Positive associations between sex hormones, bone metabolism and cognitive impairment in Chinese oldest-old females

Purpose: With a rapid increase in older adults, progressive impairment in cognitive function has become an increasing concern owing to high social and economic burdens. The current study was designed to investigate the associations of sex hormones and bone metabolism with cognitive impairment (CI) in Chinese oldest-old females. Methods: There were 396 oldest-old females from the China Hainan Oldest-old Cohort Study (CHOCS). Following standardized procedures, Mini Mental State Examination was effectively completed, and sex hormones and bone metabolism were assessed in these females. Results: The median age of all females was 101 years (range: from 80 to 116). There were 340 females (86%) with CI. Participants with CI had significantly higher levels of age, progesterone, prolactin and estradiol than those without CI (P < 0.05 for all). Total type I collagen N-terminal elongation peptide [hazard ratio (HR): 1.018, 95%CI: 1.001–1.035] and prolactin (HR: 1.065, 95%CI: 1.005–1.129) levels were positively and significantly associated with CI (P < 0.05 for all). Conclusions: Prolactin and total type I collagen N-terminal elongation peptide had positive associations with CI in Chinese oldest-old females. Thus, a balance in sex hormones and bone metabolism may have significant effects on cognitive function during the aging process.