Adiponectin, Insulin Sensitivity, β-Cell Function, and Racial/Ethnic Disparity in Treatment Failure Rates in TODAY

Insulin clearance at randomisation and in response to treatment in youth with type 2 diabetes: a secondary analysis of the TODAY randomised clinical trial

AIMS/HYPOTHESIS

Insulin resistance and compensatory hyperinsulinaemia are core features leading to beta cell failure in youth-onset type 2 diabetes. Insulin clearance (IC) is also a key regulator of insulin concentrations, but few data exist on IC in youth-onset type 2 diabetes. In a secondary analysis of our Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) randomised clinical trial, we investigated potential sex-, race-, ethnicity- and treatment-related differences in IC in youth-onset type 2 diabetes and aimed to identify metabolic phenotypes associated with IC at baseline and in response to metformin, metformin plus a lifestyle intervention, and metformin plus rosiglitazone.

METHODS

A total of 640 youth aged 10-18 years with type 2 diabetes underwent fasting blood tests, anthropometric measurements, dual-energy x-ray absorptiometry to estimate subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) mass, and OGTTs longitudinally over 5 years. IC was calculated from the fasting C-peptide:insulin ratio (fasting IC) and 2 h OGTT C-peptide incremental AUC (iAUC):insulin iAUC ratio (2 h IC). Linear mixed models were used to assess covariate effects on the mean of IC over repeated time points.

RESULTS

Baseline fasting IC (×10-2 nmol/pmol) was significantly lower in female participants than male participants (median [IQR] 0.72 [0.57-0.93] vs 0.79 [0.63-1.00], respectively; p=0.04) and in non-Hispanic Black participants than Hispanic and non-Hispanic White participants (median [IQR] 0.64 [0.51-0.81] vs 0.78 [0.64-1.00] vs 0.84 [0.68-1.01], respectively; p<0.0001). Similar results were observed for 2 h IC. Lower IC most strongly correlated with higher weight over time (% change [95% CI] in IC per 5 kg increase: fasting IC -1.52 [-2.05, -0.99]; 2 h IC -3.46 [-4.05, -2.86]). Lower IC also correlated with other markers of adiposity (higher BMI and SAT mass), and markers of insulin sensitivity (higher waist:height ratio, VAT mass, VAT:SAT mass ratio, triacylglycerol concentrations, triacylglycerol:HDL-cholesterol ratio, aspartate aminotransferase [AST] and alanine aminotransferase [ALT] concentrations, and systolic and diastolic BP, and lower HDL-cholesterol and total and high molecular weight adiponectin concentrations) over time. Beta cell function as determined from OGTTs, not insulin sensitivity or IC, was predictive of persistently elevated blood glucose levels. IC was higher with metformin+rosiglitazone than metformin alone (p=0.03 for fasting IC; p=0.02 for 2 h IC) and metformin+lifestyle (2 h IC, p=0.005), but not after adjusting for adiponectin (p value not significant for all).

CONCLUSIONS/INTERPRETATION

In youth with type 2 diabetes, low IC is correlated with female sex, non-Hispanic Black race and ethnicity, and markers of adiposity and insulin resistance, but not with beta cell function. Along with insulin sensitivity and adiponectin, IC increased in response to rosiglitazone treatment. These findings suggest that, in youth-onset type 2 diabetes, low IC is a compensatory response to changes in insulin sensitivity and/or adiponectin concentrations and is not a mediator of beta cell function.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00081328 DATA AVAILABILITY: Data from the TODAY study (V4; https://doi.org/10.58020/2w6w-pv88 ) reported here are available on request from the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) Central Repository (NIDDK-CR) Resources for Research ( https://repository.niddk.nih.gov/ ).

Type 2 diabetes in children and adolescents: Exploring the disease heterogeneity and research gaps to optimum management

Over the past 20 years, the incidence and prevalence of type 2 diabetes mellitus (T2DM) in children and adolescents have increased, particularly in racial and ethnic minorities. Despite the rise in T2DM in children and adolescents, the pathophysiology and progression of disease in this population are not clearly understood. Youth-onset T2DM has a more adverse clinical course than is seen in those who develop T2DM in adulthood or those with T1DM. Furthermore, the available therapeutic options are more limited for children and adolescents with T2DM compared to adult patients, mostly due to the challenges of implementing clinical trials. A better understanding of the mechanisms underlying the de-velopment and aggressive disease phenotype of T2DM in youth is important to finding effective prevention and management strategies. This review highlights the key evidence about T2DM in children and adolescents and its current burden and challenges both in clinical care and research activities.

Differences in metabolic biomarkers in people with schizophrenia who are of Mexican descent compared to non-Hispanic whites

Metabolic dysfunction is highly prevalent and contributes to premature mortality among people with schizophrenia (PwS), especially in Hispanic/Latino/a/x/e PwS, compared to non-Hispanic White (NHW) PwS. This study evaluated the relative contributions of Mexican descent and schizophrenia diagnosis to metabolic biomarker levels. This cross-sectional study included 115 PwS and 102 non-psychiatric comparison (NC) participants - English-speakers aged 26-66 years, 27% Mexican descent, and 52% women across both groups. Assessments included evaluations of BMI, psychopathology, and fasting metabolic biomarkers. We used ANOVA analyses to compare metabolic outcomes between diagnostic and ethnic subgroups, linear regression models to examine associations between Mexican descent and metabolic outcomes, and Spearman's correlations to examine relationships between metabolic outcomes and illness-related variables in PwS. Mexican PwS had higher hemoglobin A1c levels, insulin resistance, and body mass index than NHW PwS. Mexican descent was associated with higher hemoglobin A1c levels, insulin resistance, body mass index, and leptin levels, controlling for age, sex, depression, education, and smoking. Among Mexican PwS, worse negative symptoms were associated with greater insulin resistance. These findings support the possibility of ethnicity-based differences in metabolic dysregulation, though further investigation is warranted to create targeted health interventions for Hispanic PwS.

Growth Hormone Mediators and Glycemic Control in Youths With Type 2 Diabetes: A Secondary Analysis of a Randomized Clinical Trial

Importance

Youth-onset type 2 diabetes (T2D) has a more aggressive phenotype than adult-onset T2D, including rapid loss of glycemic control and increased complication risk.

Objective

To identify associations of growth hormone mediators with glycemic failure, beta cell function, and insulin sensitivity in youth-onset T2D.

Design, Setting, and Participants

This post hoc secondary analysis of the Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) randomized clinical trial, which enrolled participants from July 2004 to February 2009, included 398 participants from 15 university-affiliated medical centers with available plasma samples from baseline and 36 months. Participants were youths aged 10 to 17 years with a duration of T2D of less than 2 years who were randomized to metformin, metformin plus lifestyle intervention, or metformin plus rosiglitazone. Participants were followed up for a mean (SD) of 3.9 (1.5) years during the trial, ending in 2011. Statistical analysis was performed from August 2022 to November 2023.

