Tianjin Gestational Diabetes Mellitus Prevention Program. Study design, methods, and 1-year interim report on the feasibility of lifestyle intervention program

Objective: To assess whether lifestyle intervention can reduce type 2 diabetes risk in women with prior GDM in the Tianjin Gestational Diabetes Mellitus (GDM) Prevention Program. Methods: 1180 women who were diagnosed with GDM from 2005 to 2009 were randomly assigned to either a lifestyle intervention (n=. 586) or a control group (n=. 594). Major elements of the intervention include six face-to-face meetings with study dietitians in the first year, and two additional sessions and two telephone calls in second year. Results: During the first year, average body weight loss in the first 404 subjects was 1.40kg (2.1%) in the intervention group vs 0.21kg (0.3%) in the control group (P=0.001), and the decrease was more significant among baseline overweight women (body bass index [BMI]≥24kg/m²) in the intervention (2.91kg/4.2%) compared with that in the control group (0.51kg/0.7%) (P<0.001). In addition, women in the intervention group, compared with those in the control group, have decreased BMI, body fat, waist circumference, and plasma insulin levels, and have improved behaviors including increased leisure time activity and dietary fiber intake and decreased sedentary time and fat consumptions. Conclusion: The interim results support the efficacy and feasibility of the lifestyle intervention program.