A pragmatic randomized clinical trial of insulin glargine 300 U/mL vs first-generation basal insulin analogues in insulin-naïve adults with type 2 diabetes: 6-month outcomes of the ACHIEVE Control study.

AIMS: To compare the safety and efficacy of insulin glargine 300 U/mL (Gla-300) versus first-generation standard-of-care basal insulin analogues (SOC-BI; insulin glargine 100 U/mL or insulin detemir) at 6 months. METHODS: In the 12-month, open-label, multicentre, randomized, pragmatic ACHIEVE Control trial, insulin-naïve adults with type 2 diabetes (T2D) and glycated haemoglobin (HbA1c) 64 to 97 mmol/mol (8.0%-11.0%) after ≥1 year of treatment with ≥2 diabetes medications were randomized to Gla-300 or SOC-BI. The composite primary endpoint, evaluated at 6 months, was the proportion of participants achieving individualized HbA1c targets per Healthcare Effectiveness Data and Information Set (HEDIS) criteria without documented symptomatic (blood glucose ≤3.9 mmol/L [≤70 mg/dL]) or severe hypoglycaemia at any time of the day at 6 months. RESULTS: Of 1651 and 1653 participants randomized to Gla-300 and SOC-BI, respectively, 31.3% and 27.9% achieved the composite primary endpoint at 6 months (odds ratio [OR] 1.19, 95% confidence interval [CI] 1.01-1.39; P = 0.03 for superiority); 78.4% and 75.3% had no documented symptomatic or severe hypoglycaemia (OR 1.19, 95% CI 1.01-1.41). Changes from baseline to month 6 in HbA1c, fasting plasma glucose, weight, and BI analogue dose were similar between groups. CONCLUSIONS: Among insulin-naïve adults with poorly controlled T2D, Gla-300 was associated with a statistically significantly higher proportion of participants achieving individualized HEDIS HbA1c targets without documented symptomatic or severe hypoglycaemia (vs SOC-BI) in a real-life population managed in a usual-care setting. The ACHIEVE Control study results add value to treatment decisions and options for patients, healthcare providers, payers and decision makers.

Low Blood Glucose Index and Hypoglycaemia Risk: Insulin Glargine 300 U/mL Versus Insulin Glargine 100 U/mL in Type 2 Diabetes.

INTRODUCTION: We examined differences in hypoglycaemia risk between insulin glargine 300 U/mL (Gla-300) and insulin glargine 100 U/mL (Gla-100) in individuals with type 2 diabetes (T2DM) using the low blood glucose index (LBGI). METHODS: Daily profiles of self-monitored plasma glucose (SMPG) from the EDITION 2, EDITION 3 and SENIOR treat-to-target trials of Gla-300 versus Gla-100 were used to compute the LBGI, which is an established metric of hypoglycaemia risk. The analysis also examined documented (blood glucose readings < 3.0 mmol/L [54 mg/dL]) symptomatic hypoglycaemia (DSH). RESULTS: Overall LBGI in EDITION 2 and SENIOR and night-time LBGI in all three trials were significantly (p < 0.05) lower with Gla-300 versus Gla-100. The largest differences between Gla-300 and Gla-100 were observed during the night. In all three trials, individual LBGI results correlated with the observed number of DSH episodes per participant (EDITION 2 [r = 0.35, p < 0.001]; EDITION 3 [r = 0.26, p < 0.001]; SENIOR [r = 0.30, p < 0.001]). Participants at moderate risk of experiencing hypoglycaemia (defined as LBGI > 1.1) reported 4- to 8-fold more frequent DSH events than those at minimal risk (LBGI ≤ 1.1) (p ≤ 0.009). CONCLUSIONS: The LBGI identified individuals with T2DM at risk for hypoglycaemia using SMPG data and correlated with the number of DSH events. Using the LBGI metric, a lower risk of hypoglycaemia with Gla-300 than Gla-100 was observed in all three trials. The finding that differences in LBGI are greater at night is consistent with previously published differences in the pharmacokinetic profiles of Gla-300 and Gla-100, which provides the physiological foundation for the presented results.

Real-world outcomes of treatment with insulin glargine 300 U/mL versus standard-of-care in people with uncontrolled type 2 diabetes mellitus.

