Independent association between insulin-like growth factor-I and dehydroepiandrosterone sulphate in women in middle adulthood

Abstract

Objective: The age-related decrease in circulating dehydroepiandrosterone sulphate (DHEAS) and insulin-like growth factor (IGF)-I levels is suggested to be involved in various age-related changes. As both hormones are regulated differently, by ACTH and GH, respectively, reasons for the almost parallel changes of their circulating levels during ageing remain unknown. The objectives of this study were to verify variables that influence serum IGF-I as well as DHEAS levels in subjects in middle adulthood.

Subjects and methods: We determined serum DHEAS and IGF-I levels in 362 Japanese subjects aged 30-65 years (225 men and 137 women) undergoing health examinations, who had no hepatic disease, renal disease, malignant disease, diabetes mellitus, or asthma. Variables influencing DHEAS and IGF-I were analysed.

Results: DHEAS as well as IGF-I levels were higher in men than in women. DHEAS was positively associated with IGF-I and negatively with age, in both men and women. By multivariate regression analysis, age was negatively associated with DHEAS in both men and women. IGF-I was found to be independently associated with DHEAS in women. Age was the only negative independent factor for IGF-I in both men and women, while DHEAS was the only positive independent factor in women.

Conclusions: The present study demonstrates that DHEAS and IGF-I levels are associated with each other, independent of age, in women in middle adulthood.