Exposure

Plasma insulin-like growth factor-1 (IGF-1), growth hormone receptor (GHR), and insulin-like growth factor binding protein 1 (IGFBP-1).

Main Outcomes and Measures

Main outcomes were (1) loss of glycemic control during the TODAY study, defined as hemoglobin A1c (HbA1c) level of 8% or more for 6 months or inability to wean from insulin therapy, and (2) baseline and 36-month measures of glycemia (fasting glucose, HbA1c), insulin sensitivity (1/fasting C-peptide), high-molecular-weight adiponectin, and beta cell function (C-peptide index, C-peptide oral disposition index).

Results

This analysis included 398 participants (mean [SD] age, 13.9 [2.0] years; 248 girls [62%]; 166 Hispanic participants [42%]; 134 non-Hispanic Black participants [34%], and 84 non-Hispanic White participants [21%]). A greater increase in IGF-1 level between baseline and 36 months was associated with lower odds of glycemic failure (odds ratio [OR], 0.995 [95% CI, 0.991-0.997]; P < .001) and higher C-peptide index per 100-ng/mL increase in IGF-1 (β [SE], 0.015 [0.003]; P < .001). A greater increase in log2 GHR level between baseline and 36 months was associated with higher odds of glycemic failure (OR, 1.75 [95% CI, 1.05-2.99]; P = .04) and lower C-peptide index (β [SE], -0.02 [0.006]; P < .001). A greater increase in log2 IGFBP-1 level between baseline and 36 months was associated with higher odds of glycemic failure (OR, 1.37 [95% CI, 1.09-1.74]; P = .007) and higher high-molecular-weight adiponectin (β [SE], 431 [156]; P = .007).

Conclusions and Relevance

This study suggests that changes in plasma growth hormone mediators are associated with loss of glycemic control in youth-onset T2D, with IGF-1 associated with lower risk and GHR and IGFBP-1 associated with increased risk.

Trial Registration

ClinicalTrials.gov Identifier: NCT00081328.

TODAY Study Group, Nadeau KJ, El ghormli L, Arslanian S, Bacha F, Caprio S, Chan C, Chao LC, Rayas M, Siska MK, Zeitler P. Effect of Early Glycemic Control in Youth-Onset Type 2 Diabetes on Longer-Term Glycemic Control and β-Cell Function: Results From the TODAY Study

OBJECTIVE

Little is known about the impact of early attainment of tight glycemic control on long-term β-cell function and glycemic control in youth-onset type 2 diabetes. We examined the effect of the initial 6 months of glycemic control on β-cell function and glycemic control longitudinally over 9 years and the impact of sex, race/ethnicity, and BMI on these relationships in adolescents with youth-onset type 2 diabetes in the Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) study.

RESEARCH DESIGN AND METHODS

Oral glucose tolerance tests were performed longitudinally through year 9 to derive estimates of insulin sensitivity and secretion. Early glycemia was defined by mean HbA1c during the first 6 months postrandomization, categorized into five HbA1c groups (<5.7%, 5.7 to <6.4%, 6.4 to <7.0%, 7.0 to <8.0%, and ≥8.0%). The long-term period was defined as the period between years 2 and 9.

RESULTS

A total of 656 participants (64.8% female, baseline mean age 14 years, diabetes duration <2 years) had longitudinal data available over an average of 6.4 ± 3.2 years of follow-up. HbA1c significantly increased in all early glycemic groups during years 2-9, with a steeper increase (+0.40%/year) among participants with the tightest initial control (mean early HbA1c <5.7%), in parallel to a decline in the C-peptide-derived disposition index. Nevertheless, the lower HbA1c categories continued to have relatively lower HbA1c over time.

CONCLUSIONS

Early tight glycemic control in the TODAY study was related to β-cell reserve and translated to better long-term glycemic control. However, tight early glycemic control on the randomized treatment in the TODAY study did not prevent deterioration of β-cell function.

Rapid Decline in β-Cell Function and Increasing Adiposity Are Associated With Conversion to Type 2 Diabetes in At-Risk Latino Youth

Youth-onset type 2 diabetes (T2D) is becoming increasingly prevalent, especially among Latino youth, and there is limited information on its pathophysiology and causative factors. Here, we describe findings from a longitudinal cohort study in 262 Latino children with overweight/obesity at risk of developing T2D with annual measures of oral and intravenous glucose tolerance (IVGTT), body composition, and fat distribution. Logistic binomial regression was used to identify significant predictors in those who developed T2D compared with matched control participants, and mixed-effects growth models were used to compare rates of change in metabolic versus adiposity measures between groups. Overall conversion rate to T2D at year 5 was 2% (n = 6). Rate of decline in disposition index (DI), measured with an IVGTT, over 5 years was three times higher in case patients (-341.7 units per year) compared with the extended cohort (-106.7 units per year) and 20 times higher compared with control participants (-15.2 units per year). Case patients had significantly higher annual increases in fasting glucose, hemoglobin A1c (HbA1c), waist circumference, and trunk fat, and there was an inverse correlation between rate of decline in DI and rates of increase in adiposity measures. T2D development in at-risk Latino youth is associated with a substantial and rapid decrease in DI that is directly correlated with increases in fasting glucose, HbA1c, and adiposity.

ARTICLE HIGHLIGHTS

Youth-onset type 2 diabetes is becoming increasingly prevalent, especially among Latino youth, and there is limited information on its pathophysiology and causative factors. Overall conversion rate to type 2 diabetes over 5 years was 2%. In youth who converted to type 2 diabetes, disposition index decreased rapidly by 85% compared with that in patients who did not convert during the study period. There was an inverse correlation between rate of decline in disposition index and rates of increase in various adiposity measures.

