Cross-Sectional and Longitudinal Examination of Insulin Sensitivity and Secretion across Puberty among Non-Hispanic Black and White Children

BACKGROUND

Few studies using criterion measures of insulin sensitivity (SI) and insulin secretory capacity (ISC) have been conducted across puberty to adulthood. We examined how SI and ISC change from pre-puberty through adulthood.

METHODS

Hyperglycemic clamp studies were performed in a convenience sample of non-Hispanic Black (NHB) and White children evaluated at age 6 to 12 years and at approximately 5-year intervals into adulthood (maximum age 27 years). SI and ISC (first-phase and steady-state insulin secretion) were determined cross-sectionally in 133 unique participants across puberty and in adulthood. Additionally, longitudinal changes in SI and ISC were compared at two timepoints among three groups defined by changes in pubertal development: pre-pubertal at baseline and late-pubertal at follow-up (n=27), early-pubertal at baseline and late-pubertal at follow-up (n=27), and late-pubertal at baseline and adult at follow-up (n=24).

RESULTS

Cross-sectionally, SI was highest in pre-puberty and early puberty and lowest in mid-puberty (analysis of covariance [ANCOVA] P=0.001). Longitudinally, SI decreased from pre-puberty to late puberty (P<0.001), then increased somewhat from late puberty to adulthood. Cross-sectionally, first-phase and steady-state ISC increased during puberty and decreased in adulthood (ANCOVA P<0.02). Longitudinally, steady-state and first-phase ISC increased from pre-puberty to late puberty (P<0.007), and steady-state ISC decreased from late puberty to adulthood. The NHB group had lower SI (P=0.003) and greater first-phase and steady-state ISC (P≤0.001), independent of pubertal development.

CONCLUSION

This study confirms that SI decreases and ISC increases transiently during puberty and shows that these changes largely resolve in adulthood.

Weight-based teasing is associated with gain in BMI and fat mass among children and adolescents at-risk for obesity: A longitudinal study

BACKGROUND

Youths with overweight and obesity report frequent instances of weight-based teasing. However, little is known about the prospective associations between weight-based teasing and changes in body composition among youth.

OBJECTIVE

To assess associations between weight-based teasing and changes in body mass index (BMI) and fat mass in a longitudinal study of youths with, or at-risk for, overweight and obesity.

METHODS

One hundred ten youths with, or at-risk for, overweight participated in a longitudinal observational study. The Perception of Teasing Scale was administered at baseline. Height, weight, and body composition were obtained at baseline and at follow-ups (range: 1-15 years).

RESULTS

Mean age at baseline was 11.8 years; 53% had overweight/obesity; 36% were non-Hispanic Black; 55% were female; mean follow-up from baseline: 8.5 years. Adjusting for covariates and repeated measures of BMI or fat mass, linear mixed models revealed that weight-based teasing was associated with greater gain of BMI and fat mass across the follow-up period (ps ≤ .007). Adjusting for covariates, youths reporting high weight-based teasing (two standard deviations above the mean) experienced a 33% greater gain in BMI (an additional 0.20 kg/m² ) and a 91% greater gain in fat mass (an additional 0.65 kg) per year compared with peers who reported no weight-based teasing.

CONCLUSIONS

Among youths with, and at-risk for, overweight and obesity, weight-based teasing was associated with greater weight and fat gain.

Associations of the melanocortin 3 receptor C17A + G241A haplotype with body composition and inflammation in African-American adults

BACKGROUND

The MC3R haplotype C17A + G241A, which encodes a partially inactivated receptor, has high prevalence in individuals of predominately African ancestry. In pediatric cohorts, homozygosity for this common variant has been associated with obesity, reduced lean mass, and greater fasting insulin. However, metabolic and body composition measures have not been well studied in adults with this haplotype.

