Association of frailty index with incidence of chronic kidney disease: China Health and Retirement Longitudinal Study.

Aim: Frailty is an important risk factor for a wide range of chronic diseases and for mortality risk. This study aims to explore the relationship between frailty and incidence of chronic kidney disease (CKD), particularly on the change and accumulation of frailty.

Methods: Frailty status was assessed using the frailty index (FI, constructed by 31 items) and categorized as robust, pre-frail, and frail. The accumulation and change in frailty were assessed on the basis of frailty status at baseline and a second survey 4 years after baseline. Logistic regression was used to estimate the association between frailty and developing CKD.

Results: A total of 3597 participants (mean age: 59.08 ± 8.94 years old, male: 49.9%) from CHARLS were included. Participants with pre-frailty or frailty status had a higher risk of developing CKD compared with robust participants (pre-frail vs robust, OR 1.78, 95% CI 1.37-2.32, p < 0.001; frail vs robust, OR 2.52, 95% CI 1.67-3.79, p < 0.001). Participants who had a robust status in the two surveys had a significantly lower risk of developing CKD (OR 0.51, 95% CI 0.36-0.75, p < 0.001) compared with those who never had a robust status.

Conclusion: Frailty status is significantly associated with the incidence of CKD. The risk of CKD was lower in those who ever had a robust status than in participants who never had a robust status.