIV positive women in SSA are typically young and obese, with the latter being exacerbated by anti-retroviral therapy (ART). Cultural perceptions regarding weight loss and limited financial resources are the major limitations to the management of T2D. Hence prevention is vital. However, there is a paucity of studies examining the effectiveness and sustainability of interventions to reduce T2D in SSA.

The Metabolic Phenotype in Obesity: Fat Mass, Body Fat Distribution, and Adipose Tissue Function

The current obesity epidemic poses a major public health issue since obesity predisposes towards several chronic diseases. BMI and total adiposity are positively correlated with cardiometabolic disease risk at the population level. However, body fat distribution and an impaired adipose tissue function, rather than total fat mass, better predict insulin resistance and related complications at the individual level. Adipose tissue dysfunction is determined by an impaired adipose tissue expandability, adipocyte hypertrophy, altered lipid metabolism, and local inflammation. Recent human studies suggest that adipose tissue oxygenation may be a key factor herein. A subgroup of obese individuals - the 'metabolically healthy obese' (MHO) - have a better adipose tissue function, less ectopic fat storage, and are more insulin sensitive than obese metabolically unhealthy persons, emphasizing the central role of adipose tissue function in metabolic health. However, controversy has surrounded the idea that metabolically healthy obesity may be considered really healthy since MHO individuals are at increased (cardio)metabolic disease risk and may have a lower quality of life than normal weight subjects due to other comorbidities. Detailed metabolic phenotyping of obese persons will be invaluable in understanding the pathophysiology of metabolic disturbances, and is needed to identify high-risk individuals or subgroups, thereby paving the way for optimization of prevention and treatment strategies to combat cardiometabolic diseases.

Cardiovascular Disease Risk Score: Results from the Filipino-American Women Cardiovascular Study

INTRODUCTION

Although cardiovascular disease (CVD) is a leading cause of morbidity and mortality of Filipino-Americans, conventional CVD risk calculators may not be accurate for this population. CVD risk scores of a group of Filipino-American women (FAW) were measured using the major risk calculators. Secondly, the sensitivity of the various calculators to obesity was determined.

METHODS

This is a cross-sectional descriptive study that enrolled 40-65-year-old FAW (n = 236), during a community-based health screening study. Ten-year CVD risk was calculated using the Framingham Risk Score (FRS), Reynolds Risk Score (RRS), and Atherosclerotic Cardiovascular Disease (ASCVD) calculators. The 30-year risk FRS and the lifetime ASCVD calculators were also determined.

RESULTS

Levels of predicted CVD risk varied as a function of the calculator. The 10-year ASCVD calculator classified 12 % of participants with ≥10 % risk, but the 10-year FRS and RRS calculators classified all participants with ≤10 % risk. The 30-year "Hard" Lipid and BMI FRS calculators classified 32 and 43 % of participants with high (≥20 %) risk, respectively, while 95 % of participants were classified with ≥20 % risk by the lifetime ASCVD calculator. The percent of participants with elevated CVD risk increased as a function of waist circumference for most risk score calculators.

CONCLUSIONS

Differences in risk score as a function of the risk score calculator indicate the need for outcome studies in this population. Increased waist circumference was associated with increased CVD risk scores underscoring the need for obesity control as a primary prevention of CVD in FAW.

The Role of Body Fat and Fat Distribution in Hypertension Risk in Urban Black South African Women

Developing countries are disproportionately affected by hypertension, with Black women being at greater risk, possibly due to differences in body fat distribution. The objectives of this study were: (1) To examine how different measures of body composition are associated with blood pressure (BP) and incident hypertension; (2) to determine the association between baseline or change in body composition, and hypertension; and (3) to determine which body composition measure best predicts hypertension in Black South African women. The sample comprised 478 non-hypertensive women, aged 29–53 years. Body fat and BP were assessed at baseline and 8.3 years later. Body composition was assessed using dual-energy X-ray absorptiometry (DXA) (n = 273) and anthropometry. Hypertension was diagnosed based on a systolic/diastolic BP ≥140/90 mmHg, or medication use at follow-up. All body composition measures increased (p<0.0001) between baseline and follow-up. SBP and DBP increased by ≥20%, resulting in a 57.1% cumulative incidence of hypertension. Both DXA- and anthropometric-derived measures of body composition were significantly associated with BP, explaining 3–5% of the variance. Baseline BP was the most important predictor of hypertension (adjusted OR: 98–123%). Measures of central adiposity were associated with greater odds (50–65%) of hypertension than total adiposity (44–45%). Only change in anthropometric-derived central fat mass predicted hypertension (adjusted OR: 32–40%). This study highlights that body composition is not a major determinant of hypertension in the sample of black African women. DXA measures of body composition do not add to hypertension prediction beyond anthropometry, which is especially relevant for African populations globally, taking into account the severely resource limited setting found in these communities.

