Weight change and risk of obesity-related complications: A retrospective population-based cohort study of a UK primary care database.

Abstract

To examine associations between weight loss/gain and risk of developing 13 obesity-related complications (ORCs), stratified by baseline body mass index (BMI). In this retrospective cohort study, we included adults with obesity (>30 kg/m2 ) from the UK Clinical Practice Research Datalink GOLD database with weight change (-50% to +50%) between Years 1 and 4 (N = 418 774 [median follow-up: 7 years]). Associations between weight change, baseline BMI and risk of developing ORCs during follow-up were assessed using Cox proportional hazard models. The impact of weight change on ORCs was generally dependent on baseline BMI. Four clear patterns were seen across the 13 outcomes. Pattern 1 showed greatest weight loss benefit for people with low baseline BMI (type 2 diabetes, sleep apnoea, hypertension and dyslipidaemia); Pattern 2 showed most weight loss benefit at lower baseline BMI but no significant weight loss effect at higher baseline BMI (asthma, hip/knee osteoarthritis and polycystic ovary syndrome); Pattern 3 showed benefit in most cardiovascular diseases with weight loss (chronic kidney disease, heart failure, atrial fibrillation and venous thromboembolism), but no additional benefit with >10% weight loss; Pattern 4 showed no clear relationship between weight change and unstable angina/myocardial infarction and depression. We found similar but opposite patterns for weight gain. Weight loss benefit is dependent on weight loss magnitude and initial BMI, and weight gain is associated with a similar risk increase. Four patterns of association were identified between degree of weight change, baseline BMI and 13 ORCs.