Implications of Lancet framework definition of obesity in relation to cardiovascular diseases

Background and Aims The Lancet Diabetes and Endocrinology Commission recently proposed the new definition of preclinical and clinical obesity. Our study aimed to investigate the associations of the novel obesity classifications with incident cardiovascular disease (CVD). Methods In 459,102 UK Biobank participants enrolled between 2006 and 2010, we applied the new definitions of clinical and preclinical obesity, based on the presence of excess adiposity with or without organ dysfunction, to assess their associations with incident CVD and its subtypes. Participants were further stratified into a seven-category classification integrating the Lancet framework with traditional body mass index (BMI) categories. Multivariable Cox regression estimated hazard ratios (HR) and 95% confidence intervals (CI) for each obesity classification in relation to CVD risk. Results Over a median follow-up of 11.0 years, a total of 51,640 cases of CVD incidence were recorded. Compared to those with no obesity, individuals with preclinical obesity exhibited modestly elevated risks of CVD (HR 1.11, 95% CI 1.08–1.15), while clinical obesity was associated with substantially higher risks of total CVD (HR 1.77, 95% CI 1.72–1.82) and all subtypes, including coronary heart disease (CHD), stroke, and heart failure. Furthermore, newly diagnosed preclinical and clinical obesity with BMI below the conventional obesity threshold also had elevated incident CVD risk, with strongest association for CHD. Conclusions The new framework advances CVD risk stratification beyond BMI alone, emphasizing the importance of incorporating excess body fat and functional health assessments into obesity diagnosis. Stronger associations with clinical obesity highlight its utility as a cumulative disease burden classifier, identifying individuals at higher cardiovascular risk.