For type 2 diabetes patients, being overweight or obese was associated with a higher risk for nonfatal cardiovascular events, but overweight was associated with lower mortality, according to research published in Annals of Internal Medicine.

Dr. Pierluigi Costanzo of the University of Hull in Kingston upon Hull, England, and his associates reported results of a prospective cohort study of the “diabetes paradox” in 10,568 type 2 patients without cardiovascular disease who were followed for a median of 10.6 years (median baseline body mass index was 29.0 kg/m2).

Overweight (BMI, 25-29.9 kg/m2) was associated with a lower mortality risk, whereas obesity (BMI >30 kg/m2) had a mortality risk similar to that of normal-weight persons. The precise mechanisms behind the survival advantage in overweight but not obese patients is still unknown. The investigators noted that they did not have patient information on fitness levels, medication use, or cause of death.

Overweight or obese patients (BMI >25 kg/m2) also had a higher rate of cardiac events than did patients of normal weight (BMI, 18.5-24.9 kg/m2).

“The obesity paradox is open to several interpretations that should be addressed by further research rather than promoting preconceptions about the ideal BMI. These results should not discourage patients from adopting a healthy lifestyle,” the investigators wrote.

Read the full article here: Ann Intern Med. 2015;162:610-618 ( doi:10.7326/M14-1551 )