External validation of a prediction model for estimating fat mass in children and adolescents in 19 countries: individual participant data meta-analysis.

OBJECTIVE: To evaluate the performance of a UK based prediction model for estimating fat-free mass (and indirectly fat mass) in children and adolescents in non-UK settings. DESIGN: Individual participant data meta-analysis. SETTING: 19 countries. PARTICIPANTS: 5693 children and adolescents (49.7% boys) aged 4 to 15 years with complete data on the predictors included in the UK based model (weight, height, age, sex, and ethnicity) and on the independently assessed outcome measure (fat-free mass determined by deuterium dilution assessment). MAIN OUTCOME MEASURES: The outcome of the UK based prediction model was natural log transformed fat-free mass (lnFFM). Predictive performance statistics of R2, calibration slope, calibration-in-the-large, and root mean square error were assessed in each of the 19 countries and then pooled through random effects meta-analysis. Calibration plots were also derived for each country, including flexible calibration curves. RESULTS: The model showed good predictive ability in non-UK populations of children and adolescents, providing R2 values of >75% in all countries and >90% in 11 of the 19 countries, and with good calibration (ie, agreement) of observed and predicted values. Root mean square error values (on fat-free mass scale) were <4 kg in 17 of the 19 settings. Pooled values (95% confidence intervals) of R2, calibration slope, and calibration-in-the-large were 88.7% (85.9% to 91.4%), 0.98 (0.97 to 1.00), and 0.01 (-0.02 to 0.04), respectively. Heterogeneity was evident in the R2 and calibration-in-the-large values across settings, but not in the calibration slope. Model performance did not vary markedly between boys and girls, age, ethnicity, and national income groups. To further improve the accuracy of the predictions, the model equation was recalibrated for the intercept in each setting so that country specific equations are available for future use. CONCLUSION: The UK based prediction model, which is based on readily available measures, provides predictions of childhood fat-free mass, and hence fat mass, in a range of non-UK settings that explain a large proportion of the variability in observed fat-free mass, and exhibit good calibration performance, especially after recalibration of the intercept for each population. The model demonstrates good generalisability in both low-middle income and high income populations of healthy children and adolescents aged 4-15 years.

Seven-Year Weight Trajectories and Health Outcomes in the Longitudinal Assessment of Bariatric Surgery (LABS) Study.

Importance: More information is needed about the durability of weight loss and health improvements after bariatric surgical procedures. Objective: To examine long-term weight change and health status following Roux-en-Y gastric bypass (RYGB) and laparoscopic adjustable gastric banding (LAGB). Design, Setting, and Participants: The Longitudinal Assessment of Bariatric Surgery (LABS) study is a multicenter observational cohort study at 10 US hospitals in 6 geographically diverse clinical centers. Adults undergoing bariatric surgical procedures as part of clinical care between 2006 and 2009 were recruited and followed up until January 31, 2015. Participants completed presurgery, 6-month, and annual research assessments for up to 7 years. Main Outcome and Measures: Percentage of weight change from baseline, diabetes, dyslipidemia, and hypertension, determined by physical measures, laboratory testing, and medication use. Results: Of 2348 participants, 1738 underwent RYGB (74%) and 610 underwent LAGB (26%). For RYBG, the median age was 45 years (range, 19-75 years), the median body mass index (calculated as weight in kilograms divided by height in meters squared) was 47 (range, 34-81), 1389 participants (80%) were women, and 257 participants (15%) were nonwhite. For LAGB, the median age was 48 years (range, 18-78), the body mass index was 44 (range, 33-87), 465 participants (76%) were women, and 63 participants (10%) were nonwhite. Follow-up weights were obtained in 1300 of 1569 (83%) eligible for a year-7 visit. Seven years following RYGB, mean weight loss was 38.2 kg (95% CI, 36.9-39.5), or 28.4% (95% CI, 27.6-29.2) of baseline weight; between years 3 and 7 mean weight regain was 3.9% (95% CI, 3.4-4.4) of baseline weight. Seven years after LAGB, mean weight loss was 18.8 kg (95% CI, 16.3-21.3) or 14.9% (95% CI, 13.1-16.7), with 1.4% (95% CI, 0.4-2.4) regain. Six distinct weight change trajectory patterns for RYGB and 7 for LAGB were identified. Most participants followed trajectories in which weight regain from 3 to 7 years was small relative to year-3 weight loss, but patterns were variable. Compared with baseline, dyslipidemia prevalence was lower 7 years following both procedures; diabetes and hypertension prevalence were lower following RYGB only. Among those with diabetes at baseline (488 of 1723 with RYGB [28%]; 175 of 604 with LAGB [29%]), the proportion in remission at 1, 3, 5, and 7 years were 71.2% (95% CI, 67.0-75.4), 69.4% (95% CI, 65.0-73.8), 64.6% (95% CI, 60.0-69.2), and 60.2% (95% CI, 54.7-65.6), respectively, for RYGB and 30.7% (95% CI, 22.8-38.7), 29.3% (95% CI, 21.6-37.1), 29.2% (95% CI, 21.0-37.4), and 20.3% (95% CI, 9.7-30.9) for LAGB. The incidence of diabetes at all follow-up assessments was less than 1.5% for RYGB. Bariatric reoperations occurred in 14 RYGB and 160 LAGB participants. Conclusions and Relevance: Following bariatric surgery, different weight loss patterns were observed, but most participants maintained much of their weight loss with variable fluctuations over the long term. There was some decline in diabetes remission over time, but the incidence of new cases is low following RYGB. Trial Registration: clinicaltrials.gov Identifier: NCT00465829.

