These findings, which are in keeping with the full total results of previous studies involving individuals with type 2 diabetes32 and the overall population,1,33 may reflect well-known limitations in analyses of mortality among older persons, including an increased prevalence of coexisting chronic diseases, which increases the potential for reverse-causation bias; an elevated prevalence of competing risk elements, which reduces the proportional aftereffect of a single element; and decreased validity of BMI as a measure of adiposity due to age-related declines in muscle mass and wasting.34 It has additionally been suggested that excess adiposity might confer a metabolic benefit and improved survival among the elderly.