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.).

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.

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.

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.

Total body bone measurements: a cross-sectional study in children with acute lymphoblastic leukemia during and following completion of therapy.

BACKGROUND: Abnormalities in bone mineral density (BMD) occur in children treated for acute lymphoblastic leukemia (ALL). However, BMD estimates have been performed using varied instruments, reference data, and interpretations. This exploratory cross sectional study to evaluate bone mass in children with ALL, uses an algorithm that serially adjusts for variables known to affect pediatric bone measures by dual energy X-ray absorptiometry (DXA), based on models developed in 1,218 healthy children and adolescents. PROCEDURE: Anthropometry, DXA scans, and factors with possible influence on bone mass were evaluated in 21 ALL patients receiving chemotherapy and 20 in the follow-up phase. Main outcome was treatment group differences in Z-scores for total body bone mineral content (BMC), bone area (Area), and areal BMD (aBMD). RESULTS: Mean Z-scores for the entire study population for BMC, Area, and aBMD were significantly less than zero. Among possible contributing factors, only calcium intake was a significant co-variate. Comparison between treatment groups showed that least-square mean Z-scores for patients on-therapy for at least 12 months were significantly lower than those off therapy for at least 12 months (P: 0.0008-0.044), except for BMC at last step of the algorithm (adjusted for sex, age, ethnicity, height, weight, and bone area). CONCLUSIONS: Evaluation of total body DXA by this algorithm is consistent with better general bone status in those off-therapy. However, in this small exploratory study, the lack of significant difference between Z-scores for fully adjusted BMC in on- versus off-therapy groups suggests possible risk of low peak bone mass. Additional longitudinal evaluation is warranted.

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.

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.

School-based intervention acutely improves insulin sensitivity and decreases inflammatory markers and body fatness in junior high school students.

CONTEXT: Risk factors for type 2 diabetes mellitus (T2DM) include obesity, family history, dyslipidemia, a proinflammatory state, impaired insulin secretory capacity, and insulin resistance. OBJECTIVE: The aim of this study was to examine the effects of a 3- to 4-month school-based intervention consisting of health, nutrition, and exercise classes plus an aerobic exercise program on diabetes risk. DESIGN: This study was a randomized before/after controlled trial. METHODS: Seventy-three eighth-grade students in a predominantly Hispanic New York City public school were divided into a control group (studied twice without receiving the intervention) and an experimental group (studied before and after the intervention). OUTCOME MEASURES: We measured body fatness (bioelectrical impedance), insulin sensitivity, beta-cell function (insulin release in response to an iv glucose load corrected for insulin sensitivity), lipid profiles, and circulating concentrations of IL-6, C-reactive protein, adiponectin, and TNF-alpha. RESULTS: Participation in the intervention was associated with significant reductions in body fatness, insulin resistance, and circulating concentrations of C-reactive protein and IL-6, irrespective of somatotype on enrollment. CONCLUSION: Short-term school-based health, nutrition, and exercise intervention is beneficial to all students and affects multiple diabetes risk factors.

The bone mineral density in childhood study: bone mineral content and density according to age, sex, and race.

CONTEXT: Low bone mass may increase risk of fracture. Several chronic medical conditions, medications, and lifestyle factors affect bone mineral accrual. Appropriate reference values are essential for identification of children with bone deficits. OBJECTIVE: Our objective was to establish reference curves for bone mineral content (BMC) and density (BMD) in children. DESIGN AND SETTING: The Bone Mineral Density in Childhood Study is an ongoing longitudinal study in which measurements are obtained annually at five clinical centers in the United States. PARTICIPANTS: Participants included 1554 healthy children (761 male, 793 female), ages 6-16 yr, of all ethnicities. MAIN OUTCOME MEASURES: Scans of the whole body, lumbar spine, hip, and forearm were obtained using dual-energy x-ray absorptiometry. Percentile curves based on three annual measurements were generated using the LMS statistical procedure. RESULTS: BMC of the whole body and lumbar spine and BMD of the whole body, lumbar spine, total hip, femoral neck, and forearm are given for specific percentiles by sex, age, and race (Black vs. non-Black). BMC and BMD were higher for Blacks at all skeletal sites (P < 0.0001). BMC and BMD increased with age, and a plateau was not evident by age 16 (girls) or age 17 (boys). The variation in BMC and BMD also increased with age. CONCLUSIONS: Age-, race-, and sex-specific reference curves can be used to help identify children with bone deficits and for monitoring changes in bone in response to chronic diseases or therapies.

Trends in childhood obesity research: a brief analysis of NIH-supported efforts.

Childhood obesity is an increasing health threat. The National Institutes of Health (NIH) is the primary funding agency for research into the causes, mechanisms, consequences, and prevention and treatment of childhood obesity. Using the NIH Strategic Plan for Obesity Research as the framework, this article summarizes the research that has been funded in the past five years as well as new research areas with great potential.

