A recent study published in the journal, Diabetes Care, analysed obesity paradox with several adiposity measures including subgroups with type 2 diabetes mellitus (T2DM), coronary heart disease (CHD) and cancer. Obesity paradox was observed in patients with T2DM, but not in those with CHD, and was heavily modified by smoking status.
Researchers evaluated 502,631 participants from UK Biobank along with 3 subgroups of people with T2DM (n=23,842), CHD (n=24,268) and cancer (n=45,790). Effect of adiposity exposures like BMI, waist circumference, body fat percentage and waist-to-hip ratio on all-cause mortality was evaluated.
For BMI, obesity paradox was observed in patients with T2DM (lower mortality risk in obese vs normal weight [aHR, 0.78; 95% CI, 0.65-0.95]) but not in those with CHD (aHR, 1.00; 95% CI, 0.86–1.17). Obesity paradox was prominent in current smokers, absent in never smokers and more pronounced in men vs women. Evidence for obesity paradox was less evident for other adiposity measures. However, smoking consistently modified adiposity-mortality relationship.
Authors comment: “These data provide further insights into the potential mechanisms that link adiposity and mortality and deepen our understanding of the obesity paradox.” They call for more research to understand causal nature of these relationships before clinical guidance is modified.
