OBJECTIVE Whether hyperglycemia in utero less than overt diabetes is associated with altered childhood glucose metabolism is unknown. We examined associations of gestational diabetes mellitus (GDM) not confounded by treatment with childhood glycemia in the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) cohort. RESEARCH DESIGN AND METHODS HAPO Follow-up Study (FUS) included 4,160 children ages 10–14 years who completed all or part of an oral glucose tolerance test (OGTT) and whose mothers had a 75-g OGTT at ∼28 weeks gestation with blinded glucose values. The primary predictor was GDM by World Health Organization criteria. Child outcomes were impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and type 2 diabetes. Additional measures included insulin sensitivity and secretion and oral disposition index. RESULTS For mothers with GDM, 10.6% of children had IGT compared with 5.0% of children of mothers without GDM; IFG frequencies were 9.2% and 7.4%, respectively. Type 2 diabetes cases were too few for analysis. Odds ratios (95% CI) adjusted for family history of diabetes, maternal BMI, and child BMI z score were 1.09 (0.78–1.52) for IFG and 1.96 (1.41–2.73) for IGT. GDM was positively associated with child’s 30-min, 1-h, and 2-h but not fasting glucose and inversely associated with insulin sensitivity and oral disposition index (adjusted mean difference −76.3 [95% CI −130.3 to −22.4] and −0.12 [−0.17 to −0.064]), respectively, but not insulinogenic index. CONCLUSIONS Offspring exposed to untreated GDM in utero are insulin resistant with limited β-cell compensation compared with offspring of mothers without GDM. GDM is significantly and independently associated with childhood IGT.

OBJECTIVE: This study examined associations of maternal glycemia during pregnancy with childhood glucose outcomes in the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) cohort. RESEARCH DESIGN AND METHODS: HAPO was an observational international investigation that established associations of maternal glucose with adverse perinatal outcomes. The HAPO Follow-up Study included 4,832 children ages 10–14 years whose mothers had a 75-g oral glucose tolerance test (OGTT) at ∼28 weeks of gestation. Of these, 4,160 children were evaluated for glucose outcomes. Primary outcomes were child impaired glucose tolerance (IGT) and impaired fasting glucose (IFG). Additional outcomes were glucose-related measures using plasma glucose (PG), A1C, and C-peptide from the child OGTT. RESULTS: Maternal fasting plasma glucose (FPG) was positively associated with child FPG and A1C; maternal 1-h and 2-h PG were positively associated with child fasting, 30 min, 1-h, and 2-h PG, and A1C. Maternal FPG, 1-h, and 2-h PG were inversely associated with insulin sensitivity, whereas 1-h and 2-h PG were inversely associated with disposition index. Maternal FPG, but not 1-h or 2-h PG, was associated with child IFG, and maternal 1-h and 2-h PG, but not FPG, were associated with child IGT. All associations were independent of maternal and child BMI. Across increasing categories of maternal glucose, frequencies of child IFG and IGT, and timed PG measures and A1C were higher, whereas insulin sensitivity and disposition index decreased. CONCLUSIONS: Across the maternal glucose spectrum, exposure to higher levels in utero is significantly associated with childhood glucose and insulin resistance independent of maternal and childhood BMI and family history of diabetes.

