OBJECTIVE To examine racial/ethnic disparities in the prevalence of diabetes and prediabetes by BMI category. RESEARCH DESIGN AND METHODS In a consortium of three U.S. integrated health care systems, 4,906,238 individuals aged ≥20 years during 2012–2013 were included. Diabetes and prediabetes were ascertained by diagnosis and laboratory results; antihyperglycemic medications were also included for diabetes ascertainment. RESULTS The age-standardized diabetes and prediabetes prevalence estimates were 15.9% and 33.4%, respectively. Diabetes but not prediabetes prevalence increased across BMI categories among all racial/ethnic groups (P for trend < 0.001). Racial/ethnic minorities reached a given diabetes prevalence at lower BMIs than whites; Hawaiians/Pacific Islanders and Asians had a diabetes prevalence of 24.6% (95% CI 24.1–25.2%) in overweight and 26.5% (26.3–26.8%) in obese class 1, whereas whites had a prevalence of 23.7% (23.5–23.8%) in obese class 2. The age-standardized prediabetes prevalence estimates in overweight among Hispanics (35.6% [35.4–35.7%]), Asians (38.1% [38.0–38.3%]), and Hawaiians/Pacific Islanders (37.5% [36.9–38.2%]) were similar to those in obese class 4 among whites (35.3% [34.5–36.0%]), blacks (36.8% [35.5–38.2%]), and American Indians/Alaskan Natives (34.2% [29.6–38.8%]). In adjusted models, the strength of association between BMI and diabetes was highest among whites (relative risk comparing obese class 4 with normal weight 7.64 [95% CI 7.50–7.79]) and lowest among blacks (3.16 [3.05–3.27]). The association between BMI and prediabetes was less pronounced. CONCLUSIONS Racial/ethnic minorities had a higher burden of diabetes and prediabetes at lower BMIs than whites, suggesting the role of factors other than obesity in racial/ethnic disparities in diabetes and prediabetes risk and highlighting the need for tailored screening and prevention strategies.

Despite dietary recommendations of polyunsaturated fatty acids (PUFAs) for cardiometabolic health, n-3 and n-6 PUFAs and their interplay in relation to diabetes risk remain debated. Importantly, data among pregnant women are scarce. We investigated individual plasma phospholipid n-3 and n-6 PUFAs in early to midpregnancy in relation to subsequent risk of gestational diabetes mellitus (GDM). Within the National Institute of Child Health and Human Development (NICHD) Fetal Growth Studies–Singleton Cohort (n = 2,802), individual plasma phospholipid n-3 and n-6 PUFAs levels were measured at gestational weeks (GWs) 10–14, 15–26, 23–31, and 33–39 among 107 GDM cases (ascertained on average at GW 27) and 214 non-GDM controls. Conditional logistic regression was used, adjusting for major risk factors for GDM. After adjusting for covariates, individual n-3 eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA) were inversely correlated with insulin-resistance markers, whereas individual n-6 dihomo-gamma-linolenic acid (DGLA) was positively correlated with insulin-resistance markers. At GW 15–26, a standard deviation (SD) increase in total n-3 PUFAs and individual n-3 DPA was associated with a 36% (adjusted odds ratio 0.64; 95% CI 0.42–0.96; P = 0.042) and 33% (0.67; 95% CI 0.45–0.99; P = 0.047) lower risk of GDM, respectively; however, the significance did not persist after post hoc false-discovery rate (FDR) correction (FDR-corrected P values > 0.05). Associations between total n-6 PUFAs and GDM were null, whereas associations with individual n-6 PUFAs were differential. Per SD increase, gamma-linolenic acid (GLA) at GWs 10–14 and DGLA at GWs 10–14 and 15–26 were significantly associated with a 1.40- to 1.95-fold higher risk of GDM, whereas docosatetraenoic acid (DTA) at GW 15–26 was associated with a 45% (0.55; 95% CI 0.37–0.83) lower risk of GDM (all FDR-corrected P values < 0.05). Null associations were observed for linoleic acid (LA) in either gestational window in relation to risk of GDM. Women with high (≥median) n-3 PUFAs and low (<median) n-6 PUFAs levels had a 64% (95% CI 0.14–0.95; P value = 0.039) lower risk of GDM versus women with low n-3 and high n-6 PUFAs. Limitations include the inability to distinguish between exogenous and endogenous influences on circulating PUFA levels and the lack of causality inherent in observational studies. Our findings may suggest a potential role of primarily endogenously metabolized plasma phospholipid n-6 PUFAs including GLA, DGLA, and DTA in early to midpregnancy in the development of GDM. Null findings on primarily diet-derived n-3 EPA and DHA and n-6 LA do not provide strong evidence to suggest a beneficial role in prevention of GDM, although not excluding the potential benefit of EPA and DHA on glucose–insulin homeostasis given the inverse associations with insulin-resistance markers. Our findings highlight the importance of assessing individual circulating PUFAs to investigate their distinct pathophysiologic roles in glucose homeostasis in pregnancy.