Objective: To compare real-world outcomes with newer (insulin glargine 300 U/mL; Gla-300) versus standard of care (SoC) basal insulins (BIs) in the REACH (insulin-naïve; NCT02967224) and REGAIN (basal insulin-treated; NCT02967211) studies in participants with uncontrolled type 2 diabetes (T2DM) in Europe and Brazil.Methods: In these open-label, parallel-group, pragmatic studies, patients (HbA1c > 7.0%) were randomized to Gla-300 or SoC BI for a 6-month treatment period (to demonstrate non-inferiority of Gla-300 vs SoC BIs for HbA1c change [non-inferiority margin 0.3%]) and a 6-month extension period (continuing with their assigned treatment). Insulin titration/other medication changes were at investigator/patient discretion post-randomization.Results: Overall, 703 patients were randomized to treatment in REACH (Gla-300, n = 352; SoC, n = 351) and 609 (Gla-300, n = 305, SoC, n = 304) in REGAIN. The primary outcome, non-inferiority of Gla-300 versus SoC for HbA1c change from baseline to month 6, was met in REACH (least squares [LS] mean difference 0.12% [95% CI -0.046 to 0.281]) but not REGAIN (LS mean difference 0.17% [0.015-0.329]); no between-treatment difference in HbA1c change was shown after 12 months in either study. BI dose increased minimally from baseline to 12 months in REACH (Gla-300, +0.17 U/kg; SoC, +0.15 U/kg) and REGAIN (Gla-300, +0.11 U/kg; SoC, +0.07 U/kg). Hypoglycemia incidence was low and similar between treatment arms in both studies.Conclusions: In both REACH and REGAIN, no differences in glycemic control or hypoglycemia outcomes with Gla-300 versus SoC BIs were seen over 12 months. However, the suboptimal insulin titration in REACH and REGAIN limits comparisons of outcomes between treatment arms and suggests that more titration instruction/support may be required for patients to fully derive the benefits from newer basal insulin formulations.

The Diabetes Unmet Need with Basal Insulin Evaluation (DUNE) study in type 2 diabetes: Achieving HbA1c targets with basal insulin in a real-world setting.

AIMS: To describe in a real-world setting the achievement of physician-selected individualized HbA1c targets in individuals with type 2 diabetes, newly or recently initiated with basal insulin, and the association of hypoglycaemia with target achievement. MATERIALS AND METHODS: A 12-week, prospective, single-arm, observational study of adults with type 2 diabetes, either newly initiated with any basal insulin or start on basal insulin within the preceding 12 months. At enrollment, eligible participants from 28 countries were treated with or without oral antihyperglycaemic drugs and/or GLP-1 receptor agonists. RESULTS: Individualized targets for almost all of the 3139 evaluable participants (99.7%) had been set by their physicians, with 57% of participants having HbA1c targets between 7.0% and <7.5% (53 and <58 mmol/mol). By week 12, 28% and 27% of newly and previously initiated participants, respectively, achieved individualized HbA1c targets with modest average increases in daily insulin dose of 9 and 5 U (0.10 and 0.06 U/kg), respectively, from baseline (14 and 23 U [0.17 and 0.29 U/kg], respectively). Overall, 16% of participants experienced at least one episode of hypoglycaemia. Both the incidence and frequency of hypoglycaemia, but not the severity, were positively associated with a higher likelihood of achieving individualized HbA1c targets (P < 0.05). CONCLUSIONS: In this prospective real-world study, most participants using basal insulin did not achieve the individualized HbA1c targets set by their physicians. Participants who experienced symptomatic hypoglycaemia were more likely to achieve HbA1c targets than those who did not.

A post-hoc pooled analysis to evaluate the risk of hypoglycaemia with insulin glargine 300 U/mL (Gla-300) versus 100 U/mL (Gla-100) over wider nocturnal windows in individuals with type 2 diabetes on a basal-only insulin regimen.

The EDITION trials in type 2 diabetes demonstrated comparable glycaemic control with less nocturnal and anytime (24-hour) hypoglycaemia for insulin glargine 300 U/mL (Gla-300) versus glargine 100 U/mL (Gla-100). However, the predefined nocturnal window (0:00-5:59 AM) may not be the most relevant for clinical practice. This post-hoc analysis compared expansions of the predefined nocturnal interval during basal insulin treatment without prandial insulin. Patient-level, 6-month data, pooled from the EDITION 2 and 3 trials and the EDITION JP 2 trial (N = 1922, basal insulin only) were analysed. Accompanying hypoglycaemia during treatment with Gla-300 was compared to that during treatment with Gla-100, using predefined (0:00-5:59 AM) and expanded (10:00 PM-5:59 AM, 0:00-7:59 AM, 10:00 PM to pre-breakfast SMPG) windows. Confirmed (≤3.9 mmol/L [≤70 mg/dL]) or severe hypoglycaemic events were reported most frequently between 6:00 AM and 8:00 AM. Windows expanded beyond 6:00 AM included more events than other windows. The percentage of participants with at least one event was lower with Gla-300 than Gla-100 in all windows examined. Expanding the nocturnal interval allows better assessment of the risk of hypoglycaemia associated with basal insulin. The risk of nocturnal hypoglycaemia was consistently lower with Gla-300 versus Gla-100 using all four windows.

