Serum Creatinine and Cystatin C-Derived Indices Suggesting Future Deterioration in Muscular Function, Physical Performance, and Frailty Status Among Community-Dwelling Older Adults.

OBJECTIVES

Serum biomarkers, particularly serum creatinine and cystatin C, have garnered increased attention as a potential method for predicting future declines in muscle strength. Nevertheless, there is currently a dearth of research in this area. We evaluated the association of serum creatinine and cystatin C-derived indices with the subsequent decline in lower extremity muscle strength among community-dwelling older adults.

DESIGN

A prospective observational study.

SETTING AND SUBJECTS: Community-dwelling older individuals (aged ≥65 years) residing in the Sasayama-Tamba area of Japan.

PREDICTOR: Five indices based on serum creatinine, and cystatin C, including the total body muscle mass index (TBMM), were computed.

MAIN OUTCOME: Changes in muscular function including isometric knee extensor strength and handgrip strength, physical performance, and frailty status, underwent assessments at baseline and 2 years.

RESULTS

The final dataset comprised 528 community-dwelling older adults (72 [68, 76] years, 65.7% women). The median change and the proportion of individuals experiencing a significant decline in isometric knee extensor strength over a 2-year period were -37.4 N and 40.2%, respectively. total body muscle mass index showed significant associations with the subsequent decline in isometric knee extensor strength, handgrip strength, and frailty status.

CONCLUSIONS

This study demonstrates the association between serum creatinine and cystatin C-derived index, total body muscle mass index, and the subsequent decline in lower extremity muscle strength among older adults. Utilizing markers derived from serum creatinine and cystatin C enables prompt assessment of the need for proactive measures and may facilitate initiating these interventions at a suitable juncture for older individuals.