HealthDay News — Smoking status heavily modifies the obesity paradox observed in people with type 2 diabetes, according to a study published online July 3 in Diabetes Care.
David A. Jenkins, from the University of Manchester in the United Kingdom, and colleagues studied 502,631 participants in the general U.K. Biobank population as well as three subgroups of people with type 2 diabetes (23,842 participants), coronary heart disease (CHD; 24,268 participants), and cancer (45,790 participants). Adiposity exposures, including body mass index (BMI), waist circumference, body fat percentage, and waist-to-hip ratio, were considered.
The researchers found that the obesity paradox was observed for BMI among people with type 2 diabetes but not those with CHD (adjusted hazard ratio for obese versus normal BMI, 0.78 [95 percent confidence interval, 0.65 to 0.95] and 1.00 [95 percent confidence interval, 0.86 to 1.17] for type 2 diabetes and CHD, respectively). Current smokers had a more pronounced obesity paradox, while it was absent in never smokers; the paradox was more pronounced in men than women. There was less evidence for an obesity paradox for other adiposity measures; smoking consistently modified the relationship between adiposity and mortality.
“The obesity paradox was observed in people with type 2 diabetes and is heavily modified by smoking status,” the authors write. “The results of subgroup analyses and statistical adjustments are consistent with reverse causality and confounding.”