Effect of an intensive lifestyle intervention on cystatin C-based kidney function in adults with overweight and obesity: From the PREDIMED-Plus trial

Background: Large-scale trials evaluating a multicomponent lifestyle intervention aimed at weight loss on kidney function are lacking.

Methods: This was a post hoc analysis of the "PREvención con DIeta MEDiterránea-Plus" (PREDIMED-Plus) randomized controlled trial, including patients with overweight/obesity and metabolic syndrome, measured cystatin C and creatinine. Participants were randomly assigned (1:1) to an intensive weight loss lifestyle intervention (intervention group [IG]) consisting of an energy-restricted Mediterranean diet (MedDiet), physical activity promotion and behavioral support, or a control group (CG) receiving ad libitum MedDiet recommendations. The primary outcome was between-group differences in cystatin C-based kidney function (cystatin C-based estimated glomerular filtration rate-eGFRcys-and combined cystatin C-creatinine-based eGFR-eGFRcr-cys) change from baseline to 12 and 36 months. Secondary outcomes included between-group differences in creatinine-based eGFR (eGFRcr) and urinary albumin-to-creatinine ratio (UACR) change and the predictive capacity of these formulas at baseline for new-onset chronic kidney disease (CKD).

Results: A total of 1909 participants (65 ± 5 years, 54% men) were included. Twelve-month decline in eGFRcys, eGFRcr-cys, and eGFRcr was greater in the CG compared to the IG, with between-group differences of -1.77 mL/min/1.73 m² [95% confidence interval -2.92 to -0.63], -1.37 [-2.22 to -0.53], and -0.91 [-1.74 to -0.71], respectively. At 36 months, the decline in eGFRcr-cys and eGFRcr was greater in the CG. No between-group differences in UACR were found. Significant adjusted areas under the curve for baseline eGFRcys and eGFRcr-cys were observed for incident CKD at 36 months, which were similar to those for eGFRcr and UACR.

Conclusions: In older adults with overweight/obesity and metabolic syndrome, the PREDIMED-Plus intervention may be an optimal approach to preserve kidney function.