Validity of BMI as a measure of obesity in Australian white Caucasian and Australian Sri Lankan children

Background: Body mass index (BMI) is used to diagnose obesity. However, its ability to predict the percentage fat mass (%FM) reliably is doubtful. Therefore validity of BMI as a diagnostic tool of obesity is questioned. Aim: This study is focused on determining the ability of BMI-based cut-off values in diagnosing obesity among Australian children of white Caucasian and Sri Lankan origin. Subjects and methods: Height and weight was measured and BMI (W/H²) calculated. Total body water was determined by deuterium dilution technique and fat free mass and hence fat mass derived using age- and gender-specific constants. A %FM of 30% for girls and 20% for boys was considered as the criterion cut-off level for obesity. BMI-based obesity cut-offs described by the International Obesity Task Force (IOTF), CDC/NCHS centile charts and BMI-Z were validated against the criterion method. Results: There were 96 white Caucasian and 42 Sri Lankan children. Of the white Caucasians, 19 (36%) girls and 29 (66%) boys, and of the Sri Lankans 7 (46%) girls and 16 (63%) boys, were obese based on %FM. The FM and BMI were closely associated in both Caucasians (r?=?0.81, P<0.001) and Sri Lankans (r?=?0.92, P<0.001). Percentage FM and BMI also had a lower but significant association. Obesity cut-off values recommended by IOTF failed to detect a single case of obesity in either group. However, NCHS and BMI-Z cut-offs detected cases of obesity with low sensitivity. Conclusions: BMI is a poor indicator of percentage fat and the commonly used cut-off values were not sensitive enough to detect cases of childhood obesity in this study. In order to improve the diagnosis of obesity, either BMI cut-off values should be revised to increase the sensitivity or the possibility of using other indirect methods of estimating the %FM should be explored.     

Validity of BMI as a measure of obesity in Australian white Caucasian and Australian Sri Lankan children

BACKGROUND: Body mass index (BMI) is used to diagnose obesity. However, its ability to predict the percentage fat mass (%FM) reliably is doubtful. Therefore validity of BMI as a diagnostic tool of obesity is questioned. AIM: This study is focused on determining the ability of BMI-based cut-off values in diagnosing obesity among Australian children of white Caucasian and Sri Lankan origin. SUBJECTS AND METHODS: Height and weight was measured and BMI (W/H2) calculated. Total body water was determined by deuterium dilution technique and fat free mass and hence fat mass derived using age- and gender-specific constants. A %FM of 30% for girls and 20% for boys was considered as the criterion cut-off level for obesity. BMI-based obesity cut-offs described by the International Obesity Task Force (IOTF), CDC/NCHS centile charts and BMI-Z were validated against the criterion method. RESULTS: There were 96 white Caucasian and 42 Sri Lankan children. Of the white Caucasians, 19 (36%) girls and 29 (66%) boys, and of the Sri Lankans 7 (46%) girls and 16 (63%) boys, were obese based on %FM. The FM and BMI were closely associated in both Caucasians (r=0.81, P<0.001) and Sri Lankans (r=0.92, P<0.001). Percentage FM and BMI also had a lower but significant association. Obesity cut-off values recommended by IOTF failed to detect a single case of obesity in either group. However, NCHS and BMI-Z cut-offs detected cases of obesity with low sensitivity. CONCLUSIONS: BMI is a poor indicator of percentage fat and the commonly used cut-off values were not sensitive enough to detect cases of childhood obesity in this study. In order to improve the diagnosis of obesity, either BMI cut-off values should be revised to increase the sensitivity or the possibility of using other indirect methods of estimating the %FM should be explored.     

At what age do normal weight Canadian children become overweight adults? Differences according to sex and metric

Background: The prevalence of overweight and obesity doubles between adolescence and young adulthood; however, the exact age, and appropriate metric to use to identify when overweight develops is still debated.

Aim: To examine the age of onset of overweight by sex and four metrics: body mass index (BMI), fat mass (%FM), waist circumference (WC) and waist-to-height ratio (WHtR).

