Chronic kidney disease and functional impairment in a longitudinal study of older adults in China

Objectives: To examine the associations of chronic kidney disease (CKD) with dynamic functional impairment among older Chinese adults.

Design: This was a prospective longitudinal study.

Setting: Data were derived from the Chinese Longitudinal Healthy Longevity Study.

Participants: All adults aged ≥60 years were potentially eligible. This study included 2970 participants.

Primary outcome measures: CKD was defined as an estimated glomerular filtration rate <60 mL/min/1.73 m². Functional performances included instrumental activities of daily living (IADL) and basic activities of daily living (BADL), which were measured using six daily activities, including eating, dressing, transferring, using the toilet, bathing and continence, and eight daily activities, including visiting neighbours, shopping, cooking, washing clothes, walking 1 km, lifting 5 kg, crouching and standing up three times and taking public transportation, respectively.

Results: This study included 2970 participants, including 988 (33.60%) participants with CKD. Participants with CKD had higher IADL scores than those without CKD (β=0.895, 95% CI: 0.761 to 1.029). Furthermore, there was a significant linear trend in the association of CKD severity with the IADL score (p<0.001). Similarly, CKD was significantly associated with higher BADL scores (β=0.067, 95% CI: 0.017 to 0.118). However, only participants with moderate and advanced CKD had a higher BADL score (β=0.088 and 0.152, 95% CI: 0.006 to 0.171 and 0.019 to 0.286, respectively).

Conclusions: CKD was associated with worse functional impairment. Furthermore, there was a significant linear trend in the association of the severity of CKD with the IADL score. However, only participants with moderate and advanced CKD had higher BADL scores.