METHODS

A convenience sample of 237 healthy African-American adult volunteers was studied. TaqMan assays were used to genotype MC3R variants. Labs were drawn in the morning in the fasted state. Body composition data was obtained via dual-energy X-ray absorptiometry. An analysis of covariance was used to examine the associations of genotype with metabolic and body composition measures controlling for age and sex.

RESULTS

Individuals homozygous for the MC3R C17A + G241A haplotype had significantly greater body mass index, fat mass, fat mass percentage, and C-reactive protein, with reduced lean mass percentage as compared to heterozygous and wild-type participants (all ps < 0.05); fasting insulin was marginally nonsignificant between groups (p = 0.053). After adjusting for fat mass, laboratory differences no longer remained significant.

CONCLUSIONS

Homozygosity for MC3R C17A + G241A is associated with increased adiposity in African-American adults. Further studies are needed to elucidate the mechanisms behind these associations.

Evaluating the contribution of differences in lean mass compartments for resting energy expenditure in African American and Caucasian American children

BACKGROUND

Resting energy expenditure (REE), adjusted for total lean mass (LM), is lower in African American (AA) than Caucasian American (CA) children. Some adult studies suggest that AA-CA differences in lean mass compartments explain this REE difference. Similar data are limited in children.

OBJECTIVE

To evaluate differences in compartment-specific lean mass between AA and CA children and examine the individual contributions of high-metabolic rate-at-rest trunk lean mass (TrLM) and low-metabolic-rate-at-rest appendicular lean mass (AppLM) for AA-CA differences in REE.

METHODS

We studied a convenience sample of 594 AA (n = 281) and CA (n = 313) children. REE was measured by using indirect calorimetry; dual-energy X-ray absorptiometry was used to assess body composition. ANCOVAs were performed to examine AA-CA differences in TrLM, AppLM and REE. After accounting for age, sex, height, pubertal development, bone mass and adiposity, REE was evaluated adjusting for total LM (model A) and separately adjusting for TrLM and AppLM (model B).

RESULTS

African American children had greater adjusted AppLM (17.8 ± 0.2 [SE] vs. 16.0 ± 0.2 kg, p < 0.001) and lower TrLM (17.2 ± 0.2 vs. 17.7 ± 0.2 kg, p = 0.022) than CA children. REE adjusted for total LM was 77 ± 16 kcal/d lower in AA than CA (p < 0.001). However, after accounting separately for AppLM and TrLM, the discrepancy in REE between the groups declined to 28 ± 19 kcal/d (p = 0.14). In the adjusted model, both TrLM (p < 0.001) and AppLM (p < 0.027) were independently associated with REE.

CONCLUSION

In children, AA-CA differences in REE appear mostly attributable to differences in body composition. Lower REE in AA children is likely due to lower TrLM and greater AppLM.

A pilot study of the effects of niacin administration on free fatty acid and growth hormone concentrations in children with obesity

CONTEXT

Children with obesity have low spontaneous growth hormone (GH) secretion. High circulating free fatty acid (FFA) concentration is believed to inhibit GH secretion in those with obesity. In adults, lipolytic inhibition with niacin lowers FFA and increases GH, but there are no prior studies in children with obesity.

OBJECTIVE

The objective of the study was to determine the dose and frequency of niacin administration required to lower FFA and stimulate GH in children with obesity.

DESIGN

Dose-finding study of nondiabetic children ages 6-12 years with body mass index (BMI) ≥ 95th percentile given niacin 250 mg q2h × 3 doses (n = 2), 500 mg q2h × 3 doses (n = 5) or 500 mg q1h × 4 doses (n = 5).

PARTICIPANTS

Eight boys and four girls (age 9.7 ± 1.8 years; BMI 26.4 ± 3.1 kg m^-2 ; BMIz 2.2 ± .25) were studied.

MAIN OUTCOME

Percentage of serum FFA values that were below 0.2 mEq L^-1 . GH, insulin and glucose were also measured serially.