More Similarities Than Differences Testing Insulin Glargine 300 Units/mL Versus Insulin Degludec 100 Units/mL in Insulin-Naive Type 2 Diabetes: The Randomized Head-to-Head BRIGHT Trial.

OBJECTIVE: To compare insulin glargine 300 units/mL (Gla-300) versus insulin degludec 100 units/mL (IDeg-100) in this first head-to-head randomized controlled trial. RESEARCH DESIGN AND METHODS: BRIGHT (NCT02738151) was a multicenter, open-label, active-controlled, two-arm, parallel-group, 24-week, noninferiority study in insulin-naive patients with uncontrolled type 2 diabetes. Participants were randomized 1:1 to evening dosing with Gla-300 (N = 466) or IDeg-100 (N = 463), titrated to fasting self-monitored plasma glucose of 80-100 mg/dL. The primary end point was HbA1c change from baseline to week 24. Safety end points included incidence and event rates of hypoglycemia. RESULTS: At week 24, HbA1c improved similarly from baseline values of 8.7% (72 mmol/mol) in the Gla-300 group and 8.6% (70 mmol/mol) in the IDeg-100 group to 7.0% (53 mmol/mol)-least squares mean difference -0.05% (95% CI -0.15 to 0.05) (-0.6 mmol/mol [-1.7 to 0.6])-demonstrating noninferiority of Gla-300 versus IDeg-100 (P < 0.0001). Hypoglycemia incidence and event rates over 24 weeks were comparable with both insulins, whereas during the active titration period (0-12 weeks) the incidence and rate of anytime (24-h) confirmed hypoglycemia (≤70 and <54 mg/dL) were lower with Gla-300. Both insulins were properly titrated and exhibited no specific safety concerns. CONCLUSIONS: Gla-300 and IDeg-100 provided similar glycemic control improvements with relatively low hypoglycemia risk. Hypoglycemia incidence and rates were comparable with both insulins during the full study period but lower in favor of Gla-300 during the titration period. The choice between these longer-acting basal insulins may be determined by factors such as access and cost, alongside clinical considerations.

Glycaemic control and hypoglycaemia benefits with insulin glargine 300 U/mL extend to people with type 2 diabetes and mild-to-moderate renal impairment.

AIM: To investigate the impact of renal function on the safety and efficacy of insulin glargine 300 U/mL (Gla-300) and insulin glargine 100 U/mL (Gla-100). MATERIALS AND METHODS: A meta-analysis was performed using pooled 6-month data from the EDITION 1, 2 and 3 trials (N = 2496). Eligible participants, aged ≥18 years with a diagnosis of type 2 diabetes (T2DM), were randomized to receive once-daily evening injections of Gla-300 or Gla-100. Pooled results were assessed by two renal function subgroups: estimated glomerular filtration rate (eGFR) <60 and ≥60 mL/min/1.73 m2 . RESULTS: The decrease in glycated haemoglobin (HbA1c) after 6 months and the proportion of individuals with T2DM achieving HbA1c targets were similar in the Gla-300 and Gla-100 groups, for both renal function subgroups. There was a reduced risk of nocturnal (12:00-5:59 am) confirmed (≤3.9 mmol/L [≤70 mg/dL]) or severe hypoglycaemia with Gla-300 in both renal function subgroups (eGFR <60 mL/min/1.73 m2 : relative risk [RR] 0.76 [95% confidence interval {CI} 0.62-0.94] and eGFR ≥60 mL/min/1.73 m2 : RR 0.75 [95% CI 0.67-0.85]). For confirmed (≤70 mg/dL [≤3.9 mmol/L]) or severe hypoglycaemia at any time of day (24 hours) the hypoglycaemia risk was lower with Gla-300 vs Gla-100 in both the lower (RR 0.94 [95% CI 0.86-1.03]) and higher (RR 0.90 [95% CI 0.85-0.95]) eGFR subgroups. CONCLUSIONS: Gla-300 provided similar glycaemic control to Gla-100, while indicating a reduced overall risk of confirmed (≤3.9 and <3.0 mmol/L [≤70 and <54 mg/dL]) or severe hypoglycaemia, with no significant difference between renal function subgroups.