VALIDITY OF USING WAIST AND HIP CIRCUMFERENCE MEASUREMENTS TO DETERMINE BODY COMPOSITION OF YOUNG SYRIAN MEN

This study examined the relation between waist circumference (WC), hip circumference (HC), waist-to-hip ratio (WHpR), waist-to-height ratio (WHtR) and triceps skin-fold thickness and percentage body fat in young Syrian men. The aim was to develop equations that can use these anthropometric characteristics to estimate percentage body fat in this group of subjects. A total of 2470 healthy Syrian men aged 18-19 years were enrolled in the study in 2010-2011. The anthropometric characteristics of all subjects were measured. The percentage body fat of 213 of the subjects was determined using the deuterium dilution (DD) technique as a reference method. The validity of using WC, HC, WHpR and WHtR to calculate percentage body fat, in comparison with the reference method (DD technique), was assessed by calculating biases and limits of agreement. The estimates of percentage body fat using 'WC' and 'WC with triceps skin-fold' measurements ranged from 13.00±5.56% to 14.55±8.63%, and were lower than those determined using the reference method (21.32±6.42%). A better prediction equation is proposed for young adults, based on a multiple linear regression model using WC, HC and WHtR.

Evaluation of a new bio-impedance spectroscopy device in healthy Japanese

BACKGROUND

The use of a new bio-impedance spectroscopy device (Body Composition Monitor, BCM) in the field of dialysis became possible in Japan. However, it is unknown whether the data obtained using this apparatus are indicative for Japanese dialysis patients.

OBJECTIVE

To compare individual fluid status in healthy Japanese using the BCM device with the data obtained from healthy Caucasians.

METHODS

A total of 219 volunteers (female vs. male, 150 vs. 69; mean age, 68.8 ± 8.4 years; mean BMI, 22.6 ± 2.9 kg/m2) were enrolled. The measurement was performed by the end of the morning before exercise.

RESULTS

Mean over-hydration (OH) level was 0.7 ± 0.8 L. Nearly 80% of subjects had values equivalent to the standard values of healthy Caucasians (-1.1∼1.1 L). Age had a weak positive correlation to OH. The fat tissue index levels were slightly lower in Japanese than in Caucasians. On the other hand, the levels of lean tissue index and ECW/ICW (E/I) ratio did not differ between Japanese and Caucasians. E/I ratio showed a good correlation with OH level.

CONCLUSION

Fluid status of healthy Japanese was equivalent to the standard value of Caucasians. Although validity of using parameters from healthy Caucasians in healthy Japanese population was considered to be confirmed, validity of use in Japanese dialysis patients should be evaluated further using the parameters from healthy Caucasians.

Prevalence of type 2 diabetes and its association with measures of body composition among African residents in the Netherlands--The HELIUS study

AIMS

To compare type 2 diabetes prevalence among three ethnic groups resident in the Netherlands: Ghanaians, African Surinamese and Dutch origin. Secondly, to determine the contribution of measures of body composition to ethnic differences in type 2 diabetes.

METHODS

Baseline data from Ghanaian (n=1873), African Surinamese (n=2189) and Dutch (n=2151) origin participants of the HELIUS study (aged 18-70 years) were analyzed. Type 2 diabetes was determined according to the WHO criteria. Logistic regression tested ethnic differences in type 2 diabetes and the contribution of body fat percentage and waist-to-hip ratio.

RESULTS

Among men, type 2 diabetes prevalence was higher in Ghanaians (14.9%) than in African Surinamese (10.4%) and Dutch (5.0%). Among women, type 2 diabetes prevalence in Ghanaian (11.1%) was higher than in Dutch (2.3%), but similar to African Surinamese (11.5%). After adjusting for age, body fat percentage and waist-to-hip ratio, the odds ratios for having type 2 diabetes were 1.55 (95% CI: 1.12-2.15) for Ghanaian men compared with African Surinamese and 4.19 (95% CI: 2.86-6.12) compared with Dutch. Among women these odds ratios were 0.94 (95% CI: 0.70-1.26) and 4.78 (95% CI: 2.82-8.11).

CONCLUSIONS

The higher prevalence of type 2 diabetes among Ghanaian compared with African Surinamese men suggests a need to distinguish between African descent populations when assessing their type 2 diabetes risk. The higher odds for type 2 diabetes among Ghanaians cannot be attributed to differences in body composition. Further research on the contribution of lifestyle factors as well as genetic and epigenetic factors is needed to identify the reasons for the observed disparities.

Length of urban residence and obesity among within-country rural-to-urban Andean migrants

Objective

To evaluate the association between length of residence in an urban area and obesity among Peruvian rural-to-urban migrants.

Design

Cross-sectional database analysis of the migrant group from the PERU MIGRANT Study (2007). Exposure was length of urban residence, analysed as both a continuous (10-year units) and a categorical variable. Four skinfold site measurements (biceps, triceps, subscapular and suprailiac) were used to calculate body fat percentage and obesity (body fat percentage >25% males, >33% females). We used Poisson generalized linear models to estimate adjusted prevalence ratios and 95 % confidence intervals. Multicollinearity between age and length of urban residence was assessed using conditional numbers and correlation tests.

Setting

A peri-urban shantytown in the south of Lima, Peru.

Subjects

Rural-to-urban migrants (n 526) living in Lima.

