Metabolic effects of an essential amino acid supplement in adolescents with PCOS and obesity.

OBJECTIVE: Polycystic ovary syndrome (PCOS) is characterized by hyperandrogenism, insulin resistance, and hepatic steatosis (HS). Because dietary essential amino acid (EAA) supplementation has been shown to decrease HS in various populations, this study's objective was to determine whether supplementation would decrease HS in PCOS. METHODS: A randomized, double-blind, crossover, placebo-controlled trial was conducted in 21 adolescents with PCOS (BMI 37.3 ± 6.5 kg/m2, age 15.6 ± 1.3 years). Liver fat, very low-density lipoprotein (VLDL) lipogenesis, and triacylglycerol (TG) metabolism were measured following each 28-day phase of placebo or EAA. RESULTS: Compared to placebo, EAA was associated with no difference in body weight (p = 0.673). Two markers of liver health improved: HS was lower (-0.8% absolute, -7.5% relative reduction, p = 0.013), as was plasma aspartate aminotransferase (AST) (-8%, p = 0.004). Plasma TG (-9%, p = 0.015) and VLDL-TG (-21%, p = 0.031) were reduced as well. VLDL-TG palmitate derived from lipogenesis was not different between the phases, nor was insulin sensitivity (p > 0.400 for both). Surprisingly, during the EAA phase, participants reported consuming fewer carbohydrates (p = 0.038) and total sugars (p = 0.046). CONCLUSIONS: Similar to studies in older adults, short-term EAA supplementation in adolescents resulted in significantly lower liver fat, AST, and plasma lipids and thus may prove to be an effective treatment in this population. Additional research is needed to elucidate the mechanisms for these effects.

Respecting tribal voices in the development of a gestational diabetes risk reduction preconception counseling program for American Indian/Alaska Native adolescent females: a qualitative study.

BACKGROUND: American Indians and Alaska Natives (AI/AN) are disproportionately affected by adolescent obesity, adolescent pregnancy and gestational diabetes mellitus (GDM). GDM is associated with increased risk for perinatal death, obesity, and subsequent type 2 diabetes (T2D) for the offspring. Moreover, mothers with GDM are also at increased risk for T2D post-partum. Yet few lifestyle interventions exist to reduce GDM risk prior to pregnancy. We describe the process of adapting an existing validated preconception counseling intervention for AI/AN adolescent girls at-risk for GDM and their mothers. Perspectives and recommendations were gathered from a diverse array of stakeholders to assure the new program called Stopping GDM was culturally responsive and developed with tribal voices and perspectives represented. METHODS: We conducted focus groups and individual interviews with multiple AI/AN stakeholders (n = 55). Focus groups and interviews were digitally recorded, transcribed verbatim, and analyzed using a thematic content approach to construct cross-cutting themes across the focus groups and interviews. RESULTS: Four key themes emerged reflecting issues important to planning a reproductive health intervention: 1) Limited awareness, knowledge, and health education resources about GDM; 2) The importance of acknowledging traditional AI/AN values and the diversity of traditions and culture among AI/AN tribes; 3) The need to cultivate healthy decision-making skills and empower girls to make safe and healthy choices; and 4) Lack of communication about reproductive health between AI/AN mothers and daughters and between AI/AN women and health care professionals. CONCLUSION: Findings have been used to inform the cultural tailoring and adaptation of an existing preconception counseling program, originally designed for non-AI/AN adolescent girls with diabetes, for AI/AN adolescents at-risk for GDM in future pregnancies.

Combined Oral Contraceptive Treatment Does Not Alter the Gut Microbiome but Affects Amino Acid Metabolism in Sera of Obese Girls With Polycystic Ovary Syndrome.

Background: The gut microbiome is altered in obese adolescents with polycystic ovary syndrome (PCOS), and is associated with free testosterone, metabolic markers, and insulin resistance. Combined oral contraceptives (OCP) are a primary treatment for PCOS and decrease testosterone, but the effect on the serum metabolome or gut microbiome in obese adolescents with PCOS is unknown. Objective: Contrast gut microbiome profiles, targeted serum metabolomics, hormone levels, and metabolic measures in adolescents with PCOS and obesity with and without OCP treatment. Methods: Adolescent girls with obesity and PCOS underwent stool and fasting blood collection and MRI for hepatic fat fraction. Fecal bacteria were profiled by high-throughput 16S rRNA gene sequencing and fasting serum metabolomics performed with high resolution mass spectrometry. Groups were contrasted using t-tests and principle least squares discrimination analysis (PLS-DA). Associations between bacterial taxa, baseline metabolic measures, hormone levels and the metabolome were conducted using Spearman analysis. Analyses were adjusted for false discovery rate. Results: 29 adolescents with obesity [Untreated N = 21, 16 ± 1.2 years, BMI%ile 36.5 ± 3.0; OCP N = 8, 15.5 ± 0.9 years, BMI%ile 32.5 ± 3.9] participated. Of the untreated adolescents, N = 14 contributed serum for metabolomic analysis. Participants on OCP therapy had lower free testosterone and free androgen index (p < 0.001) and higher sex hormone binding globulin. There was no difference in measures of fasting glucose, insulin, lipids or HOMA-IR between groups. PLS-DA of serum metabolomics showed discrimination between the groups, secondary amino acid changes. Untreated and OCP had similar stool microbiome α-diversity based on evenness (p = 0.28), richness (p = 0.39), and Shannon diversity (p = 0.24) and global microbial composition (ß-diversity, p = 0.56). There were no differences in % relative abundance at any level. Bacterial α-diversity was negatively associated with serum long chain fatty acids and branched chain amino acids. A higher %relative abundance of family Ruminococcaceae was significantly associated with serum bile acids and HOMA-IR. Conclusion: Despite hormone and serum amino acid differences, girls treated with OCP had similar metabolic and gut microbiome profiles compared to the untreated PCOS group. The association between bacterial α-diversity, Ruminococcaceae, clinical markers and long chain fatty acids suggests a potential role of the gut microbiome in the pathogenesis of the metabolic comorbidities in PCOS.