OBJECTIVE—To evaluate whether, in adolescents with type 1 diabetes, the addition of metformin to insulin and standard diabetes management results in 1) higher insulin sensitivity and 2) lower HbA_1c, fasting glucose, insulin dosage (units per kilogram per day) and BMI. RESEARCH DESIGN AND METHODS—This was a randomized, placebo-controlled 3-month trial of metformin therapy in 27 adolescents with type 1 diabetes, high insulin dosage (>1 unit · kg⁻¹ · day⁻¹), and HbA_1c >8%, with measurements of insulin sensitivity (by frequently sampled intravenous glucose tolerance test [FSIGT]), HbA_1c, insulin dosage, and BMI at the onset and end of treatment. RESULTS—At t = 0, HbA_1c was 9.2 ± 0.9%, insulin dosage was 1.2 ± 0.2 units · kg⁻¹ · day⁻¹, fasting glucose was 10.6 ± 2.4 mmol/l, and BMI was 24.2 ± 3.9 kg/m² (means ± SD), with no difference between the metformin and placebo groups. At the end of the study, HbA_1c was 0.6% lower in the metformin group than in the placebo group (P < 0.05). This was achieved at lower daily insulin dosages (metformin group –0.14 ± 0.1 vs. placebo group 0.02 ± 0.2 units · kg⁻¹ · day⁻¹; P < 0.05), with no significant change in BMI. Fasting glucose levels improved significantly in the metformin group (P < 0.05). Change in insulin sensitivity, measured by FSIGT, was not significantly different between the two groups at study end. Mild hypoglycemia occurred more frequently in the metformin-treated than in the placebo subjects (1.75 ± 0.8 vs. 0.9 ± 0.4 events · patient⁻¹ · week⁻¹; P = 0.03). There were no differences in frequency of severe hypoglycemic episodes or gastrointestinal complaints between the two groups. CONCLUSIONS—Metformin treatment lowered HbA_1c and decreased insulin dosage with no weight gain in teens with type 1 diabetes in poor metabolic control. Changes in insulin sensitivity were not documented in this study using the FSIGT. Long-term studies will determine whether these improvements are sustained and whether certain subgroups accrue greater benefit from this therapy.

Background: A number of neurodevelopmental syndromes are caused by mutations in genes encoding proteins that normally function in epigenetic regulation. Identification of epigenetic alterations occurring in these disorders could shed light on molecular pathways relevant to neurodevelopment. Results: Using a genome-wide approach, we identified genes with significant loss of DNA methylation in blood of males with intellectual disability and mutations in the X-linked KDM5C gene, encoding a histone H3 lysine 4 demethylase, in comparison to age/sex matched controls. Loss of DNA methylation in such individuals is consistent with known interactions between DNA methylation and H3 lysine 4 methylation. Further, loss of DNA methylation at the promoters of the three top candidate genes FBXL5, SCMH1, CACYBP was not observed in more than 900 population controls. We also found that DNA methylation at these three genes in blood correlated with dosage of KDM5C and its Y-linked homologue KDM5D. In addition, parallel sex-specific DNA methylation profiles in brain samples from control males and females were observed at FBXL5 and CACYBP. Conclusions: We have, for the first time, identified epigenetic alterations in patient samples carrying a mutation in a gene involved in the regulation of histone modifications. These data support the concept that DNA methylation and H3 lysine 4 methylation are functionally interdependent. The data provide new insights into the molecular pathogenesis of intellectual disability. Further, our data suggest that some DNA methylation marks identified in blood can serve as biomarkers of epigenetic status in the brain.

Background: The delivery of excess maternal nutrients to the fetus is known to increase the risk of macrosomia, even among infants of women without gestational diabetes mellitus. With the current obesity epidemic, maternal adiposity and its associated effects on circulating adipokines and inflammatory proteins may now have a greater impact on fetal growth. We sought to evaluate the independent effects of maternal glycemia, lipids, obesity, adipokines and inflammation on infant birth weight. Methods: We included 472 women who underwent an oral glucose tolerance test in late pregnancy and were found not to have gestational diabetes; 104 (22.0%) had gestational impaired glucose tolerance. We also measured fasting levels of insulin, low-and high-density lipoprotein cholesterol, triglycerides, leptin, adiponectin and C-reactive protein. Obstetric outcomes were assessed at delivery. Results: The mean birth weight was 3481 g (standard deviation 493 g); 68 of the infants were large for gestational age. On multiple linear regression analysis, positive determinants of birth weight were length of gestation, male infant, weight gain during pregnancy up to the time of the oral glucose tolerance test, body mass index (BMI) before pregnancy and impaired glucose tolerance in pregnancy. Leptin, adiponectin and C-reactive protein levels were each negatively associated with birth weight. On logistic regression analysis, the significant metabolic predictors of having a large-for-gestational-age infant were BMI before pregnancy (odds ratio [OR] 1.16, 95% confidence interval [CI] 1.05–1.27, per 1 kg/m² increase), weight gain during pregnancy up to the time of the oral glucose tolerance test (OR 1.12, 95% CI 1.05–1.19, per 1 kg increase) and leptin level (OR 0.50, 95% CI 0.30–0.82, per 1 standard deviation change). Interpretation: Among women without gestational diabetes, maternal adiposity and leptin levels were the strongest metabolic determinants of having a large-for-gestational-age infant rather than glucose intolerance and lipid levels.