Maintaining normal weight reduces mortality risk in T1D

Having a normal weight helps delay mortality in individuals with type 1 diabetes (T1D), while being underweight may suggest underlying complications, suggests a recent study.

“Maintaining normal weight may translate into reduced risk of mortality in T1D, particularly for individuals of male sex, later diabetes-onset age and normal albumin excretion rate,” the authors said.

Of the 5,836 individuals with T1D, 876 died during a median of 13.7 years. A reverse J-shaped relationship was observed between baseline body mass index (BMI) and all-cause mortality. When analyses were restricted to those with normal albumin excretion rate, the relationship was U-shaped.

Normal BMI (24.3–24.8 kg/m²) was associated with the lowest mortality. However, the BMI with the lowest mortality was in the overweight region (25.9–26.1 kg/m²) among those with diabetic nephropathy. This finding suggested that the relationship between BMI and mortality was modified by diabetic nephropathy, diabetes-onset age and sex (p-interaction<0.05).

This prospective study examined the relationship between BMI and mortality and the interaction with clinically meaningful factors. The authors included T1D patients from the FinnDiane study and retrieved death data for all participants on 31 December 2015. A Cox proportional hazards model was used, with BMI as a restricted cubic spline as well as effect modification by adding interaction terms to the spine, to estimate the effect of BMI on the risk of mortality.

“The relationship between BMI and mortality may differ between patients with type 1 diabetes and the general population,” the authors said.