Pancreatic fat relates to fasting insulin and postprandial lipids but not polycystic ovary syndrome in adolescents with obesity.

OBJECTIVE: Adolescents with polycystic ovary syndrome (PCOS) and obesity can have insulin resistance, dysglycemia, and hepatic steatosis. Excess pancreatic fat may disturb insulin secretion and relate to hepatic fat. Associations between pancreatic fat fraction (PFF) and metabolic measures in PCOS were unknown. METHODS: This secondary analysis included 113 sedentary, nondiabetic adolescent girls (age = 15.4 [1.9] years), with or without PCOS and BMI ≥ 90th percentile. Participants underwent fasting labs, oral glucose tolerance tests, and magnetic resonance imaging for hepatic fat fraction (HFF) and PFF. Groups were categorized by PFF (above or below the median of 2.18%) and compared. RESULTS: Visceral fat and HFF were elevated in individuals with PCOS versus control individuals, but PFF was similar. PFF did not correlate with serum androgens. Higher and lower PFF groups had similar HFF, with no correlation between PFF and HFF, although hepatic steatosis was more common in those with higher PFF (≥5.0% HFF; 60% vs. 36%; p = 0.014). The higher PFF group had higher fasting insulin (p = 0.026), fasting insulin resistance (homeostatic model assessment of insulin resistance, p = 0.032; 1/fasting insulin, p = 0.028), free fatty acids (p = 0.034), and triglycerides (p = 0.004) compared with those with lower PFF. ß-Cell function and insulin sensitivity were similar between groups. CONCLUSIONS: Neither PCOS status nor androgens related to PFF. However, fasting insulin and postprandial lipids were worse with higher PFF.

Fasting plasma metabolomic profiles are altered by three days of standardized diet and restricted physical activity.

OBJECTIVE: Few studies have examined the effects of participants' diet and activity prior to sample collection on metabolomics profiles, and results have been conflicting. We compared the effects of overnight fasting with or without 3 days of standardized diet and restricted physical activity on the human blood metabolome, and examined the effects of these protocols on our ability to detect differences in metabolomics profiles in adolescent girls with obesity and polycystic ovary syndrome (PCOS) vs. sex and BMI-matched controls. METHODS: This was a cross-sectional study of 16 adolescent girls with obesity and PCOS and 5 sex and BMI-matched controls. Fasting plasma metabolomic profiles were measured twice in each participant: once without preceding restriction of physical activity or control of macronutrient content ("typical fasting visit"), and again after 12 h of monitored inpatient fasting with 3 days of standardized diet and avoidance of vigorous exercise ("controlled fasting visit"). Moderated paired t-tests with FDR correction for multiple testing and multilevel sparse partial least-squares discriminant analysis (sPLS-DA) were used to examine differences between the 2 visits and to compare the PCOS and control groups with the 2 visits combined and again after stratifying by visit. RESULTS: Twenty-three known metabolites were significantly different between the controlled fasting and typical fasting visits. Hypoxanthine and glycochenodeoxycholic acid had the largest increases in relative abundance at the controlled fasting visit compared to the typical fasting visit, while oleoyl-glycerol and oleamide had the largest increases in relative abundance at the typical fasting visit compared to the controlled fasting visit. sPLS-DA showed excellent discrimination between the 2 visits; however, when the samples from the 2 visits were combined, differences between the PCOS and control groups could not be detected. After stratifying by visit, discrimination of PCOS status was improved. CONCLUSIONS: There were differences in fasting metabolomic profiles following typical fasting vs monitored fasting with preceding restriction of physical activity and control of macronutrient content, and combining samples from the two visits obscured differences by PCOS status. In studies performing metabolomics analysis, careful attention should be paid to acute diet and activity history. Depending on the sample size of the study and the expected effect size of the outcomes of interest, control of diet and physical activity beyond typical outpatient fasting may not be required.

