Androgyny in fat patterning is associated with obesity in adolescents and young adults

Nationally representative surveys show gradual shifting of overweight and obesity towards poor and less-educated women of reproductive age in Nepal

Overweight and obesity are considered major public health concerns all over the world. They have the potential to increase the risk of developing non-communicable diseases in reproductive age women, increasing their risk of pregnancy related complications and adverse birth outcome. This study was carried out to identify the trend of prevalence of overweight and obesity, along with their determinants, among reproductive age women (15-49 years) in Nepal. Data were taken from the nationally representative 2006, 2011 and 2016 Nepal Demographic and Health Surveys (NDHSs). Women were considered to be overweight or obese when their BMI was 23.0-27.5 kg/m2 or ≥27.5 kg/m2, respectively. Univariate, bivariate and multivariate analyses were performed, with significance taken at p<0.05. The prevalences of overweight and obesity both showed rising trends in women of reproductive age in Nepal from 2006 to 2016, particularly among those with no education, only primary education and poor women. The presence of overweight and obesity was found to be significantly associated with the sample women's age, educational status, wealth index, place of residence, ecological zone, developmental region, number of household members, marital status and ethnicity. In 2016 one in every three women of reproductive age in Nepal was either overweight or obese. As overweight and obesity have detrimental effects on women's health, the Government of Nepal, in collaboration with other government and non-government organizations, should take action to halt the rising trends in overweight and obesity in the country.

Differences in the relationship of weight to height, and thus the meaning of BMI, according to age, sex, and birth year cohort

Background: Weight can be adjusted for height using the Benn parameter (kg/mB), where B is the power that minimises the correlation with height.Aim: To investigate how the Benn parameter changes across age (10-65 years) and time (1956-2015) and differs between sexes.Subjects and methods: The sample comprised 49,717 individuals born in 1946, 1958, 1970 or 2001. Cross-sectional estimates of the Benn parameter were produced and cohort differences at ages 10/11 and 42/43 years were examined using linear regression. Multilevel modelling was used to develop trajectories showing how the Benn parameter changed over age from childhood to mid-adulthood in the three older cohorts.Results: The Benn parameter was closest to 2 in childhood but consistently lower across adulthood, particularly in females and the most recent cohort. At ages 10/11 years, the Benn parameter was greater than 3 in both sexes in the 2001 cohort but between 2.2 and 2.7 in the three older cohorts. This difference was estimated to be +0.67 (0.53, 0.81) in males and +0.53 (0.38, 0.68) in females, compared to the 1946 cohort, and was driven by a much higher weight SD in the 2001 cohort. Conversely, at ages 42/43 years, the Benn parameter was lowest in the 1970 cohort due to a slightly lower weight-height correlation. This difference was estimated to be -0.12 (-0.34, 0.10) in males and -0.15 (-0.42, 0.13) in females, compared to the 1946 cohort.Conclusions: Changes over time in the obesogenic environment appear to have firstly reduced the Benn parameter due to a lowering of the weight-height correlation but secondly and more drastically increased the Benn parameter due to increasing weight variation.

Use of allometry and skinfold thicknesses to estimate the fat mass of circumpubertal boys

Background: In the pubertal period, each part of the body grows at different rates. This makes the relationship between the parts nonlinear. Particularly, the fat mass (FM) of boys tends to decrease, further exacerbating the issue of linearity in growth.Aim: To propose predictive models of FM from skinfolds (SF) adjusted allometrically.Subjects and methods: 75 pubertal boys (14.4 ± 0.9 years) composed the sample by self-selected pubic hair. FM was determined by DXA (FM_DXA) (kg), stature (cm), body mass (kg) and nine SF (mm) by anthropometric measurements. The SF were individually adjusted allometrically. FM_DXA (Y) values and each anthropometric independent variable-IV (X) underwent logarithmic transformation. Linear regressions were used. The significance of the prediction of the FM_DXA of each model (ANOVA) and the concordance analysis (Bland-Altman) were performed.Results: Predictive allometric models of FM_DXA showed high determination coefficients (r²) and reduced standard errors of estimation (SEE). The adjusted model involved reduced agreement limits, demonstrating its accuracy.Conclusions: It was possible to propose models with allometric adjustments to estimate FM of pubertal boys. Allometry may aid in the development of predictive linear models of body composition, since it has an indicative capacity of the variables for estimation.

Change in adiposity minimally affects the lipid profile in youth with recent onset type 1 diabetes

OBJECTIVE

Dyslipidemia contributes to the increased risk of cardiovascular disease in persons with type 1 diabetes (T1D). Weight control is commonly recommended as a treatment for dyslipidemia. However, the extent to which decreases in weight affect the lipid profile in youth with T1D is not known. Therefore, we tested the hypothesis that decreases in body mass index z-score (BMIz) were associated with concomitant changes in the lipid profile in youth with T1D.

STUDY DESIGN

We studied 1142 youth with incident T1D, who had at least two fasting lipid measurements over 2 yr (initial visit mean: age = 10.8 ± 3.9 yr, BMIz = 0.55 ± 0.97, T1D duration = 10.7 ± 7.6 months; 47.5% female, 77.9% non-Hispanic white) in the SEARCH for Diabetes in Youth Study. Longitudinal mixed models were used to examine the relationships between changes in BMIz and changes in total, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), non-HDL cholesterol, and log triglycerides (TG) adjusted for initial age, sex, race/ethnicity, clinical site, season of study visit, T1D duration, and glycated hemoglobin A1c (HbA1c).

RESULTS

We found that over 2 yr all lipid levels, except LDL-C, increased significantly (p < 0.05). Decreases in BMIz were associated with favorable changes in HDL-C and TG only and the magnitude of these changes depended on the initial BMIz value (interaction p < 0.05), so that greater improvements were seen in those with higher BMIz.

CONCLUSIONS

Our data suggest that weight loss may be an effective, but limited, therapeutic approach for dyslipidemia in youth with T1D.

