Oral Glucose Tolerance Test Predicts Episodic Memory Decline: A 10-Year Population-Based Follow-up Study

OBJECTIVETo examine if the 2-h value of an oral glucose tolerance test (OGTT) can predict cognitive decline.RESEARCH DESIGN AND METHODSThis study is based on a subpopulation of the Finnish population-based Health 2000 Survey and its follow-up, the Health 2011 study. Altogether, 961 individuals aged 45–74 (mean 55.6 years; 55.8% women) underwent OGTT in 2001–2002. Categorical verbal fluency, word-list learning, and word-list delayed recall were tested at baseline and at follow-up in 2011. Statistical analyses were performed with multivariable linear models adjusted for previously reported risk factors for cognitive decline.RESULTSA higher 2-h glucose value in the OGTT at baseline predicted worse performance (slope: −0.08; P = 0.01) and greater decline (slope: −0.07; P = 0.007) in the word-list delayed recall test after 10 years.CONCLUSIONSOur results indicate that higher 2-h glucose values in the OGTT predict a decline in episodic memory after 10 years.     

The Effect of Discontinuing Continuous Glucose Monitoring in Adults With Type 2 Diabetes Treated With Basal Insulin

OBJECTIVETo explore the effect of discontinuing continuous glucose monitoring (CGM) after 8 months of CGM use in adults with type 2 diabetes treated with basal without bolus insulin.RESEARCH DESIGN AND METHODSThis multicenter trial had an initial randomization to either real-time CGM or blood glucose monitoring (BGM) for 8 months followed by 6 months in which the BGM group continued to use BGM (n = 57) and the CGM group was randomly reassigned either to continue CGM (n = 53) or discontinue CGM with resumption of BGM for glucose monitoring (n = 53).RESULTSIn the group that discontinued CGM, mean time in range (TIR) 70–180 mg/dL, which improved from 38% before initiating CGM to 62% after 8 months of CGM, decreased after discontinuing CGM to 50% at 14 months (mean change from 8 to 14 months −12% [95% CI −21% to −3%], P = 0.01). In the group that continued CGM use, little change was found in TIR from 8 to 14 months (baseline 44%, 8 months 56%, 14 months 57%, mean change from 8 to 14 months 1% [95% CI −11% to 12%], P = 0.89). Comparing the two groups at 14 months, the adjusted treatment group difference in mean TIR was −6% (95% CI −16% to 4%, P = 0.20).CONCLUSIONSIn adults with type 2 diabetes treated with basal insulin who had been using real-time CGM for 8 months, discontinuing CGM resulted in a loss of about one-half of the initial gain in TIR that had been achieved during CGM use.     

A Randomized Clinical Trial Assessing Continuous Glucose Monitoring (CGM) Use With Standardized Education With or Without a Family Behavioral Intervention Compared With Fingerstick Blood Glucose Monitoring in Very Young Children With Type 1 Diabetes

OBJECTIVEThis study evaluated the effects of continuous glucose monitoring (CGM) combined with family behavioral intervention (CGM+FBI) and CGM alone (Standard-CGM) on glycemic outcomes and parental quality of life compared with blood glucose monitoring (BGM) in children ages 2 to <8 years with type 1 diabetes.RESEARCH DESIGN AND METHODSThis was a multicenter (N = 14), 6-month, randomized controlled trial including 143 youth 2 to <8 years of age with type 1 diabetes. Primary analysis included treatment group comparisons of percent time in range (TIR) (70–180 mg/dL) across follow-up visits.RESULTSApproximately 90% of participants in the CGM groups used CGM ≥6 days/week at 6 months. Between-group TIR comparisons showed no significant changes: CGM+FBI vs. BGM 3.2% (95% CI −0.5, 7.0), Standard-CGM vs. BGM 0.5% (−2.6 to 3.6), CGM+FBI vs. Standard-CGM 2.7% (−0.6, 6.1). Mean time with glucose level <70 mg/dL was reduced from baseline to follow-up in the CGM+FBI (from 5.2% to 2.6%) and Standard-CGM (5.8% to 2.5%) groups, compared with 5.4% to 5.8% with BGM (CGM+FBI vs. BGM, P < 0.001, and Standard-CGM vs. BGM, P < 0.001). No severe hypoglycemic events occurred in the CGM+FBI group, one occurred in the Standard-CGM group, and five occurred in the BGM group. CGM+FBI parents reported greater reductions in diabetes burden and fear of hypoglycemia compared with Standard-CGM (P = 0.008 and 0.04) and BGM (P = 0.02 and 0.002).CONCLUSIONSCGM used consistently over a 6-month period in young children with type 1 diabetes did not improve TIR but did significantly reduce time in hypoglycemia. The FBI benefited parental well-being.     

