https://diabetes.acponline.org/archives/2012/08/10/1.htm

Adults at normal weight when diagnosed with diabetes have higher mortality

Participants who had a normal body mass index when initially diagnosed with diabetes had higher mortality rates compared with those who were overweight or obese, a study found.


Participants who had a normal body mass index when initially diagnosed with diabetes had higher mortality rates compared with those who were overweight or obese, a study found.

The study consisted of a pooled analysis of five longitudinal studies involving 2,625 participants with new diabetes who totaled 27,125 person-years of follow-up. Participants (all age 40 or over) were classified as normal weight if their body mass index was 18.5 to 24.99 kg/m2 or overweight/obese if it was 25 kg/m2 or greater. Results appeared in the Aug. 8 Journal of the American Medical Association.

The proportion of adults who were normal weight at the time of diabetes diagnosis ranged from 9% to 21% among the studies (overall average 12%). During follow-up, 449 participants died, 178 from cardiovascular causes and 253 from noncardiovascular causes. The other 18 deaths were not classified.

The rates of total, cardiovascular, and noncardiovascular mortality were higher in normal-weight participants (284.8, 99.8, and 198.1 per 10,000 person-years, respectively) than in overweight/obese participants (152.1, 67.8, and 87.9 per 10,000 person-years, respectively).

After adjustment for demographic characteristics and blood pressure, lipid levels, waist circumference, and smoking status, hazard ratios for normal-weight participants for total, cardiovascular, and noncardiovascular mortality were 2.08 (95% CI, 1.52 to 2.85), 1.52 (95% CI, 0.89 to 2.58), and 2.32 (95% CI, 1.55 to 3.48), respectively, compared to overweight/obese participants.

The researchers wrote that “previous research suggests that normal-weight persons with diabetes have a different genetic profile than overweight or obese persons with diabetes. If those same genetic variants that predispose to diabetes are associated with other illnesses, these individuals may be ‘genetically loaded’ toward experiencing higher mortality.”

An editorial commented that medical societies are currently revising their prevention guidelines to reflect the impact of weight loss on diabetes, which may not help those with metabolically obese normal weight (MONW). “This could be a wake-up call for timely prevention and management to reduce adverse outcomes in all patients with type 2 diabetes, particularly in those MONW at diagnosis, who may have a false sense of protection because they are not overweight or obese,” wrote the editorialist. The editorial concluded by advocating for investigating the benefits of increasing physical activity and fitness to improve the prognosis of diabetics.