Weight Loss and Health Status 3 Years after Bariatric Surgery in Adolescents.

BACKGROUND: Bariatric surgery is increasingly considered for the treatment of adolescents with severe obesity, but few prospective adolescent-specific studies examining the efficacy and safety of weight-loss surgery are available to support clinical decision making. METHODS: We prospectively enrolled 242 adolescents undergoing weight-loss surgery at five U.S. centers. Patients undergoing Roux-en-Y gastric bypass (161 participants) or sleeve gastrectomy (67) were included in the analysis. Changes in body weight, coexisting conditions, cardiometabolic risk factors, and weight-related quality of life and postoperative complications were evaluated through 3 years after the procedure. RESULTS: The mean (±SD) baseline age of the participants was 17±1.6 years, and the mean body-mass index (the weight in kilograms divided by the square of the height in meters) was 53; 75% of the participants were female, and 72% were white. At 3 years after the procedure, the mean weight had decreased by 27% (95% confidence interval [CI], 25 to 29) in the total cohort, by 28% (95% CI, 25 to 30) among participants who underwent gastric bypass, and by 26% (95% CI, 22 to 30) among those who underwent sleeve gastrectomy. By 3 years after the procedure, remission of type 2 diabetes occurred in 95% (95% CI, 85 to 100) of participants who had had the condition at baseline, remission of abnormal kidney function occurred in 86% (95% CI, 72 to 100), remission of prediabetes in 76% (95% CI, 56 to 97), remission of elevated blood pressure in 74% (95% CI, 64 to 84), and remission of dyslipidemia in 66% (95% CI, 57 to 74). Weight-related quality of life also improved significantly. However, at 3 years after the bariatric procedure, hypoferritinemia was found in 57% (95% CI, 50 to 65) of the participants, and 13% (95% CI, 9 to 18) of the participants had undergone one or more additional intraabdominal procedures. CONCLUSIONS: In this multicenter, prospective study of bariatric surgery in adolescents, we found significant improvements in weight, cardiometabolic health, and weight-related quality of life at 3 years after the procedure. Risks associated with surgery included specific micronutrient deficiencies and the need for additional abdominal procedures. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others; Teen-LABS ClinicalTrials.gov number, NCT00474318.).

Cardiovascular Risk Factors in Severely Obese Adolescents: The Teen Longitudinal Assessment of Bariatric Surgery (Teen-LABS) Study.