OBJECTIVE To examine whether gestational diabetes mellitus (GDM), independent of subsequent diabetes, is an early risk factor for renal impairment long term after the index pregnancy. RESEARCH DESIGN AND METHODS In the Diabetes & Women’s Health (DWH) study (2012–2016), we examined the independent and joint associations of GDM and subsequent diabetes with long-term renal function among 607 women with and 619 women without GDM in the Danish National Birth Cohort (DNBC) index pregnancy (1996–2002). At median follow-up of 13 years after the index pregnancy, serum creatinine (mg/dL) and urinary albumin (mg/L) and creatinine (mg/dL) were measured, from which estimated glomerular filtration rate (eGFR) (mL/min/1.73 m²) and urinary albumin-to-creatinine ratio (UACR) (mg/g) were derived. RESULTS Compared with women without GDM or subsequent diabetes, women with a GDM history had significantly higher eGFR even if they had not subsequently developed diabetes (adjusted β-coefficient [95% CI] = 3.3 [1.7, 5.0]). Women who had a GDM history and later developed diabetes (n = 183) also had significantly higher UACR [exponent β = 1.3 [95% CI 1.1, 1.6]) and an increased risk of elevated UACR (≥20 mg/g) [adjusted relative risk [95% CI] = 2.3 [1.1, 5.9]) compared with women with neither. After adjusting for potential confounders including prepregnancy BMI and hypertension, GDM without subsequent diabetes was not related to UACR. CONCLUSIONS Women who develop GDM in pregnancy were more likely to show increased eGFR levels at 9–16 years’ postpartum, which could indicate early stages of glomerular hyperfiltration and renal damage. However, only those who subsequently developed diabetes showed overt renal damage as evidenced by elevated UACR.

Air pollution is both a sensory blight and a threat to human health. Inhaled environmental pollutants can be naturally occurring or human-made, and include traffic-related air pollution (TRAP), ozone, particulate matter (PM) and volatile organic compounds, among other substances, including those from secondhand smoking. Studies of air pollution on reproductive and endocrine systems have reported associations of TRAP, secondhand smoke (SHS), organic solvents and biomass fueled-cooking with adverse birth outcomes. While some evidence suggests that air pollution contributes to infertility, the extant literature is mixed, and varying effects of pollutants have been reported. Although some reviews have studied the association between common outdoor air pollutants and time to pregnancy (TTP), there are no comprehensive reviews that also include exposure to indoor inhaled pollutants, such as airborne occupational toxicants and SHS. The current systematic review summarizes the strength of evidence for associations of outdoor air pollution, SHS and indoor inhaled air pollution with couple fecundability and identifies gaps and limitations in the literature to inform policy decisions and future research. We performed an electronic search of six databases for original research articles in English published since 1990 on TTP or fecundability and a number of chemicals in the context of air pollution, inhalation and aerosolization. Standardized forms for screening, data extraction and study quality were developed using DistillerSR software and completed in duplicate. We used the Newcastle-Ottawa Scale to assess risk of bias and devised additional quality metrics based on specific methodological features of both air pollution and fecundability studies. The search returned 5200 articles, 4994 of which were excluded at the level of title and abstract screening. After full-text screening, 35 papers remained for data extraction and synthesis. An additional 3 papers were identified independently that fit criteria, and 5 papers involving multiple routes of exposure were removed, yielding 33 articles from 28 studies for analysis. There were 8 papers that examined outdoor air quality, while 6 papers examined SHS exposure and 19 papers examined indoor air quality. The results indicated an association between outdoor air pollution and reduced fecundability, including TRAP and specifically nitrogen oxides and PM with a diameter of ≤2.5 µm, as well as exposure to SHS and formaldehyde. However, exposure windows differed greatly between studies as did the method of exposure assessment. There was little evidence that exposure to volatile solvents is associated with reduced fecundability. The evidence suggests that exposure to outdoor air pollutants, SHS and some occupational inhaled pollutants may reduce fecundability. Future studies of SHS should use indoor air monitors and biomarkers to improve exposure assessment. Air monitors that capture real-time exposure can provide valuable insight about the role of indoor air pollution and are helpful in assessing the short-term acute effects of pollutants on TTP. Exposure to outdoor and indoor air pollutants may increase time to pregnancy.