Racial and Ethnic Differences in Metabolic Disease in Adolescents With Obesity and Polycystic Ovary Syndrome.

CONTEXT: Polycystic ovary syndrome (PCOS) is common and associated with metabolic syndrome. In the general population, metabolic disease varies by race and ethnicity. OBJECTIVE: This work aimed to examine in depth the interaction of race and ethnicity with PCOS-related metabolic disease in adolescent youth. METHODS: A secondary analysis was conducted of data from girls (age 12-21 years) with overweight or obesity (> 90 body mass index [BMI] percentile) and PCOS. Measurements included fasting hormone and metabolic measures, a 2-hour oral glucose tolerance test (OGTT), and magnetic resonance imaging for hepatic fat. Groups were categorized by race or ethnicity. RESULTS: Participants included 39 non-Hispanic White (NHW, age 15.7 ±â€…0.2 years; BMI 97.7 ±â€…0.2 percentile), 50 Hispanic (HW, 15.2 ±â€…0.3 years; 97.9 ±â€…0.3 percentile), and 12 non-Hispanic Black (NHB, 16.0 ±â€…0.6 years; 98.6 ±â€…0.4 percentile) adolescents. Hepatic markers of insulin resistance were worse in NHW, including lower sex hormone-binding globulin and higher triglycerides over high-density lipoprotein cholesterol (TGs/HDL-C) ratio (P = .002 overall, HW vs NHB [P = .009] vs NHW [P = 0.020]), although homeostasis model assessment of estimated insulin resistance was worst in NHB (P = .010 overall, NHW vs NHB P = .014). Fasting and 2-hour OGTT glucose were not different between groups, although glycated hemoglobin A1c (HbA1c) was lowest in NHW (overall P < .001, NHW 5.2 ±â€…0.3 vs HW 5.5 ±â€…0.3 P < .001 vs 5.7 ±â€…0.4%, P < .001). The frequency of hepatic steatosis (HW 62%, NHW 42%, NHB 25%, P = .032); low HDL-C < 40 mg/dL (HW 82%, NHW 61%, NHB 50%, P < .001) and prediabetes HbA1c 5.7% to 6.4% (NHB 50%, HW 36%, NHW 5%, P < .001) were different between the groups. CONCLUSION: Adolescents with PCOS appear to show similar racial and ethnic variation to the general population in terms of metabolic disease components.

Oral minimal model-based estimates of insulin sensitivity in obese youth depend on oral glucose tolerance test protocol duration.

INTRODUCTION: The Oral Minimal Model (OMM), a differential-equations based mathematical model of glucose-insulin dynamics, utilizes data from a frequently sampled oral glucose tolerance test (OGTT) to quantify insulin sensitivity ( S I ). OMM-based estimates of S I can detect differences in insulin resistance (IR) across population groups and quantify effects of clinical or behavioral interventions. These estimates of S I have been validated in healthy adults using data from OGTTs with durations from 2 to 7 h. However, data demonstrating how protocol duration affects S I estimates in highly IR populations such as adolescents with obesity are limited. METHODS: A 6-h frequently sampled OGTT was performed in adolescent females with obesity. Two, 3-, and 4- hour implementations of OMM assuming an exponentially-decaying rate of glucose appearance beyond measured glucose concentrations were compared to the 6-h implementation. A 4- hour OMM implementation with truncated data (4h Tr) was also considered. RESULTS: Data from 68 participants were included (age 15.8 ± 1.2 years, BMI 35.4 ± 5.6 kg/m2). Although S I values were highly correlated for all implementations, they varied with protocol duration (2h: 2.86 ± 3.31, 3h: 2.55 ± 2.62, 4h: 2.81 ± 2.59, 4h tr: 3.13 ± 3.14, 6h: 3.06 ± 2.85 x 10-4 dl/kg/min per U/ml). S I estimates based on 2 or 3 h of data underestimated S I values, whereas 4-h S I estimates more closely approximated 6-h S I values. DISCUSSION: These results suggest that OGTT protocol duration should be considered when implementing OMM to estimate S I in adolescents with obesity and other IR populations.

Hepatic steatosis relates to gastrointestinal microbiota changes in obese girls with polycystic ovary syndrome.

