SummaryPurposeSpexin, a novel peptide, has potential implications in obesity, satiety and energy homeostasis. The current study examined the relationship of spexin with various biomarkers of cardiovascular disease and endothelial function in adolescents with obesity.MethodsNineteen adolescents with obesity (age, 15.8 ± 1.7 years) were studied. Spexin, leptin and various cardiovascular disease biomarkers were measured. Endothelial function was assessed by high‐resolution Doppler ultrasonography of the right brachial artery.ResultsSpexin concentration (median [interquartile range] 0.38 ng/mL [0.29–0.59 ng/mL]) was inversely correlated (r = −0.50, P = 0.03) with leptin. When participants were clustered into two groups (‘high spexin and low leptin’ vs. ‘low spexin and high leptin’), the odds of having ‘low spexin and high leptin’ in participants with higher hs‐CRP (≥ 3 mg/L) were 12.25 times (95 per cent CI −1 to139, P = 0.026) higher than those of participants with lower hs‐CRP (<3 mg/L). Spexin levels, however, were not associated with measures of endothelial function.ConclusionsThe inverse association between spexin and leptin and the presence of higher concentrations of hs‐CRP in adolescents with obesity in the setting of ‘low spexin and high leptin’ suggest a potential role for spexin in the regulation of satiety and certain cardiovascular risk factors in children with obesity.
Can the source of hyperandrogenism in adolescents with polycystic ovary syndrome predict metabolic phenotype?
Purpose of review Despite the fact that polycystic ovary syndrome (PCOS) is a common disorder, much remains unknown or controversial regarding the cause, diagnosis, and management of this disorder, particularly in adolescents where normal pubertal events can overlap with the PCOS phenotype. Recent findings We put forth a critical assessment of recent literature on PCOS in adolescents, with particular focus on new information regarding the pathogenesis, diagnosis, associated morbidities, and management. Summary Although the evidence is increasing, there is still a critical need for large, prospective studies of adolescents with PCOS. Given the current level of evidence, a definitive diagnosis of PCOS is not necessary to effectively identify and treat manifestations of this syndrome in adolescents. Currently, ovarian imaging is not recommended in the diagnostic evaluation of PCOS in adolescents until high-quality data for defining polycystic ovarian morphology are available in this age group. Weight loss remains the safest and most effective treatment option for obese or overweight adolescents with PCOS. Clinicians should be mindful of the significant associated psychological morbidity and effectively screen and manage these conditions in adolescents with manifestations of PCOS.
Effect of vitamin D3 treatment on endothelial function in obese adolescents
SummaryBackgroundObesity in children is associated with vitamin D deficiency and endothelial dysfunction. It is not known if treatment with vitamin D improves endothelial function in obese adolescents.ObjectiveThis study aimed to determine whether treatment with vitamin D3 improves endothelial function in obese adolescents.MethodsNineteen obese adolescents, 13–18 years of age, with 25‐hydroxy vitamin D (25[OH]D) levels <75 nmol L−1 were treated with 100 000 IU vitamin D3 orally once a month for 3 months in an open‐label, single‐centre prospective trial. Endothelial function was assessed by flow‐mediated dilatation (FMD) of the brachial artery at study entry and 1 month after the third dose of vitamin D3. Biochemical parameters, including calcium, fasting lipids, glucose, insulin and high‐sensitivity C‐reactive protein, were also obtained.ResultsMean 25(OH)D levels increased from 55.9 ± 12.2 to 86.9 ± 16.7 nmol L−1 (P < 0.01). There was no correlation between 25(OH)D levels and brachial artery FMD. The brachial artery FMD (%) did not change significantly following vitamin D3 treatment (9.5 ± 3.53 vs. 10.3 ± 3.83, P = 0.83). Serum parathyroid hormone declined from 3.8 ± 1.5 to 3.1 ± 1 pmol L−1 (P = 0.01). The remainder of biochemical measurements did not show a significant change.ConclusionsTreatment with vitamin D3, 100 000 IU once a month for 3 months was effective in increasing 25(OH)D levels in obese adolescents but did not impact endothelial function.
Accuracy of thyroid nodule sonography for the detection of thyroid cancer in children: systematic review and meta‐analysis
SummaryIntroductionThyroid ultrasound (US) is a widely used tool for evaluating thyroid nodules. Various US features have been suggested as predictors of thyroid cancer in children.ObjectiveTo conduct a systematic review and meta‐analysis to assess the diagnostic accuracy of different thyroid US features in detecting thyroid cancer in children.MethodsWe searched multiple online databases for cohort studies that enrolled paediatric patients with thyroid nodules (age <21 years) and evaluated the accuracy of 12 relevant ultrasound features. Diagnostic measures were pooled across studies using a random effects model.ResultsThe search strategy yielded 1199 citations, of which 12 studies met the predefined inclusion criteria (750 nodules). The prevalence of thyroid cancer was 27·2% (40·8% in patients with a history of radiation exposure and 23·2% in patients without a history of exposure to radiation). The most common cancer was papillary thyroid cancer (86·7%). The presence of internal calcifications and enlarged cervical lymph nodes were the US features with the highest likelihood ratio [4·46 (95% CI: 1·87–10·64) and 4·96 (95% CI: 2·01–12·24), respectively] for thyroid cancer. A cystic nodule was the feature with highest likelihood ratio for benign nodules [1·96 (95% CI: 0·87–4·43)].ConclusionThyroid US features are not highly accurate predictors of benign or malignant aetiology of thyroid nodules in children. Internal calcification may predict malignancy, and cystic appearance may suggest benign aetiology.
