The aim of this study was to determine how sodium intake can affect frailty, but not anorexia, in community-dwelling older adults in Korea.

This was a cross-sectional study.

The study used data from the Korean Frailty and Aging Cohort Survey (KFACS), a multi-center longitudinal study addressing 10 centers across urban, rural, and suburban communities in Korea, between 2016 and 2017.

A total of 954 older adults who underwent both 24-hour dietary recall assessment and physical function test during the first-year baseline investigation of the KFACS.

Frailty was determined according to the Fried frailty index (FFI).

Of the 954 participants, 461 (48.3%) were male and the mean age was 76.3 years old. The average daily sodium intake was 3857 mg. The frailty prevalence in first to third quartiles was 21.8%, 7.5%, and 5.4%, respectively, and increased in the fourth quartile of sodium intake to 8.9%. Using the second quartile of sodium intake (2504–3575 mg) as reference, the odds ratios of frailty were 1.64 (95% confidence interval: 0.84–3.22), 1.33 (0.57–3.06), and 4.00 (1.72–9.27) for the first (<2504 mg), third (3575–4873 mg), and fourth (≥4873 mg) quartiles, respectively, in a multivariate-adjusted analysis.

Low sodium intake (<2504 mg) is related to frailty in older people, but it seems to be a less important factor than other nutritional factors. The prevalence of frailty did not increase up to a daily sodium intake of 3575 mg, but it increased upon a daily sodium intake higher than 3575 mg.