Inflammatory Mediators and Type 2 Diabetes Risk Factors before and in Response to Lifestyle Intervention among Latino Adolescents with Obesity

Obesity is associated with chronic inflammation that may contribute to T2D among youth. We examined the association between inflammatory biomarkers and insulin sensitivity and β-cell function and response to lifestyle intervention among Latino youth with obesity. Latino youth (n = 64) were randomized to six months of lifestyle intervention (INT, n = 40) or usual care (UC, n = 24). INT included nutrition education and physical activity. UC involved meeting with a pediatric endocrinologist and registered dietitian to discuss healthy lifestyles. At baseline, multiple linear regression assessed fasting serum interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), monocyte chemoattractant protein-1 (MCP-1), high-molecular weight adiponectin (HMW Adpn), IL-10, IL-1 receptor antagonist (IL-1ra) as predictors of insulin sensitivity (whole-body insulin sensitivity index, WBISI) and β-cell function (oral disposition index, oDI). Changes in outcomes between groups were assessed using covariance pattern models. At baseline, MCP-1 (β ± SE, -0.12 ± 0.05, p = 0.027) and IL-1ra (-0.03 ± 0.01, p = 0.005) were negatively associated with WBISI. Treatment effects were not observed for inflammatory markers. WBISI was significantly increased among both INT (from 1.8 ± 0.2 to 2.6 ± 0.4, p = 0.005) and UC (from 1.6 ± 0.2 to 2.8 ± 0.5, p = 0.002) with no significant differences between the groups. Obesity-related inflammatory mediators were associated with T2D risk factors but were unaffected by lifestyle intervention among Latino youth.

Candidate biomarkers as predictors of future kidney disease and cardiovascular dysfunction in adolescents with type 2 diabetes

AIMS

Evaluate changes in circulating biomarkers as predictors of kidney disease, and cardiac/vascular dysfunction in participants from the Treatment Options for type 2 Diabetes in Adolescents and Youth (TODAY) study.

METHODS

Candidate biomarkers were assessed annually in 507 participants over a mean follow-up of 6.9 ± 2.4 years. Moderate albuminuria was defined as urine albumin-to-creatinine ratio ≥ 30 mg/g and hyperfiltration as eGFR ≥ 135 mL/min/1.73 m2 at two consecutive visits. Echocardiography (n = 256) and pulse wave velocity (n = 193) were evaluated twice, 5 years apart. Adjusted Cox proportional hazard models and logistic regression models were used to examine associations between biomarkers and outcomes.

RESULTS

At baseline, 35.7% were male, with a mean age 13.9 years, diabetes duration 7.8 months, and HbA1c 6.0%. Higher concentrations of E-selectin and proinsulin were associated with incident moderate albuminuria and hyperfiltration. Higher concentrations of FGF-23 were associated with lower risk of hyperfiltration and negatively correlated with eGFR. No candidate biomarkers predicted a decline in cardiac or vascular function.

CONCLUSIONS

Circulating biomarkers of endothelial dysfunction and markers of β-cell dysfunction and insulin sensitivity could be used in a more personalized risk assessment of kidney disease in youth-onset type 2 diabetes. However, biomarkers studied have limited value in predicting cardiac dysfunction or vascular stiffness.

J-shape relationship between normal fasting plasma glucose and risk of type 2 diabetes in the general population: results from two cohort studies

BACKGROUND

Previous studies have reported that high fasting plasma glucose (FPG), even that within the normal range, is associated with the risk of type 2 diabetes (T2D). Nevertheless, these findings are limited to specific populations. Thus, studies in the general population are imperative.

METHODS

This study included two cohorts comprising 204 640 individuals who underwent physical examinations at the Rich Healthcare Group present at 32 locations in 11 cities of China from 2010 to 2016 and 15 464 individuals who underwent physical tests at the Murakami Memorial Hospital in Japan. Cox regression, restricted cubic spline (RCS), Kaplan-Meier (KM) curves, and subgroup analysis were used to determine the relationship between FPG and T2D. Receiver operating characteristic (ROC) curves were used to evaluate the predictive power of FPG for T2D.

RESULTS

The mean age of the 220 104 participants (204 640 Chinese and 15 464 Japanese participants) was 41.8 years (41.7 years for the Chinese and 43.7 years for the Japanese participants). During follow-up, 2611 individuals developed T2D (2238 Chinese and 373 Japanese participants). The RCS demonstrated a J-shaped relationship between FPG and T2D risk, with inflexion points of 4.5 and 5.2 for the Chinese and Japanese populations, respectively. Multivariate-adjusted hazard ratio (HR) was 7.75 for FPG and T2D risk after the inflexion point (7.3 for Chinese and 21.13 for Japanese participants).

CONCLUSIONS

In general Chinese and Japanese populations, the normal baseline FPG range showed a J-shaped relationship with the risk of T2D. Baseline FPG levels help identify individuals at high risk of T2D and may enable early primary prevention to improve their outcomes.

Ethnic disparities attributed to the manifestation in and response to type 2 diabetes: insights from metabolomics

Type 2 diabetes (T2D) associated health disparities among different ethnicities have long been known. Ethnic variations also exist in T2D related comorbidities including insulin resistance, vascular complications and drug response. Genetic heterogeneity, dietary patterns, nutrient metabolism and gut microbiome composition attribute to ethnic disparities in both manifestation and progression of T2D. These factors differentially regulate the rate of metabolism and metabolic health. Metabolomics studies have indicated significant differences in carbohydrate, lipid and amino acid metabolism among ethnicities. Interestingly, genetic variations regulating lipid and amino acid metabolism might also contribute to inter-ethnic differences in T2D. Comprehensive and comparative metabolomics analysis between ethnicities might help to design personalized dietary regimen and newer therapeutic strategies. In the present review, we explore population based metabolomics data to identify inter-ethnic differences in metabolites and discuss how (a) genetic variations, (b) dietary patterns and (c) microbiome composition may attribute for such differences in T2D.

Youth with type 2 diabetes have a high rate of treatment failure after discontinuation of insulin: A Pediatric Diabetes Consortium study

Insulin is commonly used to reverse gluco-toxicity in youth with newly diagnosed type 2 diabetes (T2D), but many are subsequently weaned off insulin. We analyzed Pediatric Diabetes Consortium (PDC) data to determine how long glycemic control is maintained after termination of initial insulin treatment. Youth with T2D who had previously been on insulin but were on either an intensive lifestyle intervention alone or metformin alone upon enrollment in the PDC T2D Registry were studied (N = 183). The primary outcome was time to treatment failure, defined by need to restart insulin or metformin or another diabetes medication. Data were analyzed using logistic regression to assess risk factors for treatment failure. Of the 183 participants studied (mean age 15 years, diabetes duration 1.7 years), 54% experienced treatment failure (median follow-up time 1.7 years). In the subgroup on metformin monotherapy (N = 140), 45% subsequently required restart of insulin. Moreover, of participants in the subgroup treated with an intensive lifestyle intervention alone (N = 43), 81% restarted insulin or were treated with metformin or other diabetes medication. In both groups, median time to treatment failure was 1.2 years. Higher HbA1c at enrollment was significantly associated with treatment failure (p < 0.001). Youth with T2D who are initially treated with insulin have a high rate of treatment failure when switched to intensive lifestyle alone or metformin alone. Our data highlight the severe and progressive nature of youth onset T2D, hence patients should be monitored closely for deteriorating glycemic control after being weaned off insulin.