Association between serum alanine aminotransferase level and obesity indices in Korean adolescents

Purpose

To analyze the correlation between serum alanine aminotransferase (ALT) and obesity indices including body mass index (BMI), body fat percentage (BFP), total fat mass (FM), truncal fat mass (TFM), waist circumference (WC), and waist-to-height ratio (WHtR) in Korean adolescents.

Methods

This was a cross-sectional study based on data derived from the 2010-2011 Korean National Health and Nutrition Examination Surveys (KNHANES). Subjects were Korean adolescents aged 10-18 years (871 total; 475 boys and 396 girls) who participated in KNHANES.

Results

In both sexes, BMI, FM, TFM, WC, and WHtR were higher when ALT levels were in the 4th quartile. In boys, there was a significant positive correlation between ALT level and BMI, BFP, FM, TFM, WC, and WHtR (r=0.55, P<0.0001 for BMI; r=0.52, P<0.0001 for BFP; r=0.58, P<0.0001 for FM; r=0.61, P<0.0001 for TFM; and r=0.56, P<0.0001 for WC; r=0.62, P<0.0001 for WHtR), and the correlation coefficient was higher than that in girls.

Conclusion

Our results suggest a significant positive association between serum ALT level and obesity indices in male adolescents.

Alanine aminotransferase and metabolic syndrome in adolescents: the Korean National Health and Nutrition Examination Survey Study

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

Adolescent NAFLD has increased in parallel with obesity. Elevated serum ALT level is a surrogate marker for NALFD. Increased ALT levels are closely related to NAFLD and metabolic syndrome.

WHAT THIS STUDY ADDS

Increased ALT within normal range are associated with an increased risk of metabolic syndrome. All of the five components of metabolic syndrome were associated with high ALT within normal range. By elevation of ALT, the prevalence of metabolic syndrome increased in obese adolescents and normal-weight adolescents as well.

BACKGROUND/AIMS

The potential interactions between alanine aminotransferase (ALT) and components of metabolic syndrome (MetS) have not been fully investigated in healthy adolescents. This study investigated the impact of a mild ALT elevation on the risks of MetS in healthy Korean adolescents.

METHODS

From the Korean National Health and Nutrition Examination Surveys 1998-2009, the data of 5026 adolescents aged 10-18 years (2604 boys and 2422 girls) were analysed. Individuals who had ALT levels equal or more than 40 IU L(-1) were excluded.

RESULTS

Subjects in the upper ALT tertile had higher mean values of body mass index (BMI), homeostasis model assessment-insulin resistance and prevalence of MetS than subjects in the lower tertile. The risk of each five components of MetS was significantly higher than subjects in the lower tertile. Compared with the subjects in the lower ALT tertile, the prevalence of MetS was higher in the upper tertile among obese adolescents (44.6-50.7% vs. 31.2-40.0%) as well as normal-weight adolescents (5.2-7.7% vs. 2.7-3.2%). Subjects in the upper ALT tertile were at a higher risk of MetS than those in the lower tertile (odds ratio [OR] = 1.95 for boys, OR = 2.00 for girls) after controlling for age and BMI.

CONCLUSIONS

A high serum ALT within normal range increased the risk of all the components of MetS. The prevalence of MetS increased with the elevation of obesity level, and it increased further with the elevation of ALT tertile. Thus, serum ALT levels in addition to BMI might be useful as a marker for early detection of MetS.

OBESITY, ACADEMIC PERFORMANCE AND REASONING ABILITY IN PORTUGUESE STUDENTS BETWEEN 6 AND 12 YEARS OLD

Obesity has been linked to several physiological and psycho-social diseases, decreases in cognitive function, poor levels of scholastic achievement, low socioeconomic status and delayed onset of maturity. This study investigates the association between obesity and both academic performance and reasoning ability in 394 male and 398 females students between the ages of 6 and 12 from Lisbon, Portugal. It also assesses how this relationship may be influenced by chronological age, maturity and socioeconomic status. The results suggest that: 1) reasoning ability is independent of socioeconomic status and level of maturity; 2) no differences in reasoning ability exist between groups of different BMI; 3) academic performance is moderated by chronological age in boys, and by maturity in both genders; 4) obesity is not associated with academic performance. It is concluded that reasoning ability and academic performance are not associated with obesity, and that inter-individual differences in academic performance in boys may be explained by differences in their level of maturity.

Serum alanine aminotransferase and its association with metabolic syndrome in children: the bogalusa heart study

BACKGROUND

The aim of this study was to examine the distribution of alanine aminotrasferase (ALT) and its association with metabolic syndrome variables and their clustering in apparently healthy children.

METHODS

A cross-sectional study of 1,524 preadolescents (age, 4-11 years, 62% white, 51% male) and 1,060 adolescents (age, 12-18 years, 58% white, 51% male) enrolled in the Bogalusa Heart Study was performed.

RESULTS

ALT levels showed a significant race (whites > blacks) difference in preadolescents and a gender (males > females) difference in adolescents. Both preadolescents and adolescents in the age, race, and gender-specific top versus bottom quartiles of ALT had significant increases in the prevalence of adverse levels (>75th percentile specific for age, race, and gender) of body mass index (BMI), systolic blood pressure, total cholesterol to high-density lipoprotein cholesterol (HDL-C) ratio (adolescents only), insulin resistance index (HOMA-IR), and clustering of all four of these metabolic syndrome variables. In multivariate analyses, BMI was the major independent predictor of ALT in both preadolescents and adolescents; other independent predictors were total cholesterol to HDL-C ratio, HOMA-IR, white race in preadolescents and male gender in adolescents. With respect to the ability of ALT to identify children with clustering of the metabolic syndrome variables, area under the receiver operating characteristic curve analysis (c-statistics) adjusted for age, race, and gender yielded a value of 0.67 for preadolescents and 0.82 for adolescents.

CONCLUSION

An elevation in serum ALT within the reference range relate adversely to all of the major components of metabolic syndrome and their clustering in children and, thus, may be useful as a biomarker of the presence of metabolic syndrome and related risk in pediatric population, especially adolescents.

