BackgroundEvidence is accumulating for a role of vitamin D in maintaining normal glucose homeostasis. However, studies that prospectively examined circulating concentrations of 25-hydroxyvitamin D (25-[OH] D) in relation to diabetes risk are limited. Our objective is to determine the association between maternal plasma 25-[OH] D concentrations in early pregnancy and the risk for gestational diabetes mellitus (GDM).MethodsA nested case-control study was conducted among a prospective cohort of 953 pregnant women. Among them, 57 incident GDM cases were ascertained and 114 women who were not diagnosed with GDM were selected as controls. Controls were frequency matched to cases for the estimated season of conception of the index pregnancy.ResultsAmong women who developed GDM, maternal plasma 25-[OH] D concentrations at an average of 16 weeks of gestation were significantly lower than controls (24.2 vs. 30.1 ng/ml, P<0.001). This difference remained significant (3.62 ng/ml lower on average in GDM cases than controls (P value = 0.018)) after the adjustment for maternal age, race, family history of diabetes, and pre-pregnancy BMI. Approximately 33% of GDM cases, compared with 14% of controls (P<0.001), had maternal plasma 25-[OH] D concentrations consistent with a pre-specified diagnosis of vitamin D deficiency (<20 ng/ml). After adjustment for the aforementioned covariates including BMI, vitamin D deficiency was associated with a 2.66-fold (OR (95% CI): 2.66 (1.01–7.02)) increased GDM risk. Moreover, each 5 ng/ml decrease in 25-[OH] D concentrations was related to a 1.29-fold increase in GDM risk (OR (95% CI): 1.29 (1.05–1.60)). Additional adjustment for season and physical activity did not change findings substantially.ConclusionsFindings from the present study suggest that maternal vitamin D deficiency in early pregnancy is significantly associated with an elevated risk for GDM.

BackgroundInsufficient sleep and poor sleep quality, considered endemic in modern society, are associated with obesity, impaired glucose tolerance and diabetes. Little, however, is known about the consequences of insufficient sleep and poor sleep quality during pregnancy on glucose tolerance and gestational diabetes.MethodsA cohort of 1,290 women was interviewed during early pregnancy. We collected information about sleep duration and snoring during early pregnancy. Results from screening and diagnostic testing for gestational diabetes mellitus (GDM) were abstracted from medical records. Generalized linear models were fitted to derive relative risk (RR) and 95% confidence intervals (95% CIs) of GDM associated with sleep duration and snoring, respectively.ResultsAfter adjusting for maternal age and race/ethnicity, GDM risk was increased among women sleeping ≤ 4 hours compared with those sleeping 9 hours per night (RR = 5.56; 95% CI 1.31-23.69). The corresponding RR for lean women (<25 kg/m2) was 3.23 (95% CI 0.34-30.41) and 9.83 (95% CI 1.12-86.32) for overweight women (≥ 25 kg/m2). Overall, snoring was associated with a 1.86-fold increased risk of GDM (RR = 1.86; 95% CI 0.88-3.94). The risk of GDM was particularly elevated among overweight women who snored. Compared with lean women who did not snore, those who were overweight and snored had a 6.9-fold increased risk of GDM (95% CI 2.87-16.6).ConclusionsThese preliminary findings suggest associations of short sleep duration and snoring with glucose intolerance and GDM. Though consistent with studies of men and non-pregnant women, larger studies that include objective measures of sleep duration, quality and apnea are needed to obtain more precise estimates of observed associations.

Our findings are consistent with a larger literature that documents elevated blood pressure and increased risks of hypertension with short and long sleep duration.

Elevated CRP is highly correlated with prepregnancy adiposity and appears to be an independent predictor of preeclampsia in lean women. Further work is needed to identify modifiable risk factors for systemic inflammation in early pregnancy and to explore further the extent to which CRP and prepregnancy adiposity independently and jointly contribute to preeclampsia risk.