Results

Multivariable analyses showed that for each 10-year unit increase in residence in an urban area, rural-to-urban migrants had, on average, a 12 % (95 % CI 6, 18 %) higher prevalence of obesity. This association was also present when length of urban residence was analysed in categories. Sensitivity analyses, conducted with non-migrant groups, showed no evidence of an association between 10-year age units and obesity in rural (P=0·159) or urban populations (P=0·078). High correlation and a large conditional number between age and length of urban residence were found, suggesting a strong collinearity between both variables.

Conclusions

Longer lengths of urban residence are related to increased obesity in rural-to-urban migrant populations; therefore, interventions to prevent obesity in urban areas may benefit from targeting migrant groups.

Longitudinal Changes in Body Fat and Its Distribution in Relation to Cardiometabolic Risk in Black South African Women

BACKGROUND

Ethnic differences in body composition and cardiometabolic risk have been reported in cross-sectional studies. This study aimed to investigate changes in body composition over 5.5 years, and its association with cardiometabolic risk in premenopausal black South African (SA) women.

METHODS

Changes in body composition and body fat distribution (dual-energy x-ray absorptiometry and computerized tomography), fasting glucose, insulin, and lipid concentrations, were measured in 63 black SA women at baseline (age: 27 ± 8 years), and 5.5 years later.

RESULTS

Body weight and fat mass (FM) increased by 6.9 ± 9.9 kg and 4.3 ± 6.9 kg, respectively, over the 5.5 years with a relative (%FM) increase in central and decrease in peripheral FM (all P < 0.05). Fasting glucose and lipid concentrations (except HDL-cholesterol) increased over the follow-up period (all P < 0.05). Both baseline and changes in body fat distribution were associated with cardiometabolic risk. Independent of baseline age, FM and insulin sensitivity, baseline trunk:leg was associated with reduced insulin sensitivity at follow-up (Matsuda index; β = -0.41, P = 0.002). Increasing trunk:gynoid ratio was associated with higher plasma insulin levels (β = 0.31, P = 0.023) and reduced insulin sensitivity (Matsuda index; β = -0.52, P < 0.001) at follow-up.

CONCLUSIONS

Weight gain in free-living black SA women over 5.5 years was associated with a centralization of fat mass, which predicted an increase in cardiometabolic risk.

Body Composition in Asians and Caucasians: Comparative Analyses and Influences on Cardiometabolic Outcomes

Within the last four decades Asia has witnessed major transformation in its population demographics, which gave rise to changes in food availability, food habits and lifestyle. A significant consequence of these changes has been the continuing rise in overweight and obesity across Asia. In parallel, there has been a significant rise in Asians in the incidence of the major chronic diseases, particularly in cardiometabolic disorders such as metabolic syndrome, type 2 diabetes, hypertension, and other cardiovascular diseases. Given that the majority of the evidence, to date, investigating the associations between adiposity and cardiometabolic disorder risk have been obtained from studies undertaken either in European or in North American Caucasians, in this chapter, we have reviewed differences in body fat content and distribution between East Asians, South Asians, and Caucasians. The evidence is consistent that the content and distribution of body fat are markedly different between the various ethnic groups. We found that Asians have a greater predisposition towards adiposity at higher BMI than in Caucasians. Moreover, at any given level of adiposity, Asians have a much greater predisposition to risk of cardiometabolic disorders than Caucasians. We therefore strongly endorse the need for different adiposity cutoffs in Asians as compared to the Caucasians. We have also reviewed the predictive abilities of the various body composition/adiposity measures in determining risk of cardiometabolic disorders in Asians.

The Interplay Between Sex, Ethnicity, and Adipose Tissue Characteristics

The obesity epidemic in the USA affects disproportionately women and the ethnic minorities. On the other hand, female sex is traditionally associated with a favorable fat distribution preferentially in the subcutaneous depots of the lower body and with improved endocrine and metabolic function of the adipose tissue. However, these data are derived from predominantly non-Hispanic white populations. This review discusses fat distribution patterns in women of diverse ethnic backgrounds, together with data on the release of adipokines from adipose tissue in these populations. Very little information is available on how the metabolic function of the adipocyte differs depending on ethnicity. Thus, it becomes clear that future clinical and translational research should explicitly discuss and take into account the sex and ethnic background of the populations studied.

Liver fat accumulation in response to overfeeding with a high-fat diet: a comparison between South Asian and Caucasian men

Background

South Asians were reported to have a higher liver fat content as compared to BMI-matched Caucasians. This study compared the increase in liver fat content in response to overfeeding with a high fat diet in South Asian and Caucasian men when matched for body fat percentage.

Methods

Ten South Asian men (BMI 18–29 kg/m²) and 10 Caucasian men (BMI 22–33 kg/m²), aged 20–40 y, matched for body fat percentage, were included. A weight maintenance diet was given for 3 days based on the individual energy requirement. Individual energy requirement of the subjects was calculated based on their body composition (measured by hydro densitometry and deuterium dilution) and activity counts (accelerometer). Liver fat content was measured before and after 4 days of overfeeding (50 % excess energy need) with a high fat diet (60 % energy from fat). Fat distribution was measured by anthropometry and an MRI scan of the abdomen while liver fat content using 1H-MRS.