Glycaemic control and hypoglycaemia in people with type 2 diabetes switching from twice-daily basal insulin to once-daily insulin glargine 300 U/mL or insulin glargine 100 U/mL (EDITION 1 and EDITION 2 subgroup analysis).

In this post hoc analysis we compared glycaemic control and hypoglycaemia between insulin glargine 300 U/mL (Gla-300) and glargine 100 U/mL (Gla-100) administered once daily in people with type 2 diabetes (T2DM) from the EDITION 1 (basal plus mealtime insulin) and EDITION 2 (basal insulin plus oral antihyperglycaemic drugs) trials who were previously receiving twice-daily insulin. At randomization, 16.9% and 20.0% of people in EDITION 1 and 2, respectively, were receiving twice-daily basal insulin. Glycated haemoglobin change from baseline to Month 6 was similar over 6 months with Gla-300 or Gla-100 (least squares mean difference -0.01%; 95% confidence interval [CI] -0.27 to 0.24] in EDITION 1 and 0.16%; 95% CI -0.25 to 0.57, in EDITION 2). Participants previously receiving twice-daily insulin in EDITION 1 had a lower risk of confirmed (≤3.9 mmol/L [≤70 mg/dL]) or severe hypoglycaemia with Gla-300 vs Gla-100 at night (00:00-05:59 hours), but not at any time (24 hours); in EDITION 2 the risk was reduced at night and any time (24 hours). In conclusion, Gla-300 provided similar glycaemic control with less hypoglycaemia compared with Gla-100 in people with T2DM switching from twice-daily to once-daily basal insulin.

Achieve control: a pragmatic clinical trial of insulin glargine 300 U/mL versus other basal insulins in insulin-naïve patients with type 2 diabetes.

OBJECTIVE: This study aims to compare the effectiveness of insulin glargine 300 U/mL (Gla-300) with its accompanying patient support program with that of other basal insulin and available patient support programs in patients with type 2 diabetes (T2D) in a real-world setting in terms of achieving HEDIS (Healthcare Effectiveness Data and Information Set) individualized glycemic targets without documented symptomatic hypoglycemia. METHODS: Achieve Control is a US-based, multicenter, randomized, open-label, active-controlled, parallel group pragmatic Phase IV trial in insulin-naïve patients with T2D uncontrolled on ≥2 oral antidiabetes drugs (OAD) and/or glucagon-like peptide-1 receptor antagonists (GLP-1 RA). Inclusion criteria include a diagnosis of T2D, age ≥18 years, and glycated hemoglobin (HbA1c) between 8.0% and 11.0%. Patients will be assigned to either the Gla-300 or other basal insulin group. The primary end point is the proportion of patients achieving HEDIS HbA1c targets (<8.0% [64 mmol/mol] in patients with comorbidities or aged ≥65 years; <7.0% [58 mmol/mol] in all other patients) without occurrence of symptomatic hypoglycemia (blood glucose ≤70 mg/dL) from baseline to 6 months. Secondary end points include rates of documented symptomatic nocturnal hypoglycemia and severe hypoglycemia; change from baseline in HbA1c, fasting glucose, and body weight; treatment persistence; patient-reported outcomes; and healthcare resource utilization. Planned enrollment is 3270 patients across approximately 400 clinical sites. CONCLUSION: Pragmatic clinical trials offer the potential to assess comparative effectiveness in broadly based patient populations receiving care (with or without a corresponding educational support program) in real-world clinical settings. The results of Achieve Control should elucidate the benefits of management of T2D with Gla-300 versus other basal insulins in terms of patient outcomes, experiences, and perceptions, and its impact on healthcare resource utilization and cost. CLINICAL TRIAL REGISTRATION: www.clinicaltrials.gov identifier is NCT02451137.

Rare variants in single-minded 1 (SIM1) are associated with severe obesity.

