Higher BMI is associated with worse survival in the general population, but appears to confer a survival advantage in patients on hemodialysis. Few studies have examined the relationship between obesity and mortality in patients with earlier stages of CKD.
In a new study of subjects with predominantly non-diabetic CKD, neither high nor low BMI was independently associated with all-cause or CVD mortality. Magdalena Madero, MD, a nephrology fellow at Tufts-New England Medical Center in Boston, and her colleagues assessed data from 1,795 participants in the Modification of Diet in Renal Disease (MDRD) Study. It examined the effects of dietary protein restriction and strict BP control on disease progression in predominantly non-diabetic, stage 3-4 CKD. Dr. Madero’s group divided subjects into four BMI quartiles.
During a mean follow-up of 10 years, 456 patients (26%) died from any cause and 272 (16%) died from CVD. The proportion of deaths was similar across BMI quartiles: 6%, 5%, 6%, and 7% in quartiles 1, 2, 3, and 4, respectively. After adjusting for age, gender, race, randomization status, and numerous other potential confounders, the researchers observed no significant difference in death risk among the quartiles.