Renal function is a determinant of subjective well-being in active seniors but not in patients with subjective memory complaints

BACKGROUND: During our whole life span, factors influencing health and functioning are accumulated. In chronic kidney disease, quality of life is adversely affected. We hypothesized that biomarkers of renal function could also be determinants of subjective well-being (SWB) in Swedish elderly subjects. SWB was assessed by the Psychological General Well-Being index (PGWB index) in two study groups: Active seniors (AS) consisted of community-dwelling elderly Swedes leading an active life (n = 389), and the DGM cohort (n = 300) consisted of subjects referred to the Memory Unit at the Department of Geriatrics for memory problems, Serum creatinine, cystatin C, and eGFR (CKD-EPI) were used as biomarkers of renal function. RESULTS: There were no significant differences in cystatin C and eGFR values between the two cohorts: cystatin C medians 0.88 vs 0.86 mg/L and eGFR 73 vs 80 mL/min/1.73 m(2) (AS vs DGM). In the AS cohort cystatin C was negatively related to PGWB index in women (P < 0.001, R(2) ≈ 5%), and the covariates age and BMI did not improve the models. The renal biomarkers were unrelated to the PGWB index in the DGM cohort. Cystatin C in the AS cohort was adversely related to the PGWB subdimensions anxiety, depressed mood, positive well-being, and vitality in women, but in men only to depressed mood (P < 0.006; R(2) ≈ 6%). In the DGM cohort, depressed mood in men was also significantly related to cystatin C (P = 0.050), but not in women. CONCLUSIONS: Renal function even within the normal range, measured by serum cystatin C concentration, has significant and sex specific associations with subjective well-being and its subdimensions in healthy elderly subjects. Maintenance of good renal function in aging may be of importance in maintaining a high subjective well-being.