Phase Angle Is a Potential Novel Early Marker for Sarcopenia and Cognitive Impairment in the General Population.

Background: Sarcopenia is associated with an increased risk for dementia. This study aimed to elucidate the relationship between sarcopenia-related indices and cognitive decline in the general population.

Methods: This was a cross-sectional study involving 263 participants (163 men with a median age of 60 years [interquartile range = 53-70] and 100 women with a median age of 58 years [interquartile range = 49-68]) who underwent a general health examination. Sarcopenia-related indices included appendicular skeletal muscle mass (ASM)/height, ASM/body mass index, handgrip strength (HGS), HGS/upper extremity skeletal muscle mass and phase angle (PhA). We examined the associations between these indices and cognitive function using the Japanese version of the Montreal Cognitive Assessment (MoCA-J).

Results: Higher PhA, an indicator of muscle quality, was associated with a lower risk of mild cognitive impairment (MCI) in women (adjusted odds ratio = 0.28 [95% confidence interval, 0.10-0.78], p = 0.014), whereas the other sarcopenia-related indices showed no significant association with MCI in both sexes. The PhA of women was positively associated with the MoCA-J scores (β = 0.27, p = 0.005). Moreover, the PhA of women showed a positive correlation with cognitive subdomains, including memory (r = 0.22, p = 0.031), which is one of the earliest manifestations of cognitive impairment. The PhA in men was also positively correlated with memory (r = 0.24, p = 0.002).

Conclusions: PhA is a potentially novel index for detecting the risk of sarcopenia and cognitive decline in the general population.