Genetic variants in UMOD associate with kidney function and hypertension. These phenotypes are also linked to sex-related differences and impairment in cognitive and physical function in older age. Here we evaluate longitudinal associations between a common UMOD rs4293393-A>G variant and changes in estimated glomerular filtration rate (eGFR), blood pressure (BP), cognitive and physical function parameters in older participants in the BASE-II after long-term follow-up as part of the GendAge study. Overall, 1010 older participants (mean age 75.7 ± 3.7 years, 51.6% women) were analyzed after follow-up (mean 7.4 years) both in cross-sectional analysis and in longitudinal analysis as compared to baseline. In cross-sectional analysis, heterozygous G–allele carriers exhibited significantly higher eGFR values (AA, 71.3 ml/min/1.73 m2, 95% CI, 70.3–72.3 vs. AG, 73.5 ml/min/1.73 m2, 95% CI, 72.1–74.9, P = 0.033). Male heterozygous G-allele carriers had lower odds of eGFR < 60 mL/min/1.73 m2 (OR 0.51, 95% CI, 0.28–0.95, P = 0.032) and in Timed Up and Go-Test ≥ 10 s (OR 0.50, 95% CI, 0.29–0.85, P = 0.011) whereas women were less likely to have hypertension (OR 0.58, CI, 0.37–0.91, P = 0.018). UMOD genotypes were not significantly associated with longitudinal changes in any investigated phenotype. Thus, while the impact of UMOD rs4293393 on kidney function is maintained in aging individuals, this variant has overall no impact on longitudinal changes in BP, kidney, cognitive or functional phenotypes. However, our results suggest a possible sex-specific modifying effect of UMOD on eGFR and physical function in men and hypertension prevalence in women.