RESULTS

FFA decreased as the dose and frequency of niacin increased (p = .01). Niacin 500 mg q1h 4 doses suppressed FFA < 0.2 mEq L^-1 and significantly increased GH (p = .04). Adverse effects were flushing/warmth (100%), tingling (60%) and GI complaints (20-40%).

CONCLUSIONS

Niacin 500 mg q1h significantly lowered serum FFA and increased GH. These pilot data suggest that high FFA is an important suppressor of GH secretion in children with obesity.

A randomized, comparative pilot trial of family-based interpersonal psychotherapy for reducing psychosocial symptoms, disordered-eating, and excess weight gain in at-risk preadolescents with loss-of-control-eating

OBJECTIVE

Preadolescent loss-of-control-eating (LOC-eating) is a risk factor for excess weight gain and binge-eating-disorder. We evaluated feasibility and acceptability of a preventive family-based interpersonal psychotherapy (FB-IPT) program. FB-IPT was compared to family-based health education (FB-HE) to evaluate changes in children's psychosocial functioning, LOC-eating, and body mass.

METHOD

A randomized, controlled pilot trial was conducted with 29 children, 8 to 13 years who had overweight/obesity and LOC-eating. Youth-parent dyads were randomized to 12-week FB-IPT (n = 15) or FB-HE (n = 14) and evaluated at post-treatment, six-months, and one-year. Changes in child psychosocial functioning, LOC-eating, BMI, and adiposity by dual-energy-X-ray-absorptiometry were assessed. Missing follow-up data were multiply imputed.

RESULTS

FB-IPT feasibility and acceptability were indicated by good attendance (83%) and perceived benefits to social interactions and eating. Follow-up assessments were completed by 73% FB-IPT and 86% FB-HE at post-treatment, 60% and 64% at six-months, and 47% and 57% at one-year. At post-treatment, children in FB-IPT reported greater decreases in depression (95% CI -7.23, -2.01, Cohen's d = 1.23) and anxiety (95% CI -6.08, -0.70, Cohen's d = .79) and less odds of LOC-eating (95% CI -3.93, -0.03, Cohen's d = .38) than FB-HE. At six-months, children in FB-IPT had greater reductions in disordered-eating attitudes (95% CI -0.72, -0.05, Cohen's d = .66) and at one-year, tended to have greater decreases in depressive symptoms (95% CI -8.82, 0.44, Cohen's d = .69) than FB-HE. There was no difference in BMI gain between the groups.

DISCUSSION

Family-based approaches that address interpersonal and emotional underpinnings of LOC-eating in preadolescents with overweight/obesity show preliminary promise, particularly for reducing internalizing symptoms. Whether observed psychological benefits translate into sustained prevention of disordered-eating or excess weight gain requires further study.

Measurement invariance of the Eating Disorder Examination in black and white children and adolescents

OBJECTIVE

The Eating Disorder Examination (EDE) was originally developed and validated in primarily white female samples. Since data indicate that eating pathology impacts black youth, elucidating the psychometric appropriateness of the EDE for black youth is crucial.

METHODS

A convenience sample was assembled from seven pediatric obesity studies. The EDE was administered to all youth. Confirmatory factor analyses (CFA) were conducted to examine the original four-factor model fit and two alternative factor structures for black and white youth. With acceptable fit, multiple-group CFAs were conducted. For measurement invariant structures, the interactive effects of race with sex, BMIz, adiposity, and age were explored (all significance levels p < .05).

RESULTS

For both black and white youth (N = 820; 41% black; 37% male; 6-18 years; BMIz -3.11 to 3.40), the original four-factor EDE structure and alternative eight-item one-factor structure had mixed fit via CFA. However, a seven-item, three-factor structure reflecting Dietary Restraint, Shape/Weight Overvaluation, and Body Dissatisfaction had good fit and held at the level of strict invariance. Girls reported higher factor scores than boys. BMIz and adiposity were positively associated with each subscale. Age was associated with Dietary Restraint and Body Dissatisfaction. The interactional effects between sex, BMIz, and age with race were not significant; however, the interaction between adiposity and race was significant. At higher adiposity, white youth reported greater pathology than black youth.

