Abstract
The effects of salt reduction and adequate nutrition intake among older adults with physical frailty remain controversial. Therefore, the present study investigated whether the association between daily salt intake and blood pressure among community-dwelling older adults, including the very old people, based on their physical frailty status. This cross-sectional study used data from the SONIC study, a cohort study on older adults, collected between 2010 and 2012. Daily salt intake was estimated from the brief self-administered diet history questionnaire. Participants were stratified by groups based on the use of antihypertensive medication and their physical frailty status. There were 1975 participants with an average age of 76.5 ± 6.5 years and 53.1% were female. No association was observed between daily salt intake and blood pressure among participants with physical frailty regardless of the use of antihypertensive medication. In contrast, an association was noted between daily salt intake and systolic blood pressure among the robust without antihypertensive medication group (β = 0.08, p = 0.038), and the odds ratios for systolic blood pressure ≥140 mmHg were significantly higher in the third and fourth quartiles of daily salt intake than in the first quartile (odds ratios = 1.78 and 1.71, respectively). The present results suggest that the physical frailty status needs to be considered when providing salt reduction guidance to older adults for blood pressure control, in order to prevent progression of frailty and maintain quality of life. Cross-sectional analysis of the association between salt intake and blood pressure in community-dwelling older adults in Japan (SONIC study): the results suggest that salt intake may not be related to blood pressure in older adults with physical frailty.