The prevalence and risk factors of abnormal circadian blood pressure in patients with IgA nephropathy

Abstract

To investigate the prevalence and risk factors of abnormal circadian blood pressure (BP) rhythm among IgA nephropathy (IgAN) patients. 375 Chinese IgAN patients with biopsy-proven primary IgAN were recruited from June 2013 to December 2014 and divided into four groups based on circadian BP rhythm (dippers, non-dippers, reversed dippers, and extreme dippers) measured by 24-hour ambulatory BP monitoring. Demographic and clinicopathologic data were collected and analyzed. The prevalence of abnormal circadian BP was 84% (315/375) in all the participants, accounting for 82.4% of the normotensive patients and 86.1% of the hypertensive patients. The prevalence increased with the decline of estimated glomerular filtration rate (eGFR) in IgAN patients. The non-dipper pattern was most frequent (63.8%, 201/315) in this population, followed by the reversed-dipper (27.3%, 86/315), and then the extreme-dipper pattern (8.9%, 28/315). Multivariate logistic regression analysis revealed that the eGFR (odds ratio (OR)=0.64, 95% conficence interval (CI): 0.45-0.93, p=0.037), serum uric acid (OR=1.60, 95% CI: 1.01-2.54, p=0.014), and small vessel hyalinosis (OR=2.17, 95% CI: 1.14-4.11, p=0.044) were independently associated with abnormal circadian BP rhythm. Abnormal circadian BP rhythm was common in IgAN patients and occurred in the early stages of chronic kidney disease. Low eGFR, high serum uric acid, and small vessel hyalinosis increased risk of abnormal BP rhythm in IgAN patients. .