Results

While having a similar body fat % (P = 0.58), South Asians had a lower BMI (P = 0.04) than Caucasians. Liver fat content at baseline did not differ between ethnicities (P = 0.48) and was associated with visceral fat area (P = 0.002, R² = 0.56) but not with ethnicity (P = 0.13). Overfeeding with a high fat diet significantly increased liver fat (P = 0.01) but the increase did not differ between ethnicities (P = 0.47). There was no difference in the total abdominal fat area (P = 0.37), subcutaneous abdominal fat area (P = 0.18) and visceral fat area (VAT, P = 0.32). However as a percentage of the total abdominal fat area, VAT was higher in South Asians (P = 0.003).

Conclusion

Despite a relatively higher percentage of visceral fat area, liver fat increased similarly in South Asian and Caucasian men in response to overfeeding with a high fat diet.

Trial registration

The study was registered in the public trial registry www.ccmo.nl No. NL31217.068.10.

Ethnic-specific cut-points for sarcopenia: evidence from black South African women

BACKGROUND/OBJECTIVES

Age-related muscle and fat mass (FM) changes are ethnicity specific. We aimed to develop a cut-point for the muscle mass component of sarcopenia for black South African (SA) women, and to assess its predictive value, in comparison to established cut-points, to identify functional ability among older black SA women.

SUBJECTS/METHODS

In a cross-sectional study, a sarcopenia cut-point was calculated from dual energy X-ray absorptiometry (DXA)-derived appendicular skeletal muscle mass (ASM) indexes (ASMI) from two young black SA reference groups. The new cut-point was compared with the most recent Foundation for the National Institutes of Health (FNIH) criteria (ASM <15.02 kg; and ASM(BMI) <0.512), an internationally accepted cut-point (ASMI <5.5 kg/m(2)) and a residual method adjusting for FM. All cut-points were then applied to 221 older black women to predict gait speed and handgrip strength.

RESULTS

A cut-point of ASMI <4.94 kg/m(2) was derived from the young SA reference groups. Using this cut-point, 9.1% of older women were classified as sarcopenic, compared with 16.7-38.7% using other cut-points. The only cut-points that significantly predicted low functional ability (low gait speed and low handgrip strength) in older black women were the new SA cut-point and the FNIH ASM criterion. Multivariate logistic regression models for both these cut-points significantly predicted low handgrip strength (odds ratio (OR)=3.71, P=0.007 and OR=3.42, P=0.001, respectively) and low gait speed (OR=9.82, P=0.004 and OR=8.71, P=0.008, respectively).

CONCLUSIONS

The new SA cut-point had similar or greater odds of predicting reduced functional ability in older SA women when compared with other internationally accepted cut-points.

Ability of body mass index and waist circumference to identify risk factors for non-communicable disease in the Pacific Islands

Body mass index and waist circumference are widely used tools to identify risk of non-communicable diseases. Research has indicated that the risk relationships differ by ethnicity. In this study, data from chronic disease surveys in Fiji, Nauru, Solomon Islands and Wallis and Futuna were merged and analysed using receiver operator curves. The action points for body mass index and waist circumference with the highest specificity and sensitivity for identifying the risk of NCDs were identified. The analysis showed considerable differences between Melanesians and other Pacific Islanders, and also gender differences. Action points for non-Melanesians were higher than for Melanesians, and region-wide values are therefore inappropriate.:

A comparison study of portable foot-to-foot bioelectrical impedance scale to measure body fat percentage in Asian adults and children

Objective. To compare the measurements of body fat percentage (BF%) using the foot-to-foot bioelectrical impedance analysis (FTF-BIA) with the direct segmental multifrequency BIA (DSM-BIA). Methods. There were 36 men and 52 women (37.1 ± 14.3 years) with 57% Malays, 30% Chinese, and 13% Indian. For children, there were 45 boys and 26 girls (11.5 ± 2.5 years) with 52% Malay, 15% Chinese, and 33% Indian. Results. Mean height for men was 168.4 cm, 11 cm taller than women. Men were 10 kg heavier than women at 70 kg. BF% in women was 32% and 33% whereas BF% in men was 23% and 25% when measured using FTF-BIA and DSM-BIA, respectively. In children, BF% measured with FTF-BIA and DSM-BIA was 49% and 46%, respectively. The correlations were significant for men (r = 0.92, SEE = 2.80), women (r = 0.91, SEE = 3.31), boys (r = 0.95, SEE = 5.44), and girls (r = 0.96, SEE = 5.27). The BF% in underweight/normal (r = 0.92, SEE = 2.47) and that in overweight/obese adults (r = 0.89, SEE = 3.61) were strongly correlated. The correlations were significant in normal/underweight (r = 0.94, SEE = 3.78) and obese/overweight children (r = 0.83, SEE = 6.49). All ethnic groups showed significant correlation with BF%. Malay adults (r = 0.92, SEE = 3.27) and children (r = 0.94, SEE = 0.88) showed significant mean differences in BF%. Conclusion. The FTF-BIA showed higher accuracy for all normal/underweight and Chinese group with acceptable overestimation in children and underestimation in adults. Caution should be taken when interpreting BF% depending on gender, BMI, and ethnicity.