IMPORTANCE: Severe obesity is increasingly common in the adolescent population but, as of yet, very little information exists regarding cardiovascular disease (CVD) risks in this group. OBJECTIVE: To assess the baseline prevalence and predictors of CVD risks among severely obese adolescents undergoing weight-loss surgery. DESIGN, SETTING, AND PARTICIPANTS: A prospective cohort study was conducted from February 28, 2007, to December 30, 2011, at the following 5 adolescent weight-loss surgery centers in the United States: Nationwide Children's Hospital in Columbus, Ohio; Cincinnati Children's Hospital Medical Center in Cincinnati, Ohio; Texas Children's Hospital in Houston; University of Pittsburgh Medical Center in Pittsburgh, Pennsylvania; and Children's Hospital of Alabama in Birmingham. Consecutive patients aged 19 years or younger were offered enrollment in a long-term outcome study; the final analysis cohort consisted of 242 participants. MAIN OUTCOMES AND MEASURES: This report examined the preoperative prevalence of CVD risk factors (ie, fasting hyperinsulinemia, elevated high-sensitivity C-reactive protein levels, impaired fasting glucose levels, dyslipidemia, elevated blood pressure, and diabetes mellitus) and associations between risk factors and body mass index (calculated as weight in kilograms divided by height in meters squared), age, sex, and race/ethnicity. Preoperative data were collected within 30 days preceding bariatric surgery. RESULTS: The mean (SD) age was 17 (1.6) years and median body mass index was 50.5. Cardiovascular disease risk factor prevalence was fasting hyperinsulinemia (74%), elevated high-sensitivity C-reactive protein levels (75%), dyslipidemia (50%), elevated blood pressure (49%), impaired fasting glucose levels (26%), and diabetes mellitus (14%). The risk of impaired fasting glucose levels, elevated blood pressure, and elevated high-sensitivity C-reactive protein levels increased by 15%, 10%, and 6%, respectively, per 5-unit increase in body mass index (P < .01). Dyslipidemia (adjusted relative risk = 1.60 [95% CI, 1.26-2.03]; P < .01) and elevated blood pressure (adjusted relative risk = 1.48 [95% CI, 1.16-1.89]; P < .01) were more likely in adolescent boys compared with adolescent girls. White individuals were at greater risk of having elevated triglyceride levels (adjusted relative risk = 1.76 [95% CI, 1.14-2.72]; P = .01) but were less likely to have impaired fasting glucose levels (adjusted relative risk = 0.58 [95% CI, 0.38-0.89]; P = .01). CONCLUSIONS AND RELEVANCE: Numerous CVD risk factors are apparent in adolescents undergoing weight-loss surgery. Increasing body mass index and male sex increase the relative risk of specific CVD risk factors. These data suggest that even among severely obese adolescents, recognition and treatment of CVD risk factors is important to help limit further progression of disease.

Severe obesity and comorbid condition impact on the weight-related quality of life of the adolescent patient.

OBJECTIVES: To assess links between comorbid health status, severe excess weight, and weight-related quality of life (WRQOL) in adolescents with severe obesity and undergoing weight-loss surgery (WLS) to inform clinical care. STUDY DESIGN: Baseline (preoperative) data from Teen Longitudinal Assessment of Bariatric Surgery, a prospective multicenter observational study of 242 adolescents with severe obesity (MedianBMI = 50.5 kg/m(2); Meanage = 17.1; 75.6% female; 71.9% white) undergoing WLS, were used to examine the impact of demographics, body mass index (BMI), presence/absence of 16 comorbid conditions, and a cumulative comorbidity load (CLoad) index on WRQOL scores (Impact of Weight on Quality of Life-Kids). RESULTS: WRQOL was significantly lower than reference samples of healthy weight, overweight, and obese samples. Of 16 comorbid conditions, the most prevalent were dyslipidemia (74.4%), chronic pain (58.3%), and obstructive sleep apnea (56.6%). Male subjects had a greater CLoad (P = .01) and BMI (P = .01), yet less impairment in total WRQOL (P < .01) than females. CLoad was a significant predictor of male WRQOL. For females, psychosocial (vs physical) comorbidities, BMI, and white race were significant predictors of WRQOL impairment. Less prevalent conditions (eg, stress urinary incontinence) also emerged as contributors to lower WRQOL. CONCLUSIONS: WRQOL impairment is substantial for adolescents with severe obesity undergoing WLS, with predictors varying by sex. These patient-data highlight targets for education, support, and adjunctive care referrals before WLS. Furthermore, they provide a comprehensive empirical base for understanding heterogeneity in adolescent WRQOL outcomes after WLS, as weight and comorbidity profiles change over time.