TCF7L2 Genetic Variants Do Not Influence Insulin Sensitivity or Secretion Indices in Autoantibody-Positive Individuals at Risk for Type 1 Diabetes

OBJECTIVE

We aimed to test whether type 2 diabetes (T2D)-associated TCF7L2 genetic variants affect insulin sensitivity or secretion in autoantibody-positive relatives at risk for type 1 diabetes (T1D).

RESEARCH DESIGN AND METHODS

We studied autoantibody-positive TrialNet Pathway to Prevention study participants (N = 1,061) (mean age 16.3 years) with TCF7L2 single nucleotide polymorphism (SNP) information and baseline oral glucose tolerance test (OGTT) to calculate indices of insulin sensitivity and secretion. With Bonferroni correction for multiple comparisons, P values < 0.0086 were considered statistically significant.

RESULTS

None, one, and two T2D-linked TCF7L2 alleles were present in 48.1%, 43.9%, and 8.0% of the participants, respectively. Insulin sensitivity (as reflected by 1/fasting insulin [1/IF]) decreased with increasing BMI z score and was lower in Hispanics. Insulin secretion (as measured by 30-min C-peptide index) positively correlated with age and BMI z score. Oral disposition index was negatively correlated with age, BMI z score, and Hispanic ethnicity. None of the indices were associated with TCF7L2 SNPs. In multivariable analysis models with age, BMI z score, ethnicity, sex, and TCF7L2 alleles as independent variables, C-peptide index increased with age, while BMI z score was associated with higher insulin secretion (C-peptide index), lower insulin sensitivity (1/IF), and lower disposition index; there was no significant effect of TCF7L2 SNPs on any of these indices. When restricting the analyses to participants with a normal OGTT (n = 743; 70%), the results were similar.

CONCLUSIONS

In nondiabetic autoantibody-positive individuals, TCF7L2 SNPs were not related to insulin sensitivity or secretion indices after accounting for BMI z score, age, sex, and ethnicity.

Durability of Changes in Biomarkers of Cardiometabolic Disease: 1-Year Family-Based Intervention in Children with Obesity

Background: The sustainability of health benefits in response to lifestyle-based interventions remains unclear in children with overweight and obesity, and cardiometabolic disease (CMD). We determined the changes in novel biomarkers of CMD in a 1-year family-based intervention (FBI) program, during 6-month active monitoring phase and at 12-month follow-up. Methods: Children with an age-adjusted body mass index (BMI) percentile ≥85 (N = 130; age 8-11 years) were recruited for a 1-year (6-month monitored and 6-month unmonitored) randomized controlled FBI program. Anthropometry and selected biomarkers of CMD were measured in 87 participants, randomly allocated to intervention (INT) and education-only (EDU) groups, at baseline, immediately after a 6-month active intervention or control period, and at 12-month unmonitored follow-up. Results: Samples from 87 participants (age 10.00 ± 0.11 years and Tanner stage ≤3) with obesity (BMI%ile = 97.45 ± 0.15) were available. Overall intervention effect (between groups), was observed for total (T) and high molecular weight (HMW) adiponectin, ratio of total to HMW adiponectin, fibrinogen, and interleukin (IL)-6 (P < 0.05 for all). However, between-group beneficial changes after adjusting for baseline levels were limited to BMI percentile, T and HMW adiponectin and their ratio, IL-6, and fibrinogen (P < 0.05 for all) mainly during the 6-month period of monitored intervention. Changes in traditional risk factors such as lipids and triglycerides were inconsistent. During the 6-month follow-up period, the changes in biomarkers leveled-off, except for T and HMW adiponectin, IL-6, and fibrinogen that continued to show benefits (P < 0.05) from the 6- to 12-month follow-up. Conclusions: The FBI program beneficially altered novel biomarkers of CMD during the monitored intervention phase in school-age children with obesity, but they mostly moved back toward baseline during the unmonitored follow-up phase. The changes in novel biomarkers of CMD appear to be more sensitive compared to the traditional risk factors. The study implies the need for refinements in lifestyle-based approaches in the preservation of cardiovascular health and calls for robust biomarkers to monitor the changes. The study was registered at ClinicalTrials.gov (NCT01146314).

Ethnic differences in beta cell function occur independently of insulin sensitivity and pancreatic fat in black and white men

INTRODUCTION

It is increasingly recognized that type 2 diabetes (T2D) is a heterogenous disease with ethnic variations. Differences in insulin secretion, insulin resistance and ectopic fat are thought to contribute to these variations. Therefore, we aimed to compare postprandial insulin secretion and the relationships between insulin secretion, insulin sensitivity and pancreatic fat in men of black West African (BA) and white European (WE) ancestry.

RESEARCH DESIGN AND METHODS

A cross-sectional, observational study in which 23 WE and 23 BA men with normal glucose tolerance, matched for body mass index, underwent a mixed meal tolerance test with C peptide modeling to measure beta cell insulin secretion, an MRI to quantify intrapancreatic lipid (IPL), and a hyperinsulinemic-euglycemic clamp to measure whole-body insulin sensitivity.

RESULTS

Postprandial insulin secretion was lower in BA versus WE men following adjustment for insulin sensitivity (estimated marginal means, BA vs WE: 40.5 (95% CI 31.8 to 49.2) × 10³ vs 56.4 (95% CI 48.9 to 63.8) × 10³ pmol/m² body surface area × 180 min, p=0.008). There was a significantly different relationship by ethnicity between IPL and insulin secretion, with a stronger relationship in WE than in BA (r=0.59 vs r=0.39, interaction p=0.036); however, IPL was not a predictor of insulin secretion in either ethnic group following adjustment for insulin sensitivity.

CONCLUSIONS

Ethnicity is an independent determinant of beta cell function in black and white men. In response to a meal, healthy BA men exhibit lower insulin secretion compared with their WE counterparts for their given insulin sensitivity. Ethnic differences in beta cell function may contribute to the greater risk of T2D in populations of African ancestry.

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 ± 0.2 years; BMI 97.7 ± 0.2 percentile), 50 Hispanic (HW, 15.2 ± 0.3 years; 97.9 ± 0.3 percentile), and 12 non-Hispanic Black (NHB, 16.0 ± 0.6 years; 98.6 ± 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 A_1c (HbA_1c) was lowest in NHW (overall P < .001, NHW 5.2 ± 0.3 vs HW 5.5 ± 0.3 P < .001 vs 5.7 ± 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 HbA_1c 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.