Variation in relative fat distribution associated with maturational timing: The Wrocław Growth study

Complete longitudinal data of 136 boys aged 8-16 years and 124 girls aged 8-15 years were used to evaluate the association between maturational timing and the relative distribution of subcutaneous adipose tissue, specifically a trunk-oriented pattern of distribution. Age at peak height velocity (PHV) was the indicator of maturational timing and three skinfolds (triceps, subscapular, abdomen) were the indicators of subcutaneous fatness. Principal components analysis of the three skinfolds was used to identify indicators of relative subcutaneous adipose tissue distribution. Age at PHV and chronological age significantly influenced scores on the first principal components, which indicated centripetal fat patterning. The data suggest that early maturing subjects accumulate more subcutaneous adipose tissue on the lower trunk compared with later maturing peers of the same age and sex.

Adiposity, central body fat distribution and blood pressure among young Bengalee adults of Kolkata, India: sexual dimorphism

A cross-sectional study of 174 men and 153 women of Bengalee ethnicity was undertaken to compare levels of adiposity, central body fat distribution and blood pressure. The mean age of both the sexes were similar (men = 20.1 years; women = 20.0 years). Significantly more women (n = 42, 27.5%) were overweight (body mass index, BMI > or = 25.0 kg/m2) as compared with men (19, 10.9%). Men were significantly taller and heavier. They also had significantly greater mean waist (WC) and mid upper arm (MUAC) circumferences compared with women. On the other hand, women had significantly (p < 0.001) greater mean BMI, biceps (BSF), triceps (TSF) and subscapular (SSF) skinfolds. The mean values of systolic (SBP), diastolic (DBP) and mean arterial (MAP) blood pressure were significantly greater among men. These significant differences existed even after controlling for BMI. Regression analyses revealed that sex had significant effect on all these variables even after controlling for BMI. Correlation studies showed that WC was found to be much more strongly correlated than BMI with SBP, DBP and MAP, in both sexes. However, when the effect of WC (along with BMI) was also controlled for, there was no significant sex difference in blood pressure.

Adiposity, adipose tissue distribution and mortality rates in the Canada Fitness Survey follow-up study

OBJECTIVE

To compare mortality rates across indicators of adiposity and relative adipose tissue distribution in the Canadian population.

SUBJECTS

The sample included 10,323 adult participants 20-69 y of age from the Canada Fitness Survey who were monitored for all-cause mortality over 13 y.

METHODS

BMI, waist circumference (WC) and the sum of five skinfolds (SF5) were indicators of adiposity, and the first principal component of skinfold residuals (PC1) represented subcutaneous adipose tissue distribution. Proportional hazards regression was used to estimate relative mortality risk from mortality rates across levels of adiposity and adipose tissue distribution, controlling for the confounding effects of age, smoking status and alcohol consumption.

RESULTS

:Significant curvilinear (J-shaped) relationships in men and linear relationships in women were observed between BMI, WC and SF5 and all-cause mortality rates. PC1 was not related to mortality rates in either men or women. In women, the inclusion of the other indicators of adiposity and adipose tissue distribution did not significantly add to the prediction of mortality rates beyond BMI; however, combinations of BMI and both WC and SF5 produced significant models in men.

CONCLUSION

The results support the hypothesis that overall level of adiposity is an important predictor of all-cause mortality, more so than the relative distribution of subcutaneous body fat, once overall level of body fatness has been accounted for.

Variation in subcutaneous adipose tissue distribution associated with age, sex, and maturation

Age-, sex-, and maturity-associated variation in subcutaneous adipose tissue (SAT) distribution is reviewed and then considered longitudinally in a sample of Polish youth. Current study of adipose tissue distribution places considerable emphasis on abdominal adiposity, specifically intra-abdominal or visceral adipose tissue (VAT). Most studies of children and adolescents do not include an abdominal skinfold, and when it is available, the skinfold is grouped with others as a sum of skinfolds. Correlations between abdominal VAT and SAT based on computerized tomography in non-obese children are moderate to high, and those between the suprailiac and abdominal skinfolds and abdominal VAT are moderately high. Changes in three individual skinfolds (triceps, subscapular, abdominal) and ratios of the skinfolds were considered by chronological age and relative to the timing of peak height velocity (PHV), and in children of contrasting maturity status in participants of the Wroclaw Growth Study, 193 boys and 197 girls, who were followed longitudinally from 8 to 18 years of age. Individual skinfolds behave differently during childhood and adolescence, and the changes are influenced by the timing of the adolescent growth spurt. Sex differences in estimated velocities are negligible up to about 2 years before PHV; then velocities tend to be higher in girls. The velocity of the triceps skinfold is negative in boys just before and after PHV; estimated velocities for the trunk skinfolds are positive through the growth spurt in both sexes, and are somewhat greater after PHV, especially in girls. The individuality of changes in individual skinfolds during the adolescent spurt contributes to changes in the relative distribution of SAT at this time. The timing of the adolescent growth spurt is an important factor influencing the distribution of SAT both in the total sample and in youth classified as early and late maturing. Am. J. Hum. Biol. 11:189-200, 1999. Copyright 1999 Wiley-Liss, Inc.

Critical value for the index of body fat distribution based on waist and hip circumferences and stature in obese girls

OBJECTIVE

To determine the critical value for the standard deviation score (SDS) of waist-hip ratio (WHR)/height (Ht), as an age-adjusted measure of body fat distribution, in relation to occurrence of biochemical complications in obese girls.

DESIGN

Cross-sectional, clinical study. The (WHR/Ht)-SDS was calculated as described previously. Obese girls were classified into two groups according to the occurrence of abnormal values in either serum triglyceride, alanine aminotransferase or insulin level. The criteria for obesity were subjected to the receiver operating characteristic (ROC) analysis.

SUBJECTS

One-hundred and twenty-four outpatient Japanese obese girls, ranging in age from 9 to 15 y.

MEASUREMENTS

Height, body weight, waist girth and hip girth as anthropometric measures. Percentage overweight, waist girth, WHR and (WHR/Ht)-SDS as criteria for obesity. Clinical laboratory analysis for fasting blood samples of obese children.

