January 27 Highlights

Abstract

Moffat et al. examined the association between Alzheimer disease (AD) risk and endogenous total and free testosterone before diagnosis in 574 men from the Baltimore Longitudinal Study of Aging. Increased free testosterone index (FTI) but not total testosterone was associated with decreased risk of AD after covariate adjustment (26% reduction per 10 nmol/nmol increase in FTI). see page 188 Paoletti et al. found that androgen bioavailability was lower in 96 lean elderly subjects with AD than in 104 age-matched lean control subjects. Thus endocrine pattern may impair cognitive function and may be dependent on increased sex hormone binding globulin levels. see page 301 The accompanying editorial by Henderson and Hogervorst points out that testosterone reduces formation of s-amyloid and hyperphosphorylation of tau protein in animal models of AD and may enhance specific cognitive skills in men. For hypogonadal men who are otherwise healthy, they note the possibility that interventions to increase free testosterone could reduce their risk of developing AD. However, whether testosterone might actually reduce AD incidence for hypogonadal men …