Background: Limited data exist regarding the relationship between kidney function and incident asymptomatic peripheral arterial disease (PAD).
Methods: The study population consisted of 2881 participants of the Intervention Project on Cerebrovascular Diseases and Dementia in the Community of Ebersberg, Bavaria, a community-based cohort of elderly individuals. Kidney function was calculated as creatinine clearance (Ccr) estimated by the Cockcroft-Gault formula. Incident PAD was defined as a new onset of ankle-brachial index < 0.9 assessed at regular examinations among those with an ankle brachial pressure index (ABPI) ≥ 0.9 at baseline. Relative risks (RR) for PAD were compared across declining kidney function quartiles.
Results: Mean serum concentration of creatinine and Ccr were 0.82 ± 0.31 mg/dL and 78 ± 21 mL/min/1.73 m(2). After 6 years of follow-up, 478 (17%) participants developed incident asymptomatic PAD. After adjustment for demographic factors and cardiovascular risk factors, lower Ccr quartiles were directly associated with a higher risk of PAD. Compared with participants in quartile 1 (> 89 mL/min/1.73 m(2)), the adjusted RR (95% CI) for PAD were 1.01 (0.88-1.19) for quartile 2 (75-89 mL/min/1.73 m(2)), 1.05 (0.93-1.23) for quartile 3 (64-75 mL/min/1.73 m(2)) and 1.10 (1.01-1.44) for quartile 4 (< 64 mL/min/1.73 m(2); P = 0.009 for trend). Cardiovascular events as a function of baseline Ccr and incident PAD showed that most vascular events occurred in participants with Ccr < 60 mL/min/1.73 m(2) at baseline and incident PAD (log-rank test, P = 0.0018).
Conclusions: Lower kidney function is associated with incident asymptomatic PAD. In addition, the combination of impaired kidney function and incident PAD better predicts cardiovascular outcomes.