Hyperglucagonemia Does Not Explain the β-Cell Hyperresponsiveness and Insulin Resistance in Dysglycemic Youth Compared With Adults: Lessons From the RISE Study

OBJECTIVETo determine whether β-cell hyperresponsiveness and insulin resistance in youth versus adults in the Restoring Insulin Secretion (RISE) Study are related to increased glucagon release.RESEARCH DESIGN AND METHODSIn 66 youth and 350 adults with impaired glucose tolerance (IGT) or recently diagnosed type 2 diabetes (drug naive), we performed hyperglycemic clamps and oral glucose tolerance tests (OGTTs). From clamps we quantified insulin sensitivity (M/I), plasma fasting glucagon and C-peptide, steady-state glucagon and C-peptide at glucose of 11.1 mmol/L, and arginine-stimulated glucagon (acute glucagon response [AGR]) and C-peptide (ACPRmax) responses at glucose >25 mmol/L.RESULTSMean ± SD fasting glucagon (7.63 ± 3.47 vs. 8.55 ± 4.47 pmol/L; P = 0.063) and steady-state glucagon (2.24 ± 1.46 vs. 2.49 ± 1.96 pmol/L, P = 0.234) were not different in youth and adults, respectively, while AGR was lower in youth (14.1 ± 5.2 vs. 16.8 ± 8.8 pmol/L, P = 0.001). Significant age-group differences in insulin sensitivity, fasting C-peptide, steady-state C-peptide, and ACPRmax were not related to glucagon. Fasting glucose and glucagon were positively correlated in adults (r = 0.133, P = 0.012) and negatively correlated in youth (r = −0.143, P = 0.251). In both age-groups, higher fasting glucagon was associated with higher fasting C-peptide (youth r = 0.209, P = 0.091; adults r = 0.335, P < 0.001) and lower insulin sensitivity (youth r = −0.228, P = 0.066; adults r = −0.324, P < 0.001). With comparable fasting glucagon, youth had greater C-peptide and lower insulin sensitivity. OGTT suppression of glucagon was greater in youth.CONCLUSIONSYouth with IGT or recently diagnosed type 2 diabetes (drug naive) have hyperresponsive β-cells and lower insulin sensitivity, but their glucagon concentrations are not increased compared with those in adults. Thus, α-cell dysfunction does not appear to explain the difference in β-cell function and insulin sensitivity in youth versus adults.     

Genetic Risk Score for Type 2 Diabetes and Traits Related to Glucose-Insulin Homeostasis in Youth: The Exploring Perinatal Outcomes Among Children (EPOCH) Study

OBJECTIVEThe metabolic phenotype of youth-onset type 2 diabetes (T2D) differs from that of adult-onset T2D, but little is known about genetic contributions. We aimed to evaluate the association between a T2D genetic risk score (GRS) and traits related to glucose-insulin homeostasis among healthy youth.RESEARCH DESIGN AND METHODSWe used data from 356 youth (mean age 16.7 years; 50% female) in the Exploring Perinatal Outcomes Among Children (EPOCH) cohort to calculate a standardized weighted GRS based on 271 single nucleotide polymorphisms associated with T2D in adults. We used linear regression to assess associations of the GRS with log-transformed fasting glucose, 2-h glucose, HOMA of insulin resistance (HOMA-IR), oral disposition index, and insulinogenic index adjusted for age, sex, BMI z score, in utero exposure to maternal diabetes, and genetic principal components. We also evaluated effect modification by BMI z score, in utero exposure to maternal diabetes, and ethnicity.RESULTSHigher weighted GRS was associated with lower oral disposition index (β = −0.11; 95% CI −0.19, −0.02) and insulinogenic index (β = −0.08; 95% CI −0.17, −0.001), but not with fasting glucose (β = 0.01; 95% CI −0.01, 0.02), 2-h glucose (β = 0.03; 95% CI −0.0004, 0.06), or HOMA-IR (β = 0.02; 95% CI −0.04, 0.07). BMI z score and in utero exposure to maternal diabetes increased the effect of the GRS on glucose levels.CONCLUSIONSOur results suggest that T2D genetic risk factors established in adults are relevant to glucose-insulin homeostasis in youth and that maintaining a healthy weight may be particularly important for youth with high genetic risk of T2D.     

