Background: When diagnosing hypertension (HT) it is essential to determine not only the level of raised blood pressure (BP), but also how the condition relates to organ damage. The best time to measure BP for diagnosing HT in patients on hemodialysis (HD) remains unclear.
Methods: A total of 100 HD patients (mean age 63.8 years, 60 males) were studied. Left ventricular hypertrophy (LVH) was detected by echocardiography and BP monitored for 1 week at 20 different times in the morning and night, before and after dialysis. We also checked for masked HT, i.e., patients with weekly morning HT, but not pre-dialysis HT.
Results: Average BP for the week was 141.9 ±19.0/79.6 ± 10.6 mmHg, with 68 patients classified as hypertensive. Average morning BP was 144.6 ± 19.8/81.7 ± 11.3 mmHg, and 71 patients had weekly morning HT. In addition, 62 patients had LVH and 51 patients had relative morning HT. Multiple logistic analyses showed that LVH was associated with weekly morning HT, morning HT on HD and non-HD days, average HT, and relative morning HT. However, evening, pre-dialysis, and post-dialysis HT showed no association with LVH. Masked HT was found in 20 % of patients. If HT had been diagnosed using only pre-dialysis BP, 20 of the 71 patients with weekly morning HT would not have been detected.
Conclusion: Morning BP is useful for detecting LVH in HD patients. Monitoring of morning BP may be superior to measurements taken at other times for diagnosing HT.