OBJECTIVE: Hepatic steatosis (HS) is common in adolescents with obesity and polycystic ovary syndrome (PCOS). Gut microbiota are altered in adults with obesity, HS, and PCOS, which may worsen metabolic outcomes, but similar data is lacking in youth. METHODS: Thirty-four adolescents with PCOS and obesity underwent stool and fasting blood collection, oral glucose tolerance testing, and MRI for hepatic fat fraction (HFF). Fecal bacteria were profiled by high-throughput 16S rRNA gene sequencing. RESULTS: 50% had HS (N = 17, age 16.2±1.5 years, BMI 38±7 kg/m2, HFF 9.8[6.5, 20.7]%) and 50% did not (N = 17, age 15.8±2.2 years, BMI 35±4 kg/m2, HFF 3.8[2.6, 4.4]%). The groups showed no difference in bacterial α-diversity (richness p = 0.202; evenness p = 0.087; and diversity p = 0.069) or global difference in microbiota (ß-diversity). Those with HS had lower % relative abundance (%RA) of Bacteroidetes (p = 0.013), Bacteroidaceae (p = 0.009), Porphyromonadaceae (p = 0.011), and Ruminococcaceae (p = 0.008), and higher Firmicutes:Bacteroidetes (F:B) ratio (47.8% vs. 4.3%, p = 0.018) and Streptococcaceae (p = 0.034). Bacterial taxa including phyla F:B ratio, Bacteroidetes, and family Bacteroidaceae, Ruminococcaceae and Porphyromonadaceae correlated with metabolic markers. CONCLUSIONS: Obese adolescents with PCOS and HS have differences in composition of gut microbiota, which correlate with metabolic markers, suggesting a modifying role of gut microbiota in HS and PCOS.

Beta Testing of a Gestational Diabetes Risk Reduction Intervention for American Indian and Alaska Native Teens.

INTRODUCTION: American Indian and Alaska Native (AIAN) girls have double the risk of obesity, pregnancy, and gestational diabetes mellitus (GDM) than the general U.S. POPULATION: The purpose of this study was to beta test Stopping GDM (SGDM), a GDM risk reduction intervention for at-risk AIAN teens, before beginning a randomized controlled trial. METHOD: A sample of 11 AIAN mothers and daughters were recruited through an urban Indian health program. Daughters were at risk of GDM as assessed by a BMI ≥ 85th percentile. Pre- and posttest online questionnaires evaluated the online intervention (e-book and video). RESULTS: Mean pre- to posttest knowledge increased for mothers and daughters on diabetes prevention, reproductive health, and GDM knowledge. Daughters demonstrated an increased self-efficacy for healthy living and pregnancy planning. Satisfaction for the e-book, video, and online survey was moderately high to very high. DISCUSSION: The SGDM intervention is feasible and acceptable in AIAN mother-daughter dyads. These findings informed the SGDM intervention and the randomized controlled trial evaluation protocol.

Good agreement between hyperinsulinemic-euglycemic clamp and 2 hours oral minimal model assessed insulin sensitivity in adolescents.

BACKGROUND/OBJECTIVE: Rates of dysglycemia are increasing in youth, secondary to obesity and decreased insulin sensitivity (IS) in puberty. The oral minimal model (OMM) has been developed in order to measure IS using an easy oral glucose load, such as an oral glucose tolerance test (OGTT), instead of an hyperinsulinemic-euglycemic clamp (HE-clamp), a more invasive and time-consuming procedure. However, this model, following a standard 2 hour- OGTT has never been validated in youth, a population known for a different physiologic response to OGTT than adults. Thus, we compared IS measurements obtained from OMM following a 2-hour OGTT to HE-clamp and isotope tracer-assessed tissue IS in adolescents. We also compared the liver/muscle-specific IS from HE-clamp with other liver/muscle-specific IS surrogates following an OGTT previously validated in adults. METHODS: Secondary analysis of a cross-sectional study. Adolescent girls with (n = 26) and without (n = 7) polycystic ovary syndrome (PCOS) (14.6 ± 1.7 years; BMI percentile 23.3%-98.2%) underwent a 2-hour 75 g OGTT and a 4-phase HE-clamp. OMM IS (Si), dynamic Si (Sid ) and other OGTT-derived muscle and liver IS indices were correlated with HE-clamp tissue-specific IS. RESULTS: OMM Si and Sid correlated with HE-clamp-measured peripheral IS (r = 0.64, P <.0001 and r = 0.73; P <.0001, respectively) and the correlation coefficient trended higher than the Matsuda index (r = 0.59; P =.003). The other tissue-specific indices were poorly correlated with their HE-clamp measurements. CONCLUSION: In adolescent girls, the 2-hour OMM provided the best estimate of peripheral IS. Additional surrogates for hepatic IS are needed for youth.

Obese Adolescents With PCOS Have Altered Biodiversity and Relative Abundance in Gastrointestinal Microbiota.