Single-minded 1 (SIM1) is a basic helix-loop-helix transcription factor involved in the development and function of the paraventricular nucleus of the hypothalamus. Obesity has been reported in Sim1 haploinsufficient mice and in a patient with a balanced translocation disrupting SIM1. We sequenced the coding region of SIM1 in 2,100 patients with severe, early onset obesity and in 1,680 controls. Thirteen different heterozygous variants in SIM1 were identified in 28 unrelated severely obese patients. Nine of the 13 variants significantly reduced the ability of SIM1 to activate a SIM1-responsive reporter gene when studied in stably transfected cells coexpressing the heterodimeric partners of SIM1 (ARNT or ARNT2). SIM1 variants with reduced activity cosegregated with obesity in extended family studies with variable penetrance. We studied the phenotype of patients carrying variants that exhibited reduced activity in vitro. Variant carriers exhibited increased ad libitum food intake at a test meal, normal basal metabolic rate, and evidence of autonomic dysfunction. Eleven of the 13 probands had evidence of a neurobehavioral phenotype. The phenotypic similarities between patients with SIM1 deficiency and melanocortin 4 receptor (MC4R) deficiency suggest that some of the effects of SIM1 deficiency on energy homeostasis are mediated by altered melanocortin signaling.

Rosiglitazone improves glucose metabolism in obese adolescents with impaired glucose tolerance: a pilot study.

Impaired glucose tolerance (IGT) is a prediabetic state fueling the rising prevalence of type 2 diabetes mellitus (T2DM) in adolescents with marked obesity. Given the importance of insulin resistance, the poor ß-cell compensation and the altered fat partitioning as underlying defects associated with this condition, it is crucial to determine the extent to which these underlying abnormalities can be reversed in obese adolescents. We tested, in a pilot study, whether rosiglitazone (ROSI) restores normal glucose tolerance (NGT) in obese adolescents with IGT by improving insulin sensitivity and ß-cell function. In a small randomized, double-blind, placebo (PLA)-controlled study, lasting 4 months, 21 obese adolescents with IGT received either ROSI (8 mg daily) (n = 12, 5M/7F, BMI z-score 2.44 ± 0.11) or PLA (n = 9, 4M/5F, BMI z-score 2.41 ± 0.09). Before and after treatment, all subjects underwent oral glucose tolerance test (OGTT), hyperinsulinemic-euglycemic clamp, magnetic resonance imaging, and (1)H NMR assessment. After ROSI treatment, 58% of the subjects converted to NGT compared to 44% in the PLA group (P = 0.528). Restoration of NGT was associated with a significant increase in insulin sensitivity (P < 0.04) and a doubling in the disposition index (DI) (P < 0.04), whereas in the PLA group, these changes were not significant. The short-term use of ROSI appears to be safe in obese adolescents with IGT. ROSI restores NGT by increasing peripheral insulin sensitivity and ß-cell function, two principal pathophysiological abnormalities of IGT.

Cellularity and adipogenic profile of the abdominal subcutaneous adipose tissue from obese adolescents: association with insulin resistance and hepatic steatosis.

OBJECTIVE: We explored whether the distribution of adipose cell size, the estimated total number of adipose cells, and the expression of adipogenic genes in subcutaneous adipose tissue are linked to the phenotype of high visceral and low subcutaneous fat depots in obese adolescents. RESEARCH DESIGN AND METHODS: A total of 38 adolescents with similar degrees of obesity agreed to have a subcutaneous periumbilical adipose tissue biopsy, in addition to metabolic (oral glucose tolerance test and hyperinsulinemic euglycemic clamp) and imaging studies (MRI, DEXA, (1)H-NMR). Subcutaneous periumbilical adipose cell-size distribution and the estimated total number of subcutaneous adipose cells were obtained from tissue biopsy samples fixed in osmium tetroxide and analyzed by Beckman Coulter Multisizer. The adipogenic capacity was measured by Affymetrix GeneChip and quantitative RT-PCR. RESULTS: Subjects were divided into two groups: high versus low ratio of visceral to visceral + subcutaneous fat (VAT/[VAT+SAT]). The cell-size distribution curves were significantly different between the high and low VAT/(VAT+SAT) groups, even after adjusting for age, sex, and ethnicity (MANOVA P = 0.035). Surprisingly, the fraction of large adipocytes was significantly lower (P < 0.01) in the group with high VAT/(VAT+SAT), along with the estimated total number of large adipose cells (P < 0.05), while the mean diameter was increased (P < 0.01). From the microarray analyses emerged a lower expression of lipogenesis/adipogenesis markers (sterol regulatory element binding protein-1, acetyl-CoA carboxylase, fatty acid synthase) in the group with high VAT/(VAT+SAT), which was confirmed by RT-PCR. CONCLUSIONS: A reduced lipo-/adipogenic capacity, fraction, and estimated number of large subcutaneous adipocytes may contribute to the abnormal distribution of abdominal fat and hepatic steatosis, as well as to insulin resistance in obese adolescents.