The Combination of High Levels of Adiponectin and Insulin Resistance Are Affected by Aging in Non-Obese Old Peoples

BACKGROUND

Adipokine dysregulation is a key feature of insulin resistance and a metabolic syndrome associated with obesity. Low adiponectin levels are associated with higher risks of cardiovascular diseases (CVD). However, high adiponectin levels have also been associated with increased all-cause and cardiovascular mortality in the elderly. This adiponectin paradox has yet to be clarified, which has hindered our understanding of the biological role of adiponectin. Adipokine dysregulation and insulin resistance are also associated with energy-deprivation conditions, such as frailty in old age. The objective of this study was to investigate the association between plasma adiponectin and insulin resistance using the homeostasis model assessment for insulin resistance (HOMA-IR) classified by age. In particular, we sought to determine the factors of the subjects associated with both high adiponectin levels and HOMA-IR (H-adiponectin/H-HOMA) and high adiponectin levels and low HOMA-IR (H-adiponectin/L-HOMA).

METHODS

The eligible subjects in this cross-sectional study were 33,216 individuals who had undergone health checkups at the Physical Checkup Center of Sumitomo Hospital between April 2008 and December 2018. After excluding 26,371 individuals who were under 60 years old, 529 who had been taking medications for diabetes mellitus, and 690 with missing data, the present study included 5,673 (3,467 males, 2,206 females) subjects with no missing data. The relationship between serum adiponectin levels and HOMA-IR was assessed using logistic regression models adjusted by clinically relevant factors.

RESULTS

In the multivariable logistic regression analysis, age and low BMI were shown to positively correlate with the characteristics of H-adiponectin/H-HOMA. In females, systolic blood pressure was also shown to be an associated factor.

CONCLUSION

In conclusion, this study showed that aging or a low BMI may contribute to high adiponectin levels and insulin resistance.

Puberty Status Modifies the Effects of Genetic Variants, Lifestyle Factors and Their Interactions on Adiponectin: The BCAMS Study

BACKGROUND

Hypoadiponectinemia has been associated with various cardiometabolic disease states. Previous studies in adults have shown that adiponectin levels were regulated by specific genetic and behavioral or lifestyle factors. However, little is known about the influence of these factors on adiponectin levels in children, particularly as mitigated by pubertal development.

METHODS

We performed a cross-sectional analysis of data from 3,402 children aged 6-18 years from the Beijing Child and Adolescent Metabolic Syndrome (BCAMS) study. Pubertal progress was classified as prepubertal, midpuberty, and postpuberty. Six relevant single nucleotide polymorphisms (SNPs) were selected from previous genome-wide association studies of adiponectin in East Asians. Individual SNPs and two weighted genetic predisposition scores, as well as their interactions with 14 lifestyle factors, were analyzed to investigate their influence on adiponectin levels across puberty. The effect of these factors on adiponectin was analyzed using general linear models adjusted for age, sex, and BMI.

RESULTS

After adjustment for age, sex, and BMI, the associations between adiponectin levels and diet items, and diet score were significant at prepuberty or postpuberty, while the effect of exercise on adiponectin levels was more prominent at mid- and postpuberty. Walking to school was found to be associated with increased adiponectin levels throughout puberty. Meanwhile, the effect of WDR11-FGFR2-rs3943077 was stronger at midpuberty (P = 0.002), and ADIPOQ-rs6773957 was more effective at postpuberty (P = 0.005), while CDH13-rs4783244 showed the strongest association with adiponectin levels at all pubertal stages (all P < 3.24 × 10^-15). We further found that effects of diet score (P_interaction = 0.022) and exercise (P_interaction = 0.049) were stronger in children with higher genetic risk of hypoadiponectinemia, while higher diet score and exercise frequency attenuated the differences in adiponectin levels among children with different genetic risks.

CONCLUSIONS

Our study confirmed puberty modulates the associations between adiponectin, and genetic variants, lifestyle factors, and gene-by-lifestyle interactions. These findings provide new insight into puberty-specific lifestyle suggestions, especially in genetically susceptible individuals.

Association of plasma adiponectin with pulmonary hypertension, mortality and heart failure in African Americans: Jackson Heart Study

Background

Adiponectin is a polypeptide hormone related to obesity, and a known modulator of pulmonary vascular remodeling. Association between plasma adiponectin levels and pulmonary hypertension (PH) has not been studied in African Americans (AAs) who are disproportionately affected by obesity. The relationship between adiponectin and heart failure (HF) and mortality, outcomes associated with PH, is unclear.

Methods

We performed cross-sectional and longitudinal analysis to examine if there is an association between plasma adiponectin and PH and associated clinical outcomes, in participants of Jackson Heart Study (JHS). JHS is a prospective observational cohort study of heart disease in AAs from Jackson, Mississippi.

Results

Of the 3161 participants included in the study, mean age (SD) was 56.38 (12.61) years, 1028 were men (32.5%), and mean (SD) BMI was 31.42 (7.05) kg/m². Median (IQR) adiponectin was 4516.82 (2799.32–7065.85) ng/mL. After adjusting for potential confounders including BMI, higher adiponectin levels were associated with increased odds of PH (adjusted odds ratio per log increment in adiponectin, (1.81; 95% CI, 1.41–2.32). High adiponectin levels were also associated with associated HF admissions (adjusted hazard ratio [HR] per log increment in adiponectin, 1.63, 95% CI, 1.24–2.14) and mortality (adjusted HR per log increment in adiponectin, 1.20; 95% CI 1.02–1.41).

Conclusions

Elevated plasma adiponectin levels are associated with PH, HF admissions and mortality risk in AAs. High adiponectin levels may help identify an at-risk population that could be evaluated for targeted prevention and management strategies in future studies

Inverse correlation between serum high-molecular-weight adiponectin and proinsulin level in a Japanese population: The Dynamics of Lifestyle and Neighborhood Community on Health Study

Serum high-molecular-weight adiponectin (HMWA) has a positive correlation with insulin secretion in the Japanese population. To validate this correlation, we investigated the correlation between serum HMWA and proinsulin, a marker of β-cell dysfunction, in this population. A total of 488 participants (53.9% women) aged 35-79 years not taking oral hypoglycemic agents and/or insulin were enrolled. HMWA was significantly and inversely correlated with proinsulin adjusted for age and sex (partial regression coefficient β = -0.37; 95% confidence interval -0.46 to -0.28). When the participants were divided into two groups by median values of body mass index (23.2 kg/m² ), serum insulin (4.3 µU/mL) or homeostasis model assessment of insulin resistance (1.0), similar inverse correlations were observed adjusted for age and sex in both groups. Our results showed that the HMWA level was inversely correlated with the proinsulin level in a general Japanese population.

Glycemic variability indices determined by self-monitoring of blood glucose are associated with β-cell function in Chinese patients with type 2 diabetes

INTRODUCTION

Glycemic control plays an important role in diabetes management, and self-monitoring of blood glucose (SMBG) is critical to achieving good glycemic control. However, there are few studies about the relationship between SMBG-estimated glycemic indices and β-cell function. Here we investigated the association between glucose variation indices estimated by SMBG and β-cell function among Chinese patients with type 2 diabetes mellitus (T2DM).

