Feng L, Nyunt MS, Gao Q, et al.
J Gerontol A Biol Sci Med Sci 2016; Mar 24 [Epub ahead of print]
Publication date: March 24, 2016
The independent and combined effects of physical and cognitive domains of frailty in predicting the development of mild cognitive impairment (MCI) or dementia are not firmly established. This study by Feng et al. included cross-sectional and longitudinal analyses of physical frailty (Cardiovascular Health Study criteria), cognitive impairment (Mini-Mental State Examination [MMSE]), and neurocognitive disorder (DSM-5 criteria) among 1,575 community-living Chinese older adults from the Singapore Longitudinal Ageing Studies.
At baseline, 2% were frail, 32% were prefrail, and 9% had cognitive impairment (MMSE score <23). Frailty at baseline was significantly associated with prevalent cognitive impairment. Physical frailty categories were not significantly associated with incident neurocognitive disorder, but continuous physical frailty score and MMSE score showed significant individual and joint associations with incident mild neurocognitive disorder and dementia.
Compared with those who were robust and cognitively normal, prefrail or frail older adults without cognitive impairment had no increased risk of incident neurocognitive disorder, but elevated odds of association with incident neurocognitive disorder were observed for robust individuals with cognitive impairment (odds ratio [OR] = 4.04, P<0.001), prefrail individuals with cognitive impairment (OR = 2.22, P=0.044), and especially for frail individuals with cognitive impairment (OR = 6.37, P=0.005). The prevalence of co-existing frailty and cognitive impairment (cognitive frailty) was 1% (95% confidence interval [CI]: 0.5-1.4) overall but was higher (5%) among participants aged 75 and older.
Physical frailty is associated with increased prevalence and incidence of cognitive impairment, and co-existing physical frailty and cognitive impairment confers additionally greater risk of incident neurocognitive disorder.