Association between renal function and memory-related disease: evidence from the China Health and Retirement Longitudinal Study.

Background: Previous studies have reported that renal function is associated brain structure and cognitive dysfunction. However, the association between renal function and memory-related disease was not well characterized.

Methods: Altogether, 5,282 individuals were included in this study based on China Longitudinal Study of Health and Retirement. Four estimated glomerular filtration rate indicators (eGFR), including CG, CKD-EPIscr, CKD-EPIscr-cys, and CKD-EPIcys were used to evaluate the association between renal function and memory-related disease.

Results: The multivariable-adjusted HRs (95% CIs) of the memory-related disease in the low eGFR group (eGFR < 90 mL/min/1.73m) were 1.56 (1.13-2.16) for CG, 1.56 (1.19-2.06) for CKD-EPIscr, 1.45 (1.06-1.99) for CKD-EPIscr-cys and 1.27 (0.91-1.77) for CKD-EPIcys, respectively. Similarly, each SD increase of eGFR was associated with reduced risk of memory-related disease on continuous analyses. Subgroup analyses further confirmed these associations. Moreover, the addition of eGFR to conventional risk factors improved the predictive power for memory-related disease (net reclassification improvement: 13.90% for CG, 19.83% for CKD-EPIscr and 30.65% for CKD-EPIscr-cys).

Conclusions: In conclusion, impaired renal function was associated with the increasing risk of memory-related disease, indicating that renal function may be a potential indicator for memory-related disease. Further studies from other races and populations are needed to replicate our findings and to clarify the potential mechanisms.