Long-term outcomes of bariatric surgery: a National Institutes of Health symposium.

IMPORTANCE: The clinical evidence base demonstrating bariatric surgery's health benefits is much larger than it was when the National Institutes of Health last held a consensus panel in 1991. Still, it remains unclear whether ongoing studies will address critical questions about long-term complication rates and the sustainability of weight loss and comorbidity control. OBJECTIVE: To summarize findings from a multidisciplinary workshop convened in May 2013 by the National Institute of Diabetes and Digestive and Kidney Diseases and the National Heart, Lung, and Blood Institute. The workshop aimed to summarize the current state of knowledge of bariatric surgery, review research findings on the long-term outcomes of bariatric surgery, and establish priorities for future research directions. EVIDENCE REVIEW: The evidence presented at the workshop was selected by the planning committee for both its quality and duration of follow-up. The data review emphasized randomized clinical trials and large observational studies with long-term follow-up, with or without a control group. FINDINGS: Several small randomized clinical trials showed greater weight loss and type 2 diabetes mellitus remission compared with nonsurgical treatments within the first 2 years of follow-up after bariatric surgery. Large, long-term observational studies have shown durable (>5 years) weight loss, diabetes, and lipid improvements with bariatric surgery. Still unclear are predictors of outcomes, long-term complications, long-term survival, microvascular and macrovascular events, mental health outcomes, and costs. The studies needed to address these knowledge gaps would be expensive and logistically difficult to perform. CONCLUSIONS AND RELEVANCE: High-quality evidence shows that bariatric surgical procedures result in greater weight loss than nonsurgical treatments and are more effective at inducing initial type 2 diabetes mellitus remission in obese patients. More information is needed about the long-term durability of comorbidity control and complications after bariatric procedures and this evidence will most likely come from carefully designed observational studies.

Perioperative outcomes of adolescents undergoing bariatric surgery: the Teen-Longitudinal Assessment of Bariatric Surgery (Teen-LABS) study.

IMPORTANCE: Severe obesity in childhood is a major health problem with few effective treatments. Weight-loss surgery (WLS) is being used to treat severely obese adolescents, although with very limited data regarding surgical safety for currently used, minimally invasive procedures. OBJECTIVE: To assess the preoperative clinical characteristics and perioperative safety outcomes of severely obese adolescents undergoing WLS. DESIGN, SETTING, AND PARTICIPANTS: This prospective, multisite observational study enrolled patients from February 28, 2007, through December 30, 2011. Consecutive patients aged 19 years or younger who were approved to undergo WLS (n = 277) were offered enrollment into the study at 5 academic referral centers in the United States; 13 declined participation and 22 did not undergo surgery after enrollment, thus the final analysis cohort consisted of 242 individuals. There were no withdrawals. MAIN OUTCOMES AND MEASURES: This analysis examined preoperative anthropometrics, comorbid conditions, and major and minor complications occurring within 30 days of operation. All data were collected in a standardized fashion. Reoperations and hospital readmissions were adjudicated by independent reviewers to assess relatedness to the WLS procedure. RESULTS: The mean (SD) age of participants was 17.1 (1.6) years and the median body mass index (calculated as weight in kilograms divided by height in meters squared) was 50.5. Fifty-one percent demonstrated 4 or more major comorbid conditions. Laparoscopic Roux-en-Y gastric bypass, vertical sleeve gastrectomy, and adjustable gastric banding were performed in 66%, 28%, and 6% of patients, respectively. There were no deaths during the initial hospitalization or within 30 days of operation; major complications (eg, reoperation) were seen in 19 patients (8%). Minor complications (eg, readmission for dehydration) were noted in 36 patients (15%). All reoperations and 85% of readmissions were related to WLS. CONCLUSIONS AND RELEVANCE: In this series, adolescents with severe obesity presented with abundant comorbid conditions. We observed a favorable short-term complication profile, supporting the early postoperative safety of WLS in select adolescents. Further longitudinal study of this cohort will permit accurate assessment of long-term outcomes for adolescents undergoing bariatric surgery. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00474318.