RESULTS

Fifty-nine girls were classified into the no complication group, and 65 girls into the complication group. Those with complications were older, more obese, and their waist girth and WHR were larger, than the girls without complications. The (WHR/Ht)-SDS was >2-fold higher and lipoprotein profile was more atherogenic in the complication group than in the no complication group. Among the four criteria of obesity, (WHR/Ht)-SDS gave the ROC curve skewed furthest into the top left corner of the diagram. Both sensitivity and specificity for (WHR/Ht)-SDS were >80% at the critical value of 2.00. The sensitivity for waist girth was as high as that for specificity for the rest of the criteria were <80%.

CONCLUSION

Only (WHR/Ht)-SDS showed high enough sensitivity and specificity to predict metabolic derangement in the present obese girls. (WHR/Ht)-SDS can serve as the diagnostic criterion that classifies obesity in Japanese adolescent girls into two types.

The relationship between different subcutaneous adipose tissue layers, fat mass and leptin in obese children and adolescents

We studied the relationships of subcutaneous adipose tissue layers (SAT-layers), body fat mass (FM) and waist-to-hip ratio (WHR) with leptin in obese children and adolescents. Twenty-nine obese children and adolescents (12 boys: age: 11.3 +/- 3.7 yr; body mass index [BMI]: 28.5 +/- 4) and 17 girls (age: 12.2 +/- 2.2 yr; BMI: 29.8 +/- 4.7) (mean +/- SD) were studied. FM was estimated by bioelectrical impedance. SAT-layers were determined at 15 different body sites from 1-neck to 15-calf by the Lipometer optical device. Leptin and insulin were determined by RIA. Maturity was associated with a greater thickness of certain SAT-layers from the upper body and with a lower thickness of SAT-layers from the abdominal region and lower extremities. Significant correlations were found for all estimates of adiposity and leptin (all p<0.001). Waist and hip circumferences were not correlated to leptin after adjustment for FM. SAT-layers from the upper body were significantly and positively correlated to leptin. Multiple regression analysis revealed FM as a main contributor to the variation in leptin (R2=0.53, p<0.0001). FM together with SAT-layers 5-front chest and 13-rear thigh explained 72% of the variation in leptin (p<0.0001). In a body fat distribution model, hip circumference together with SAT-layers 4-upper back and 2-triceps explained 75% of the variation in leptin (p< 0.0001). The results suggest that SAT-layers and their topography are main determinants for leptin in obese children and adolescents. Maturity in obese children is associated with higher values of upper body SAT-layers and lower values of abdominal and lower extremities SAT-layers. Whether leptin is under the control of certain subcutaneous adipose tissue depots from the upper body remains to be elucidated by longitudinal studies.

Familial resemblance in fatness and fat distribution

The purpose of the study was to estimate the degree of familial resemblance in anthropometric indicators of fatness and fat distribution. The sample consisted of 327 Caucasian participants from 102 nuclear families. Indicators of fatness included the body mass index (BMI), the sum of six skinfolds (SF6: triceps + biceps + medial calf + subscapular + suprailiac + abdominal), and waist circumference (WAIST), while indicators of fat distribution included WAIST adjusted for BMI (WAIST(ADJ)), the trunk-to-extremity skinfold ratio, adjusted for SF6 (TER(ADJ)), and the first principal component of skinfolds, adjusted for the mean skinfold of the individual (PC1). A general familial correlation model was fit to the data, and a series of nested reduced models were also fit so as to test hypotheses about familial resemblance. The hypothesis of no familial resemblance (all familial correlations are zero) was rejected for all phenotypes, indicating that fatness and fat distribution aggregate within families. For the three indicators of fatness (BMI, SF6, and WAIST), the sibling and parent-offspring correlations were significant. Further, there were no sex or generation differences in the familial correlations. For the three indicators of fat distribution (TER(ADJ), WAIST(ADJ), and PC1), there was no parent-offspring resemblance; sibling resemblance was significant for TER(ADJ) and PC1. Further, spouse resemblance was not significant for WAIST(ADJ), but was for TER(ADJ) and PC1. For both WAIST(ADJ) and PC1 there were significant sex differences in the familial correlations. A combination of models including no sex or generation differences and no spouse resemblance was the most parsimonious model for BMI, SF6, and TER(ADJ). The environmental model (all correlations equal) was the most parsimonious for WAIST, the model of no sibling resemblance was the most parsimonious for WAIST(ADJ), and the model of no spousal resemblance was the most parsimonious for PC1. Estimates of maximal heritability range from 46-60% for fatness and from 29-48% for fat distribution, independent of overall fatness, suggesting that in this sample the heritability of fatness is greater than that for fat distribution. Further, the pattern of correlations, which generally includes no spousal resemblance but significant parent-offspring and sibling correlations, suggests the role of genes in explaining at least part of the heritability. Am. J. Hum. Biol. 12:395-404, 2000. Copyright 2000 Wiley-Liss, Inc.

Temporal association between obesity and hyperinsulinemia in children, adolescents, and young adults: the Bogalusa Heart Study

Obesity is generally associated with hyperinsulinemia. However, whether obesity precedes or follows hyperinsulinemia is not clear. The present study examined the temporal nature of the association between obesity and hyperinsulinemia in a biracial (black-white) community-based population enrolled in the Bogalusa Heart Study. Three longitudinal cohorts of children (n = 427; baseline age, 5 to 7 years), adolescents (n = 674; baseline age, 12 to 14 years), and young adults (n = 396; baseline age, 20 to 24 years) were selected retrospectively, with a follow-up period of approximately 3 years. In general, longitudinal changes in the mean body mass index (kilograms per meter squared), an indicator of adiposity, and fasting insulin level did not parallel each other. In a bivariate analysis, baseline insulin levels correlated significantly with the follow-up body mass index in adolescents and adults, but not in children. On the other hand, the baseline body mass index correlated significantly with follow-up insulin levels in all cases. Logistic regression analysis showed that the proportion of subjects who developed obesity (body mass index > 75th percentile, specific for age, race, gender, and survey year) at follow-up study increased significantly across baseline quintiles (specific for age, race, gender, and survey year) of insulin only among adolescents, irrespective of race and gender. This relationship disappeared after adjusting for the baseline body mass index. By contrast, a significant positive trend between baseline quintiles of the body mass index and incidence of hyperinsulinemia (> 75th percentile) at follow-up study was noted among all age groups independent of race, gender, and baseline insulin levels. Further, in a multiple stepwise regression model, the best predictor of the follow-up insulin level was the baseline body mass index in children and adults and the baseline insulin in adolescents. The baseline body mass index was the best predictor of the follow-up body mass index in all three age groups. These results, by showing the temporal nature of the relation between obesity and hyperinsulinemia beginning in childhood, support the role of obesity in the development of hyperinsulinemia.

