Cardiovascular disease and mortality in a community-based cohort with mild renal insufficiency

Background. Little is known about the prevalence of cardiovascular disease (CVD) and associated risk factors in individuals with mild renal insufficiency (RI). Furthermore, the longterm outcomes associated with mild RI in the community have not been described. Methods. Serum creatinine (S-Cr) was measured in 6233 adult participants of the Framingham Heart Study (mean age 54 years, 54% women). Mild RI was defined as S-Cr 136 to 265 mu mol/liter (1.5 to 3.0 mg/dl) in men and 120 to 265 mu mol/liter (1.4 to 3.0 mg/dl) in women. The lower limits for mild RI were defined by the sex-specific 95th percentile S-Cr values in a healthy subgroup of our sample. The upper limit for mild RI was chosen to exclude those subjects with more advanced renal failure. Cox proportional hazards analyses were used to determine the relationship of baseline RI to CVD and all-cause mortality. Results. At baseline, 8.7% of men (N = 246) and 8.0% of women (N = 270) had mild RI. Nineteen percent of the subjects with mild RI had prevalent CVD. During 15 years of followup, there were 1000 CVD events and 1406 deaths. In women, mild RI was not associated with increased risk for CVD events [hazards ratio (HR) 1.04, 95% CI, 0.79 to 1.37] or all-cause mortality (HR 1.08, 95% CI, 0.87 to 1.34). In men, mild RI showed no significant associations with CVD events (HR 1.17, 95% CI, 0.85 to 1.57), but it was associated with all-cause mortality in age-adjusted (HR 1.42, 95% CI, 1.12 to 1.79) and multivariable adjusted (HR 1.31,95% CI, 1.02 to 1.67) analyses. Conclusion. Mild RI in the community is common and is associated with a high prevalence of CVD. The association of RI with risk for adverse outcomes is strongly related to coexisting CVD and CVD risk factors.