METHODS

In this cross‑sectional study, 397 patients with T2DM were recruited from February 2015 to October 2016. β-cell function was monitored using the Homeostasis Model Assessment 2 (HOMA2)-%β index. The parameters evaluated by SMBG were the mean blood glucose (MBG), standard deviation of MBG (SDBG), largest amplitude of glycemic excursions (LAGE), and postprandial glucose excursion (PPGE).

RESULTS

HOMA2-%β was negatively correlated with SDBG, LAGE, PPGE, and MBG (r = -0.350, -0.346, -0.178, and -0.631, respectively; all p < 0.01). After adjusting for confounding characteristics (diabetic duration, triglyceride, total cholesterol, fasting C-peptide, HOMA2-insulin resistance index, hypoglycemia, and diabetic treatments) and glycated hemoglobin A1c on a continuous scale, odds ratios of SDBG, LAGE, PPGE, and MBG between the patients in the lowest and highest HOMA2-%β quartiles were 2.02 (1.14-3.57), 1.24 (1.04-1.49), 1.13 (0.86-1.51), and 2.26 (1.70-3.00). HOMA2-%β was independently associated with SDBG, LAGE, and MBG.

CONCLUSIONS

Increased SDBG and LAGE assessed by SMBG are associated with β-cell dysfunction in Chinese patients with T2DM.

Beta cell function and insulin sensitivity in obese youth with maturity onset diabetes of youth mutations vs type 2 diabetes in TODAY: Longitudinal observations and glycemic failure

OBJECTIVE

In treatment options for type 2 diabetes in adolescents and youth (TODAY), 4.5% of obese youth clinically diagnosed with type 2 diabetes (T2D) had genetic variants consistent with maturity onset diabetes of youth (MODY) diagnosis. The course of IS and β-cell function in obese youth with MODY remains unknown. In this secondary analysis, we examined IS and β-cell function in MODY vs. non-MODY obese youth at randomization and over time.

METHODS

Genetic data in TODAY included 426 non-MODY (T2D) and 22 MODY youth (7 glucokinase MODY mutation positive [GCK-MODY], 12 hepatocyte nuclear factor MODY mutation positive [HNF-MODY], 2 Insulin gene mutation [insulin (INS)-MODY], and 1 Kruppel-like factor 11 [KLF11-MODY]). Oral glucose tolerance test (OGTT)-derived IS, C-peptide index, and β-cell function relative to IS oral disposition index (oDI) was measured at randomization, and over 24 months in addition to total and high-molecular-weight adiponectin (HMWA).

RESULTS

At randomization, IS, total adiponectin, and HMWA were significantly higher in the two MODY groups than in non-MODY. β-cell function measured by C-peptide oDI was 3-fold higher in GCK-MODY than in HNF-MODY and 1.5-fold higher than non-MODY (P for both <.05). Glycemic failure rate was 75.0% in HNF-MODY, 46.9% in non-MODY, and zero in GCK-MODY youth. While the changes in IS and oDI were not different among the three groups in the first 6 months, IS improved from 6 to 24 months in HNF-MODY vs GCK-MODY youth.

CONCLUSIONS

In TODAY, β-cell function at randomization was worse in obese HNF-MODY youth compared with GCK-MODY youth, while insulin sensitivity was worse in non-MODY compared with the other two MODY groups. Over time, IS showed the greatest improvement in HNF-MODY youth. This raises the possibility that TODAY therapeutic modalities of insulin sensitization in these obese HNF-MODY youth may have played a beneficial role.

Circulating Osteonectin and Adipokine Profiles in Relation to Metabolically Healthy Obesity in Chinese Children: Findings From BCAMS

Background The role of adipokine dysregulation in determining the metabolic fate of obesity is not well studied. We aimed to examine whether the matricellular protein osteonectin and the profiles of certain adipokines could differentiate metabolically healthy obese ( MHO ) versus metabolically unhealthy obese phenotypes in childhood. Methods and Results This study included 1137 obese children and 982 normal-weight healthy ( NWH ) controls recruited from the BCAMS (Beijing Child and Adolescent Metabolic Syndrome) study. MHO was defined by the absence of insulin resistance and/or any metabolic syndrome components. Six adipokines-osteonectin, leptin, adiponectin, resistin, FGF21 (fibroblast growth factor 21), and RBP-4 (retinol binding protein 4)-were assessed. Approximately 20% of obese children displayed the MHO phenotype. MHO children had a more favorable adipokine profile than metabolically unhealthy obese children, with lower osteonectin, leptin, and RBP -4 and higher adiponectin (all P<0.05). Compared with normal-weight healthy controls, MHO children displayed increased leptin, resistin, and RBP -4 levels and reduced adiponectin concentrations (all P<0.05) but similar osteonectin and FGF 21 levels. Among obese subjects, decreased osteonectin (odds ratio [OR]: 0.82; 95% confidence interval [CI] per standard deviation, 0.70-0.97), RBP -4 (OR: 0.77; 95% CI per standard deviation, 0.64-0.93), and leptin/adiponectin ratio (OR: 0.58; 95% CI per standard deviation, 0.43-0.77) were independent predictors of MHO . In addition, compared with children without abnormalities, those with any 3 adipokine abnormalities were 80% less likely to exhibit the MHO phenotype ( OR : 0.20; 95% CI , 0.10-0.43) and 3 times more likely to have metabolic syndrome ( OR : 2.77; 95% CI , 1.52-5.03). Conclusions These findings suggest that dysregulation of adipokines might govern the metabolic consequences of obesity in children. Low osteonectin levels, along with a healthy adipokine profile, might be used as an early marker of the MHO phenotype.

Predictors of response to insulin therapy in youth with poorly-controlled type 2 diabetes in the TODAY trial

OBJECTIVE

To understand the factors associated with glycemic control after starting insulin in youth with type 2 diabetes following glycemic failure (persistent HbA1c ≥8%) with metformin alone, metformin + rosiglitazone or metformin + lifestyle in the TODAY study.

METHODS

Change in HbA1c after add-on insulin therapy and the factors predictive of glycemic response were evaluated. At 1-year postinsulin initiation, 253 youth had a mean of 3.9 ± 1.0 visits since the time of insulin initiation. Participants were divided into three groups according to glycemic control: consistent decrease in HbA1c by ≥0.5%, change <0.5%, or consistent increase in HbA1c ≥0.5%, at 75% or more of the visits.