Subjects and methods: Between 1991 and 2017, serial measures of body composition were taken on 237 (108 males) individuals (aged 8–40?years of age). Hierarchical random effects models were used to develop growth curves. Curves were compared to BMI, %FM and WC overweight age- and sex-specific cut-points.

Results: In males, the BMI growth curve crossed the cut-point at 22.0?years, compared to 23.5 and 26.5?years for WHtR and %FM, respectively; WC cut-off was not reached until 36?years. In females, the BMI growth curve crossed the overweight cut-point at 21.5?years, compared to 14.2?years for %FM and 21.9 and 27.5?years for WC and WHtR, respectively.

Conclusion: In summary, overweight onset occurs during young adulthood with the exception of WC in males. BMI in males and %FM in females were the metrics identifying overweight the earliest.     

Diagnostic performance of Body Mass Index,Waist Circumference and the Waist-to-Height Ratio for identifying cardiometabolic risk in Scottish pre-adolescents

Background: Limited studies have examined the diagnostic performance of body mass index (BMI), waist circumference (WC) or waist-to-height ratio (WHtR) for identifying cardiometabolic risk (increased clustered glucose, triglycerides, mean arterial pressure and inv-HDL-cholesterol) in pre-adolescent youth.

Aim: To compare the utility of BMI, WC and WHtR as predictors of cardiometabolic risk (CMR) in Scottish pre-adolescent children.

Subjects and methods: A cross-sectional analysis of 223 Scottish children (55.2% boys, mean age =8.4 years) was undertaken. BMI, WC and WHtR were used as exposure variables within multivariate logistic regression analysis and ROC analysis to examine the utility of these anthropometrical indices in identifying those at cardiometabolic risk.

Results: Individuals with an elevated WHtR, WC and BMI were 3.51 (95% CI?=?1.71–7.23; p?p =?.002) and 2.59 (95% CI?=?1.42–4.73; p?=?.002) times more likely to be at cardiometabolic risk, respectively. The areas under the curves [AUC] to identify children with cardiometabolic risk were significant and similar among anthropometric indices (AUC’s?=?0.60–0.65). When stratified by BMI, both WC and WHtR demonstrated a fair-to-good ability for identifying those at cardiometabolic risk (AUC?=?0.75–0.81).

Conclusions: Findings suggest that the combination of BMI with either WC or WHtR may provide an added benefit in the assessment of cardiometabolic risk amongst pre-adolescents.     

Interactive effects of adiposity and insulin resistance on the impaired lung function in asthmatic adults: cross-sectional analysis of NHANES data

Background: Obesity is considered a risk factor for both asthma and insulin resistance in adults. Insulin resistance (IR) also influences pulmonary function in the non-obese population.

Aim: To investigate the modifying effect of insulin resistance on the predictive role of anthropometric measures in the estimation of impaired lung function among asthmatic adults.

Subjects and methods: A cross-sectional study of 1276 adults extracted from the NHANES 2009–2012 database was performed. Adjusted multiple linear regression was conducted to analyse the contributory role of obesity and IR in predicting lung function among asthmatic adults.

Results: BMI, waist circumference (WC) and waist-to-height ratio (WHtR) showed significantly negative correlations with FVC (r=–0.24, –0.18, –0.39, respectively; p?<?0.001), FEV1(r=–0.24, –0.21, –0.40, respectively; p?<?0.001) and FEF 25–75% (r=–0.15, –0.18, –0.27, respectively; p?<?0.001). Even after adjustment for the covariates (age, gender, smoking history and standing height), BMI and HOMA-IR had significant relationships with FVC (β=??10.3; p?<?0.01 and β=??16.0; p?<?0.05) and FEV1 (β=??8.7; p?<?0.01 and β=??11.7; p?<?0.05). BMI could significantly predict the decreased FVC (β=??13.7; p?<?0.01) and FEV1 (β=??10.7; p?<?0.01) only in the insulin resistant asthmatics.

Conclusion: WHtR and IR predict impaired lung function in overweight/obese asthmatic adults independently. IR also modifies the association between excessive adiposity and respiratory function in asthmatic adults.     