Effects of sex steroid hormones on regional fat depots as assessed by magnetic resonance imaging in transsexuals

We investigated prospectively the effect of sex steroids on regional fat depots and thigh muscle mass in adult transsexuals. Ethinyl estradiol in combination with cyproterone acetate, a progestational antiandrogen, was given to 20 male-to-female (M-F) transsexuals, and parenteral testosterone esters were given to 17 female-to-male (F-M) transsexuals. Before and after 12 mo of cross-sex hormone administration, several anthropometric measurements (weight, skinfolds, body circumferences, and bioimpedance) were performed, and transverse magnetic resonance images were obtained at the level of the abdomen, hip, and thigh to quantify fat depots (subcutaneous and visceral) and muscle areas. We observed that treatment with ethinyl estradiol in M-F transsexuals induced a significant increase in all subcutaneous fat depots, with a lesser but proportional and significant increase in the visceral fat depot and a decrease in thigh muscle area. Testosterone administration in F-M transsexuals markedly increased thigh muscle area, reduced subcutaneous fat deposition at all levels measured, but slightly increased the visceral fat area. We conclude that sex steroid hormones are important determinants of the sex-specific localization of body fat.

Adolescent blood pressure, anger expression and hostility: possible links with body fat

An uncertain relation between health and angry/hostile behaviour exists in the literature on adolescents. With data from a pilot study, one possible reason for this is explored: health measures such as blood pressure as well as angry/hostile behaviours may change with, or depend upon physical maturity, body size and body fatness. The sample consists of 60 African-, Hispanic-, and Anglo-American adolescents (15 to 16 years of age) drawn from a public school in Houston, TX. Using resting diastolic blood pressure as a model, in a sex stratified analysis, the following conclusions were reached: Physical maturity in girls and body height in boys were related to ethnicity in the sample and were confounders of the blood pressure and anger relationship. In girls secretive anger ('anger-in') and hostility were associated with increased body fat; expressive anger ('anger-out') in boys is associated with increased conicity (central body fat distribution) (p < 0.01). These associations were independent of height and physical maturity. Hostility was not significantly related to diastolic blood pressure in boys after adjusting for height and conicity. 'Anger-in' was significantly and positively related to diastolic blood pressure in girls (p < 0.01). This relationship was strongly mediated by per cent body fat, because the association of 'anger-in' and blood pressure was no longer statistically significant when the model included body fat. The results suggest that measures of physical maturity and more refined measures of body fat and body fat distribution should be considered in studies attempting to link adolescent blood pressure with anger expression.

Implications of the Camden Study of adolescent pregnancy: interactions among maternal growth, nutritional status, and body composition

One of the principal goals of the Camden Study over the past decade has been to document the extent to which pregnancy during adolescence is affected by continued maternal growth. Findings from the Camden Study relating to the other main goal, the effects of maternal growth during pregnancy on the outcome of pregnancy (maternal-fetal competition), are reviewed elsewhere. Contrary to widely held beliefs, we have found that there is considerable growth in late adolescence for girls, and, in particular, continued development of weight (> 1 kg/year) and increases in subcutaneous fatness at central sites. Thus, when pregnancy occurs during this final phase of adolescent growth, the normal growth processes may be exacerbated. That is, the adolescent potential for weight gain (as fat) may be exploited. Along with others, we have documented that adolescent pregnancy is associated with larger gestational weight gains. Using methods sufficiently sensitive to detect maternal growth prospectively, we also found that the larger-than-average total weight gains among adolescents appear attributable primarily to the growing adolescent gravidas and reflect their continued accrual of subcutaneous fat and increased risk for weight retention. Excessive gestational weight gain, as is more common among growing adolescent gravidas, appears to exacerbate the accumulation of fat at central sites. Aside from the consequences to the outcome of pregnancy, adolescents who begin their childbearing early while still growing themselves, such as those we have followed in the Camden Study over the past decade, may be at particularly increased risk for overweight and obesity. Further, the excessive deposition of subcutaneous fat at central body sites, as we have documented for adolescent pregnancy, will often in later life presage the development of cardiovascular disease, noninsulin-dependent diabetes mellitus (NIDDM), and hypertension. Thus, far from being benign, pregnancy during adolescence, particularly when the adolescent is herself still growing, may contribute to long-term risk for obesity-related diseases and diminish the quality of life.

Birth weight and its relationship to size attained and relative fat distribution at 7 to 12 years of age

The relationship between birth weight and relative subcutaneous fat distribution at school age was considered in 131 boys and 106 girls 7 to 12 years of age. Relative fat distribution at school age was estimated with the ratio of the subscapular to triceps skinfolds (S/T) for the total sample, and with the ratio of the sum of two trunk (subscapular, midaxillary) to the sum of two extremity (triceps, medial calf) skinfolds (T/E) for subsamples of 102 boys and 63 girls. There were no sex differences in the S/T ratio (mm/mm), boys 0.62 +/- 0.15, girls 0.63 +/- 0.18; T/E ratio (mm/mm), boys 0.58 +/- 0.13, girls 0.59 +/- 0.16; and BMI (kg/m2), boys 17.1 +/- 2.4, girls 16.9 +/- 2.2. Second order partial correlations, controlling for age and the BMI or age and sum of skinfolds, between birth weight and the skinfold ratios are, respectively, -0.22 and -0.20 (p < 0.01) for S/T and -0.29 and -0.32 (p < 0.01) for T/E in girls, and -0.18 and -0.17 (p < 0.05) for S/T and -0.06 and -0.6 for T/E in boys. Though low, the correlations suggest that as birth weight decreases proportionally more subcutaneous fat is accumulated on the trunk than on the extremities, more so in females than in males. Results of stepwise multiple regression analyses indicate that birth weight accounts for from 2% to 8% of the variance in relative subcutaneous fat distribution at school age.