Natriuretic Effect of Two Weeks of Dapagliflozin Treatment in Patients With Type 2 Diabetes and Preserved Kidney Function During Standardized Sodium Intake: Results of the DAPASALT Trial

OBJECTIVESodium–glucose cotransporter 2 (SGLT2) inhibitors reduce the risk for heart failure hospitalization potentially by inducing sodium excretion, osmotic diuresis, and plasma volume contraction. Few studies have investigated this hypothesis, but none have assessed cumulative sodium excretion with SGLT2 inhibition during standardized sodium intake in patients with type 2 diabetes.RESEARCH DESIGN AND METHODSThe DAPASALT trial was a mechanistic, nonrandomized, open-label study in patients with type 2 diabetes with preserved kidney function on a controlled standardized sodium diet (150 mmol/day). It evaluated the effects of dapagliflozin on sodium excretion, 24-h blood pressure, and extracellular, intracellular, and plasma volumes at the start of treatment (ST) (days 2–4), end of treatment (ET) (days 12–14), and follow-up (FU) (days 15–18).RESULTSFourteen patients were included in the efficacy analysis. Mean (SD) baseline sodium excretion (150 [32] mmol/24-h) did not significantly change during treatment (change at ST: −7.0 mmol/24-h [95% CI −22.4, 8.4]; change at ET: 2.1 mmol/24-h [−28.8, 33.0]). Mean baseline 24-h systolic blood pressure was 128 (10) mmHg and significantly reduced at ST (−6.1 mmHg [−9.1, −3.1]; P < 0.001) and ET (−7.2 mmHg [−10.0, −4.3]; P < 0.001). Dapagliflozin did not significantly alter plasma volume or intracellular volume, while extracellular volume changed at ST (−0.7 L [−1.3, −0.1]; P = 0.02). As expected, 24-h urinary glucose excretion significantly increased during dapagliflozin treatment and reversed during FU.CONCLUSIONSDuring standardized sodium intake, dapagliflozin reduced blood pressure without clear changes in urinary sodium excretion, suggesting that factors other than natriuresis and volume changes may contribute to the blood pressure–lowering effects.     

Effect of Ranolazine Monotherapy on Glycemic Control in Subjects With Type 2 Diabetes

OBJECTIVE

Ranolazine is an antianginal drug that mediates its effects by inhibition of cardiac late sodium current. Although ranolazine is not approved for the treatment of type 2 diabetes, in post hoc analyses of pivotal angina trials, ranolazine was associated with reductions in percent glycosylated hemoglobin (HbA_1c) in subjects with type 2 diabetes. The study prospectively assessed the safety and efficacy of ranolazine in subjects with type 2 diabetes with inadequate glycemic control managed by lifestyle alone.

RESEARCH DESIGN AND METHODS

The study was conducted worldwide in 465 subjects, with baseline HbA_1c of 7–10% (53–86 mmol/mol) and fasting serum glucose of 130–240 mg/dL, randomized to placebo versus ranolazine.

RESULTS

Compared with placebo, there was a greater decline in HbA_1c at week 24 from baseline (primary end point) in subjects taking ranolazine (mean difference −0.56% [−6.1 mmol/mol]; P < 0.0001). Moreover, the proportion of subjects achieving an HbA_1c <7.0% was greater with ranolazine (25.6% vs. 41.2%; P = 0.0004). Ranolazine was associated with reductions in fasting (mean difference −8 mg/dL; P = 0.0266) and 2-h postprandial glucose (mean difference −19 mg/dL; P = 0.0008 vs. placebo). Subjects taking ranolazine trended toward a greater decrease from baseline in fasting insulin (P = 0.0507), a greater decrease in fasting glucagon (P = 0.0003), and a lower postprandial 3-h glucagon area under the curve (P = 0.0031 vs. placebo). Ranolazine was safe and well tolerated.

CONCLUSIONS

Compared with placebo, use of ranolazine monotherapy over 24 weeks, in subjects with type 2 diabetes and inadequate glycemic control on diet and exercise alone, significantly reduced HbA_1c and other measures of glycemic control.     

A Higher-Complex Carbohydrate Diet in Gestational Diabetes Mellitus Achieves Glucose Targets and Lowers Postprandial Lipids: A Randomized Crossover Study

OBJECTIVE

The conventional diet approach to gestational diabetes mellitus (GDM) advocates carbohydrate restriction, resulting in higher fat (HF), also a substrate for fetal fat accretion and associated with maternal insulin resistance. Consequently, there is no consensus about the ideal GDM diet. We hypothesized that, compared with a conventional, lower-carbohydrate/HF diet (40% carbohydrate/45% fat/15% protein), consumption of a higher-complex carbohydrate (HCC)/lower-fat (LF) Choosing Healthy Options in Carbohydrate Energy (CHOICE) diet (60/25/15%) would result in 24-h glucose area under the curve (AUC) profiles within therapeutic targets and lower postprandial lipids.