Glucocorticoid receptor gene expression in adipose tissue and associated metabolic risk in black and white South African women

BACKGROUND

Black women have lower visceral adipose tissue (VAT) but are less insulin sensitive than white women; the mechanisms responsible are unknown.

OBJECTIVE

The study aimed to test the hypothesis that variation in subcutaneous adipose tissue (SAT) sensitivity to glucocorticoids might underlie these differences.

METHODS

Body fatness (dual energy X-ray absorptiometry) and distribution (computerized tomography), insulin sensitivity (SI, intravenous and oral glucose tolerance tests), and expression of 11β-hydroxysteroid dehydrogenase-1 (11HSD1), hexose-6-phosphate dehydrogenase and glucocorticoid receptor-α (GRα), as well as genes involved in adipogenesis and inflammation were measured in abdominal deep SAT, superficial SAT and gluteal SAT (GLUT) depots of 56 normal-weight or obese black and white premenopausal South African (SA) women. We used a combination of univariate and multivariate statistics to evaluate ethnic-specific patterns in adipose gene expression and related body composition and insulin sensitivity measures.

RESULTS

Although 11HSD1 activity and mRNA did not differ by ethnicity, GRα mRNA levels were significantly lower in SAT of black compared with white women, particularly in the GLUT depot (0.52±0.21 vs 0.91±0.26 AU, respectively, P<0.01). In black women, lower SAT GRα mRNA levels were associated with increased inflammatory gene transcript levels and abdominal SAT area, and reduced adipogenic gene transcript levels, VAT/SAT ratio and SI. Abdominal SAT 11HSD1 activity associated with increased VAT area and decreased SI in white, but not in black women.

CONCLUSIONS

In black SA women, downregulation of GRα mRNA levels with obesity and reduced insulin sensitivity, possibly via increased SAT inflammation, is associated with reduced VAT accumulation.

Metabolic profile before and after short-term overfeeding with a high-fat diet: a comparison between South Asian and White men

For the same BMI, South Asians have a higher body fat percentage and an adverse metabolic profile compared with whites. The objective of the present study was to determine the metabolic profiles of South Asian and white men matched for body fat percentage in response to short-term overfeeding with a high-fat diet. A total of ten healthy non-diabetic South Asian men matched for body fat percentage with ten white men were included in the study. A weight-maintenance diet (containing 30 % fat, 55 % carbohydrate and 15 % protein) was provided for 3 d followed by 4 d of overfeeding (150 % of energy requirement) with a high-fat diet (60 % fat, 25 % carbohydrate and 15 % protein). Before and after the overfeeding period, plasma glucose, insulin, TAG, NEFA, total cholesterol and HDL-cholesterol concentrations were determined. Glucose clearance was calculated using a 2 h oral glucose tolerance test. The results revealed that in South Asian and white men, respectively, overfeeding with a high-fat diet decreased plasma TAG concentrations by 0·4 (sd 0·6) and 0·4 (sd 0·5) mmol/l (P diet= 0·008; P ethnicity= 0·24), increased HDL-cholesterol concentrations by 0·12 (sd 0·1) and 0·14 (sd 0·2) mmol/l (P diet= 0·001; P ethnicity= 0·06) and decreased glucose clearance by 48·8 (sd 53·5) and 37·2 (sd 34·2) ml/min per m2 body surface (P diet= 0·004; P ethnicity= 0·18). There was a significant interaction between diet and ethnicity with regard to the changes in total and LDL-cholesterol concentrations (P= 0·01 and 0·007, respectively), which trended towards a larger increase in South Asian subjects than in white subjects. Despite a similar body fat percentage, short-term overfeeding with a high-fat diet had more adverse effects on the lipid profile of South Asians than on that of whites.

Association of physical activity with sarcopenia and sarcopenic obesity in community-dwelling older adults: the Fourth Korea National Health and Nutrition Examination Survey

OBJECTIVE

this study examined the association of physical activity with sarcopenia and sarcopenic obesity among the community-dwelling Korean elderly.

METHODS

subjects consisted of 2,264 aged 65 years or older in the 2008-09 Korea National Health and Nutrition Examination Survey. Sarcopenia was defined as 2 SD below the mean of the appendicular skeletal muscle/weight for healthy young adults. Obesity was defined as waist circumference ≥ 90 cm for men and ≥ 85 cm for women. Levels of physical activity were classified using the metabolic equivalent task method.

RESULTS

the prevalence of sarcopenia was 12.1% in men and 11.9% in women. Among those with sarcopenia, obesity was prevalent in 68.3% of men and 65.0% of women. Adjusting for all covariates, compared with those with low physical activity, men who engaged in moderate and high activity were 38% and 74%, respectively, less likely to have sarcopenia (Ptrend < 0.001). In women, the relationship between physical activity and sarcopenia was not significant. For sarcopenic obesity, men participating in moderate [odds ratio (OR) = 0.47; 95% confidence interval (CI) 0.26-0.87] and high (OR = 0.27; 95% CI: 0.12-0.60) physical activity, compared with low activity, had significantly lower risk (Ptrend = 0.001). In women, high physical activity was associated with a lower risk of sarcopenic obesity (OR = 0.43; 95% CI: 0.22-0.86).