Adolescent overweight is associated with adult overweight and related multiple cardiovascular risk factors: the Bogalusa Heart Study

Overweight in adolescence is considered an important predictor of long-term morbidity and mortality. The impact of adolescent overweight on adult overweight and related multiple cardiovascular risk factors was examined in a biracial (black-white) cohort (N = 783) who participated in two cross-sectional surveys as adolescents aged 13 to 17 years and as young adults aged 27 to 31 years. The cohort was categorized as adolescent-onset adult overweight (N = 110) or lean (N = 81) according to age-, race-, and sex-specific body mass index (BMI) greater than the 75th percentile or between the 25th and 50th percentiles on both surveys. The risk for overweight adolescents to remain overweight as young adults ranged from 52% in black males to 62% in black females. As young adults, the overweight cohort showed adverse levels of body fatness measures, systolic and diastolic blood pressure, lipoprotein cholesterol, insulin, and glucose as compared with the lean cohort (P < .01 to P < .0001). The prevalence of clinically recognized hypertension and dyslipidemia increased 8.5-fold and 3.1- to 8.3-fold, respectively, in the overweight cohort versus the lean cohort (P < .05 to P < .0001). The prevalence of parental history of diabetes mellitus and hypertension increased 2.4-fold (P < .01) and 1.3-fold (P < .05), respectively, in the overweight cohort. Clustering of adverse values (> 75th percentile) for the total cholesterol to high-density lipoprotein (HDL) cholesterol ratio, insulin level, and systolic blood pressure occurred only among the overweight cohort (P < .0001). Thus, excess weight in adolescence persists into young adulthood, and has a strong adverse impact on multiple cardiovascular risk factors, requiring primary prevention early in life.

Hemostatic function in young subjects with central obesity: relationship with left ventricular function

This study was designed to evaluate coagulation and fibrinolysis activity and their relationship with left ventricular function in young obese subjects with central fat distribution. We assessed coagulation and fibrinolysis activity by evaluation of factor VII activity, fibrinogen and plasminogen, plasminogen activator inhibitor (PAI), and tissue plasminogen activator antigen basally (tPA1) and after venous occlusion (tPA2). These measures were evaluated in young (< 40 years) obese subjects with central fat distribution (n = 19) and in comparable lean subjects (n = 20). Blood glucose, triglycerides, total and high-density lipoprotein (HDL) cholesterol, apolipoprotein (apo) A1 and apo B, fasting immunoreactive insulin, and lipoprotein(a) levels were also measured by current methods. Left ventricular ejection fraction (LVEF) and peak filling rate (PFR) determined by radionuclide angiocardiography and left ventricular mass (LVM) and LVM indexed for body height (LVM/H) determined by echocardiographic study were calculated. Central obesity was evaluated by the waist to hip ratio (WHR) according to the criteria of the Italian Consensus Conference of Obesity. Factor VII (P < .001), fibrinogen (P < .001), plasminogen (P < .001), PAI activity (P < .001), tPA1 (P < .02), fasting blood glucose (P < .01), apo B (P < .02), and immunoreactive insulin (P < .01) were significantly higher in obese than in lean subjects. In contrast, HDL cholesterol (P < .01), tPA2 (P < .01), LVEF (P < .001), and PFR (P < .02) were significantly lower in obese than in lean subjects. In all subjects, WHR correlated directly with fibrinogen and inversely with tPA2; LVEF correlated inversely with tPA1, PAI, and fibrinogen; and PFR correlated inversely with factor VII activity.(ABSTRACT TRUNCATED AT 250 WORDS)

The precision of anthropometric assessment of body fat distribution in children

Precision estimates are given for indices of body mass, fatness and body fat distribution in a sample of n = 19 subjects selected at random from a larger study of cardiovascular disease risk in school-aged children. The value of this study is that little is known about the measurement precision of ratio indices and multivariate constructs of body fat distribution in children or any other age group. Intra- and inter-observer precisions were highest for weight, height, body mass index and six body circumferences (0.95-0.99), and were lower and more variable for five skinfold thicknesses (0.80-0.99). The measurement precision of ratio indices derived from the circumferences (waist/hip and waist/thigh) and the skinfolds (subscapular/thigh and triceps/subscapular) were lower and more variable than precisions of the single variables. Circumference ratio precisions varied from 0.81 to 0.96 and skinfold ratios varied from 0.28 to 0.94. Precisions of a multivariate construct of central fat distribution from five skinfold measures were better (0.77-0.95), suggesting its greater efficacy. Inter-examiner precisions tended to be significantly lower than intra-examiner precisions for skinfold thicknesses and all composite indices. The lower precisions of ratio indices, compared to the measurement accuracy of the variables which make them up, needs to be considered in epidemiological studies of body fat distribution.

The distribution of body fat from childhood to adulthood in a longitudinal study population

Body fat distribution, its continuity from childhood (4-6 years) to 30 years of age, and its link to that of parents is described in a longitudinal study population. A computer-assisted image analysis technique was used to measure body fat distribution (as measured by waist and hip diameters) from somatotype photographs. Pearson correlation coefficients were used to assess the association between the waist/hip diameter ratio (WHDR) and the body mass index (BMI) at all ages and between the WHDR of parents and offspring. Both Pearson correlation coefficients and the Foulkes-Davis tracking index were used to assess tracking of the WHDR from childhood to age 30 years. Stepwise regression analyses were performed to determine the predictability of the WHDR at age 30 years from WHDRs in childhood and adolescence. Among both sexes the WHDR decreased and BMIs increased with age from childhood to 18 years, then both increased from age 18 to 30 years. The correlation between the WHDR and BMI was significant only at 30 years for males (r = 0.37; p < 0.05) and during all stages of adolescence in females (p < 0.05). Age-to-age correlations were high for both sexes (p < 0.0001), and remained significant over a span of up to 25 years. Using the Foulkes-Davis tracking index, tracking from the year of peak height velocity to 30 years (a span of approximately 20 years) was strong for both sexes. Parent and child WHDRs were correlated and differed by sex. Father-son correlations were not significant in childhood, but reached significance in early adolescence (2 years before the year of peak velocity) and remained significant to 30 years (p < 0.05). Mother-daughter correlations were significant at all ages (p < 0.05). The level of the WHDR at the peak of the pubertal growth spurt (year of peak height velocity) predicted up to 58% of the variance in males and 51% of the variance in females of the WHDR at 30 years. We conclude that the adult WHDR (a proxy for the waist/hip ratio) becomes evident by the year of the pubertal growth spurt in height.