CONTEXT: Alterations in gut microbiota relate to the metabolic syndrome, but have not been examined in at-risk obese youth with polycystic ovary syndrome (PCOS). OBJECTIVE: Compare the composition and diversity of the gut microbiota and associations with metabolic and hormonal measures between 2 groups of female adolescents with equal obesity with or without PCOS. DESIGN: Prospective, case-control cross-sectional study. SETTING: Tertiary-care center. PARTICIPANTS: A total of 58 obese female adolescents (n = 37 with PCOS; 16.1 ± 0.3 years of age; body mass index [BMI] 98.5th percentile) and (n = 21 without PCOS; 14.5 ± 0.4 years of age; BMI 98.7th percentile). OUTCOMES: Bacterial diversity, percent relative abundance (%RA), and correlations with hormonal and metabolic measures. RESULTS: Participants with PCOS had decreased α-diversity compared with the non-PCOS group (Shannon diversity P = 0.045 and evenness P = 0.0052). ß-diversity, reflecting overall microbial composition, differed between groups (P < 0.001). PCOS had higher %RA of phyla Actinobacteria (P = 0.027), lower Bacteroidetes (P = 0.004), and similar Firmicutes and Proteobacteria. PCOS had lower %RA of families Bacteroidaceae (P < 0.001) and Porphyromonadaceae (P = 0.024) and higher Streptococcaceae (P = 0.047). Lower bacterial α-diversity was strongly associated with higher testosterone concentrations. Several individual taxa correlated with testosterone and metabolic measures within PCOS and across the entire cohort. Receiver operative curve analysis showed 6 taxa for which the %RA related to PCOS status and lower Bacteroidaceae conferred a 4.4-fold likelihood ratio for PCOS. CONCLUSION: Alterations in the gut microbiota exist in obese adolescents with PCOS versus obese adolescents without PCOS and these changes relate to markers of metabolic disease and testosterone. Further work is needed to determine if microbiota changes are reflective of, or influencing, hormonal metabolism.

Poor Sleep Is Related to Metabolic Syndrome Severity in Adolescents With PCOS and Obesity.

CONTEXT: Polycystic ovary syndrome (PCOS) is a common endocrine disorder and is associated with metabolic syndrome (MS). Development of MS in PCOS is likely multifactorial and may relate to poor sleep. OBJECTIVE: The objective of this research is to investigate differences in objective markers of sleep in adolescents with obesity and PCOS with and without MS. We also aimed to examine the relationships between markers of sleep with MS markers. DESIGN: A cross-sectional study was conducted. PARTICIPANTS: Participants included adolescents with PCOS and obesity with MS (N = 30) or without MS (N = 36). OUTCOME MEASURES: Hormone and metabolic measurements, abdominal magnetic resonance imaging for hepatic fat fraction, actigraphy to estimate sleep, and overnight polysomnography (PSG). RESULTS: Adolescents with obesity and PCOS who also had MS had significantly worse sleep-disordered breathing including higher apnea-hypopnea index (AHI, P = .02) and arousal index (P = .01) compared to those without MS. Actigraphy showed no differences in habitual patterns of sleep behaviors including duration, timing, or efficiency between groups. However, a greater number of poor sleep health behaviors was associated with greater number of MS components (P = .04). Higher AHI correlated with higher triglycerides (TG) (r = 0.49, P = .02), and poorer sleep efficiency correlated with higher percentage of liver fat (r = -0.40, P = .01), waist circumference (r = -0.46, P < .01) and higher TG (r = -0.34, P = .04). CONCLUSIONS: Among girls with PCOS and obesity, sleep-disordered breathing was more prevalent in those with MS, and poor sleep behaviors were associated with metabolic dysfunction and more MS symptoms. Sleep health should be included in the assessment of adolescents with PCOS and obesity.

Clinical prediction score of nonalcoholic fatty liver disease in adolescent girls with polycystic ovary syndrome (PCOS-HS index).

OBJECTIVE: Nonalcoholic fatty liver disease (NAFLD) is common in obese adolescents with polycystic ovary syndrome (PCOS), but there are no inexpensive ways to accurately identify NAFLD in PCOS. The objective was to develop a simple clinical score to screen for NAFLD risk in obese adolescents with PCOS. DESIGN: This is a secondary analysis of 3 cross-sectional studies on metabolic characterization of obese adolescents with PCOS. 108 overweight and obese adolescents with PCOS (BMI > 90th percentile, age 12-19 years) were enrolled from 2012 to 2018. METHODS: Magnetic resonance imaging was used to quantify hepatic fat fraction (HFF). A development cohort of 87 girls were divided by presence of NAFLD (HFF > 5.5%). A logistic regression model with the outcome of NAFLD and candidate predictor variables was fit. A simplified model (PCOS-HS index) was created using backwards stepdown elimination. Validation was performed using 200 bootstrapped sample and in a second cohort of 21 PCOS participants. RESULTS: 52% of the development cohort had NAFLD. The PCOS-HS index that included BMI percentile, waist circumference, ALT and SHBG had an AUCROC of 0.81, sensitivity 82%, specificity 69%, negative predictive value (NPV) 78% and positive predictive value 74%, using a threshold of 0.44 to predict HS. A threshold of 0.15 ruled out NAFLD with a NPV 90%. In the validation cohort, the model showed an accuracy of 81%, sensitivity of 91% and specificity of 70%. CONCLUSIONS: We developed a clinical index to identify NAFLD in girls with PCOS who would need further evaluation and treatment.

