Correlation between clinic, cumulative, 24h-ambulatory systolic blood pressure, and chronic kidney damage in Chinese elderly.

The aim of this study was to investigate whether clinic, cumulative, and 24h ambulatory systolic blood pressure (SBP) was associated with chronic kidney damage, defind as estimated glomerular filtration rate (eGFR) <60 ml/(min·1.73 m2) and/or microalbuminuria ≥30 mg/L, and, if so, which measurement of SBP is more associated with chronic kidney damage in Chinese elderly. A total of 1207 participants older than 60 years old were included in the final analysis. Clinical blood pressure, cumulative blood pressure exposure was calculated and ambulatory 24h blood pressure was assessed. Multiple logistic regression analysis showed that the clinic (p < .001), cumulative (p = .033), 24h average (p < .001), daytime (p = .001) and nighttime SBP (p = .001) were respectively associated with lower eGFR, and cumulative (p = .008), 24 average (p < .001), daytime (p < .001), and nighttime SBP (p < .001) were the risk factors of microalbuminuria. The degree of correlation were strongest between 24h average SBP and chronic kidney damage (odds ratio, 1.78; 95% confidence interval, 1.46-2.15; p < .001), clinic SBP and eGFR (odds ratio, 1.57; 95% confidence interval, 1.13-2.17; p = .007), nighttime SBP and microalbuminuria (odds ratio, 1.45; 95% confidence interval, 1.05-2.00; p = .024). The likelihood ratio test demonstrated that the introduction of 24h average SBP will improve the goodness of fit of the clinic SBP model(p < .05), while the introduction of cumulative SBP exposure has no such effect(p > .05). Cumulative SBP exposure seems inferior to other measurement in indentifying chronic kidney damage, including decreased GFR and microalbuminuria.