Association Between Thyrotropin Levels and Insulin Sensitivity in Euthyroid Obese Adolescents
Background: Thyrotropin (TSH) levels display a positive association with body mass index (BMI), and the prevalence of isolated hyperthyrotropinemia is higher in obese adolescents compared to their normal weight controls. However, the metabolic significance of the higher TSH in obese adolescents is less clear. The objective of this study was to determine the relationship between TSH concentrations and insulin sensitivity, lipids, and adipokines in euthyroid, non-diabetic, obese adolescents. Methods: Thirty-six euthyroid, non-diabetic, obese adolescents between the ages of 12 and 18 years underwent a 75 g oral glucose tolerance test. Insulin sensitivity (S i ) and pancreatic β-cell function as assessed by disposition index (DI) were measured using the oral glucose minimal model approach. Cholesterol (total, low-density lipoprotein [LDL-C], and high-density lipoprotein [HDL-C]), triglycerides (TG), interleukin-6 (IL-6), total and high molecular weight (HMW) adiponectin, and retinol binding protein-4 (RBP4) were also determined. Associations between measures of thyroid function and S i , DI, lipids, and adipokines were computed using Pearson's correlation coefficient and multiple regression analysis. Results: The mean age of the subjects was 14.3±1.88 years, and the mean BMI was 32.5±4.65 kg/m 2 ; 97% were non-Hispanic white and 47% were male. The mean TSH was 2.7±1.2 mIU/L. Increasing serum TSH was correlated with decreasing S i (log S i ) in the entire cohort ( p =0.03), but this relationship persisted only in males ( p =0.02). The correlation between TSH and S i in males remained significant after adjusting for BMI ( p =0.02). There was no correlation between TSH and pancreatic β-cell function as assessed by DI ( p =0.48). TSH correlated positively with LDL-C ( p =0.04) and IL-6 ( p =0.03), but these associations vanished or weakened after adjusting for BMI (LDL-C p- value=0.44; IL-6 p- value=0.07). Conclusions: This study suggests a sex-specific association between TSH and insulin sensitivity in euthyroid, non-diabetic, obese adolescent males. Prospective studies are warranted to explore further this sexual dimorphism in the relationship between thyroid function and insulin sensitivity and to determine if obese adolescents with insulin resistance receiving thyroid supplements for hypothyroidism would benefit from targeting TSH levels in the lower half of normal range.
Diagnostic performance of body mass index to identify obesity as defined by body adiposity in children and adolescents: a systematic review and meta‐analysis
SummaryBackgroundThe ideal means of identifying obesity in children and adolescents has not been determined although body mass index (BMI) is the most widely used screening tool.ObjectiveWe performed a systematic review and meta‐analysis of studies assessing the diagnostic performance of BMI to detect adiposity in children up to 18 years.MethodsData sources were EMBASE, MEDLINE, Cochrane, Database of Systematic Reviews Cochrane CENTRAL, Web of Science and SCOPUS up to March 2013. Studies providing measures of diagnostic performance of BMI and using body composition technique for body fat percentage measurement were included.ResultsThirty‐seven eligible studies that evaluated 53 521 patients, with mean age ranging from 4 to 18 years were included in the meta‐analysis. Commonly used BMI cut‐offs for obesity showed pooled sensitivity to detect high adiposity of 0.73 (confidence interval [CI] 0.67–0.79), specificity of 0.93 (CI 0.88–0.96) and diagnostic odds ratio of 36.93 (CI 20.75–65.71). Males had lower sensitivity. Moderate heterogeneity was observed (I2 = 48%) explained in meta‐regression by differences across studies in race, BMI cut‐off, BMI reference criteria (Center for Disease Control vs. International Obesity Task Force) and reference standard method assessing adiposity.ConclusionBMI has high specificity but low sensitivity to detect excess adiposity and fails to identify over a quarter of children with excess body fat percentage.
Temporal Trends in the Diagnosis and Management of Childhood Obesity/Overweight in Primary Care
Objective: To determine the temporal trends in diagnosis and management of pediatric overweight/obesity by primary care providers at a single medical center. Patients: Children 2 to 18 years old undergoing a general medical examination during 3 calendar years (2003, 2006, and 2009). The number of visits for general medical examination were 6390 in 2003, 6646 in 2006, and 7408 in 2009. Methods: We performed a retrospective review of the electronic medical records for weight related diagnostic and/or management terms and laboratory screening in children with body mass index at or greater than the 85th percentile (n = 1630 in 2003, 1495 in 2006, and 1730 in 2009). Results: There was a significant increase in the diagnosis of obesity among obese children seen in 2009 (53.3%) compared with 2006 (36%, P < .001) and 2003 (24.3%, P < .001). Weight-related counseling was documented in a higher proportion of obese children in 2009 (49.4%) compared with 2006 (34.8%) and 2003 (26.6%). There was a significant increase in counseling regarding screen time in 2009 compared with 2006. A significant increase in screening for nonalcoholic fatty liver disease was also noted (30.5% in 2009 vs 21.9% in 2006, P = .018). Conclusions: There has been steady improvement in the rates of obesity diagnosis and obesity-related counseling by primary care providers. However, continued efforts to increase awareness of these issues are needed as nearly half of obese children remained undiagnosed and recommended laboratory screening for obesity-related comorbidities was performed in only a third of obese children.