Nutritional assessment in Duchenne muscular dystrophy

A specific-weight chart and simple clinical tools are sufficient to obtain an accurate diagnosis of undernutrition or obesity among patients with Duchenne muscular dystrophy (DMD). The authors collected weight-for-age measures from a sample of 252 boys and anthropometric data from 109 of those boys with DMD. The data confirm the accuracy of the DMD ideal-weight chart previously proposed by Griffiths and Edwards (1988). Obesity may occur from the age of seven years; its prevalence seems to reach 54 per cent by the age of 13 years. Undernutrition occurs after the age of 14 years, involving 54 per cent of boys at about 18 years of age. Obese boys show a centralized body-fat distribution, in agreement with other obese populations.

Long-term morbidity and mortality of overweight adolescents. A follow-up of the Harvard Growth Study of 1922 to 1935

BACKGROUND

Overweight in adults is associated with increased morbidity and mortality. In contrast, the long-term effect of overweight in adolescence on morbidity and mortality is not known.

METHODS

We studied the relation between overweight and morbidity and mortality in 508 lean or overweight adolescents 13 to 18 years old who participated in the Harvard Growth Study of 1922 to 1935. Overweight adolescents were defined as those with a body-mass index that on two occasions was greater than the 75th percentile in subjects of the same age and sex in a large national survey. Lean adolescents were defined as those with a body-mass index between the 25th and 50th percentiles. Subjects who were still alive were interviewed in 1988 to obtain information about their medical history, weight, functional capacity, and other risk factors. For those who had died, information on the cause of death was obtained from death certificates.

RESULTS

Overweight in adolescent subjects was associated with an increased risk of mortality from all causes and disease-specific mortality among men, but not among women. The relative risks among men were 1.8 (95 percent confidence interval, 1.2 to 2.7; P = 0.004) for mortality from all causes and 2.3 (95 percent confidence interval, 1.4 to 4.1; P = 0.002) for mortality from coronary heart disease. The risk of morbidity from coronary heart disease and atherosclerosis was increased among men and women who had been overweight in adolescence. The risk of colorectal cancer and gout was increased among men and the risk of arthritis was increased among women who had been overweight in adolescence. Overweight in adolescence was a more powerful predictor of these risks than overweight in adulthood.

CONCLUSIONS

Overweight in adolescence predicted a broad range of adverse health effects that were independent of adult weight after 55 years of follow-up.

Is body fat distribution associated with cardiovascular risk factors in childhood?

The authors studied the association of cardiovascular risk variables with body fat distribution (BFD) in a cross-sectional sample of 743 Texas schoolchildren of both sexes ages 6-14 years. This association is well known in adults and several useful indices of BFD are available. Whether they are applicable to children remains a question of importance for epidemiological investigations in this age group. Canonical correlations between anthropometric (five skinfolds, four circumferences) and risk (blood pressures, cholesterol, pulse) variables ranged from 0.37 to 0.82 depending on sex/age group (p < 0.01). The skinfold vector suggested an association of risk with central fat at most but not all ages. The circumference vectors, on the other hand, suggest that size or fatness, not BFD, was related to risk. Partial correlation and stepwise regression of fatness and BFD indices with cardiovascular risk factors as dependent variables, showed that 'fatness' or 'size' was more clearly associated with risk factors than BFD. The variables most consistently entering the regression were hip circumference and sum of skinfolds. These results contrast with studies of adults or sexually mature adolescents, in which BFD is more clearly related to CV risk variables and the hip circumference is a 'low-risk' variable.

Accuracy of recall by middle-aged participants in a longitudinal study of their body size and indices of maturation earlier in life

The validity of long-term recall and current assessments of height, weight, and fatness relative to peers was investigated among 91 middle-aged participants in a longitudinal growth study. The recollections of 50-year-old participants concerning perceived body size in comparison to peers during childhood (aged 5-7 years), adolescence (aged 10-18 years), and at ages 30, and 40 years were compared with physical measurements taken at these times. Correlations between perceived and actual body size at all ages from childhood through middle-age were moderate but significant (P less than 0.005) and were influenced by gender and phases of physical growth (early and late adolescence). In general, accuracy of self-reports of current body size were not significantly better than recalls of body size up to 50 years earlier. Respondents' recall of various physiological events was also assessed. Females' actual and recalled year of menarche were correlated (r = 0.67; P less than 0.0001). Age at menarche was recalled within 1 year of the actual event by 84% of the females. Fifty percent of both sexes recalled their year of maximal growth in height within 1 year and recalled the timing of their maturation (early, average, or late) in relationship to their peers equally well (P less than 0.001).

The association of body fat location with haemodynamic and metabolic status in men and women aged 21-60 years

The importance of body fat location as a predictor of metabolic aberrations was evaluated in 214 males and 244 females [aged 21-60] randomly selected from the patients of one general practice of Castel D'Azzano (Italy). The metabolic pattern, indexed by blood pressure, blood glucose, uric acid, serum triglycerides, HDL- and LDL-cholesterol was summarized in a haemodynamic-metabolic score (HMS). Association of HMS with age, anthropometric variables (skinfold thicknesses, girth lengths) and degree of overweight (body mass index, BMI) was evaluated in males and females using multiple regression analysis. Body fat location was associated with metabolic status independent of age in both sexes. This association was also independent of the degree of overweight. BMI, in general, was associated with HMS to a greater extent than anthropometric variables, except for waist girth; when its effect was taken into account BMI did not significantly improve the prediction power of HMS values in males. Among skinfolds, epimesogastric showed in both sexes the highest association with HMS. These results support the abdominal adiposity hypothesis and suggest that waist circumference could be a good index for assessing metabolic status. The abdominal location of adipose tissue, more than just the degree of overweight, could play a role in obesity related disorders.