Short- and Medium-Term Impact of a Structured Medical Intervention in Adolescents with Overweight,Obesity, or Increased Waist Circumference

Introduction and ObjectivesThis study aimed to assess the impact of a structured medical intervention in adolescents with overweight or obesity at medical discharge and after 5 years and identify the factors responsible for the reappearance of anthropometric alterations.MethodsA total of 42 adolescents with overweight, obesity, and/or increased waist circumference (WC) participated in a survey on eating habits, physical exercise, and sedentary habits. Body mass index (BMI), fat mass (FM), and WC were evaluated quarterly during a structured medical intervention, with a maximum duration of 3 years (2007–2010) and 5 years after its conclusion (2015–2016). SPSS 19.0®was used for statistical analysis.ResultsInitially, 23.8% adolescents were overweight, 28.6% were obese, 83.3% had increased FM, and 95.2% had high WC. A significant improvement was noted until medical discharge with respect to BMI, FM, and WC (p < 0.001) owing to an increased number of meals; reduction in the consumption of hypercaloric foods/drinks (p < 0.001); increase in the consumption of fruits, vegetables, and soup (p < 0.001); increase in physical exercise and daily walks (p < 0.001); and reduction in sedentary habits (p < 0.001). At reassessment, after 5 years, the majority had normal BMI, FM, and WC (p < 0.001), although 45.2% had abandoned sports (p < 0.001).ConclusionsA relation exists between the improvement or normalization of BMI, FM, and WC and the number of meals, healthy eating habits, physical exercise, and less sedentary habits. The intervention was associated with an improvement in the parameters during the short and medium terms.     

Waist circumference to height ratio predicts inflammatory risk in children

Background: The increase in obesity, especially the increase of visceral fat, has been directly associated with health risk. Additionally, a waist-to-height ratio (WHtR) (0.5) has been proposed as an indicator of early health risk.

Aims: To test the association between anthropometric measurements and inflammatory mRNA expression and to evaluate the effectiveness of WHtR to predict inflammatory risk in children.

Subjects and methods: Anthropometric measurements and fasting blood samples were collected in 94 Brazilian children (46 boys) aged 9–11 years. Children were identified as being at inflammatory risk based on cytokine mRNA expression levels at and above the 75th percentile. Inflammatory cytokine mRNA expression levels were determined through buff-coat using real-time polymerase chain reaction.

Results: Body mass index (BMI), waist circumference (WC) and WHtR showed moderate-to-strong association with inflammatory cytokine mRNA gene expression. WHtR?=?0.51 was the most accurate cut-off point in distinguishing children at inflammatory risk. Compared with children with WHtR <0.51, children with a WHtR ≥0.51 presented an odds ratio of 2.643 (95% CI?=?1.749–3.994) for both diagnosed IL-6 and MCP-1 above the 75th percentile and 2.796 (95% CI?=?1.802–4.338) for TNF-α above the 75th percentile. WHtR?=?0.50 presented the same values of sensitivity and odds ratio and ～7% lower specificity compared to WHtR?=?0.51.

Conclusion: Anthropometric measurements have shown a moderate-to-strong association with the mRNA expression of inflammatory genes and a WHtR of 0.5 could serve as a cut-off point, suggesting increased risk of inflammatory responses.     

Central Obesity in Africans: Anthropometric Assessment of Abdominal Adiposity and its Predictors in Urban Nigerians

Objective

To assess the occurrence of central obesity and identify its predictors in urban Africans using anthropometric tools. Another objective was to evaluate the anthropometric indices and their interaction with various cardiovascular risk factors.