A simple method to monitor hepatic gluconeogenesis and triglyceride synthesis following oral sugar tolerance test in obese adolescents.

Hepatic energy metabolism is a key element in many metabolic diseases. Hepatic anaplerosis provides carbons for gluconeogenesis (GNG) and triglyceride (TG) synthesis. We aimed to optimize a protocol that measures hepatic anaplerotic contribution for GNG, TG synthesis, and hepatic pentose phosphate pathway (PPP) activity using a single dose of oral [U-13C3]glycerol paired with an oral sugar tolerance test (OSTT) in a population with significant insulin resistance. The OSTT (75 g glucose + 25 g fructose) was administered to eight obese adolescents with polycystic ovarian syndrome (PCOS) followed by ingestion of [U-13C3]glycerol at t = 180 or t = 210 min. 13C-labeling patterns of serum glucose and TG-glycerol were determined by nuclear magnetic resonance. 13C enrichment in plasma TG-glycerol was detectable and stable from 240 to 390 min with the [U-13C3]glycerol drink at t = 180 min(3.65 ± 2.3 to 4.47 ± 1.4%; P > 0.4), but the enrichment was undetectable at 240 min with the glycerol drink at t = 210 min. The relative contribution from anaplerosis was determined at the end of the OSTT [18.5 ±3.4% (t = 180 min) vs. 16.0 ± 3.5% (t = 210 min); P = 0.27]. [U-13C3]glycerol was incorporated into GNG 390 min after the OSTT with an enrichment of 7.5-12.5%. Glucose derived from TCA cycle activity was 0.3-1%, and the PPP activity was 2.8-4.7%. In conclusion, it is possible to obtain relative measurements of hepatic anaplerotic contribution to both GNG and TG esterification following an OSTT in a highly insulin-resistant population using a minimally invasive technique. Tracer administration should be timed to allow enough de novo TG esterification and endogenous glucose release after the sugar drink.

Morning Circadian Misalignment Is Associated With Insulin Resistance in Girls With Obesity and Polycystic Ovarian Syndrome.

CONTEXT: To our knowledge, circadian rhythms have not been examined in girls with polycystic ovarian syndrome (PCOS), despite the typical delayed circadian timing of adolescence, which is an emerging link between circadian health and insulin sensitivity (SI), and decreased SI in PCOS. OBJECTIVE: To examine differences in the circadian melatonin rhythm between obese adolescent girls with PCOS and control subjects, and evaluate relationships between circadian variables and SI. DESIGN: Cross-sectional study. PARTICIPANTS: Obese adolescent girls with PCOS (n = 59) or without PCOS (n = 33). OUTCOME MEASURES: Estimated sleep duration and timing from home actigraphy monitoring, in-laboratory hourly sampled dim-light, salivary-melatonin and fasting hormone analysis. RESULTS: All participants obtained insufficient sleep. Girls with PCOS had later clock-hour of melatonin offset, later melatonin offset relative to sleep timing, and longer duration of melatonin secretion than control subjects. A later melatonin offset after wake time (i.e., morning wakefulness occurring during the biological night) was associated with higher serum free testosterone levels and worse SI regardless of group. Analyses remained significant after controlling for daytime sleepiness and sleep-disordered breathing. CONCLUSION: Circadian misalignment in girls with PCOS is characterized by later melatonin offset relative to clock time and sleep timing. Morning circadian misalignment was associated with metabolic dysregulation in girls with PCOS and obesity. Clinical care of girls with PCOS and obesity would benefit from assessment of sleep and circadian health. Additional research is needed to understand mechanisms underlying the relationship between morning circadian misalignment and SI in this population.

Amino acid and fatty acid metabolomic profile during fasting and hyperinsulinemia in girls with polycystic ovarian syndrome.

Polycystic ovarian syndrome (PCOS) is associated with insulin resistance (IR) and altered muscle mitochondrial oxidative phosphorylation. IR in adults with obesity and diabetes is associated with changes in amino acid, free fatty acid (FFA), and mitochondrial acylcarnitine (AC) metabolism. We sought to determine whether these metabolites are associated with IR and/or androgens in youth-onset PCOS. We enrolled obese girls with PCOS [ n = 15, 14.5 yr (SD 1.6), %BMI 98.5 (SD 1.0)] and without PCOS [ n = 6, 13.2 yr (SD 1.2), %BMI 98.0 (SD 1.1)]. Insulin sensitivity was assessed by hyperinsulinemic euglycemic clamp. Untargeted metabolomics of plasma was performed while fasting and during hyperinsulinemia. Fasting arginine, glutamine, histidine, lysine, phenylalanine, and tyrosine were higher ( P < 0.04 for all but P < 0.001 for valine), as were glutamine and histidine during hyperinsulinemia ( P < 0.03). Higher valine during hyperinsulinemia was associated with IR ( r = 0.59, P = 0.006). Surprisingly, end-clamp AC C4 was lower in PCOS, and lower C4 was associated with IR ( r = -0.44, P = 0.04). End-clamp FFAs of C14:0, C16:1, and C18:1 were higher in PCOS girls, and C16:1 and C18:1 strongly associated with IR ( r = 0.73 and 0.53, P < 0.01). Free androgen index related negatively to short-, medium-, and long-chain AC ( r = -0.41 to -0.71, P < 0.01) but not FFA or amino acids. Obese girls with PCOS have a distinct metabolic signature during fasting and hyperinsulinemia. As in diabetes, IR related to valine and FFAs, with an unexpected relationship with AC C4, suggesting unique metabolism in obese girls with PCOS.

