Favourable effects of the Dietary Approaches to Stop Hypertension diet on glucose tolerance and lipid profiles in gestational diabetes: a randomised clinical trial

This was a randomized clinical trial in pregnant women with gestational diabetes mellitus in mid-pregnancy conducted in Kashan, Iran, at Kashan University of Medical Sciences. The DASH arm was stratified by BMI and included 17 participants in the baseline dietary extraction; participants were instructed not to change routine physical activity. Outcomes were assessed at baseline and after 4 weeks.

The active intervention was a DASH eating pattern for 4 weeks, emphasizing fruits, vegetables, whole grains, and low-fat dairy while limiting saturated fat, cholesterol, refined grains, sweets, and sodium to 2400 mg/day. The control group received a control diet over the same period. Source extractions also note a once-daily calcium and ferfolic supplement, but the packet does not clearly indicate that this was the tested intervention itself.

The DASH eating pattern produced favorable short-term effects on glucose tolerance and lipid profiles versus the control diet. Plasma glucose was lower at 60 min (21•86 v. 20•45 mmol/l, P group = 0•02), 120 min (2 2•3 v. 0•2 mmol/l, P group = 0•001), and 180 min (2 1•7 v. 0•22 mmol/l, P group = 0•002), and HbA1c decreased (20•2 v. 0•05 %, P group = 0•001). Mean changes also favored DASH for total cholesterol (−20•42 v. 0•31 mmol/l, P group = 0•01), LDL-cholesterol (−20•47 v. 0•22 mmol/l, P group = 0•005), TAG (−20•17 v. 0•34 mmol/l, P group = 0•01), total:HDL-cholesterol ratio (2 0•6 [SD 0•9] v. 0•3 [SD 0•8], P group = 0•008), and systolic blood pressure (22•6 v. 1•7 mmHg, P group = 0•001). Fasting plasma glucose change was not significant (−20•29 v. 0•15 mmol/l, P group = 0•09).

The trial was short at 4 weeks and single-center, which limits longer-term and broader generalizability. The active arm sample size appears small, and adverse events were not reported. The packet also does not provide full baseline values for all outcomes, and the supplementation detail is not fully clear as to whether it was part of the tested intervention or background care.