METHODS: The PURE study is a prospective cohort study of 127 594 adults aged 35-70 years from 20 high-income, middle-income, and low-income countries. Diet was assessed at baseline using country-specific validated food frequency questionnaires. The glycaemic index and the glycaemic load were estimated on the basis of the intake of seven categories of carbohydrate-containing foods. Participants were categorised into quintiles of glycaemic index and glycaemic load. The primary outcome was incident type 2 diabetes. Multivariable Cox Frailty models with random intercepts for study centre were used to calculate hazard ratios (HRs).
FINDINGS: During a median follow-up of 11·8 years (IQR 9·0-13·0), 7326 (5·7%) incident cases of type 2 diabetes occurred. In multivariable adjusted analyses, a diet with a higher glycaemic index was significantly associated with a higher risk of diabetes (quintile 5 vs quintile 1; HR 1·15 [95% CI 1·03-1·29]). Participants in the highest quintile of the glycaemic load had a higher risk of incident type 2 diabetes compared with those in the lowest quintile (HR 1·21, 95% CI 1·06-1·37). The glycaemic index was more strongly associated with diabetes among individuals with a higher BMI (quintile 5 vs quintile 1; HR 1·23 [95% CI 1·08-1·41]) than those with a lower BMI (quintile 5 vs quintile 1; 1·10 [0·87-1·39]; p interaction=0·030).
INTERPRETATION: Diets with a high glycaemic index and a high glycaemic load were associated with a higher risk of incident type 2 diabetes in a multinational cohort spanning five continents. Our findings suggest that consuming low glycaemic index and low glycaemic load diets might prevent the development of type 2 diabetes.
FUNDING: Full funding sources are listed at the end of the Article.
METHOD: Data from 1,538 women were analyzed. At the first visit for prenatal care, the 50-gram glucose challenge test was followed by the 75-gram glucose tolerance test in those who screened positive. GDM was diagnosed based on the WHO (1999) criteria. Maternal complete blood count was obtained at the first visit, hospitalization for birth, and after birth. Receiver operator characteristic curves were generated to establish thresholds. Multivariable logistic regression analyses were performed to establish independent predictors of GDM.
RESULTS: GDM was diagnosed in 182/1,538 (11.8%). GDM was associated with hemoglobin level, hematocrit and erythrocyte count at the first visit for prenatal care only. Hemoglobin threshold at the first visit was established at 11.5 g/dl. After adjustment, high hemoglobin [AOR 1.5 (95% CI 1.0-2.1); p = 0.027] remained predictive of GDM.
CONCLUSIONS: High maternal hemoglobin level at the first prenatal visit is independently predictive of GDM.