Artificially sweetened beverages (ASBs) are commonly consumed and recommended for individuals at high risk for cardiometabolic diseases; however, the health effects of ASBs remain contradictory. Given that cross-sectional analyses are subject to reverse causation, prospective studies with long-term follow-up are needed to evaluate associations between ASBs and cardiometabolic health, especially among high-risk individuals. The aim of this study was to examine associations of ASB intake and cardiometabolic health among high-risk women with prior gestational diabetes mellitus (GDM). We included 607 women with GDM from the Danish National Birth Cohort (DNBC; 1996–2002) who completed a clinical exam 9–16 y after the DNBC pregnancy for the Diabetes & Women's Health (DWH) Study (2012–2014). We assessed ASB intake using FFQs completed during the DNBC pregnancy and at the DWH Study clinical exam. We examined cardiometabolic outcomes at the DWH clinical exam. We estimated percentage differences in continuous cardiometabolic markers and RRs for clinical endpoints in association with ASB intake both during pregnancy and at follow-up adjusted for prepregnancy BMI, diet, and lifestyle factors. Sensitivity analyses to account for reverse causation were performed. In pregnancy and at follow-up, 30.4% and 36.4% of women regularly (≥2 servings/wk) consumed ASB, respectively. Consumption of ASBs, both during pregnancy and at follow-up, was associated with higher glycated hemoglobin (HbA1c), insulin, HOMA-IR, triglycerides, liver fat, and adiposity and with lower HDL at follow-up. After adjustment for covariates, particularly prepregnancy BMI, the majority of associations between ASB intake in pregnancy and outcomes at follow-up became null with the exception of HbA1c. ASB intake at follow-up (≥1 serving/d compared with <1 serving/mo) was associated with higher HbA1c (6.5%; 95% CI: 1.9, 11.3; P-trend = 0.007); however, associations were not upheld in sensitivity analyses for reverse causation. Among Danish women with a history of GDM, ASB intake was not significantly associated with cardiometabolic profiles.

Gestational diabetes mellitus (GDM) predisposes pregnant individuals to perinatal complications and long-term diabetes and cardiovascular diseases. We developed and validated metabolomic markers for GDM in a prospective test-validation study. In a case-control sample within the PETALS cohort (GDM n = 91 and non-GDM n = 180; discovery set), a random PETALS subsample (GDM n = 42 and non-GDM n = 372; validation set 1), and a case-control sample within the GLOW trial (GDM n = 35 and non-GDM n = 70; validation set 2), fasting serum untargeted metabolomics were measured by gas chromatography/time-of-flight mass spectrometry. Multivariate enrichment analysis examined associations between metabolites and GDM. Ten-fold cross-validated LASSO regression identified predictive metabolomic markers at gestational weeks (GW) 10–13 and 16–19 for GDM. Purinone metabolites at GW 10–13 and 16–19 and amino acids, amino alcohols, hexoses, indoles, and pyrimidine metabolites at GW 16–19 were positively associated with GDM risk (false discovery rate <0.05). A 17-metabolite panel at GW 10–13 outperformed the model using conventional risk factors, including fasting glycemia (area under the curve: discovery 0.871 vs. 0.742, validation 1 0.869 vs. 0.731, and validation 2 0.972 vs. 0.742; P < 0.01). Similar results were observed with a 13-metabolite panel at GW 17–19. Dysmetabolism is present early in pregnancy among individuals progressing to GDM. Multimetabolite panels in early pregnancy can predict GDM risk beyond conventional risk factors.