Waist-to-Height Ratio as an Index for Cardiometabolic Risk in Adolescents: Results from the 1998-2008 KNHANES

PurposeTo describe the relationship between the waist-to-height ratio (WHtR) and cardiometabolic risk factors (CMRFs) and to evaluate the validity of WHtR in identifying adolescents with metabolic syndrome.ResultsWHtR was significantly related to systolic blood pressure, HDL-C, and triglycerides in both non-overweight and overweight adolescents (all p<0.01). Among overweight adolescents, the area under the curve (AUC) for WHtR in identifying multiple CMRFs was significantly greater than that for BMI (p=0.014). Metabolic syndrome was more common in overweight adolescents with a WHtR of ≥0.5 than in those with a WHtR of <0.5 (p<0.001). In non-overweight adolescents, the prevalences of multiple CMRFs (p=0.001) and metabolic syndrome (p<0.001) were higher in those with a WHtR of ≥0.5 than in those with a WHtR of <0.5. Among those without central obesity, the prevalence of multiple CMRFs was higher in those with a WHtR of ≥0.5 than in those with a WHtR of <0.5 (p=0.021).ConclusionWHtR is a simple and valid index for identifying adolescents with increased cardiometabolic risk and is related to CMRFs even in non-overweight adolescents. In adolescents already screened via BMI and waist circumference (WC), WHtR seems to be of additional help in discriminating those at higher cardiometabolic risk.     

Profiles of body mass index and blood pressure among young adults categorised by waist-to-height ratio cut-offs in Shandong,China

Abstract

Background: Waist-to-height ratio (WHtR) is proposed as a valid measure of abdominal obesity and health risks in practice. The present study examined the profiles of weight status and blood pressure (BP) among young adults categorised by WHtR cut-offs.

Methods: A total of 4226 college students (2107 males and 2119 females) aged 19–22?years participated in the study. The body mass index (BMI) cut-offs recommended by the Working Group on Obesity in China (WGOC) were used to define underweight, normal weight, overweight and obesity. The BMI and BP profiles within each WHtR category were examined.

Results: For both males and females, ‘the high WHtR group’ (WHtR ≥ 0.5) had the highest, and ‘the low WHtR group’ (WHtR < 0.4) had the lowest BMI and BP levels. In the WHtR = 0.30–0.34 sub-group, 66.10% of males and 66.67% of females were underweight; in the WHtR ≥ 0.55 sub-group, 91.49% of males and 83.33% of females were obese; in the WHtR = 0.40–0.44 sub-group, 88.88% of males and 89.85% of females were normal weight. The prevalence of high BP in the WHtR < 0.5 group was 9.99% in males and 2.19% in females; the corresponding figures were 28.92% (males) and 14.06% (females) in the WHtR ≥ 0.5 group; the latter is significantly higher than the former (p?<?0.01).

Conclusion: Individuals with low WHtR were underweight and those with high WHtR were obese with high BP. Results from this study support WHtR as a simple and effective screening tool for abdominal obesity and high BP in practice.     

哈萨克族成人6种肥胖评价指标准确性比较

目的 比较身体质量指数（BMI）、腰围（WC）、腰臀比（WHR）、腰围身高比（WHtR）、肥胖指数（BAI）、体脂率（PBF）对哈萨克族肥胖筛查的准确性,并确定6种指标在判断哈萨克族肥胖的最佳切点。方法 采用卡方检验、直线相关分析及受试者工作特征曲线（ROC）分析,比较BMI、WC、WHR、WHtR、BAI、PBF对肥胖预测的准确性,并确定各项指标的最佳切点。结果 经卡方检验分析结果显示,WC与WHtR、BMI与BAI对哈萨克族肥胖判断的结果相近。在直线相关分析中,BMI、WC与身体脂肪含量具有很强的相关性。ROC曲线分析显示,WC的曲线下面积(AUC)最大,其次是BMI。 结论 哈萨克族是超重、肥胖的高发人群,腰围对哈萨克族肥胖筛查的准确性最高,建议使用BMI、WC及WHtR 3项指标共同判定哈萨克族肥胖情况。     

Does waist indicate dyslipidemia better than BMI in Korean adult population?

