Abstracts

Obesity paradox holds in people who develop type 2 diabetes despite normal weight

We know that in some chronic diseases, such as heart failure and chronic kidney, people of normal weight die, on average, sooner than those who are overweight. The same has been shown for people whose body weight was normal at the time they were diagnosed as having type 2 diabetes.

The data came from 5 large US cohort studies. Diabetes was newly detected in 2 625 people, of whom 449 died during more than 27 000 person years follow-up. Across studies, 9 - 21% (mean 12%) of people were of normal weight at the time of diagnosis. Mortality rates were consistently higher in these people than in participants with a body mass index of 25 or more. In people of normal weight, total mortality, cardiovascular mortality and non-cardiovascular mortality were 284.8, 99.8 and 198.1 per 10 000 person years, respectively, compared with 152.1, 67.8 and 87.9 per 10 000 person years for those who were overweight or obese. After adjustment for demographic data and cardiovascular risks, people with normal weight had double the risk of dying of any cause, compared with those who were overweight or obese. Risks for cardiovascular and non-cardiovascular mortality were increased 1.5-fold and 2.3-fold, respectively.

Poor cardiorespiratory fitness and physical inactivity may pose a greater threat to health than obesity, write the editorialists.

Carnethon MR, et al. JAMA 2012;308:581-590.