Low-grade systemic inflammation is associated with an increased risk of type 2 diabetes mellitus. Limited available data suggest inflammatory factors are predictive of gestational diabetes (GDM), a condition that is biochemically similar to type 2 diabetes. We examined the association between C-reactive protein (CRP) and GDM risk. Women were recruited before 16 weeks gestation and were followed until delivery. Maternal serum CRP (collected at 13 weeks' gestation, on average) was measured by a competitive immunoassay. We used generalised linear models to derive estimates of relative risks and 95% confidence intervals [CI]. Approximately 4.5% of the cohort (38 of 851) developed GDM. Elevated CRP was positively associated with GDM risk (P for trend = 0.007). After adjusting for maternal prepregnancy body mass index (BMI), family history of type 2 diabetes and nulliparity, women with CRP in the highest tertile experienced a 3.5-fold increased risk of GDM [95% CI 1.2, 9.8] as compared with those in the lowest tertile. The association between CRP and GDM was evident when analyses were restricted to lean women (BMI < 25 kg/m(2)). Lean women with CRP > or = 5.3 mg/L experienced a 3.7-fold increased risk of GDM [95% CI 1.6, 8.7] as compared with women with CRP < 5.3 mg/L. Systemic inflammation is associated with an increased risk of GDM, and the association is independent of maternal prepregnancy adiposity.

OBJECTIVEHigher heme iron intake is associated with increased type 2 diabetes risk. However, no previous study has evaluated gestational diabetes mellitus (GDM) risk in relation to heme iron intake during pregnancy. We investigated associations of maternal preconceptional and early pregnancy heme and nonheme iron intake with subsequent GDM risk.RESEARCH DESIGN AND METHODSWe conducted a prospective cohort study of 3,158 pregnant women. A food frequency questionnaire was used to assess maternal diet. Multivariable generalized linear regression models were used to derive estimates of relative risks (RRs) and 95% CIs.RESULTSApproximately 5.0% of the cohort developed GDM (n = 158). Heme iron intake was positively and significantly associated with GDM risk (Ptrend = 0.04). After adjusting for confounders, women reporting the highest heme iron intake levels (≥1.52 vs. <0.48 mg per day) experienced a 3.31-fold–increased GDM risk (95% CI 1.02–10.72). In fully adjusted models, we noted that a 1-mg per day increase in heme iron was associated with a 51% increased GDM risk (RR 1.51 [95% CI 0.99–2.36]). Nonheme iron was inversely, though not statistically significantly, associated with GDM risk, and the corresponding RRs were 1.00, 0.83, 0.62, and 0.61 across quartiles of nonheme iron intake (Ptrend = 0.08).CONCLUSIONSHigh levels of dietary heme iron intake during the preconceptional and early pregnancy period may be associated with increased GDM risk. Associations of GDM risk with dietary nonheme iron intake are less clear. Confirmation of these findings by future studies is warranted.

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Objective To evaluate the cross-sectional relationship between migraine and pre-gravid obesity; and to assess the risk of adult weight gain among women with history of a pediatric diagnosis of migraine. Background Obesity, comorbid with pain disorders including migraine, shares common pathophysiological characteristics including systemic inflammation, and derangements in adipose-tissue derived cytokines. Despite biochemical and epidemiological commonalities, obesity-migraine associations have been inconsistently observed. Methods A cohort of 3,733 women was interviewed during early pregnancy. We ascertained participants’ self-reported history of physician-diagnosed migraine and collected self-reported information about pre-gravid weight, adult height and net weight change from age 18 to the 3-monthsperiodpriorto pregnancy. Using pre-gravid body mass index, we categorized participants as follows: lean (<18.5 kg/m2); normal (18.5–24.9 kg/m2); overweight (25–29.9 kg/m2), obese (30–34.9 kg/m2), severely obese (35–39.9 kg/m2), and morbidly obese (≥ 40 kg/m2). Logistic regression procedures were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Results After adjusting for confounders, relative to normal weight women, obese women had a 1.48-fold increased odds of migraine(OR=1.48; 95%CI 1.12–1.96). Severely obese (OR=2.07; 95%CI 1.27–3.39) and morbidly obese (OR=2.75; 95%CI 1.60–4.70) had the highest odds of migraines. Women with a history of diagnosed pediatric migraine had a 1.67-fold higher odds of gaining ≥10.0 kg above their weight at age 18, as compared with non-migraineurs (OR=1.67; 95%CI 1.13–2.47). Conclusion These data support earlier observations of migraine-obesity association among women, and extend the literature to include evidence of adult weight gain among women with a history of pediatric migraine.