RESEARCH DESIGN AND METHODS

Using a randomized, crossover design, we provided 16 GDM women (BMI 34 ± 1 kg/m²) with two 3-day isocaloric diets at 31 ± 0.5 weeks (washout between diets) and performed continuous glucose monitoring. On day 4 of each diet, we determined postprandial (5 h) glucose, insulin, triglycerides (TGs), and free fatty acids (FFAs) following a controlled breakfast meal.

RESULTS

There were no between-diet differences for fasting or mean nocturnal glucose, but 24-h AUC was slightly higher (∼6%) on the HCC/LF CHOICE diet (P = 0.02). The continuous glucose monitoring system (CGMS) revealed modestly higher 1- and 2-h postprandial glucose on CHOICE (1 h, 115 ± 2 vs. 107 ± 3 mg/dL, P ≤ 0.01; 2 h, 106 ± 3 vs. 97 ± 3 mg/dL, P = 0.001) but well below current targets. After breakfast, 5-h glucose and insulin AUCs were slightly higher (P < 0.05), TG AUC was no different, but the FFA AUC was significantly lower (∼19%; P ≤ 0.01) on the CHOICE diet.

CONCLUSIONS

This highly controlled study randomizing isocaloric diets and using a CGMS is the first to show that liberalizing complex carbohydrates and reducing fat still achieved glycemia below current treatment targets and lower postprandial FFAs. This diet strategy may have important implications for preventing macrosomia.     

No influence of high- and low-carbohydrate diet on the oral glucose tolerance test in pregnancy

OBJECTIVE: Our objective was to determine the influence of the carbohydrate content of the diet preceding the oral glucose tolerance test (OGTT) in pregnancy on the test results and to evaluate the necessity of the recommended preparatory high-carbohydrate diet. STUDY DESIGN: Thirty-four women from our outpatient clinic were enrolled in this prospective study. After giving informed consent, each women underwent a 90-min lesson (supervised by a dietary assistant) covering the carbohydrate, protein and fat content of different foods. Women were then randomized and in a crossover design started a diet with either a low or a high carbohydrate content. We were aiming at a carbohydrate intake of 40% in the low-carbohydrate week (LCH) and 50% in the high-carbohydrate week (HCH). Compliance was monitored by a detailed food diary which the women kept and which included the weight of the foods they consumed. RESULTS: The actual dietary intakes as calculated from the food diaries showed that the mean caloric intake was 1801 +/- 314 kcal in the LCH and 2118 +/- 312 kcal in the HCH week (<0.001). During the LCH diet, CH intake was 39 +/- 6.1% and 49 +/- 6.6% in the HCH week (P < 0.001). The carbohydrate intake per kilogram bodyweight was 30 +/- 5.3 kcal vs. 35 +/- 5.2 kcal (P < 0.001). The number of patients diagnosed with gestational diabetes was two in the LCH and three in the HCH week (not significant). The sum of the OGTT values (fasting, 1 h and 2 h) after the LCH was 18.9 +/- 2.1 mmol/l vs. 18.8 +/- 2.1 mmol/l after the HCH (P = 0.51). No differences could be found in both groups regarding the fasting, 1-h, or 2-h glucose values. Including patients with a CH difference of at least 5%, 10%, and 15% carbohydrate between the weeks, we still did not observe any differences in the OGTT sum. We also looked at a possible influence of the CH content of the diet on the day before the test and of the last meal before the OGTT results and observed there was none. CONCLUSION: This is the first study which has observed the influence of the previous day's meal on the test results. We conclude from our results that the carbohydrate percentage of the preparatory diet did not influence the results of an OGTT, even when we increased the difference in carbohydrate intake stepwise up to 15%. This might indicate that a preparatory diet before the OGTT is not necessary for women with normal nutritional behavior.     

Association Between Cardiorespiratory Fitness and the Determinants of Glycemic Control Across the Entire Glucose Tolerance Continuum

OBJECTIVECardiorespiratory fitness (VO_2max) is associated with glycemic control, yet the relationship between VO_2max and the underlying determinants of glycemic control is less clear. Our aim was to determine whether VO_2max is associated with insulin sensitivity, insulin secretion, and the disposition index, a measure of compensatory pancreatic β-cell insulin secretion relative to insulin sensitivity, in subjects representing the entire range of the glucose tolerance continuum.RESULTSA low VO_2max was associated with high HbA_1c (r = −0.33), high fasting glucose (r = −0.34), high 2-h OGTT glucose (r = −0.33), low Si_OGTT (r = 0.73), and high early-phase (r = −0.34) and late-phase (r = −0.36) GSIS_OGTT. Furthermore, a low VO_2max was associated with low early- and late-phase DI_OGTT (both r = 0.41). Interestingly, relationships between VO_2max and either glycemic control or late-phase GSIS_OGTT deteriorated across the glucose tolerance continuum.CONCLUSIONSThe association between poor cardiorespiratory fitness and compromised pancreatic β-cell compensation across the entire glucose tolerance continuum provides additional evidence highlighting the importance of fitness in protection against the onset of a fundamental pathophysiological event that leads to type 2 diabetes.     