CONCLUSION

physical activity is associated with a reduced risk of sarcopenia and sarcopenic obesity in older Korean adults. There were gender differences in the relationship, with stronger associations observed in men than in women.

Obesity and its health impact in Africa: a systematic review

Abstract

Obesity and its association with co-morbidities in Africa are on the rise. This systematic review examines evidence of obesity and its association with co-morbidities within the African continent. Comparative studies conducted in Africa on adults 17 years and older with mean body mass index (BMI) ≥ 28 kg/m² were included. Five electronic databases were searched. Surveys, case–control and cohort studies from January 2000 to July 2010 were evaluated. Of 720 potentially relevant articles, 10 met the inclusion criteria. Prevalence of obesity was higher in urban than rural subjects with significant increases in obesity rates among women. Inflammatory marker levels were significantly elevated among Africans compared with Caucasians. The co-relationship between obesity and chronic diseases was also highlighted. This systematic review demonstrates that while obesity remains an area of significant public health importance to Africans, particularly in urban areas, there is little evidence of proper diagnosis, treatment and/or prevention.

Role of obesity in the risk of breast cancer: lessons from anthropometry

An estimated 1.38 million new cases of breast cancer (BC) are diagnosed each year in women worldwide. Of these, the majority are categorized as invasive ductal cell carcinoma. Subgroups of BC are frequently distinguished into five "intrinsic" subtypes, namely, luminal A, luminal B, normal-like, HER2-positive, and basal-like subtypes. Epidemiological evidence has shown that anthropometric factors are implicated in BC development. Overall consistent positive associations have been observed between high body mass index (BMI) and waist-to-hip ratio (WHR) and the risk of BC among postmenopausal women, while conflicting results persist for premenopausal BC, both for BMI and for other anthropometric parameters as well as across ethnic groups. Furthermore, some evidence suggests that body size, body shape, and weight gain during childhood or adolescence may play a role in the risk of BC. In this paper, we describe the evidence linking anthropometric indices at different ages and BC risk, in order to improve our understanding of the role of body fat distribution in the risk of BC, investigate differences in these associations according to menopausal status and ethnic groups, and discuss the potential biological mechanisms linking body size and BC risk.

Relationship between BMI and body fatness in three European countries

BACKGROUND/OBJECTIVES

Body fatness and heart disease risk factors can differ considerably between ethnities for a given body mass index (BMI). Information is lacking on differences between various Caucasian populations within Europe. The aim was to investigate the differences in anthropometrics and risk factors between adults from Iceland, Spain and Ireland.

SUBJECT/METHODS

This was a secondary analysis of the baseline data from the SEAFOODplus YOUNG intervention study, in which 324 subjects (20-40 years, BMI 27.5-32.5 kg/m(2), from Iceland, Spain and Ireland) participated. Fasting glucose, insulin, blood lipids and body compossition were measured, insulin resistance was calculated using the homeostasis model assessment of insulin resistance.

RESULTS

Although age and BMI did not differ between Spanish, Irish and Icelandic subjects, Irish subjects had significantly higher waist circumference (3.2 and 6.7 cm) and body fat percentage (4.4 and 2.0%) compared with Icelandic and Spanish participants, respectively. Irish participants had also more unfavorable cardio-metabolic risk factors compared with Spanish and Icelandic subjects. However, correction for waist attenuated the observed differences considerably, in particular for total cholesterol, low-density lipoprotein and triglycerides.

CONCLUSIONS

Despite having near identical BMI and age, our results show that study participants from different populations within Europe differ considerably in cardio-metabolic risk factors, partly due to differences in body fat distribution.

Concurrent validity of the non-exercise based VO2max prediction equation using percentage body fat as a variable in asian Indian adults

BACKGROUND

Aerobic capacity (VO2max) is highly dependent upon body composition of an individual and body composition varies with ethnicity. The purpose of this study was to check the concurrent validity of the non-exercise prediction equation developed by Jackson and colleagues (1990) using percentage body fat as a variable in Asian Indian adults.

METHODS

One hundred twenty college-aged participants (60 male, 60 female, mean age 22.02 ± 2.29 yrs) successfully completed a maximal graded exercise test (GXT) on a motorized treadmill to assess VO2max. VO2max was then estimated by the non-exercise prediction equation developed by Jackson and colleagues (1990) using percentage body fat. Percentage body fat was calculated by three different models (Sandhu et al's fat mass equation, Durnin-womersley's 4 site percentage body fat and Jackson & Pollock's 4 site percentage body fat) and was used in the above equation. The results of VO2max obtained using "gold standard" treadmill methods were then compared with the three results of VO2max obtained by Jackson et al's equation (using three different models to calculate percentage body fat) and it was determined which equation is best suited to determine percentage body fat and in turn VO2 max for Indian population.

