Above‐Threshold Ambulatory Systolic Pressure and Left Ventricular Mass in Chronic Kidney Disease: Does AUC Add Beyond Mean Pressure?

ABSTRACT

Above‐threshold ambulatory systolic blood pressure (SBP) area under the curve (AUC) captures both the magnitude and duration of SBP above daytime and nighttime reference values. We examined whether this measure provided information about left ventricular mass index (LVMI) beyond daytime and nighttime mean SBP. In this cross‐sectional study, 212 Chinese adults with non‐dialysis chronic kidney disease (CKD) underwent ambulatory blood pressure monitoring and echocardiography. Daytime AUC above 135 mmHg and nighttime AUC above 120 mmHg were entered jointly. Together, daytime and nighttime AUC were significantly associated with LVMI ( P < 0.001; adjusted R ² = 0.345). From the 25th to the 75th percentile, adjusted LVMI was 3.46 g/m ² · ⁷ higher for daytime AUC and 5.56 g/m ² · ⁷ higher for nighttime AUC. AUC attributable to daytime and nighttime mean SBP accounted for 89.7% of the cohort‐average above‐threshold burden. The remaining AUC not captured by those period means was not significantly associated with LVMI after adjustment for daytime and nighttime mean SBP (0.69 g/m ² · ⁷ per interquartile range; 95% confidence interval, ‐2.00 to 3.37). Above‐threshold AUC was associated with greater LVMI but added limited information beyond daytime and nighttime mean SBP in this cohort.