Validation of a 3-dimensional photonic scanner for the measurement of body volumes, dimensions, and percentage body fat.

BACKGROUND: The 3-dimensional photonic scan (3DPS) technique has been used during the past decade in the fashion industry and for epidemiologic surveys to estimate human body sizes. OBJECTIVE: The objective of the study was to validate the accuracy of a recently developed 3DPS (C9036-02; Hamamatsu Photonics KK, Hamamatsu, Japan) for the measurement of body volume, circumferences, lengths, and percentage body fat with the use of underwater weighing (UWW) and tape measures as criterion methods. DESIGN: Ninety-two subjects (44 females and 48 males) aged 6-83 y and weighing 23-182 kg (52-400 lbs) participated in the study. The subjects were measured while they wore minimal clothing and a head cap. Similar measurements were performed on a mannequin with and without clothing RESULTS: All subjects were measured with 3DPS and a tape measure; 63 subjects underwent UWW and residual lung volume measurements. The values obtained with 3DPS were slightly but significantly greater than those obtained with UWW for body volume (81.9 +/- 4.0 L compared with 81.5 +/- 4.0 L, P < 0.0001) and those obtained with a tape measure for circumferences (P < 0.001), but the values for percentage body fat were not significantly different between 3DPS and UWW (P = 0.648). The values obtained with 3DPS were significantly greater than those obtained by UWW and a tape measure for the clothed mannequin, but the values were not uniformly significantly different for the mannequin without clothing. CONCLUSIONS: The 3DPS measures body volume, circumferences, and length rapidly and accurately. However, to generate an accurate total-body volume measurement with 3DPS to estimate percentage body fat, the subjects must wear close-fitting minimal clothing and be able to stand motionless for 10 s (normal scan mode) while holding their breath, which is done immediately after a maximum expiration.

Trunk fat and blood pressure in children through puberty.

BACKGROUND: Fat distribution is well recognized as a cardiovascular risk factor in adults. The association between android fat distribution and cardiovascular risk factors, such as blood pressure (BP), was previously reported in an African-American and Caucasian pediatric population. The aim of the present study was to investigate the relationship between BP and body fat distribution in a large cross-sectional pediatric sample. The effects of race, sex, and puberty on this relationship were assessed. METHODS AND RESULTS: BP was measured in 920 healthy children and adolescents (African-American, Asian, and Caucasian, ages 5 to 18 years). Fat distribution was determined by skinfold thickness and dual-energy X-ray absorptiometry (DXA). Pubertal status was assessed by the criteria of Tanner. Regression analysis was used to explore the association between BP and fat distribution. Significant positive relationships between systolic and diastolic BP and trunk fat adjusted for total fat were seen in boys at all pubertal stages in all 3 races by both DXA and skinfold measurements. In girls, trunk fat was not a significant predictor of BP. CONCLUSIONS: Our results demonstrate a sex difference in the relationship between BP and trunk fat in that a significant positive relationship was present in boys only. These findings, based on 2 independent measures of fat distribution, may help identify the specific features of individuals at risk, allow earlier intervention, and suggest sex-specific determinants for BP.

QDR 4500A dual-energy X-ray absorptiometer underestimates fat mass in comparison with criterion methods in adults.

BACKGROUND: Dual-energy X-ray absorptiometry (DXA) has become one of the most frequently used methods for estimating human body composition. Although the DXA technique has been validated for the measurement of fat-free mass and fat mass, differences in calibration between instruments produced by different manufacturers, as well as between different models produced by the same manufacturer, have been reported. OBJECTIVE: The objective was to compare the calibration of the QDR 4500A against criterion methods in a large heterogeneous population. DESIGN: DXA-derived body-composition data were obtained from 7 studies: 6 data sets were provided by the investigators, one of which was published. The data included fat mass and fat-free mass measured with a QDR 4500A and criteria measurements of body composition from total body water by dilution at 4 centers, densitometry from 1 center, and four-compartment analysis at 2 centers. RESULTS: In the cohort of 1195 subjects, 602 men and 593 women aged 19-82 y with a body mass index (in kg/m2) of 16-44, the fan-beam DXA overestimated fat-free mass (P < 0.05). A significant difference was observed in all 7 data sets, and the mean (+/-SE) was 5 +/- 1%. CONCLUSIONS: It is recommended that the lean soft tissue mass estimate with the fan-beam QDR 4500A be reduced by 5% and that for fat mass be increased by that same mass. This finding is particularly important because the National Health and Nutrition Examination Survey is using the QDR 4500A to assess body composition in a nationally representative sample of persons in the United States.

Reproducibility of pediatric whole body bone and body composition measures by dual-energy X-ray absorptiometry using the GE Lunar Prodigy.