RESULTS

Jackson et al's prediction equation overpredicts VO2max in Asian Indian subjects who have a lower VO2max (33.41 ± 14.39 ml/kg/min) than those reported in other age matched populations. percentage body fats calculated by the three equations were significantly different and the correlation coefficient (r) between VO2max calculated by Jackson and colleagues (1990) using Sandhu et al's equation for percentage body fat with VO2 max calculated using treadmill (gold standard) (r = .817) was found slightly more significantly correlated than the other two equations and was not statistically different from the measured value.

CONCLUSIONS

This study proves that VO2max equation using Sandhu et al's model for percentage body fat yields more accurate results than other studied equations in healthy college-aged participants in India.

Dietary and 24-h fat oxidation in Asians and whites who differ in body composition

BACKGROUND

With the same BMI, age, and sex, Asians were reported to have a higher body fat percentage than whites.

OBJECTIVE

This study aimed to determine the difference in body composition and its effect on dietary and 24-h fat oxidation between Asians and whites when they were fed a diet that contained 30% of energy as fat.

DESIGN

Seventeen Asians (8 men) were matched with 17 whites (8 men) for BMI, age, and sex. Physical activity was measured for 7 d with an accelerometer. During the last 3 d of the activity measurement, subjects were given a diet to maintain energy balances. Energy expenditure and substrate use were measured for 24 h in a respiration chamber. Dietary fat oxidation was determined from the percentage recovery of deuterium in the urine after a breakfast meal that contained deuterated palmitic acid. Body composition was calculated with a 3-compartment model from body mass, body volume (hydrodensitometry), and total body water (deuterium dilution).

RESULTS

Asians had 5% higher body fat than whites (28.1 ± 7.3% compared with 23.0 ± 6.9%, respectively; P = 0.03). The fat-free mass index tended to be lower in Asians than in whites (16.3 ± 1.6 compared with 17.0 ± 1.7 kg/m(2), respectively; P = 0.07). Dietary fat oxidation as a percentage of fat consumed was 11.7 ± 3.6% compared with 10.8 ± 4.5% (P = 0.50) for Asians and whites, respectively. In Asians and whites, the 24-h fat oxidation as a percentage of total energy expenditure was 17.7 ± 6.9% compared with 19.2 ± 5.1% (P = 0.63), respectively; carbohydrate oxidation was 68.0 ± 6.8% compared with 66.1 ± 5.1% (P = 0.51), respectively; and protein oxidation was 14.3 ± 2.2 compared with 14.7 ± 1.6% (P = 0.61), respectively.

CONCLUSION

Dietary and 24-h fat oxidation were not different between Asians and whites despite differences in body composition. This study was registered in the public trial registry at www.ccmo.nl as NL31217.068.10.

Validation of a non-exercise prediction equation for cardiorespiratory fitness in the Asian Indian population

The non-exercise based prediction equation is widely used to predict cardiorespiratory fitness (CRF), however it has not been validated for the Asian Indian population. To increase the generalisation of the equation we validated it in Asian Indians. 230 participants aged 40-75 years were recruited after excluding any medical illness. Parameters recorded were body mass index, resting heart rate and a self-reported physical activity score questionnaire. CRF was measured using metabolic equivalent at the final speed and grade of treadmill. CRF was also estimated using the non-exercise based prediction equation. The correlation of measured CRF and that calculated through the equation was 0.769 (P<0.001). Paired t-test yielded t=1.207 with a confidence interval of -0.08-0.34, indicating that the equation was statistically significant for our study population. We conclude that the non-exercise based prediction equation is valid in sedentary Asian Indians in the age group of 40-75 years.

Reduced gluteal expression of adipogenic and lipogenic genes in Black South African women is associated with obesity-related insulin resistance

CONTEXT

Black South African women are less insulin sensitive than their White counterparts, despite less central and greater peripheral fat deposition. We hypothesized that this paradox may be explained, in part, by differences in the adipogenic capacity of sc adipose tissue (SAT).

OBJECTIVE

Our objective was to measure adipogenic and lipogenic gene expression in abdominal and gluteal SAT depots and determine their relationships with insulin sensitivity (S(I)) in South African women.

PARTICIPANTS AND DESIGN

Fourteen normal-weight [body mass index (BMI) <25 kg/m(2)] Black, 13 normal-weight White, 14 obese (BMI >30 kg/m(2)) Black, and 13 obese White premenopausal South African women participated in this cross-sectional study.

MAIN OUTCOMES

S(I) (frequently sampled i.v. glucose tolerance test) in relation to expression of adipogenic and lipogenic genes in abdominal and gluteal SAT depots.

RESULTS

With increasing BMI, Black women had less visceral fat (P = 0.03) and more abdominal (P = 0.017) and gynoid (P = 0.041) SAT but had lower S(I) (P < 0.01) than White women. The expression of adipogenic and lipogenic genes was proportionately lower with obesity in Black but not White women in the gluteal and deep SAT depots (P < 0.05 for ethnicity × BMI effect). In Black women only, the expression of these genes correlated positively with S(I) (all P < 0.05), independently of age and fat mass.

CONCLUSIONS

Obese Black women have reduced SAT expression of adipogenic and lipogenic genes compared with White women, which associates with reduced S(I). These findings suggest that obesity in Black women impairs SAT adipogenesis and storage, potentially leading to insulin resistance and increased risk of type 2 diabetes.