RESULTS

Within 1-year postinsulin initiation, 33.2% of participants had a consistent HbA1c decrease of ≥0.5%, 46.2% changed HbA1c <0.5%, and 20.6% had an increase ≥0.5%. At randomization into TODAY and at time of insulin initiation, the three glycemia groups were similar in age, sex, race-ethnicity, pubertal stage, BMI z-score, diabetes duration, and insulin secretion indices. Consistent HbA1c improvement was associated with higher insulin sensitivity (1/fasting insulin) at randomization and at time of failure, higher adiponectin at randomization, and was not associated with indices of β-cell function.

CONCLUSIONS

Response to add-on insulin was highly variable among youth in TODAY. Greater insulin sensitivity and higher adiponectin concentrations at randomization were associated with improved glycemic control after initiation of insulin. Due to limited information on adherence to insulin injections, the roles of adherence to the prescribed insulin regimen or psychosocial factors are unknown.

Changes in Visceral and Subcutaneous Fat in Youth With Type 2 Diabetes in the TODAY Study

OBJECTIVE

In the Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) study, metformin plus rosiglitazone (M + R) maintained glycemic control better than metformin alone (M) or metformin plus lifestyle (M + L) in youth with type 2 diabetes (T2D). We hypothesized that changes in visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) would explain the differential treatment effects on glycemia.

RESEARCH DESIGN AND METHODS

In 626 youth ages 11-17 years with T2D duration <2 years, VAT and SAT were estimated by DXA at baseline and at 6 and 24 months. Changes from baseline were analyzed in linear mixed models.

RESULTS

Baseline mean age was 13.9 years, 66.4% were female, 72.2% were Hispanic/non-Hispanic black, and 20.3% were non-Hispanic white (NHW). Mean BMI was 33.7 kg/m². VAT increased more in M + R (13.1%) than M + L (3.9%, P = 0.0006) or M (6.5%, P = 0.0146). SAT also increased more in M + R (13.3%) than in M + L (5.4%, P < 0.0001) or M (6.4%, P = 0.0005), indicating no significant fat redistribution in M + R. In NHWs, VAT increased more in M + R than M (P = 0.0192) and M + L (P = 0.0482) but did not explain the race-ethnicity differences in treatment effects on glycemic control among treatment groups. VAT and SAT increases correlated with higher HbA_1c, lower insulin sensitivity, and lower oral disposition index (all P < 0.05), but associations did not differ by treatment group.

CONCLUSIONS

In contrast to the existing reports in adults with T2D, in TODAY, M + R resulted in the most VAT accumulation compared with M + L or M. Differential effects on depot-specific indirect measures of adiposity are unrelated to treatment effects in sustaining glycemic control. Additional studies are needed to understand the clinical markers of metabolic risk profile in youth with T2D on rosiglitazone.

Fructose Consumption Contributes to Hyperinsulinemia in Adolescents With Obesity Through a GLP-1-Mediated Mechanism

CONTEXT

The consumption of high-fructose beverages is associated with a higher risk for obesity and diabetes. Fructose can stimulate glucagon-like peptide 1 (GLP-1) secretion in lean adults, in the absence of any anorexic effect.

OBJECTIVE

We hypothesized that the ingestion of glucose and fructose may differentially stimulate GLP-1 and insulin response in lean adolescents and adolescents with obesity.

DESIGN

We studied 14 lean adolescents [four females; 15.9 ± 1.6 years of age; body mass index (BMI), 21.8 ± 2.2 kg/m2] and 23 adolescents with obesity (five females; 15.1 ± 1.6 years of age; BMI, 34.5 ± 4.6 kg/m2). Participants underwent a baseline oral glucose tolerance test to determine their glucose tolerance and estimate insulin sensitivity and β-cell function [oral disposition index (oDIcpep)]. Eligible subjects received, in a double-blind, crossover design, 75 g of glucose or fructose. Plasma was obtained every 10 minutes for 60 minutes for the measures of glucose, insulin, and GLP-1 (radioimmunoassay) and glucose-dependent insulinotropic polypeptide (GIP; ELISA). Incremental glucose and hormone levels were compared between lean individuals and those with obesity by a linear mixed model. The relationship between GLP-1 increment and oDIcpep was evaluated by regression analysis.

RESULTS

Following the fructose challenge, plasma glucose excursions were similar in both groups, yet the adolescents with obesity exhibited a greater insulin (P < 0.001) and GLP-1 (P < 0.001) increase than did their lean peers. Changes in GIP were similar in both groups. After glucose ingestion, the GLP-1 response (P < 0.001) was higher in the lean group. The GLP-1 increment during 60 minutes from fructose drink was correlated with a lower oDIcpep (r2 = 0.22, P = 0.009).

CONCLUSION

Fructose, but not glucose, ingestion elicits a higher GLP-1 and insulin response in adolescents with obesity than in lean adolescents. Fructose consumption may contribute to the hyperinsulinemic phenotype of adolescent obesity through a GLP-1-mediated mechanism.

The Shape of the Glucose Response Curve During an Oral Glucose Tolerance Test: Forerunner of Heightened Glycemic Failure Rates and Accelerated Decline in β-Cell Function in TODAY

OBJECTIVE

Obese youth without diabetes with monophasic oral glucose tolerance test (OGTT) glucose response curves have lower insulin sensitivity and impaired β-cell function compared with those with biphasic curves. The OGTT glucose response curve has not been studied in youth-onset type 2 diabetes. Here we test the hypothesis that the OGTT glucose response curve at randomization in youth in the TODAY (Treatment Options for Type 2 Diabetes in Adolescents and Youth) study forecasts heightened glycemic failure rates and accelerated decline in β-cell function.

RESEARCH DESIGN AND METHODS

OGTTs (n = 662) performed at randomization were categorized as monophasic, biphasic, or incessant increase. Demographics, insulin sensitivity (1/fasting insulin), C-peptide index (△C₃₀/△G₃₀), and β-cell function relative to insulin sensitivity (oral disposition index [oDI]) were compared among the three groups.

RESULTS

At randomization, 21.7% had incessant increase, 68.6% monophasic, and 9.7% biphasic glucose response curves. The incessant increase group had similar insulin sensitivity but significantly lower C-peptide index and lower oDI, despite similar diabetes duration, compared with the other two groups. Glycemic failure rates were higher in the incessant increase group (58.3%) versus the monophasic group (42.3%) versus the biphasic group (39.1%) (P < 0.0001). The 6-month decline in C-peptide index (32.8% vs. 18.1% vs. 13.2%) and oDI (32.2% vs. 11.6% vs. 9.1%) was greatest in incessant increase versus monophasic and biphasic with no difference in insulin sensitivity.