Myo-Inositol,Probiotics, and Micronutrient Supplementation From Preconception for Glycemia in Pregnancy: NiPPeR International Multicenter Double-Blind Randomized Controlled Trial

OBJECTIVEBetter preconception metabolic and nutritional health are hypothesized to promote gestational normoglycemia and reduce preterm birth, but evidence supporting improved outcomes with nutritional supplementation starting preconception is limited.RESEARCH DESIGN AND METHODSThis double-blind randomized controlled trial recruited from the community 1,729 U.K., Singapore, and New Zealand women aged 18–38 years planning conception. We investigated whether a nutritional formulation containing myo-inositol, probiotics, and multiple micronutrients (intervention), compared with a standard micronutrient supplement (control), taken preconception and throughout pregnancy could improve pregnancy outcomes. The primary outcome was combined fasting, 1-h, and 2-h postload glycemia (28 weeks gestation oral glucose tolerance test).RESULTSBetween 2015 and 2017, participants were randomized to control (n = 859) or intervention (n = 870); 585 conceived within 1 year and completed the primary outcome (295 intervention, 290 control). In an intention-to-treat analysis adjusting for site, ethnicity, and preconception glycemia with prespecified P < 0.017 for multiplicity, there were no differences in gestational fasting, 1-h, and 2-h glycemia between groups (β [95% CI] log_e mmol/L intervention vs. control −0.004 [−0.018 to 0.011], 0.025 [−0.014 to 0.064], 0.040 [0.004–0.077], respectively). Between the intervention and control groups there were no significant differences in gestational diabetes mellitus (24.8% vs. 22.6%, adjusted risk ratio [aRR] 1.22 [0.92–1.62]), birth weight (adjusted β = 0.05 kg [−0.03 to 0.13]), or gestational age at birth (mean 39.3 vs. 39.2 weeks, adjusted β = 0.20 [−0.06 to 0.46]), but there were fewer preterm births (5.8% vs. 9.2%, aRR 0.43 [0.22–0.82]), adjusting for prespecified covariates.CONCLUSIONSSupplementation with myo-inositol, probiotics, and micronutrients preconception and in pregnancy did not lower gestational glycemia but did reduce preterm birth.     

Glucose Effectiveness in Obese Children: Relation to Degree of Obesity and Dysglycemia

OBJECTIVE

Impaired glucose effectiveness (GE) plays a role in the deterioration of glucose metabolism. Our aim was to validate a surrogate of GE derived from an oral glucose tolerance test (OGTT) and to assess the impact of degrees of obesity and of glucose tolerance on it.

RESEARCH DESIGN AND METHODS

The OGTT-derived surrogate of GE (oGE) was validated in obese adolescents who underwent an OGTT and an intravenous glucose tolerance test (IVGTT). We then evaluated anthropometric determinants of the oGE and its impact on the dynamics of glucose tolerance in a cohort of children with varying degrees of obesity.

RESULTS

The correlation of oGE and IVGTT-derived GE in 98 obese adolescents was r = 0.35 (P < 0.001) as a whole and r = 0.51 (P < 0.001) in subjects with normal glucose tolerance. In a cohort of 1,418 children, the adjusted GE was associated with increasing obesity (P < 0.001 for each category of obesity). Quartiles of oGE and the oral disposition index were associated with 2-h glucose levels (P < 0.001 for both). Among 421 nondiabetic obese subjects (276 subjects with normal glucose tolerance/145 subjects with impaired glucose tolerance who repeated their OGTT after a mean time of 28 ± 16 months), oGE changes were tightly associated with weight (r = 0.83, P < 0.001) and waist circumference changes (r = 0.67, P < 0.001). Baseline oGE and changes in oGE over time emerged as significant predictors of the change in 2-h glucose levels (standardized B = −0.76 and B = −0.98 respectively, P < 0.001 for both).

CONCLUSIONS

The oGE is associated with the degree of and changes in weight and waist circumference and is an independent predictor of glucose tolerance dynamics.     

A New Approach for Diagnosing Type 1 Diabetes in Autoantibody-Positive Individuals Based on Prediction and Natural History

OBJECTIVE

We assessed whether type 1 diabetes (T1D) can be diagnosed earlier using a new approach based on prediction and natural history in autoantibody-positive individuals.