Obesity is an independent and modifiable risk factor for cardiovascular disease, and known as a core of the metabolic syndrome. Obesity has been largely diagnosed based upon anthrompometric measurements like waist circumference (WC) and body mass index (BMI). We sought to determine associations between anthropometric measurements and dyslipidemia in a community adult sample composed of 1,032 community residents (356 men, 676 women) aged 50 yr and over in Namwon, Korea. Blood tests for lipid profiles, including total cholesterol (TC) and HDL cholesterol (HDL) were performed, and dyslipidemia was defined as TC/HDL greater than 4. Anthropometric measurements included WC, waist-to-height ratio (WHtR), waist-to-hip ratio, and BMI. All anthropometric measures were categorized into quartiles and evaluated for associations with dyslipidemia. TC/HDL showed the significant associations with the anthropometric measures, independently of potential confounders. In women, increases of obesity indexes by quartile analyses showed linear increases of odds ratios for dyslipidemia (p values <0.01 by trend test). In men, except BMI, same patterns of association were noted. WC and WHtR were significantly associated with dyslipidemia in Korean adult population. As a simple and non-invasive method for a detection of obesity and dyslipidemia, anthropometric measurements could be efficiently used in clinical and epidemiologic fields.     

Association of leg length with overweight and obesity in children aged 5–15 years: A cross-sectional study

Background: Short leg length (LL) and childhood obesity have been independently associated with a higher risk for adult disease. However, the contribution of relative LL to overweight and obesity in children remains an under-researched area.

Aim: To utilize data from a large cross-sectional anthropometric survey to assess the association of LL to height ratio (LLHR, leg length/height) with measures of overweight and obesity in British children.

Methods: Children were analysed from the bottom and top body mass index (BMI) standard deviation score (SDS) quartiles (3825 children, boys=1686) or waist circumference (WC) SDS quartiles (3824 children, boys=1687). The top quartile was defined as the ‘high’ BMI or WC SDS group and the lower bottom quartile as the ‘low’ BMI or WC SDS group. Height and LL were expressed as SDSs using current references and LLHR was calculated.

Results: Children in the ‘high’ groups were taller with longer legs but had a lower LLHR across most ages. The magnitude of the difference was greater for BMI than WC in both genders.

Conclusion: Altered body dimensions appear to be linked to measures of overweight and obesity in children but longitudinal studies are needed to confirm this suggestion.     

Changes in central fatness and abdominal obesity in children and adolescents from Cracow,Poland 1983–2000

Abstract

Background: In the light of the world increase of overall and abdominal obesity, little is known about the trends in abdominal obesity and its prevalence in Poland, a country which at the end of 20th underwent a socio-economic transformation that conduced to obesogenic environments.

Aim: The study traced the trends and prevalence of abdominal obesity in two successive cohorts of children and adolescents from Cracow, Poland between 1983 and 2000.

Subjects and methods: The data examined in this study were from two series of cross-sectional studies; the first in 1983 included 3252 boys and 3288 girls, and the second in 2000 included 2409 boys and 2093 girls aged 4–20. Waist circumference (WC) and waist-to-height ratio (WHtR) were applied to assess the type of fat distribution.

Results: Means of WC and WHtR were higher in juvenile but lower in childhood and late adolescence periods in boys and girls from the 2000 cohort as compared to the 1983 one. The prevalence of abdominal obesity in Cracow children examined in 1983 was 3.9% for boys and 2.4% for girls, and in 2000 was 6.4% and 3.1%, respectively (in boys: χ² = 16.03, p = 0.0001; in girls: χ² = 1.90, p = 0.1684).

Conclusions: The 1983–2000 trend towards increasing prevalence of abdominal obesity in children and adolescents from Cracow is not as intensive as in other European countries, e.g. Britain, but it requires further monitoring.     

Genetic and Environmental Correlations Between Body Mass Index and Waist Circumference in China: The Qingdao Adolescent Twin Study

