Adherence to the dietary inflammatory index and dietary approaches to stop hypertension and risk of gestational diabetes: a case-control study.

Background: Although multiple studies have explored the connection between dietary patterns and gestational diabetes mellitus (GDM) risk in Iran, there are limited and inconsistent results on the DASH diet's relationship, especially with attention to diet-related inflammation. Given the high prevalence of GDM and the limited number of studies in the Middle East, this study aimed to investigate the link between the DASH diet, Dietary Inflammatory Index (DII), and GDM among Iranian women.

Methods: This case-control study, conducted in healthcare facilities in Abadan, Iran, included 138 pregnant women with GDM and 136 healthy controls. GDM was diagnosed based on a 2-hour 75-gram oral glucose tolerance test conducted between 24 to 28 weeks of gestation. The FFQ with 147 items was used to assess the usual food intake of all women during the year before pregnancy and DASH/DII scores were calculated.

Results: The mean age of the case and control group was 30.28 ± 5.01 and 29.07 ± 5.57 years respectively. In the fully adjusted model, participants in the first tertile of DII compared to the third tertile had a lower GDM risk (OR: 0.52; 95% CI: 0.27, 0.98; P = 0.04). Meanwhile, in the fully adjusted model, those in the third tertile of the DASH diet had a lower risk of GDM than those in the first tertile (OR: 0.36; 95% CI: 0.19, 0.69; P = 0.002).

Conclusions: Higher adherence to the DASH diet and lower intake of a pro-inflammatory diet are associated with decreased risk of GDM.