Carbohydrate intake during early pregnancy is inversely associated with abnormal glucose challenge test results in Japanese pregnant women.

BACKGROUND: In East Asian countries, which have a high prevalence of underweight individuals, there is little information about the association between dietary factors and abnormal glucose tolerance during pregnancy. We examined the association between carbohydrate intake and moderately abnormal glucose tolerance in Japanese pregnant women.

METHODS: We conducted a prospective study on 325 Japanese pregnant women without a diagnosis of diabetes mellitus prior to pregnancy. Dietary carbohydrate intake (% of total energy intake) was assessed using a 3-day dietary record during weeks 8-15 of pregnancy. Glucose tolerance was assessed by the 50 g glucose challenge test (GCT) during weeks 24-28 of pregnancy. A positive GCT result was defined by a 1-hour plasma concentration ≥ 7.8 mmol/L. Odds ratios of a positive GCT were calculated for the top and middle tertile categories of carbohydrate intake using the bottom category as reference.

RESULTS: Mean (standard deviation) body mass index at the first prenatal visit was 19.7 (1.9) kg/m2 , and 95 women were underweight. Seventy-four women had positive GCT results. Carbohydrate intake was negatively associated with a positive GCT result after adjusting for age, parity, body mass index at first prenatal visit, family history of diabetes mellitus, rate of gestational weight gain, energy intake, and dietary fiber intake (odds ratio for top category: 0.46 [95% CI, 0.23-0.93]).

CONCLUSIONS: These findings suggest that high carbohydrate intake was negatively associated with moderately abnormal glucose tolerance in a population with a high prevalence of underweight individuals.