Too Late and Not Enough: School Year Sleep Duration, Timing, and Circadian Misalignment Are Associated with Reduced Insulin Sensitivity in Adolescents with Overweight/Obesity.

OBJECTIVES: To examine the relationship between insulin resistance (IR) and sleep/circadian health in overweight/obese adolescents. We hypothesized that insufficient and delayed sleep would be associated with IR in this population. STUDY DESIGN: Thirty-one adolescents (mean age, 16.0 ± 1.4 years; 77% female) with body mass index ≥90th percentile for age/sex were recruited from outpatient clinics at a children's hospital. Participants underwent 1 week of objective home sleep monitoring with wrist actigraphy during the academic year. A 3-hour oral glucose tolerance test was conducted, followed by in-laboratory salivary dim-light melatonin sampling every 30-60 minutes from 5 p.m. to noon the next day. Regression analyses between sleep and circadian variables with IR were examined. RESULTS: Longer sleep time and time in bed on weekends and weekdays and earlier weekday bedtime were significantly associated with better insulin sensitivity. Participants who obtained less than the median duration of sleep per night (6.6 hours) had evidence of IR with compensatory insulin secretion compared with those obtaining ≥6.6 hours of sleep. A wider phase angle between bedtime and melatonin onset, indicating a later circadian timing of sleep onset, was significantly associated with IR. CONCLUSIONS: Short sleep duration, later weekday bedtime, and later circadian timing of sleep were associated with IR in a cohort of adolescents with overweight/obesity during the school year. Further research is needed to better understand the physiology underlying these observations and to evaluate the impact of improved sleep and circadian health on metabolic health in this at-risk population.

Metformin Improves Insulin Sensitivity and Vascular Health in Youth With Type 1 Diabetes Mellitus.

BACKGROUND: Cardiovascular disease is the leading cause of mortality in type 1 diabetes mellitus (T1DM) and relates strongly to insulin resistance (IR). Lean and obese adolescents with T1DM have marked IR. Metformin improves surrogate markers of IR in T1DM, but its effect on directly measured IR and vascular health in youth with T1DM is unclear. We hypothesized that adolescents with T1DM have impaired vascular function and that metformin improves this IR and vascular dysfunction. METHODS: Adolescents with T1DM and control participants underwent magnetic resonance imaging of the ascending (AA) and descending aorta to assess pulse wave velocity, relative area change, and maximal (WSSMAX) and time-averaged (WSSTA) wall shear stress. Participants with T1DM also underwent assessment of carotid intima-media thickness by ultrasound, brachial distensibility by DynaPulse, fat and lean mass by dual-energy x-ray absorptiometry, fasting laboratories after overnight glycemic control, and insulin sensitivity by hyperinsulinemic-euglycemic clamp (glucose infusion rate/insulin). Adolescents with T1DM were randomized 1:1 to 3 months of 2000 mg metformin or placebo daily, after which baseline measures were repeated. RESULTS: Forty-eight adolescents with T1DM who were 12 to 21 years of age (40% body mass index [BMI] ≥90th percentile; 56% female) and 24 nondiabetic control participants of similar age, BMI, and sex distribution were enrolled. Adolescents with T1DM demonstrated impaired aortic health compared with control participants, including elevated AA and descending aorta pulse wave velocity, reduced AA and descending aorta relative area change, and elevated AA and descending aorta WSSMAX and WSSTA. Adolescents with T1DM in the metformin versus placebo group had improved glucose infusion rate/insulin (12.2±3.2 [mg·kg-1·min-1]/µIU/µL versus -2.4±3.6 [mg·kg-1·min-1]/µIU/µL, P=0.005; 18.6±4.8 [mg·lean kg-1·min-1]/µIU/µL versus -3.4±5.6 [mg·lean kg-1·min-1]/µIU/µL, P=0.005) and reduced weight (-0.5±0.5 kg versus 1.6±0.5 kg; P=0.004), BMI (-0.2±0.15 kg/m2 versus 0.4±0.15 kg/m2; P=0.005), and fat mass (-0.7±0.3 kg versus 0.6±0.4 kg; P=0.01). Glucose infusion rate/insulin also improved in normal-weight participants (11.8±4.4 [mg·kg-1·min-1]/µIU/µL versus -4.5±4.4 [mg·kg-1·min-1]/µIU/µL, P=0.02; 17.6±6.7 [mg·lean kg-1·min-1]/µIU/µL versus -7.0±6.7 [mg·lean kg-1·min-1]/µIU/µL, P=0.02). The metformin group had reduced AA WSSMAX (-0.3±0.4 dyne/cm2 versus 1.5±0.5 dyne/cm2; P=0.03), AA pulse wave velocity (-1.1±1.20 m/s versus 4.1±1.6 m/s; P=0.04), and far-wall diastolic carotid intima-media thickness (-0.04±0.01 mm versus -0.00±0.01 mm; P=0.049) versus placebo. CONCLUSIONS: Adolescents with T1DM demonstrate IR and impaired vascular health compared with control participants. Metformin improves IR, regardless of baseline BMI, and BMI, weight, fat mass, insulin dose, and aortic and carotid health in adolescents with T1DM. Metformin may hold promise as a cardioprotective intervention in T1DM. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT01808690.

