Home blood pressure (BP) monitoring is considered to be an optimal method to treat hypertensive patients. The ideal goal of antihypertensive treatment using home BP monitoring is to maintain BP both in the morning and at night less than the target BP. However, some patients have hypertension in the morning resistant to antihypertensive medication with well-controlled BP at night. As repetitive apnea and hypopnea in sleep disordered breathing (SDB) is considered to be one of the causes of morning hypertension, we aimed to elucidate the prevalence of SDB in patients with resistant morning hypertension.Design and method:
Outpatients under treatment of hypertension were requested to perform home BP monitoring in the morning before breakfast and at night before sleep for consecutive two weeks. 11 patients whose average morning blood pressure of or higher than 135/85 mmHg and average evening BP lower than 135/ 85 mmHg underwent portable monitoring of SDB, irrelevant of the existence of symptoms suggestive of SDB (daytime sleepiness, snoring or apnea). Frequency of urination during sleep was interviewed. Data are expressed as mean ± SEM.Results:
The average morning and night BP were 140.5 ± 3.9/82.5 ± 5.1mmHg and 120.3 ± 6.8/77.0 ± 5.7mmHg, respectively. BMI was 23.6 ± 2.6, and 60% of the patients were non-obese (BMI < 25) Respiratory disturbance index (RDI) was 14.0 ± 10.0, and 9 patients (90%) had SDB as defined by RDI>5. Frequency of urination during sleep was 1.8 ± 1.1, and 40% of the patients had nocturia (≧2 during sleep).Conclusions:
Patients with morning hypertension and normal night BP had high prevalence of SDB and nocturia. Comparison to hypertensive patients with well-controlled home BP both in the morning and at night will be required.