The association between the estimated glomerular filtration rate and cognitive impairment: the Suita Study

This cross-sectional study investigated the association between the estimated glomerular filtration rate (eGFR), a measure of chronic kidney disease (CKD), and cognitive impairment. We used data from 6215 Japanese individuals registered in the Suita Study. Cognitive impairment was defined as a Mini-Mental State Examination (MMSE) score of <= 26. Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs) of cognitive impairment for eGFR 45-59.9 and < 45 mL/min/1.73 m(2) (mild and moderate-to-severe eGFR reductions) compared to eGFR >= 60 mL/min/1.73 m(2) (normal eGFR). The results showed that both mild and moderate-to-severe eGFR reductions were associated with cognitive impairment: ORs (95% CIs) = 1.49 (1.22-1.83) and 2.35 (1.69-3.26), respectively (p-trend < 0.001). Each increment of eGFR by 10 mL/min/1.73m(2) was associated with 4.8% lower odds of cognitive impairment. In conclusion, eGFR reduction was associated with cognitive impairment. Managing CKD is essential for preventing cognitive impairment.