Background: Although end-stage renal disease has been associated with cognitive impairment, the relation between lesser degrees of chronic kidney disease (CKD) and cognitive impairment is less well understood.
Methods: Data for 1,015 women enrolled at 10 of the 20 Heart Estrogen/Progestin Replacement Study clinical sites were analyzed. All participants were younger than 80 years and had established coronary artery disease at study entry. Participants underwent 6 standard tests of cognitive function evaluating various domains. Unadjusted, residual age- and race-adjusted, and multivariable-adjusted linear and logistic regression models were used. Glomerular filtration rate (GFR) was estimated using the Modification of Diet in Renal Disease regression equation. In addition to analyses across the spectrum of GFRs, CKD was categorized as mild (estimated GFR [eGFR], 45 to 60 mL/min/1.73 m2), moderate (eGFR, 30 to 44 mL/min/1.73 m2), and severe (eGFR, <30 mL/min/1.73 m2) according to a modification of recently established classification guidelines.
Results: Mean eGFR was 57 +/- 14 mL/min/1.73 m2. In multivariable analyses, eGFR was associated significantly with impairment in global cognition, executive function, language, and memory (approximately 15% to 25% increase in risk for dysfunction/10-mL/min/1.73 m2 decrement in eGFR). Associations among eGFR and cognitive function were independent of residual effects of age and race (2 key determinants of GFR) and the contributions of education, lifestyle factors, stroke, diabetes, and other laboratory variables.
Conclusion: CKD is associated with cognitive impairment in menopausal women with coronary artery disease.