We aimed to analyze how genetic and environmental factors account for variations in body mass index (BMI), waist circumference (WC) and their mutual correlation in Chinese children. We measured BMI and WC in 588 pairs of twins (53 % monozygotic twins) aged 8–17 years and applied structural equation modeling to the data. For the younger children (8–12 years of age), heritability estimates of BMI were 0.56 for boys and 0.69 for girls; for the older children (13–17 years of age), the corresponding figures were 0.64 and 0.71, respectively. We observed moderate heritability estimates in WC: the corresponding figures were 0.24 and 0.56 for the younger children, and 0.27 and 0.33 for the older children, respectively. The heterogeneity test for genetic variance of BMI and WC was statistically significant between the two age groups for both sexes (p < 0.001). The proportions of BMI and WC variations due to shared and non-shared environmental factors remained stable during childhood in both sexes. Bivariate genetic analyses showed that genetic correlations between BMI and WC were strong for the younger children (r_g = 0.75 for boys, r_g = 0.98 for girls) and the older children (r_g = 1.0 for both boys and girls). Both sexes showed moderate non-shared environmental correlations in the two age groups, whereas shared environmental correlations––except among male younger children––were not statistically significant. Genetic factors play an important role in variations in BMI and WC during childhood. Common genetic and non-shared environmental factors explained most of the association between BMI and WC for both boys and girls.     

Relative importance of lean and fat mass on bone mineral density in a group of adolescent girls and boys

The aim of this study was to determine the relative importance of lean mass (LM) and fat mass (FM) on bone mineral density (BMD) in a group of adolescent girls and boys. A total of 65 adolescent boys and 35 adolescent girls participated in this study. Whole body (WB) and lumbar spine (L1–L4) BMD were measured by dual-energy X-ray absorptiometry (DXA). Body composition was assessed using the same technique. In boys, LM was strongly related to WBBMD (r = 0.68; p < 0.001) and to L1–L4 BMD (r = 0.61; p < 0.001), whereas FM was not positively related to BMD and was negatively associated with WB bone mineral apparent density (WBBMAD). In girls, both LM and FM were positively related to WBBMD (r = 0.41; p < 0.05 and r = 0.49; p < 0.01, respectively), whereas only FM was correlated to L1–L4 BMD (r = 0.33; p < 0.05). Finally, in a multiple regression analysis, FM was found to be a better positive determinant of WBBMD than LM in girls, whereas in boys, FM was found to be a negative determinant of WBBMD and L1–L4 BMD. This study suggests that LM is a strong determinant of WBBMD and L1–L4 BMD in boys, and that FM is a stronger determinant of WBBMD than LM in girls.     

Maternal fat mass at mid-pregnancy and birth weight in Brazilian women

Abstract

Background: The relationship between maternal body composition and foetal development is unclear.

Aim: To determine the relationship between maternal body composition [fat mass (FM) and fat-free mass (FFM)] and foetal growth and birth weight, independent of potential confounding factors.

Subjects and methods: This study consisted of 92 women, normal and overweight/obese, recruited from the Instituto Fernandes Figueira in Rio de Janeiro, Brazil. Body composition (FM and FFM) was estimated using bioelectrical impedance. Foetal growth was assessed using serial ultrasound measurements at the second and third trimester and infant's weight and length were measured at birth. Multiple linear regression analyses were used to determine the association between maternal FM and FFM and birth weight adjusted for gestational age (BWt) and change in estimated foetal weight (ΔEFW), controlling for infant gender, maternal serum glucose, energy intake, parity, height and income.

Results: Maternal FM, but not FFM, was positively associated with BWt (p?=?0.02) and borderline with ΔEFW (p?=?0.05). FM expressed as a percentage of body weight (%FM) showed a significant positive association with BWt (p?<?0.001) and ΔEFW (p?<?0.01). Using backward linear regression analysis, FM was a significant predictor of BWt (p?<?0.001) and ΔEFW (p?=?0.03), but not change in femur length.

Conclusion: In this small sample of normal and overweight/obese women, maternal FM at mid-pregnancy is associated with neonatal BW and foetal growth.     

Indices of central and general obesity and cardiometabolic risk among adolescents in three ethnic groups in north-west China

Abstract

Background: ‘A Body Shape Index-Adolescents’ (ABSI-Adolescents) and waist-to-height ratio are recently proposed indices that quantify central obesity in adolescents.

Aims: To investigate the scaling exponents to standardise waist circumference (WC) for body mass index (BMI) and height and to investigate the association between BMI, WC-based indices and cardiometabolic outcomes in adolescents of three ethnic groups.