Weight change and health outcomes at 3 years after bariatric surgery among individuals with severe obesity.

IMPORTANCE: Severe obesity (body mass index [BMI] ≥35) is associated with a broad range of health risks. Bariatric surgery induces weight loss and short-term health improvements, but little is known about long-term outcomes of these operations. OBJECTIVE: To report 3-year change in weight and select health parameters after common bariatric surgical procedures. DESIGN AND SETTING: The Longitudinal Assessment of Bariatric Surgery (LABS) Consortium is a multicenter observational cohort study at 10 US hospitals in 6 geographically diverse clinical centers. PARTICIPANTS AND EXPOSURE: Adults undergoing first-time bariatric surgical procedures as part of routine clinical care by participating surgeons were recruited between 2006 and 2009 and followed up until September 2012. Participants completed research assessments prior to surgery and 6 months, 12 months, and then annually after surgery. MAIN OUTCOMES AND MEASURES: Three years after Roux-en-Y gastric bypass (RYGB) or laparoscopic adjustable gastric banding (LAGB), we assessed percent weight change from baseline and the percentage of participants with diabetes achieving hemoglobin A1c levels less than 6.5% or fasting plasma glucose values less than 126 mg/dL without pharmacologic therapy. Dyslipidemia and hypertension resolution at 3 years was also assessed. RESULTS: At baseline, participants (N = 2458) were 18 to 78 years old, 79% were women, median BMI was 45.9 (IQR, 41.7-51.5), and median weight was 129 kg (IQR, 115-147). For their first bariatric surgical procedure, 1738 participants underwent RYGB, 610 LAGB, and 110 other procedures. At baseline, 774 (33%) had diabetes, 1252 (63%) dyslipidemia, and 1601 (68%) hypertension. Three years after surgery, median actual weight loss for RYGB participants was 41 kg (IQR, 31-52), corresponding to a percentage of baseline weight lost of 31.5% (IQR, 24.6%-38.4%). For LAGB participants, actual weight loss was 20 kg (IQR, 10-29), corresponding to 15.9% (IQR, 7.9%-23.0%). The majority of weight loss was evident 1 year after surgery for both procedures. Five distinct weight change trajectory groups were identified for each procedure. Among participants who had diabetes at baseline, 216 RYGB participants (67.5%) and 28 LAGB participants (28.6%) experienced partial remission at 3 years. The incidence of diabetes was 0.9% after RYGB and 3.2% after LAGB. Dyslipidemia resolved in 237 RYGB participants (61.9%) and 39 LAGB participants (27.1%); remission of hypertension occurred in 269 RYGB participants (38.2%) and 43 LAGB participants (17.4%). CONCLUSIONS AND RELEVANCE: Among participants with severe obesity, there was substantial weight loss 3 years after bariatric surgery, with the majority experiencing maximum weight change during the first year. However, there was variability in the amount and trajectories of weight loss and in diabetes, blood pressure, and lipid outcomes. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00465829.

The effect of obesity in adolescence on adult health status.