RESEARCH DESIGN AND METHODS

Diabetes Prevention Trial–Type 1 (DPT-1) and TrialNet Natural History Study (TNNHS) participants were studied. A metabolic index, the T1D Diagnostic Index60 (Index60), was developed from 2-h oral glucose tolerance tests (OGTTs) using the log fasting C-peptide, 60-min C-peptide, and 60-min glucose. OGTTs with Index60 ≥2.00 and 2-h glucose <200 mg/dL (Ind60+Only) were compared with Index60 <2.00 and 2-h glucose ≥200 mg/dL (2hglu+Only) OGTTs as criteria for T1D. Individuals were assessed for C-peptide loss from the first Ind60+Only OGTT to diagnosis.

RESULTS

Areas under receiver operating characteristic curves were significantly higher for Index60 than for the 2-h glucose (P < 0.001 for both DPT-1 and the TNNHS). As a diagnostic criterion, sensitivity was higher for Ind60+Only than for 2hglu+Only (0.44 vs. 0.15 in DPT-1; 0.26 vs. 0.17 in the TNNHS) OGTTs. Specificity was somewhat higher for 2hglu+Only OGTTs in DPT-1 (0.97 vs. 0.91) but equivalent in the TNNHS (0.98 for both). Positive and negative predictive values were higher for Ind60+Only OGTTs in both studies. Postchallenge C-peptide levels declined significantly at each OGTT time point from the first Ind60+Only OGTT to the time of standard diagnosis (range −22 to −34% in DPT-1 and −14 to −27% in the TNNHS). C-peptide and glucose patterns differed markedly between Ind60+Only and 2hglu+Only OGTTs.

CONCLUSIONS

An approach based on prediction and natural history appears to have utility for diagnosing T1D.     

Baseline Predictors of Glycemic Worsening in Youth and Adults With Impaired Glucose Tolerance or Recently Diagnosed Type 2 Diabetes in the Restoring Insulin Secretion (RISE) Study

OBJECTIVETo identify predictors of glycemic worsening among youth and adults with impaired glucose tolerance (IGT) or recently diagnosed type 2 diabetes in the Restoring Insulin Secretion (RISE) Study.RESEARCH DESIGN AND METHODSA total of 91 youth (10–19 years) were randomized 1:1 to 12 months of metformin (MET) or 3 months of glargine, followed by 9 months of metformin (G-MET), and 267 adults were randomized to MET, G-MET, liraglutide plus MET (LIRA+MET), or placebo for 12 months. All participants underwent a baseline hyperglycemic clamp and a 3-h oral glucose tolerance test (OGTT) at baseline, month 6, month 12, and off treatment at month 15 and month 21. Cox models identified baseline predictors of glycemic worsening (HbA_1c increase ≥0.5% from baseline).RESULTSGlycemic worsening occurred in 17.8% of youth versus 7.5% of adults at month 12 (P = 0.008) and in 36% of youth versus 20% of adults at month 21 (P = 0.002). In youth, glycemic worsening did not differ by treatment. In adults, month 12 glycemic worsening was less on LIRA+MET versus placebo (hazard ratio 0.21, 95% CI 0.05–0.96, P = 0.044). In both age-groups, lower baseline clamp-derived β-cell responses predicted month 12 and month 21 glycemic worsening (P < 0.01). Lower baseline OGTT-derived β-cell responses predicted month 21 worsening (P < 0.05). In youth, higher baseline HbA_1c and 2-h glucose predicted month 12 and month 21 glycemic worsening, and higher fasting glucose predicted month 21 worsening (P < 0.05). In adults, lower clamp- and OGTT-derived insulin sensitivity predicted month 12 and month 21 worsening (P < 0.05).CONCLUSIONSGlycemic worsening was more common among youth than adults with IGT or recently diagnosed type 2 diabetes, predicted by lower baseline β-cell responses in both groups, hyperglycemia in youth, and insulin resistance in adults.     

Efficacy and Safety of Once-Weekly Efpeglenatide Monotherapy Versus Placebo in Type 2 Diabetes: The AMPLITUDE-M Randomized Controlled Trial