Subjects and methods: A cross-sectional study of 1755 adolescents (516 Hans, 565 Uygurs, 674 Kazakhs) was conducted in north-west China. Correlation between indices of obesity and blood pressure (BP) and fasting blood glucose (FBG) were estimated and compared.

Results: Two ethnic groups (Han and Kazakh) had WC-BMI-height profiles different from the previously proposed ABSI-Adolescents and, therefore, required different scaling exponents for WC standardization. After adjustment for age and gender, WC and BMI have similar associations with BP and FBG. After further adjustment for BMI, WC remained significantly associated with FBG in all three ethnic groups (each p?<?0.01) and with BP in Han and Kazakh adolescents (each p?<?0.05).

Conclusion: Body proportionality varied between the ethnic groups. WC and WC-based indices were associated with blood pressure and fasting blood glucose in adolescents of three ethnicities. The WC-based indices did not out-perform WC per se.     

Comparison between body mass index and a body shape index with adiponectin/leptin ratio and markers of glucose metabolism among adolescents

Background: Besides body mass index (BMI), new parameters have been developed to classify individual body shape.

Aim: To investigate the relationship between BMI, waist circumference (WC), a body shape index (ABSI) and ABSI-adolescents among adolescents and verify which would better predict lower adiponectin/leptin (A/L) ratio and disturbances on glucose metabolism.

Subjects and methods: A cross-sectional study with 197 Brazilian adolescents of 14–18?years. Serum leptin, adiponectin, glucose and insulin were measured. A/L ratio, ABSI, ABSI-adolescents, BMI, homeostasis model assessment estimates of insulin resistance (HOMA-IR) and β-cell function (HOMA-β) and the quantitative insulin sensitivity check index (QUICKI) were calculated.

Results: ABSI-adolescents positively correlated with WC (r?=?0.83, p?r?=?0.66, p?r?=?0.95, p?p?r?=??0.63, p?p?r?=??0.75; HOMA-IR: r?=?0.76; HOMA-β: r?=?0.77; insulin: r?=?0.79). Associations were confirmed by linear regression analysis, adjusted for sex and age.

Conclusions: ABSI-adolescents, but not ABSI, was related to A/L ratio and to markers of glucose metabolism, but not more strongly than BMI and WC.     

The influence of sexual maturation on blood pressure and body fatness in African‐American adolescent girls and boys

To examine the influence of sexual maturation (SM) on blood pressure (BP) and body fatness during puberty among African‐American children. Longitudinal data were collected from 283 African‐American children aged 9–15 years over a 1.5‐year period. Measured anthropometric measures included height, weight, skinfold thickness, waist circumference (WC), and systolic and diastolic BP (SBP/DBP) at baseline, 1‐year, and 1.5‐year follow‐up were used. SM was assessed using self‐reported Tanner stages (range 1–5) at baseline. Spearman correlation and regression analyses were conducted to test associations between study variables. Early maturing girls had higher BP and body mass index (BMI = weight (kg)/height (m)²) at follow‐up than nonearly maturing girls (SBP: 117.4 vs. 111.7; DBP: 66.3 vs. 60.7; BMI: 27.7 vs. 23.5; all P < 0.05, respectively). Baseline Tanner stage was positively associated with follow‐up SBP (r = 0.28), DBP (r = 0.37), BMI (r = 0.45), skinfold thickness (r = 0.37), and WC (r = 0.40) in girls, but not in boys. The influence of SM on BP independent of body size was tested via several different multiple linear regression models by adding measures of body size and their changes (height and BMI) between baseline and follow‐up. Early maturing girls had higher SBP and DBP (β = 4.30, P < 0.05; β = 3.28, P < 0.05; respectively) and BMI (β = 1.69, P < 0.05) at 1.5‐year follow‐up than their counterparts. In boys, a marginally significant reverse association (β = ?1.05 to ?1.19) between SM stages and DBP was detected. SM affects BP and body fatness in girls, and should be considered in assessment of BP and obesity in adolescents. Am. J. Hum. Biol., 2009. © 2008 Wiley‐Liss, Inc.