Central role of fatty liver in the pathogenesis of insulin resistance in obese adolescents.

OBJECTIVE: We evaluated the role of fatty liver in the alteration of insulin sensitivity and beta-cell function in two groups of obese adolescents, differing in hepatic fat content (hepatic fat fraction [HFF]) but with similar intrabdominal intramyocellular lipid content (IMCL) and overall degree of obesity. RESEARCH DESIGN AND METHODS: We studied 23 obese adolescents with high HFF (HFF >5.5%) and 20 obese adolescents with low HFF (HFF <5.5%), matched for age, Tanner stage, BMI z score, and percentages of body fat, visceral fat, and IMCL. All subjects underwent an oral glucose tolerance test and a two-step hyperinsulinemic-euglycemic clamp, magnetic resonance imaging and (1)H nuclear magnetic resonance to assess abdominal fat distribution, HFF, and IMCL, respectively. RESULTS: The high HFF group showed significantly lower whole-body insulin sensitivity index (P = 0.001) and estimates of insulin secretion (P = 0.03). The baseline hepatic glucose production (EGP) rate was not different between the two groups. Suppression of EGP was significantly lower (P = 0.04) in the high HFF group during low-dose insulin; no differences were observed during the second step. Baseline fatty acids, glycerol concentrations, and clamp suppression of glycerol turnover did not differ between the groups. During the second step, the glucose disposal rate was significantly lower (P = 0.01) in the high HFF group. CONCLUSIONS: Fatty liver, independent of visceral fat and IMCL, plays a central role in the insulin-resistant state in obese adolescents.

Downregulation of ADIPOQ and PPARγ2 gene expression in subcutaneous adipose tissue of obese adolescents with hepatic steatosis.

Hepatic steatosis is associated with hypoadiponectinemia. The mechanism(s) resulting in lower serum adiponectin levels in obese adolescents with fatty liver is unknown. In two groups of equally obese adolescents, but discordant for hepatic fat content, we measured adiponectin, leptin, peroxisome proliferator-activated receptor γ 2 (PPARγ2) and tumor necrosis factor-α (TNFα) gene expression in the abdominal subcutaneous adipose tissue (SAT). Twenty six adolescents with similar degrees of obesity underwent a subcutaneous periumbilical adipose tissue biopsy, in addition to metabolic (oral glucose tolerance test, and hyperinsulinemic--euglycemic clamp), and imaging studies (magnetic resonance imaging (MRI), DEXA). Using quantitative real-time-PCR; adiponectin, PPARγ2, TNFα, and leptin mRNA were measured. Based on a hepatic fat content (hepatic fat fraction, HFF) >5.5%, measured by fast MRI, the subjects were divided into low and high HFF group. In addition to the hypoadiponectinemia in the high HFF group, we found that the expression of adiponectin as well as PPARγ2 in the SAT was significantly decreased in this group. No differences were noted for TNFα and leptin plasma or mRNA levels between the groups. An inverse relationship was observed between adiponectin or PPARγ2 expression and hepatic fat content, whereas, adiponectin expression was positively related to PPARγ2 expression. Independent of overall obesity, a reduced expression of adiponectin and PPARγ2 in the abdominal SAT is associated with high liver fat content, as well as with insulin resistance in obese adolescents.

Glucose dysregulation and hepatic steatosis in obese adolescents: is there a link?

UNLABELLED: Fatty liver is increasingly common in obese adolescents. We determined its association with glucose dysregulation in 118 (37M/81F) obese adolescents of similar age and percent total fat. Fast-magnetic resonance imaging (MRI) and simple MRI were used to quantify hepatic fat content and abdominal fat distribution. All subjects had a standard oral glucose tolerance test. Insulin sensitivity was estimated by the Matsuda Index and homeostasis model assessment of insulin resistance. Baseline total and high molecular weight (HMW)-adiponectin and interleukin (IL)-6 levels were measured. The cohort was stratified according to tertiles of hepatic fat content. Whereas age and %fat were comparable across tertiles, ethnicity differed in that fewer Blacks and more Whites and Hispanics were in the moderate and high category of hepatic fat fraction (HFF). Visceral and the visceral-to-subcutaneous fat ratio increased and insulin sensitivity decreased across tertiles. Two-hour plasma glucose rose with increasing hepatic steatosis (P < 0.008). 73.7% of the subjects in the high HFF had the metabolic syndrome compared to 19.5% and 30.6%, respectively, in the low and moderate categories. Both total and HMW-adiponectin decreased, and IL-6 increased with increasing hepatic steatosis. CONCLUSION: In obese adolescents, independent of total fat, increasing severity of fatty liver is associated with glucose dysregulation, metabolic syndrome, and with a proinflammatory milieu.

