4-year lifestyle intervention cuts type 2 diabetes risk by 46% in post-GDM womenLifestyle Changes Reduce Type 2 Diabetes Risk After Pregnancy

BACKGROUND: Women with a history of gestational diabetes mellitus (GDM) are at increased risk of developing type 2 diabetes later in life. This study evaluated whether lifestyle intervention can reduce the risk of type 2 diabetes in women with previous GDM. METHODS: This was a two-arm randomized controlled study conducted at the Tianjin Women and Children's Health Center. Women in six urban districts of Tianjin with previous GDM were randomly assigned in a 1: 1 ratio to either a 4-year lifestyle intervention group or a standard care control group between August 1, 2009 and July 31, 2011. Random allocation sequences were generated in patients but not in study coordinators. Each participant in the intervention group received individualized counseling aimed at reducing body weight in overweight women, increasing physical activity, and maintaining appropriate intakes of fat and carbohydrates especially fiber. Major components included six face-to-face meetings with a dietitian in the first year and two additional sessions in each subsequent year. The primary outcome was the development of type 2 diabetes, assessed using an oral glucose-tolerance test (OGTT). Participants were followed until the date of the diagnosis of diabetes, the last date of an OGTT, or death, whichever occurred first, up to December 2020. For participants who missed any OGTTs, self-reported physician-diagnosed diabetes data were collected. RESULTS: A total of 1180 women with a recent history of GDM were randomized to either an intensive lifestyle intervention ( n = 586) or usual care ( n = 594) 1-5 years postpartum (mean: 2.26 years). The mean follow-up was 4.5 years. During the trial, women in the intervention group, compared with the control group, lost more weight, increased physical activity and consumed more fiber. The incidence of diabetes after four years or more of follow-up was 9.0 and 15.3 cases per 1000 person-years in the lifestyle intervention and control groups, respectively. The lifestyle intervention reduced the incidence of diabetes by 46% (95% confidence interval: 10-67%) using the OGTT to diagnose diabetes, and by 40% (95% confidence interval: 11-59%) using either the OGTT or self-reported physician-diagnosed diabetes. CONCLUSIONS: Healthy lifestyle management significantly reduced the incidence of diabetes among young women with previous GDM. TRIAL REGISTRATION: ClinicalTrials.gov , NCT01554358.