Nakayama M et al. (2007) Kidney dysfunction as a risk factor for first symptomatic stroke events in a general Japanese population—the Ohasama study. Nephrol Dial Transplant 22: 1910–1915

Chronic kidney disease (CKD) is an independent risk factor for cardiovascular disease (CVD) in both Western and Japanese populations. The relative incidences of stroke events and coronary heart diseases differ between these populations, however, with stroke events highly prevalent in Japan, and coronary heart disease representing the majority of CVD cases in the US. Nakayama and co-workers have conducted a longitudinal study in a rural Japanese population to investigate whether CKD is a risk factor for stroke events.

Data were available for a total of 1,977 individuals from Ohasama, Japan. The mean age of the population was 62.9 years and 37% were male. Over a mean observation period of 7.76 years, 112 first symptomatic stroke events were observed. Relative to individuals with normal renal function (creatinine clearance rate [CCR; estimated by the Cockcroft–Gault equation] >70 ml/min [>1.17 ml/s]), those with reduced renal function had significantly increased risk for first symptomatic stroke (CCR <40 ml/min [<0.67 ml/s]: hazard ratio [HR] 3.1; CCR 40–70 ml/min [0.67–1.17 ml/s]: HR 1.9). Presence of macroalbuminuria (urinary protein level >300 mg/l; 154 individuals) was also associated with an increased risk of first stroke (HR 1.4), but this relationship was nonsignificant. Both reduced CCR and macroalbuminuria were significantly associated with increased risk of all-cause mortality.

These results suggest that stroke and cardiac events in CKD might have a common pathologic factor, possibly unrelated to traditional risk factors for CVD.