Ectopic fat deposition and the metabolic syndrome in obese children and adolescents.

AIMS: We examined the impact of varying degrees of obesity on the prevalence of the metabolic syndrome and its relation to ectopic fat deposition in a large, multi-ethnic cohort of children and adolescents. METHODS: A standard glucose tolerance test was administered to 438 obese, 31 overweight and 20 nonobese children and adolescents. Baseline measures included blood pressure and plasma lipid and insulin levels. In a subset of 118 subjects, abdominal fat distribution was measured by magnetic resonance imaging (MRI) and further stratified into tertiles based on the proportion of abdominal fat in the visceral depot. Liver fat was measured by fast MRI and intramyocellular fat by proton magnetic resonance spectroscopy. RESULTS: Overall, the prevalence of the metabolic syndrome increased with the severity of obesity. In the subset of 118 obese adolescents undergoing MRI, there were no differences in age or body mass index z-scores across tertiles. However, as the proportion of visceral fat increased, subcutaneous fat decreased. There were significant increases in the occurrence of hepatic steatosis, insulin resistance and metabolic syndrome, with subjects in tertile 3 being 5.2-times more likely to have the metabolic syndrome than those in tertile 1. CONCLUSIONS: The prevalence of the metabolic syndrome is high in obese children and adolescents and increases with worsening obesity. Obese adolescents with a high proportion of visceral fat and relatively low abdominal subcutaneous fat have a phenotype reminiscent of partial lipodystrophy: hepatic steatosis, profound insulin resistance and an increased risk of the metabolic syndrome.

Primary defects in beta-cell function further exacerbated by worsening of insulin resistance mark the development of impaired glucose tolerance in obese adolescents.

OBJECTIVE: Impaired glucose tolerance (IGT) is a pre-diabetic state of increasing prevalence among obese adolescents. The purpose of this study was to determine the natural history of progression from normal glucose tolerance (NGT) to IGT in obese adolescents. RESEARCH DESIGN AND METHODS: We determined the evolution of beta-cell function, insulin sensitivity (S(I)), and glucose tolerance in a multiethnic group of 60 obese adolescents over the course of approximately 30 months. Each subject underwent three serial 3-h oral glucose tolerance tests. Dynamic, static, and total beta-cell responsivity (Phi(d), Phi(s), and Phi(tot), respectively) and S(i) were assessed by oral C-peptide and glucose minimal models. The disposition index (DI), which adjusts insulin secretion for S(i), was calculated. RESULTS: At baseline, all 60 subjects had NGT. Seventy-seven percent (46 subjects) maintained NGT over the three testing periods (nonprogressors), whereas 23% (14 subjects) developed IGT over time (progressors). At baseline, percent fat and BMI Z score were comparable between the groups. Fasting plasma glucose, 2-h glucose, glucose area under the curve at 180 min, and Phi(d) were significantly different between the two groups at baseline, whereas S(i) was comparable between the two groups. Over time, although S(i) remained unchanged in nonprogressors, it steadily worsened by approximately 45% (P > 0.04) in progressors. beta-Cell responsivity decreased by 20% in progressors, whereas it remained stable in nonprogressors. The DI showed a progressive decline in progressors compared with a modest improvement in nonprogressors (P = 0.02). CONCLUSIONS: Obese adolescents who progress to IGT may manifest primary defects in beta-cell function. In addition, progressive decline in S(i) further aggravates beta-cell function, contributing to the worsening of glucose intolerance.

Obesity in children and adolescents.