Reducing unhealthy weight gain in Fijian adolescents: results of the Healthy Youth Healthy Communities study

Obesity is a significant problem among adolescents in Pacific populations. This paper reports on the outcomes of a 3-year obesity prevention study, Healthy Youth Healthy Communities, which was part of the Pacific Obesity Prevention in Communities project, undertaken with Fijian adolescents. The intervention was developed with schools and comprised social marketing, nutrition and physical activity initiatives and capacity building designed to reduce unhealthy weight, and the individual exposure period was just over 2-year duration. The evaluation incorporated a quasi-experimental, longitudinal design in seven intervention secondary schools near Suva (n=874) and a matched sample of 11 comparison secondary schools from western Viti Levu (n=2,062). There were significant differences between groups at baseline; the intervention group was shorter, weighed less, had a higher proportion of underweight and lower proportion of overweight, and better quality of life (Pediatric Quality of Life Inventory only). At follow-up, the intervention group had lower percentage body fat (-1.17) but also a lower increase in quality of life (Assessment of Quality of Life instrument: -0.02; Pediatric Quality of Life Inventory: -1.94) than the comparison group. There were no other differences in anthropometry, and behaviours' changes showed a mixed pattern. In conclusion, this school-based health promotion programme lowered percentage body fat but did not reduce unhealthy weight gain or influence most obesity-promoting behaviours among Fijian adolescents. Despite growing evidence supporting the efficacy of community-based approaches to reduce obesity among children of European descent, findings from this study failed to demonstrate the efficacy of a community capacity-building approach among an adolescent sample drawn from a different sociocultural, economic and geographical context. Additional 'top-down' or other innovative approaches may be needed to reduce adolescent obesity in the Pacific.

Diagnostic ability of obesity measures to identify metabolic risk factors in South African women

BACKGROUND

Currently, guidelines for obesity thresholds relating to metabolic risk in South African women have not been established. Therefore, the aim of the study was to investigate the level and diagnostic ability of obesity measures [waist circumference (WC), waist-to-height ratio (WHtR), and visceral adipose tissue (VAT) area] to identify black and white South African women with elevated blood pressure, dyslipidemia, and insulin resistance.

METHODS

Blood pressure, fasting insulin, glucose, and lipids were measured in 241 black and 188 white South African women. Receiver operator characteristic (ROC) curve analyses were performed to determine the diagnostic ability of WC, WHtR, and computer tomography (CT)-derived VAT to identify subjects above metabolic risk thresholds. The Youden index was used to calculate obesity thresholds for metabolic risk variables.

RESULTS

WC, WHtR, and VAT were significant determinants of all metabolic risk variables (P<0.05), and differences in the ROC area under the curve (AUC) between obesity measures were small (≈0.08) for all metabolic risk variables, in both ethnic groups. However, the ROC AUC vales for all obesity measures were greater in white compared to black women (P<0.01). WC and VAT thresholds were lower in black women compared to white women, whereas WHtR thresholds varied less between ethnicities.

CONCLUSIONS

Due to the cost, access, and radiation exposure, CT-derived VAT is not recommended above the use of simple anthropometric measures (WC and WHtR) for the determination of metabolic risk. Furthermore, thresholds of WHtR, due to low variability between ethnicities, may be more useful than WC for ethnic comparisons of risk.

Ethnic differences in body composition and obesity related risk factors: study in Chinese and white males living in China

The purpose of this cross-sectional observational study was to identify ethnic differences in body composition and obesity-related risk factors between Chinese and white males living in China. 115 Chinese and 114 white male pilots aged 28-63 years were recruited. Fasting body weight, height and blood pressure were measured following standard procedures. Whole-body and segmental body composition were measured using an 8-contact electrode bioimpedance analysis (BIA) system. Fasting serum glucose, fasting plasma total cholesterol (TC), high-density lipoprotein (HDL) cholesterol, and triglycerides (TG) were assessed using automatic biochemistry analyzer. After adjusting for age and body mass index (BMI), Chinese males had significantly higher percentage of body fat (PBF) both with respect to whole body (Chinese: 23.7%±0.2% vs. Whites: 22.4%±0.2%) and the trunk area (Chinese: 25.0%±0.3% vs. Whites: 23.2%±0.3%) compared to their white counterparts. At all BMIs, Chinese males had significantly higher fasting glucose levels (Chinese: 5.7±1.0 mmol/L vs. Whites: 5.2±1.0 mmol/L) but lower high-density lipoprotein levels (Chinese: 0.8±1.0 mmol/L vs. Whites: 1.0±1.0 mmol/L) than white males. In addition, a marginally significantly higher diastolic blood pressure was found among Chinese men than that among white men (Chinese: 80±1.0 mmHg vs. Whites: 77±1.0 mmHg). Chinese males had more body fat and a greater degree of central fat deposition pattern than that seen in white males in the present study. Furthermore, data on blood pressure, fasting glucose and blood lipids suggest that Chinese men may be more prone to obesity-related risk factors than white men.