OBJECTIVE: To test the hypothesis that adolescent obesity would be associated with greater risks of adverse health in severely obese adults. METHODS: Before weight loss surgery, adult participants in the Longitudinal Assessment of Bariatric Surgery-2 underwent detailed anthropometric and comorbidity assessment. Weight status at age 18 was retrospectively determined. Participants who were ≥80% certain of recalled height and weight at age 18 (1502 of 2308) were included. Log binomial regression was used to evaluate whether weight status at age 18 was independently associated with risk of comorbid conditions at time of surgery controlling for potential confounders. RESULTS: Median age and adult body mass index (BMI) were 47 years and 46, respectively. At age 18, 42% of subjects were healthy weight, 29% overweight, 16% class 1 obese, and 13% class ≥2 obese. Compared with healthy weight at age 18, class ≥2 obesity at age 18 independently increased the risk of lower-extremity venous edema with skin manifestations by 435% (P < .0001), severe walking limitation by 321% (P < .0001), abnormal kidney function by 302% (P < .0001), polycystic ovary syndrome by 74% (P = .03), asthma by 48% (P = .01), diabetes by 42% (P < .01), obstructive sleep apnea by 25% (P < .01), and hypertension (by varying degrees based on age and gender). Conversely, the associated risk of hyperlipidemia was reduced by 61% (P < .01). CONCLUSIONS: Severe obesity at age 18 was independently associated with increased risk of several comorbid conditions in adults undergoing bariatric surgery.

A comparison of the Slaughter skinfold-thickness equations and BMI in predicting body fatness and cardiovascular disease risk factor levels in children.

BACKGROUND: Although estimation of percentage body fat with the Slaughter skinfold-thickness equations (PBF(Slaughter)) is widely used, the accuracy of this method has not been well studied. OBJECTIVE: The objective was to determine the accuracy of the Slaughter skinfold-thickness equations. DESIGN: We compared agreement between PBF(Slaughter) and estimations derived from dual-energy X-ray absorptiometry (PBF(DXA)) in 1169 children in the Pediatric Rosetta Body Composition Project and the relation to cardiovascular disease risk factors, as compared with body mass index (BMI), in 6725 children in the Bogalusa Heart Study. RESULTS: PBF(Slaughter) was highly correlated (r = 0.90) with PBF(DXA), but it markedly overestimated levels of PBF(DXA) in children with large skinfold thicknesses. In the 65 boys with a sum of skinfold thicknesses (subscapular- plus triceps-skinfold thicknesses) ≥ 50 mm, PBF(Slaughter) overestimated PBF(DXA) by 12 percentage points. The comparable overestimation in girls with a high skinfold sum was 6 percentage points. We also found that, after adjustment for sex and age, BMI showed slightly stronger associations with lipid, lipoprotein, insulin, and blood pressure values than did PBF(Slaughter). CONCLUSIONS: These results indicate that PBF(Slaughter), which was developed among a group of much thinner children and adolescents, is fairly accurate among nonobese children, but markedly overestimates the body fatness of children who have thick skinfold thicknesses. Furthermore, PBF(Slaughter) has no advantage over sex- and age-adjusted BMIs at identifying children who are at increased risk of cardiovascular disease based on lipid, lipoprotein, insulin, and blood pressure values.

Reporting weight change: standardized reporting accounting for baseline weight.

BACKGROUND: Although it is recognized that a standardized approach to reporting weight change is essential to meaningful comparisons among cohorts and across studies, consensus is lacking. This study aimed to propose a method of reporting weight change that would allow meaningful comparisons among studies of patients who underwent bariatric surgery and to demonstrate its utility using an example from the Longitudinal Assessment of Bariatric Surgery (LABS). METHODS: Relationships among several measures of weight change are described. Results from an observational, longitudinal cohort study of adults undergoing bariatric surgery and from simulation studies are used to illustrate the proposed method. RESULTS: Baseline weight is a critical parameter when assessing weight change. Men undergoing a bariatric procedure other than gastric bypass or adjustable band tended to have greater weight loss 12 months after surgery than men undergoing gastric bypass when not accounting for baseline weight, but the opposite was found when results were adjusted for baseline weight. Simulation results show that with relatively modest sample sizes, the adjusted weight loss was significantly different between the 2 groups of men. CONCLUSION: A consistent metric for reporting weight loss after bariatric surgery is essential to interpret outcomes across studies and among subgroups. The baseline weight adjusted percent of weight loss (A%WL) uses a standard population (e.g., the LABS cohort) to account for differences between cohorts with respect to baseline weight, and its use can change the interpretation of results compared with an unadjusted measure.

Effect of supplementation with cholecalciferol and calcium on 2-y bone mass accrual in HIV-infected children and adolescents: a randomized clinical trial.