CONTEXT: Although the prevalence rates of childhood obesity have seemingly been stable over the past few years, far too many children and adolescents are still obese. Childhood obesity, and its associated metabolic complications, is rapidly emerging as one of the greatest global challenges of the 21st century. About 110 million children are now classified as overweight or obese. EVIDENCE ACQUISITION: In this review we first describe the most recent data on the prevalence, severity, and racial/ethnic differences in childhood obesity. Obesity is associated with significant health problems in the pediatric age group and is an important early risk factor for much of adult morbidity and mortality. EVIDENCE SYNTHESIS: We review the metabolic complications associated with childhood obesity. Particular emphasis is given to the description of studies regarding the impact of varying degrees of obesity on the cardiometabolic risk factors in youth. We further describe studies in obese adolescents that have examined the importance of ectopic lipid deposition in the visceral abdominal depot and in insulin sensitive tissues in relation to the presence of insulin resistance. We end by describing studies that have examined beta-cell function in obese adolescents with normal glucose tolerance. CONCLUSIONS: The growing number of obese children and adolescents worldwide is of great concern. Many obese children and adolescents already manifest some metabolic complications, and these children are at high risk for the development of early morbidity. Understanding the underlying pathogenesis of this peculiar phenotype is of critical importance.

Metabolic abnormalities underlying the different prediabetic phenotypes in obese adolescents.

OBJECTIVE: The aim of this study was to define the metabolic abnormalities underlying the prediabetic status of isolated impaired fasting glucose (IFG), isolated impaired glucose tolerance (IGT), and combined IFG/IGT in obese youth. RESEARCH DESIGN AND METHODS: We used state-of-the-art techniques (hyperinsulinemic-euglycemic and hyperglycemic clamps), applying a model of glucose-stimulated insulin secretion to the glucose and C-peptide concentration, in 40 normal glucose tolerance (NGT), 17 IFG, 23 IGT, and 11 IFG/IGT obese adolescents. Percent fat (by dual-energy x-ray absorptiometry), age, gender and ethnicity were comparable among groups. RESULTS: Peripheral insulin sensitivity was similar between the IFG and NGT groups. In contrast, the IGT and IFG/IGT groups showed marked reductions in peripheral insulin sensitivity (P < 0.002). Basal hepatic insulin resistance index (basal hepatic glucose production x fasting plasma insulin) was significantly increased in IFG, IGT, and IFG/IGT (P < 0.009) compared with NGT. Glucose sensitivity of first-phase insulin secretion was progressively lower in IFG, IGT, and IFG/IGT compared with NGT. Glucose sensitivity of second-phase secretion showed a statistically significant defect only in the IFG/IGT group. In a multivariate regression analysis, glucose sensitivity of first-phase secretion and basal insulin secretion rate were significant independent predictors of FPG (total r(2) = 25.9%). CONCLUSIONS: IFG, in obese adolescents, is linked primarily to alterations in glucose sensitivity of first-phase insulin secretion and liver insulin sensitivity. The IGT group is affected by a more severe degree of peripheral insulin resistance and reduction in first-phase secretion. IFG/IGT is hallmarked by a profound insulin resistance and by a new additional defect in second-phase insulin secretion.

High visceral and low abdominal subcutaneous fat stores in the obese adolescent: a determinant of an adverse metabolic phenotype.

OBJECTIVE: To explore whether an imbalance between the visceral and subcutaneous fat depots and a corresponding dysregulation of the adipokine milieu is associated with excessive accumulation of fat in the liver and muscle and ultimately with insulin resistance and the metabolic syndrome. RESEARCH DESIGN AND METHODS: We stratified our multi-ethnic cohort of 118 obese adolescents into tertiles based on the proportion of abdominal fat in the visceral depot. Abdominal and liver fat were measured by magnetic resonance imaging and muscle lipid (intramyocellular lipid) by proton magnetic resonance spectroscopy. RESULTS: There were no differences in age, BMI Z score, or fat-free mass across tertiles. However, as the proportion of visceral fat increased across tertiles, BMI and percentage of fat and subcutaneous fat decreased, while hepatic fat increased. In addition, there was an increase in 2-h glucose, insulin, c-peptide, triglyceride levels, and insulin resistance. Notably, both leptin and total adiponectin were significantly lower in tertile 3 than 1, while C-reactive protein and interleukin-6 were not different across tertiles. There was a significant increase in the odds ratio for the metabolic syndrome, with subjects in tertile 3 5.2 times more likely to have the metabolic syndrome than those in tertile 1. CONCLUSIONS: Obese adolescents with a high proportion of visceral fat and relatively low abdominal subcutaneous fat have a phenotype reminiscent of partial lipodystrophy. These adolescents are not necessarily the most severely obese, yet they suffer from severe metabolic complications and are at a high risk of having the metabolic syndrome.