CONCLUSIONS

In the TODAY study cohort, an incessant increase in the OGTT glucose response curve at randomization reflects reduced β-cell function and foretells increased glycemic failure rates with accelerated deterioration in β-cell function independent of diabetes duration and treatment assignment compared with monophasic and biphasic curves. The shape of the OGTT glucose response curve could be a metabolic biomarker prognosticating the response to therapy in youth with type 2 diabetes.

Trajectories of changes in glucose tolerance in a multiethnic cohort of obese youths: an observational prospective analysis

BACKGROUND

Type 2 diabetes is preceded by a prediabetic stage of impaired glucose tolerance that affects 10-23% of youth and is expected to double over the next decade. The natural history of impaired glucose tolerance and the determinants of β-cell dynamic response have never been investigated longitudinally in young people. We aimed to investigate the clinical and metabolic determinants of longitudinal glucose tolerance changes and β-cell function in a multiethnic cohort of obese youth.

METHODS

We followed up prospectively a multiethnic cohort of overweight and obese (body-mass index >85th percentile) adolescents with baseline normal glucose tolerance (plasma glucose <140 mg/dL) or impaired glucose tolerance (plasma glucose 140-199 mg/dL) at the Yale Pediatric Obesity Clinic (CT, USA). All participants underwent a 3-h oral glucose tolerance test at baseline and after 2 years to estimate insulin secretion (oral disposition index) in the context of body insulin sensitivity. As part of standard care at the clinic, all participants received dietary advice and underwent dietary assessment every 5-6 months. No structured lifestyle or pharmacological intervention was administered.

FINDINGS

Between January, 2010, and December, 2016, 526 adolescents (mean age 12·7 years, range 10·6-14·2) were enrolled to our study. At baseline, 364 had normal and 162 had impaired glucose tolerance. Median follow-up was 2·9 years (IQR 2·7-3·1). 105 (65%) of 162 with impaired glucose tolerance at baseline reverted to normal glucose tolerance at follow-up, 44 (27%) had persistent impaired glucose tolerance, and 13 (8%) progressed to type 2 diabetes. A feature of reversion to normal glucose tolerance was a roughly four-fold increase in the oral disposition index (from median 0·94 [IQR 0·68-1·35] at baseline to 3·90 [2·58-6·08] at follow-up; p<0·0001) and a significantly higher oral disposition index at follow-up compared with participants who maintained normal glucose tolerance across the study period (median 3·90 [IQR 2·58-6·08] vs 1·59 [1·12-2·23]; p<0·0001). By contrast, a decrease in insulin secretion was seen in participants who had persistent impaired glucose tolerance (median 1·31 [IQR 1·01-1·85]; p<0·0001) or who progressed to type 2 diabetes (0·20 [0·12-0·58]; p<0·0001), compared with participants who maintained normal glucose tolerance across the study period. Non-Hispanic white ethnic origin conferred five times the odds of reversion to normal glucose tolerance compared with non-Hispanic black ethnic origin (OR 5·06, 95% CI 1·86-13·76; p=0·001), with a two times greater annual increase in the oral disposition index (β 2·32, 95% CI 0·05-4·60; p=0·045).

INTERPRETATION

Impaired glucose tolerance is highly reversible in obese adolescents. Ethnic origin is the main clinical modifier of the dynamic β-cell response to prediabetic hyperglycaemia and, thus, determines the reversibility of impaired glucose tolerance, or its persistence. Therapeutic interventions for impaired glucose tolerance should target the specific mechanisms underpinning glucose tolerance changes in high-risk ethnic groups.

FUNDING

National Institutes of Health (National Institute of Child Health and Human Development, National Center for Research Resources, and National Institute of Diabetes and Digestive and Kidney Diseases), American Diabetes Association, International Society for Pediatric and Adolescent Diabetes, Robert Leet Patterson and Clara Guthrie Patterson Trust, European Society for Pediatric Endocrinology, American Heart Association, and the Allen Foundation.

Serum adiponectin and insulin secretion: A direct or inverse association?

We investigated the association between serum high molecular weight (HMW) adiponectin and insulin secretion in a population-based study, with or without adjustment for insulin sensitivity. A total of 488 participants (263 women) were included in the present study. Insulin secretion was estimated using the homeostasis model assessment of β-cell function ± adjustment for insulin resistance using the disposition index. Multivariate analysis showed that HMW adiponectin was significantly and inversely associated with homeostasis model assessment of β-cell function (partial regression coefficient -0.19, 95% confidence interval -0.28, -0.10, P < 0.0001). However, HMW adiponectin was significantly and positively associated with disposition index (partial regression coefficient 0.15, 95% confidence interval 0.06, 0.24, P = 0.0016). The present study showed that a positive association between HMW adiponectin levels and insulin secretion evaluated using an index incorporating adjustment for insulin resistance was identified, and vice versa using an index that did not adjust for insulin resistance.

From Sea to Shining Sea and the Great Plains to Patagonia: A Review on Current Knowledge of Diabetes Mellitus in Hispanics/Latinos in the US and Latin America

The past two decades have witnessed many advances in the prevention, treatment, and control of diabetes mellitus (DM) and its complications. Increased screening has led to a greater recognition of type 2 diabetes mellitus (type 2 DM) and prediabetes; however, Hispanics/Latinos, the largest minority group in the US, have not fully benefited from these advances. The Hispanic/Latino population is highly diverse in ancestries, birth places, cultures, languages, and socioeconomic backgrounds, and it populates most of the Western Hemisphere. In the US, the prevalence of DM varies among Hispanic/Latino heritage groups, being higher among Mexicans, Puerto Ricans, and Dominicans, and lower among South Americans. The risk and prevalence of diabetes among Hispanics/Latinos are significantly higher than in non-Hispanic Whites, and nearly 40% of Hispanics/Latinos with diabetes have not been formally diagnosed. Despite these striking facts, the representation of Hispanics/Latinos in pharmacological and non-pharmacological clinical trials has been suboptimal, while the prevalence of diabetes in these populations continues to rise. This review will focus on the epidemiology, etiology and prevention of type 2 DM in populations of Latin American origin. We will set the stage by defining the terms Hispanic, Latino, and Latin American, explaining the challenges identifying Hispanics/Latinos in the scientific literature and databases, describing the epidemiology of diabetes-including type 2 DM and gestational diabetes mellitus (GDM)-and cardiovascular risk factors in Hispanics/Latinos in the US and Latin America, and discussing trends, and commonalities and differences across studies and populations, including methodology to ascertain diabetes. We will discuss studies on mechanisms of disease, and research on prevention of type 2 DM in Hispanics/Latinos, including women with GDM, youth and adults; and finalize with a discussion on lessons learned and opportunities to enhance research, and, consequently, clinical care oriented toward preventing type 2 DM in Hispanics/Latinos in the US and Latin America.