Gender differences in the association of cognitive impairment with the risk of hip fracture in the older population

Abstract Objectives To test the hypothesis that differences by gender will be observed in the association of hip fracture risk with stages of cognitive impairment; and to explore the association between Petersen’s “mild cognitive impairment” (MCI) and DSM-5 “mild neurocognitive disorder” (MND). Study design A community sample of 4803 individuals aged 55+ years was assessed in a two-phase case-finding enquiry in Zaragoza, Spain, and was followed up for 16 years. Medical and psychiatric history was collected with standardized instruments, including the Mini-Mental Status Examination (MMSE), Geriatric Mental State (GMS), History and Aetiology Schedule, and a Risk Factors Questionnaire. The statistical analysis included calculations of Hazard Ratios (HR) in multivariate Cox proportional hazards regression models. Main outcome measures Identified cases of hip fracture, validated by blind researchers. Results In men, hip fracture risk was increased at the “mild” (HR = 4.99 (1.39–17.91)) and at the “severe” (HR = 9.31 (1.35–64.06)) stages of cognitive impairment, indicated by MMSE performance. In contrast, in women no association could be documented at the “mild stage” (power = 89%), and the association disappeared altogether at the “severe stage” in the final multivariate statistical model (power 100%). No association observed between hip fracture and mild cognitive impairment in both men (power = 28% for P-MCI) and women (power = 44% and 19% for Petersen’s MCI and DSM-5 MND, respectively). Conclusions Increased hip fracture risk was associated with “mild” stages of cognitive impairment in men, but not in women. To explore the potential association with the construct MCI or MND, studies with greater statistical power would be required.