Diurnal variation of blood pressure; reproducibility and association with left ventricular hypertrophy in hemodialysis patients.

OBJECTIVE: The objective of this paper is to describe the pattern of diurnal blood pressure (BP) change in hemodialysis patients, determine the association of the non-dipping pattern of diurnal BP with left ventricular mass index (LVMI), and to determine if the nocturnal profile of BP is reproducible when repeated over time.
METHODS: In a cross-sectional study, ambulatory blood pressure monitoring (ABPM) was performed over a midweek 44-h period and echocardiography was performed on the interdialytic day. Patients with a night/day systolic and diastolic BP ratio on both days >0.9 were defined as non-dippers. Ambulatory blood pressure monitoring was repeated at 6 and 12 months follow-up.
RESULTS: Of the 59 patients, 88% were African-American, and 48% were non-dippers. Mean LVMI was significantly higher in the non-dipper (68.3+/-25 g/height) compared to the dipper patients (55.6+/-16, P<0.05). Mean nocturnal systolic BP (r=0.35) and the night/day systolic BP ratio (r=0.39) had a higher correlation with M-mode LVMI than pre-dialysis (r=0.32). After adjustment for 44-h mean SBP, night/day systolic BP ratio remained independently associated with LVMI (beta coefficient 147.62, P=0.004). Of 12 patients who had a non-dipper profile at baseline, 11 (92%) demonstrated the same profile after 6 months and 1 year of follow-up.
CONCLUSION: Many hemodialysis patients demonstrate a non-dipper profile; the degree of decline in nocturnal BP is independently associated with LVMI even after adjustment for mean BP. Patients who are identified as non-dippers consistently reproduce the same profile over time.