BACKGROUND: Skeletal abnormalities have been reported in HIV-infected children and adolescents. Although the etiology is not well understood, vitamin D deficiency may be involved. OBJECTIVE: The study objective was to evaluate the effect of vitamin D and calcium supplementation on bone mass accrual in HIV-infected youth. DESIGN: Perinatally HIV-infected children were randomly assigned to receive vitamin D (100,000 IU cholecalciferol given every 2 mo) and calcium (1 g/d) (supplemented group) or double placebo (placebo group) for 2 y. The total-body bone mineral content (TBBMC), total-body bone mineral density (TBBMD), spine bone mineral content (SBMC), and spine bone mineral density (SBMD) were assessed by using dual-energy X-ray absorptiometry at baseline and at 2 annual follow-up visits. RESULTS: Fifty-nine participants, aged 6-16 y, were randomly assigned to either the supplemented (n = 30) or the placebo (n = 29) group. At enrollment, supplemented and placebo groups did not differ with respect to age, sex, dietary intakes of vitamin D and calcium, mean baseline serum 25-hydroxyvitamin D [25(OH)D] concentration, TBBMC, TBBMD, SBMC, or SBMD. Significant increases in serum 25(OH)D were observed in the supplemented group but not in the placebo group. TBBMC, TBBMD, SBMC, and SBMD increased significantly at 1 and 2 y in both groups. No between-group differences were observed at any time before or after adjustment for stage of sexual maturation by mixed linear model analysis. CONCLUSION: One gram of calcium per day and oral cholecalciferol at a dosage of 100,000 IU every 2 mo administered to HIV-infected children and adolescents did not affect bone mass accrual despite significant increases in serum 25(OH)D concentrations. This trial was registered at clinicaltrials.gov as NCT00724178.

Classification of body fatness by body mass index-for-age categories among children.

OBJECTIVE: To examine the ability of various body mass index (BMI)-for-age categories, including the Centers for Disease Control and Prevention's 85th to 94th percentiles, to correctly classify the body fatness of children and adolescents. DESIGN: Cross-sectional. SETTING: The New York Obesity Research Center at St Luke's-Roosevelt Hospital from 1995 to 2000. PARTICIPANTS: Healthy 5- to 18-year-old children and adolescents (N = 1196) were recruited in the New York City area through newspaper notices, announcements at schools and activity centers, and word of mouth. MAIN OUTCOME MEASURES: Percent body fat as determined by dual-energy x-ray absorptiometry. Body fatness cutoffs were chosen so that the number of children in each category (normal, moderate, and elevated fatness) would equal the number of children in the corresponding BMI-for-age category (<85th percentile, 85th-94th percentile, and > or =95th percentile, respectively). RESULTS: About 77% of the children who had a BMI for age at or above the 95th percentile had an elevated body fatness, but levels of body fatness among children who had a BMI for age between the 85th and 94th percentiles (n = 200) were more variable; about one-half of these children had a moderate level of body fatness, but 30% had a normal body fatness and 20% had an elevated body fatness. The prevalence of normal levels of body fatness among these 200 children was highest among black children (50%) and among those within the 85th to 89th percentiles of BMI for age (40%). CONCLUSION: Body mass index is an appropriate screening test to identify children who should have further evaluation and follow-up, but it is not diagnostic of level of adiposity.

Longitudinal changes in regional fat content in HIV-infected children and adolescents.