The use of dual-energy X-ray absorptiometry (DXA) in pediatrics is increasing. It is safe, readily available, and easily performed, but there is little information on reproducibility. The aim of this study is to evaluate the reproducibility of whole body DXA scans in children. Total and regional bone mineral density, bone mineral content, nonbone, lean fat mass, and percent fat were measured twice by whole body DXA (GE Lunar Prodigy) in 49 subjects (5 to 17 yr). Within each subject, between subjects, and reading standard deviations for each body component were evaluated as well as intraclass correlations (IC) and coefficients of variation (CV). Total body measurements had better IC and CV than regional results from the whole body scan, with legs and arms better than trunk and spine. IC values were >or=0.989 for total body, >or=0.976 for legs and arms, and >or=0.875 for trunk and spine. CV values ranged 0.18 to 1.97% for total body, and 0.96 to 6.91% for regional measures. These values confirm that body composition and bone mass by DXA are highly reproducible among pediatric subjects. The results of this study can be used by clinicians and researchers for interpretation of longitudinal observations and for power calculations.

Four commonly used dual-energy X-ray absorptiometry scanners do not identically classify subjects for osteopenia or osteoporosis by T-score in four bone regions BIz11.5.

We investigated whether four commonly used dual-energy X-ray absorptiometry (DXA) scanners (DPX, DPX-L,and Prodigy by GE Lunar, and Delphi-A by Hologic) could classify identical subjects as osteopenic or osteoporotic using the T-score for bone mineral density in four regions of interest: PA spine (L1-L4), femur (total), forearm (total),and 33% radius in 77 adults (38 females) free of treatment for bone metabolic disease (age range 20-81 yr). There were no significant differences between T-score means for posterior-anterior spine by DPX, DPX-L, and Prodigy, but they were higher than the mean T-score by Delphi-A (p < 0.05). Prodigy gave the lowest and DPX and Delphi-A gave the highest T-score for 33% radius (p < 0.05). No subject was classified as osteoporotic in the femur region by the four scanners, although other classifications varied by region and scanner. No two scanners classified subjects identically for osteopenia in any of the four regions. These results indicate that classification of bone density in individual subjects using T-scores varies by different DXA scanners, even the scanners were made by the same manufacturer.

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.

Sex and race differences in fat distribution among Asian, African-American, and Caucasian prepubertal children.

Sexual dimorphism in fat distribution is thought to emerge during puberty. Truncal or android body fat distribution is characteristic of adult males but is also recognized as a human cardiovascular risk factor. Race differences in truncal fat are clearly evident in adults and have been described in prepubertal children but not between Asians and other race groups. The aim of this study in African-American, Asian, and Caucasian prepubertal children was to evaluate sex differences and race differences in body fat distribution. Analysis of covariance was used to explore fat distribution in 358 prepubertal children (176 girls and 182 boys; 143 Asians, 95 African-Americans, and 120 Caucasians), measured by skinfold thickness and dual-energy x-ray absorptiometry (DXA) in a cross-sectional study. Extremity and gynoid fat masses were evaluated after adjustment for trunk or android fat, respectively, and for covariates including age, weight, height, and interactions. In Asian children, sex differences were present in models for gynoid fat by DXA only (P < 0.001), with girls having greater gynoid fat than boys. In African-American and Caucasian children, sex differences were present in models for extremity and gynoid fat masses, measured by both methods. Among girls, Asians had generally lower adjusted extremity and gynoid fat than Caucasians and African-Americans. Among boys, Asians had lower adjusted extremity fat by DXA than Caucasians (P < 0.01) but greater gynoid fat by skinfolds than African-Americans (P < 0.01). This study of prepubertal children demonstrates that: 1) sex differences in body fat distribution are present in prepubertal children but that the specific characteristics for Asians differ from African-Americans and Caucasians, and 2) differences in body fat distribution in Asian children, compared with African-Americans and Caucasians, are present but vary by sex. This comparison of African-American, Asian, and Caucasian prepubertal children suggests phenotypic differences. Additional studies are needed to explore the metabolic and health risk implications of these findings.

beta-Cell function and insulin sensitivity in early adolescence: association with body fatness and family history of type 2 diabetes mellitus.

The prevalence of type 2 diabetes mellitus (T2DM) among adolescents has increased 5- to 10-fold over the past decade. T2DM results from pancreatic beta-cell dysfunction and insulin resistance. Using rapid iv glucose tolerance testing, we examined beta-cell function and insulin resistance in 72 predominantly Latino eighth grade students (41 males and 31 females; mean +/- sem age, 13.6 +/- 0.1 yr). Thirty-six percent of the children had body mass indexes above the 85th percentile for age and gender, and 50% had a first- or second-degree relative with T2DM. Overweight children were five times more likely to be in the highest quartile for insulin resistance. Children with a family history of T2DM were five times more likely to be in the lowest quartile for insulin secretory capacity, 4.5 times more likely to be in the lowest quartile for glucose disposal, and three times more likely to be in the lowest quartile for insulin resistance. These findings are consistent with a model for the physiology of T2DM in which a familial beta-cell dysfunction is unmasked by increasing insulin resistance secondary to overweight in this predominantly Latino population.