Body circumferences as alternatives to skinfold measures of body fat distribution in children

The ratios of circumferences (waist/hip, waist/thigh) have been proposed in lieu of skinfold measurements for studies of obesity and body fat distribution in adults. The skinfold method has been used successfully in children to study the growth and development of patterns of body fat distribution, but circumferences have not. We studied the relationship between these two methodologies as indicators of body fat and its anatomical distribution among 365 normal children aged 6-11 years, using canonical correlation analysis. With this method, weighted vectors of four body circumferences on the one hand and five skinfolds on the other are formed in such a way that the correlation between the two sets of variables is maximized. Weights (regression coefficients) are assigned each variable and their strength and sign help us to select the best combination of circumferences which describe a component of centralised obesity. A first canonical correlation was substantial in both boys and girls (0.84) and was independent of age. It appeared to relate to fatness level. A second canonical correlation was low (0.34 in boys, 0.35 in girls) (p less than 0.01). It too was age independent and in both sexes it reflected differences between fat on the trunk and on the lower extremity, and was thus a component of centralised fat distribution. The simple waist/thigh ratio correlated better with this canonical variable (0.67-0.88) than the more commonly used waist/hip ratio (0.45-0.79). The 'best' index of centralised fat in children is therefore, the waist/thigh circumference ratio, the same one that has been suggested for adults.

Relationship of body fat distribution to metabolic complications in obese prepubertal boys: gender related differences

Our purpose was to assess the relationship of obesity and body fat distribution to serum glucose values, insulin concentration and insulin resistance in obese prepubertal boys. Thirteen obese and 15 control prepubertal boys were studied. Biceps, triceps, subscapular and suprailiac skin fold thicknesses were measured. Percentage of body fat and total body fat were calculated. Body fat distribution was assessed by analyzing the central (supra-iliac, subscapular)/peripheral (biceps, triceps) ratios. During an oral glucose tolerance test, serum glucose and insulin were measured and insulin/glucose was calculated. Body fat data and body fat distribution indices were significantly higher in the obese group. The obese population presented significantly elevated values of insulin and insulin/glucose. In the obese group insulin showed significant correlations with percentage of body fat, total body fat and subscapular skin fold thickness, whereas insulin/glucose had significant positive correlations with percentage of body fat, total body fat and supra-iliac skin fold thickness. In obese boys significant positive correlations were also shown by subscapular/supra-iliac with insulin and insulin/glucose, and by subscapular/triceps with insulin. In prepubertal boys obesity is centripetal and an upper central body fat distribution seems to be first associated with an abnormal glucose-insulin homeostasis.

Fat distribution in children with cerebral palsy

Triceps and subscapular skinfolds were measured on 95 North American children with cerebral palsy. Triceps fat was far more depleted than subscapular fat in comparison with population standards for sex, age and race. This truncal distribution of fat may be related to the high prevalence of under nutrition found in the sample.

Fat patterning of adolescents

Fat patterning of 110 adolescent males and 80 adolescent females was determined by principal components analysis of five skinfolds (triceps, subscaplular, iliac, abdominal and thigh). Densiometrically determined body fatness was employed to create two groups: obese (greater than 30% fat) and non-obese (less than 30% fat). Three fat patterning components emerged: trunk-extremity, upper-lower trunk and medial-lateral abdomen. The first two components accounted for 80% of the variance in fat distribution. The obese males and females demonstrate increased trunk fat patterning compared to the non-obese. Furthermore, obese males deposit increased trunk fat in the lower trunk while obese females deposit fat in the upper trunk.

Relationship of fat patterning to coronary artery disease risk in obese adolescents

Fatness and fat patterning of 27 male and 33 female obese adolescents were identified by principal-components analysis of five skinfolds (triceps, subscapular, iliac, abdominal, and thigh). Correlations were computed between the component scores, based on the eigen vectors, and anthropometric and physiological variables. Overall fatness, component I, was highly correlated with all anthropometric and body composition variables. Also, component I significantly correlated with fasting insulin and VO2 max for both sexes and with basal metabolism and HDL-cholesterol for females and males, respectively. Extremity fat patterning, component II, was poorly correlated with all the anthropometric and physiological variables except diastolic blood pressure for the females. Upper-lower body fat patterning, component III, was correlated with the fewest physiological variables.

Socioeconomic status, sex, age, and ethnicity as determinants of body fat distribution for Guatemalan children

The distribution of subcutaneous fat at the triceps and subscapular skinfold sites is described for four groups of children living in Guatemala. These groups are high socioeconomic status (SES) children of Ladino (mixed Spanish and Indian) ancestry, high SES children of European ancestry, low SES Ladino children, and very low SES Indian children. The method of Healy and Tanner (1981) is used, employing regression and principal components analysis of log transformed skinfold values to divide "fatness" into two uncorrelated variables: size (amount of fat) and shape (fat pattern). Significant differences exist between groups in size, with lower SES groups having less fat than higher SES groups. No significant difference in fat pattern exists between the high SES Ladino and high SES European children. Significant differences do exist between the high SES groups and the low SES groups. The relative amount of subscapular fat increases from the high SES Ladinos and high SES Europeans, to the low SES Ladinos, to the very low SES Indians. In the high SES European and high SES Ladino samples, girls have significantly more arm fat than boys. There is no significant difference in fat patterning between boys and girls in the two low SES samples. Finally, the relative amount of subscapular fat tends to increase with age in all four samples. These results indicate that fatness and fat patterning are independent anatomical characteristics, SES influences fat patterning; low SES children of both Ladino and Indian ancestry show greater reductions in arm fat than in trunk fat compared to high SES children, sexual dimorphism in fat patterning is SES dependent.(ABSTRACT TRUNCATED AT 250 WORDS)