CONCLUSION

An abbreviated seven-item, three-factor version of the EDE captures eating pathology equivalently across black and white youth. Full psychometric testing of the modified EDE factor structure in black youth is warranted.

Associations of adolescent emotional and loss of control eating with 1-year changes in disordered eating, weight, and adiposity

OBJECTIVE

Adolescent emotional-eating, referring to eating in response to negative affective states, is frequently reported by those with loss of control (LOC) eating. Although LOC eating has been shown to predict exacerbated disordered eating and excess weight/adiposity gain, the extent to which emotional-eating, either alone or in combination with LOC, predicts adverse outcomes has not been determined. Thus, we examined associations of baseline emotional-eating with changes in disordered eating, BMI, and adiposity over 1-year, and to what degree the presence or absence of baseline LOC moderated these associations.

METHODS

189 non-treatment-seeking youth (15.4 ± 1.4y; 66% female; 67% non-Hispanic White, 38% overweight [BMI ≥ 85th %ile]) completed the emotional-eating Scale for Children/Adolescents and the Eating Disorder Examination interview at baseline and again at 1-year. Air displacement plethysmography assessed adiposity at both time points.

RESULTS

Baseline emotional-eating alone was not significantly associated with the development of objective binge eating or changes in disordered eating attitudes, BMI or adiposity 1-year later. However, baseline emotional-eating interacted with the presence of baseline LOC in the prediction of 1-year outcomes. Among adolescents with LOC eating, greater baseline emotional-eating was related to increased disordered eating attitudes (p = .03), BMI (p = .04), and adiposity (p = .04) at 1-year, after correcting for false discovery rate.

DISCUSSION

Emotional-eating among youth also reporting LOC was associated with adverse outcomes over 1-year. Adolescents who report both behaviors may represent a subset of individuals at especially high risk for exacerbated disordered eating and excess weight gain. © 2016 Wiley Periodicals, Inc.(Int J Eat Disord 2017; 50:551-560).

Pediatric Loss of Control Eating and High-Sensitivity C-Reactive Protein Concentrations

BACKGROUND

Loss of control (LOC) eating in youth is associated with excess body weight and adiposity. After adjusting for fat mass, youth with LOC eating have higher blood pressure and higher low-density lipoprotein cholesterol compared to youth without LOC eating. Increased inflammation may account for this relationship, although few data have examined this hypothesis. Therefore, this study explored the association between LOC eating and high-sensitivity C-reactive protein (hsCRP), a marker of inflammation.

METHODS

We investigated hsCRP concentrations in relation to LOC eating in a convenience sample of 194 youth (age 14.3 ± 2.1 years; 63.9% female; BMI-z 1.64 ± 1.06). The presence of LOC eating in the past month was assessed by the Eating Disorder Examination interview. Serum hsCRP was measured by enzyme-linked immunosorbent assay. Adiposity was measured by air displacement plethysmography or dual-energy x-ray absorptiometry. We compared hsCRP in those with and without LOC eating in analyses accounting for sex, adiposity, height, depressive symptoms, and eating psychopathology.

RESULTS

Youth with LOC eating had significantly greater hsCRP than youth without LOC eating (p = 0.02), after accounting for all covariates. The number of LOC eating episodes in the past month was positively associated with hsCRP (p = 0.01). The relationship between LOC eating and hsCRP was not mediated by depressive symptoms or eating psychopathology (ps > 0.05).

CONCLUSIONS

Youth with disinhibited eating may manifest increased chronic inflammation. Those with LOC eating may be an important subgroup at risk for adverse health outcomes associated with both chronic inflammation and obesity. Future research should examine whether hsCRP concentrations mediate the relationship between LOC eating and its association with cardiometabolic risk.