Using simple clinical measures to predict insulin resistance or hyperglycemia in girls with polycystic ovarian syndrome.

BACKGROUND: Polycystic ovarian syndrome (PCOS) includes insulin resistance (IR) and impaired glucose tolerance (IGT) in youth, and a greatly elevated risk of type 2 diabetes in adulthood. Identifying IR is challenging and documenting IGT requires an oral glucose tolerance test (OGTT). OBJECTIVE: Identify easily applied surrogate measures for IR and IGT in girls with PCOS. METHODS: We studied 28 girls with PCOS (body mass index [BMI] percentile 98 (83.99); 15.5 (14.5,16.6) years of age) and 20 with normal menses [BMI percentile (97 (88.99); 15.5 (13.3,16.1) years]. Hyperinsulinemic-euglycemic clamps (insulin dose of 80 µU/ml/min) to determine glucose infusion rate (GIR) and a 75 g OGTT were performed. Surrogates for IR including fasting insulin, homeostatic model assessment-insulin resistant (HOMA-IR), Matsuda index, and estimate of insulin sensitivity (e-IS) were compared to IGT status and GIR. Spearman correlations were performed between surrogates and GIR or IGT, and receiver operator curve (ROC) analysis to predict GIR below the median or IGT status. RESULTS: GIR was lower in PCOS (12.9 ± 4.6 vs 17.1 ± 5.1 mg/kg fat-free mass·min; P = 0.01). Within PCOS, HOMA-IR (r = -0.78, P < 0.0001), e-IS (r = 0.70, P < 0.001), and Matsuda (r = 0.533, P < 0.001) correlated with GIR. e-IS provided a good sensitivity (100%) and specificity (71%) to identify IR (e-IS cutoff: <6.3, ROC-area under curve = 0.898). Fasting insulin >22 IU/mL had the best sensitivity (88%), specificity (78%), and ROC (0.760) for IGT status. CONCLUSIONS: Girls with PCOS have significant IR, and IGT is common. Both e-IS and fasting insulin are obtainable without an OGTT or clamp and could be used clinically to guide treatment in PCOS.

Oral Glucose Tolerance Test Glucose Peak Time Is Most Predictive of Prediabetes and Hepatic Steatosis in Obese Girls.

Obese adolescent girls are at increased risk for type 2 diabetes, characterized by defects in insulin secretion and action. We sought to determine if later glucose peak timing (>30 minutes), 1-hour glucose >155 mg/dl, or monophasic pattern of glucose excursion during an oral glucose tolerance test (OGTT) reflect a worse cardiometabolic risk profile. Post-pubertal overweight/obese adolescent girls without diabetes were studied (N = 88; age, 15.2 ± 0.2 years; body mass index percentile, 97.7 ± 0.5). All participants completed an OGTT and body composition measures. Thirty-two girls had a four-phase hyperinsulinemic euglycemic clamp with isotope tracers, vascular imaging, and muscle mitochondrial assessments. Participants were categorized by glucose peak timing (≤30 min = early; >30 min = late), 1-hour glucose concentration (±155 mg/dL) and glucose pattern (monophasic, biphasic). Girls with a late (N = 54) vs earlier peak (n = 34) timing had higher peak glucose (P < 0.001) and insulin (P = 0.023), HbA1c (P = 0.021); prevalence of hepatic steatosis (62% vs 26%; P = 0.003) and lower oral disposition index (P < 0.001) and glucagon-like peptide-1 response (P = 0.037). When classified by 1-hour glucose, group differences were similar to peak timing, but minimal when classified by glucose pattern. In the >155 mg/dL group only, peripheral insulin sensitivity and fasting free fatty acids were worse. A later glucose peak or >155 mg/dL 1-hour glucose predicts metabolic disease risk in obese adolescent girls. This may defect incretin effects and first phase insulin response, and muscle and adipose insulin resistance.