Shani Botha, Lorna Forde, Sheila MacNaughton, Ross Shearer, Robert Lindsay, Naveed Sattar, David Morrison, Paul Welsh, Jennifer Logue

Lifestyle weight management interventions are recommended in clinical guidelines for patients with type 2 diabetes and obesity, but lack evidence regarding their long term effectiveness. Electronic health records were used to follow 23,208 patients with type 2 diabetes and obesity in Glasgow, Scotland, for up to 3 years between 2005 and 2014. Patients were stratified by referral to and attendance at a lifestyle weight management intervention, and by attainment of a target weight loss of ≥5kg over 7-9 sessions ("successful completers"). Outcomes were change in weight, HbA1c, and diabetes medications. 3471 potentially eligible patients were referred to the service, and less than half of those attended (n=1537). Of those who attended 7-9 sessions, >40% successfully completed with a 5kg weight loss (334/808). Successful completers maintained greater weight loss (change at 3 years -8.03kg; 95%CI -9.44;-6.62) than the non-completers (-3.26kg; 95%CI; -4.01;-2.51; p<0.001) and those not referred to the service (-1.00kg; 95%CI -1.15;-0.85; p<0.001). Successful completers were the only patient group who did not increase their use of diabetes medication and insulin over 3 years. In adjusted models, successful completers had a clinically significant reduction in HbA1c ((-3.7mmol/mol; 95%CI -5.82;-1.51) after 3 years; p≤0.001) compared to non-completers and unsuccessful completers. A real-life structured weight management intervention in patients with diabetes can reduce weight in the medium term, result in improved glycaemic control with fewer medications, and may be more effective than pharmacological alternatives. Challenges include getting a higher proportion of patients referred to and engaged with interventions.