BACKGROUND: Alterations in regional fat are often reported in HIV infection. Prior studies have not distinguished between normal changes in regional fat related to sexual maturation and those due to HIV. The study aim was to compare changes in regional fat distribution in HIV-infected (HIV+) and healthy (HIV-) children and adolescents living in the United States. METHODS: Serial dual energy X-ray absorptiometry was performed at baseline and two annual follow-up visits in 64 HIV+ and 147 HIV--participants aged 6-16 years. Total, leg, arm, and trunk fat masses (kg) and regional fat distribution as the percentage of total body fat (%) were compared. RESULTS: HIV+ and HIV--participants did not differ in total fat mass, but the HIV+ group had significantly lower leg and greater arm fat and trunk fat percentage at all time points. Over time, decreases in leg fat percentage and increases in arm fat percentage were more marked among the HIV+ group. Differences between HIV+ and HIV--groups in arm and leg fat percentage remained significant when age, sex, race, height, and pubertal stage were accounted for by mixed effect modeling. Apart from prior treatment with stavudine, no differences in fat distribution were observed according to treatment or degree of immunodeficiency or viremia. CONCLUSION: Although no single pattern of change in regional fat distribution was uniquely associated with HIV, perinatally HIV-infected youth manifest significantly decreased leg fat and increased arm and trunk fat. These differences increase over time and may contribute to cardiovascular disease risk.

Body composition in premature adrenarche by structural MRI, 1H MRS and DXA.

BACKGROUND: Premature adrenarche (PA) is recognized to be a possible precursor of polycystic ovarian syndrome, type 2 diabetes mellitus and cardiovascular disease. Visceral adiposity and increased intramyocellular lipid (IMCL) are associated with insulin resistance and increased risk of cardiovascular disease. AIM: To determine whether prepubertal girls with PA have altered visceral adiposity and/or increased muscle lipid content compared to prepubertal girls without PA using proton magnetic resonance imaging (MRI) and spectroscopy (1H MRS). PATIENTS AND METHODS: We performed total body dual energy X-ray absorptiometry (DXA) scans, MRI of the trunk, and MRS of the tibialis anterior muscle in the right calf on six girls with PA and eight prepubertal controls. RESULTS: Amount of visceral adipose tissue (VAT), abdominal subcutaneous adipose tissue (SAT), and VAT to SAT ratio did not differ significantly between the PA and control girls. Those with PA, however, had significantly greater IMCL than controls (p = 0.004). CONCLUSIONS: This study adds further evidence that PA is not a benign condition, and future studies investigating early intervention with dietary and exercise counseling may help diminish potential risk for diabetes mellitus and/or cardiovascular disease.

Effect of bimonthly supplementation with oral cholecalciferol on serum 25-hydroxyvitamin D concentrations in HIV-infected children and adolescents.

OBJECTIVE: Vitamin D insufficiency occurs commonly in HIV-infected youth in the United States. In light of the importance of vitamin D for skeletal and nonskeletal health, including innate immunity, developing methods for improving vitamin D status in HIV-infected children and adolescents is an important area of clinical research. The objective of this study was to evaluate the effect of administration of oral cholecalciferol, 100,000 IU every 2 months, and 1 g/day calcium on serum 25-hydroxyvitamin D concentrations, serum and urine calcium, and HIV disease progression during a 12-month period. METHODS: HIV-infected children and adolescents who were aged 6 to 16 years were randomly assigned to receive vitamin D (100,000 IU bimonthly) and calcium (1 g/day; n = 29) or double placebo (n = 27). Serum 25-hydroxyvitamin D concentrations as measured by radioimmunoassay, albumin-corrected calcium concentrations, and spot urinary calcium-creatinine ratios were determined monthly. RESULTS: No abnormalities in serum calcium concentration were observed. One participant who received placebo developed hypercalciuria. No group differences were seen in the change in CD4 count or CD4% or viral load during 12 months. The overall mean monthly serum 25-hydroxyvitamin D concentrations were higher in the group that received vitamin D and calcium than in the placebo group, as was the monthly serum 25-hydroxyvitamin D area under the curve. After completing 12 months of study, 2 (6.7%) participants in the group that received vitamin D and calcium had a trough serum 25-hydroxyvitamin D concentration <20 ng/mL compared with 14 (50%) in the placebo group. Twelve (44.4%) in the group that received vitamin D and calcium had a trough serum 25-hydroxyvitamin D concentration of > or =30 ng/mL compared with 3 (11.1%) in the placebo group. CONCLUSIONS: Administration of oral cholecalciferol to HIV-infected children and adolescents at a dosage of 100,000 IU every 2 months, together with 1 g/day calcium, is safe and results in significant increases in serum 25-hydroxyvitamin D concentrations.