The Effects of a Lifestyle Intervention to Prevent Deterioration in Glycaemic Status Among South Asian Women with Recent Gestational Diabetes Mellitus: A Randomised Control Trial

Background: Women with recent gestational diabetes mellitus (GDM) have increased risk of developing type 2 diabetes mellitus (T2DM). We aimed to determine whether a resource- and culturally-appropriate lifestyle intervention could prevent glycaemic deterioration in South Asia. Methods: This was an open-label parallel-group randomised trial. Women with GDM from 19 urban hospitals in India, Sri Lanka and Bangladesh underwent an oral glucose tolerance test (OGTT) 3-18 months post-partum. Those without T2DM were randomised to a 12-month lifestyle intervention focused on diet and physical activity or usual care. The primary outcome was the proportion with worsening category of glycaemia based on OGTT using American Diabetes Association criteria: 1) normal glucose tolerance to pre-diabetes (impaired fasting glucose and/or impaired glucose tolerance) or T2DM; or 2) pre-diabetes to T2DM. Secondary outcomes included new-onset T2DM, and change in body weight. Findings: 1823 women underwent OGTT at a median of 6·9 months post-partum. After excluding 162 (8·9%) with T2DM, 1612 (37·5% with pre-diabetes and 62·5% with normoglycaemia) were randomised between November 2017 and January 2020. Baseline mean age was 30·9 years (SD 4·9), mean BMI was 26·6 kg/m 2 (SD 4·7). Among participants randomised to the intervention, 79·7% were exposed to all programme content although pandemic lockdowns impacted the delivery model. After 14·5 months median follow-up, 1308 (81·2%) participants had primary outcome data. The intervention, compared to usual care, did not reduce worsening glycaemic status (25·5% vs. 27·1%; hazard ratio, 0·92 [95% CI: 0·76‒1·12]) or any secondary outcome. There was no evidence of heterogeneity of intervention effect by baseline characteristics.  Interpretation: A large proportion of South Asian women in urban centres develop dysglycaemia soon after a GDM-affected pregnancy. A low-intensity lifestyle intervention, substantially modified due to the COVID-19 pandemic, did not prevent subsequent deterioration in glycaemic status. Alternate or additional approaches are needed, especially among high-risk individuals. Trial Registration: Clinical Trials Registry of India (CTRI/2017/06/008744), Sri Lanka Clinical Trials Registry (SLCTR/2017/001) and ClinicalTrials.gov (NCT03305939). Funding: Global Alliance for Chronic Disease grants from the Indian Council of Medical Research (NO.58/1/1/GACD/NCD-II) and Australian National Health and Medical Research Council (1093171). Additional funding was received from USV Pharmaceuticals Ltd. and Lupin Pharmaceuticals Ltd. for sub-studies (data not reported here). Declaration of Interest: None to declare. Ethical Approval: The study protocol was approved by Human Research Ethics Committees of the All India Institute of Medical Sciences (India), icddr,b (Bangladesh), Faculty of Medicine, University of Kelaniya (Sri Lanka) and the University of Sydney (Australia)