OBJECTIVETo assess the efficacy and safety of the glucagon-like peptide 1 receptor agonist (GLP-1 RA) efpeglenatide versus placebo in patients with type 2 diabetes inadequately controlled with diet and exercise alone.RESEARCH DESIGN AND METHODSAMPLITUDE-M was a phase 3, double-blind, placebo-controlled, multicenter trial that randomized adults with type 2 diabetes suboptimally controlled with diet and exercise alone to once-weekly efpeglenatide (2, 4, or 6 mg) or placebo for up to 56 weeks. The primary objective was to demonstrate the superiority of efpeglenatide versus placebo for HbA_1c reduction at week 30. Secondary objectives included changes in other measures of glycemic control and body weight at weeks 30 and 56.RESULTSAt week 30, HbA_1c was reduced from a baseline of 8.1% (65 mmol/mol) to 6.9% (52 mmol/mol), 6.6% (49 mmol/mol), and 6.4% (47 mmol/mol) with efpeglenatide 2, 4, and 6 mg, respectively. Least squares mean HbA_1c reductions from baseline were statistically superior for each efpeglenatide dose versus placebo (2 mg, −0.5% [95% CI −0.9, −0.2; P = 0.0054]; 4 mg, −0.8% [−1.2, −0.5; P < 0.0001]; 6 mg, −1.0% [−1.4, −0.7; P < 0.0001]). A greater proportion of efpeglenatide-treated patients (all doses) achieved HbA_1c <7% (53 mmol/mol) versus placebo by week 30 (P < 0.0001 for all), and significant reductions in body weight and fasting plasma glucose were also observed for efpeglenatide (4 and 6 mg doses) versus placebo at week 30 (P < 0.05 for all). Consistent with the GLP-1 RA class, gastrointestinal adverse events were most commonly reported; these were generally transient and mild/moderate in severity. Few patients reported hypoglycemia.CONCLUSIONSAs monotherapy in patients with type 2 diabetes, once-weekly efpeglenatide significantly improved glycemic control and body weight with a safety and tolerability profile similar to that of other GLP-1 RAs.     

Carbohydrate Requirements for Prolonged,Fasted Exercise With and Without Basal Rate Reductions in Adults With Type 1 Diabetes on Continuous Subcutaneous Insulin Infusion

OBJECTIVEExercising while fasted with type 1 diabetes facilitates weight loss; however, the best strategy to maintain glucose stability remains unclear.RESEARCH DESIGN AND METHODSFifteen adults on continuous subcutaneous insulin infusion completed three sessions of fasted walking (120 min at 45% VO_2max) in a randomized crossover design: 50% basal rate reduction, set 90 min pre-exercise (−90_min50%_BRR); usual basal rate with carbohydrate intake of 0.3 g/kg/h (CHO-only); and combined 50% basal rate reduction set at exercise onset with carbohydrate intake of 0.3 g/kg/h (Combo).RESULTSCombo had a smaller change in glucose (5 ± 47 mg/dL) versus CHO-only (−49 ± 61 mg/dL, P = 0.03) or −90_min50%_BRR (−34 ± 45 mg/dL). The −90_min50%_BRR strategy produced higher β-hydroxybutyrate levels (0.4 ± 0.3 vs. 0.1 ± 0.1 mmol/L) and greater fat oxidation (0.51 ± 0.2 vs. 0.39 ± 0.1 g/min) than CHO-only (both P < 0.05).CONCLUSIONSAll strategies examined produced stable glycemia for fasted exercise, but a 50% basal rate reduction, set 90 min pre-exercise, eliminates carbohydrate needs and enhances fat oxidation better than carbohydrate feeding with or without a basal rate reduction set at exercise onset.     

The Bihormonal Bionic Pancreas Improves Glycemic Control in Individuals With Hyperinsulinism and Postpancreatectomy Diabetes: A Pilot Study

OBJECTIVETo determine whether the bihormonal bionic pancreas (BHBP) improves glycemic control and reduces hypoglycemia in individuals with congenital hyperinsulinism (HI) and postpancreatectomy diabetes (PPD) compared with usual care (UC).RESEARCH DESIGN AND METHODSTen subjects with HI and PPD completed this open-label, crossover pilot study. Coprimary outcomes were mean glucose concentration and time with continuous glucose monitoring (CGM) glucose concentration <3.3 mmol/L.RESULTSMean (SD) CGM glucose concentration was 8.3 (0.7) mmol/L in the BHBP period versus 9 (1.8) mmol/L in the UC period (P = 0.13). Mean (SD) time with CGM glucose concentration <3.3 mmol/L was 0% (0.002) in the BHBP period vs. 1.3% (0.018) in the UC period (P = 0.11).CONCLUSIONSRelative to UC, the BHBP resulted in comparable glycemic control in our population.     

Effect of Salsalate on Insulin Action,Secretion, and Clearance in Nondiabetic,Insulin-Resistant Individuals: A Randomized,Placebo-Controlled Study

OBJECTIVE

Salsalate treatment has been shown to improve glucose homeostasis, but the mechanism remains unclear. The aim of this study was to evaluate the effect of salsalate treatment on insulin action, secretion, and clearance rate in nondiabetic individuals with insulin resistance.

RESEARCH DESIGN AND METHODS

This was a randomized (2:1), single-blind, placebo-controlled study of salsalate (3.5 g daily for 4 weeks) in nondiabetic individuals with insulin resistance. All individuals had measurement of glucose tolerance (75-g oral glucose tolerance test), steady-state plasma glucose (SSPG; insulin suppression test), and insulin secretion and clearance rate (graded-glucose infusion test) before and after treatment.

RESULTS

Forty-one individuals were randomized to salsalate (n = 27) and placebo (n = 14). One individual from each group discontinued the study. Salsalate improved fasting (% mean change −7% [95% CI −10 to −14] vs. 1% [−3 to 5], P = 0.005) but not postprandial glucose concentration compared with placebo. Salsalate also lowered fasting triglyceride concentration (−25% [−34 to −15] vs. −6% [−26 to 14], P = 0.04). Salsalate had no effect on SSPG concentration or insulin secretion rate but significantly decreased insulin clearance rate compared with placebo (−23% [−30 to −16] vs. 3% [−10 to 15], P < 0.001). Salsalate was well tolerated, but four individuals needed a dose reduction due to symptoms.

CONCLUSIONS

Salsalate treatment in nondiabetic, insulin-resistant individuals improved fasting, but not postprandial, glucose and triglyceride concentration. These improvements were associated with a decrease in insulin clearance rate without change in insulin action or insulin secretion.     

Women With Gestational Diabetes Mellitus Randomized to a Higher–Complex Carbohydrate/Low-Fat Diet Manifest Lower Adipose Tissue Insulin Resistance,Inflammation, Glucose,and Free Fatty Acids: A Pilot Study

OBJECTIVE

Diet therapy in gestational diabetes mellitus (GDM) has focused on carbohydrate restriction but is poorly substantiated. In this pilot randomized clinical trial, we challenged the conventional low-carbohydrate/higher-fat (LC/CONV) diet, hypothesizing that a higher–complex carbohydrate/lower-fat (CHOICE) diet would improve maternal insulin resistance (IR), adipose tissue (AT) lipolysis, and infant adiposity.

RESEARCH DESIGN AND METHODS

At 31 weeks, 12 diet-controlled overweight/obese women with GDM were randomized to an isocaloric LC/CONV (40% carbohydrate/45% fat/15% protein; n = 6) or CHOICE (60%/25%/15%; n = 6) diet. All meals were provided. AT was biopsied at 37 weeks.

RESULTS

After ∼7 weeks, fasting glucose (P = 0.03) and free fatty acids (P = 0.06) decreased on CHOICE, whereas fasting glucose increased on LC/CONV (P = 0.03). Insulin suppression of AT lipolysis was improved on CHOICE versus LC/CONV (56 vs. 31%, P = 0.005), consistent with improved IR. AT expression of multiple proinflammatory genes was lower on CHOICE (P < 0.01). Infant adiposity trended lower with CHOICE (10.1 ± 1.4 vs. 12.6 ± 2%, respectively).

CONCLUSIONS

A CHOICE diet may improve maternal IR and infant adiposity, challenging recommendations for a LC/CONV diet.     

One-hour post-load glucose improves the prediction of cardiovascular events in the OPERA study

BackgroundTo estimate the ability of fasting, 1-h, and 2-h post-load glucose to predict cardiovascular outcomes.MethodsWe examined a population-based study consisting of 977 middle-aged subjects who underwent an oral glucose tolerance test with glucose values measured at 0, 60, and 120 min. Participants were followed up to 24 years, and cardiovascular outcomes were collected from national registers. Predictive abilities of fasting, 1-h, and 2-h glucose were evaluated alone and in the prediction models with traditional cardiovascular risk factors using Cox proportional hazard models, the likelihood-ratio test, Harrell''s concordance index and integrated discrimination improvement.ResultsCardiovascular endpoint occurred in 222 (22.7%) participants during a median follow-up of 19.8 years. In the prognostic models, 1-h glucose (HR 1.67, 95%CI 1.10–2.53), but not fasting or 2-h glucose, predicted cardiovascular events statistically significantly. In addition, when adding glucose parameters into the model including traditional cardiovascular risk factors, only 1-h glucose improved the predictive ability (LR-test p=.046). Finally, 1-h glucose found slightly over 50% more cardiovascular endpoints that were not recognized by fasting or 2-h glucose levels.ConclusionsOur findings support the earlier ones suggesting that 1-h glucose would be a better long-term predictor of cardiovascular morbidity and mortality than fasting or 2-h glucose.

KEY MESSAGES

1. In addition to conventional CV risk factors,1-h but not fasting or 2-h post-load glucoses seems to be an independent predictor of cardiovascular events and seems to improve the predictive ability of the traditional cardiovascular risk model.
2. Elevated 1-hpost-load glucose finds a large number (slightly over 50%)of cardiovascular endpoints that were not recognized by fasting or 2-h post-load glucose levels.
3. One-hour glucose seems to be a better long-term predictor of cardiovascular morbidity and mortality than fasting or 2-h post-load glucose.