Behavior of ambulatory blood pressure surrounding episodes of headache in mildly hypertensive patients

Background: Headache is usually associated with high blood pressure (BP) de spite the lack of evidence of such an association in most observational stu dies. Ambulatory BP monitoring provides an opportunity to analyze this rela tion because it permits measurement of BP before, during, and after episode s of headache. Methods: We evaluated 76 patients with mild hypertension who underwent clin ical evaluation, ambulatory BP monitoring, and questioning about the occurr ence of headache and its characteristics during monitoring. The 24-hour BP curves of patients with and without headache during monitoring were compare d using analysis of variance for multiple factors and repeated measurements . Hourly averages of BP surrounding the episode and 24-hour mean BP of pati ents with headache were compared using paired sample t tests. Results: Twenty-five participants (33%) experienced headache during monitor ing. Their 24-hour BP curves did not differ from those of participants with out headache. Mean 24-hour BP was not different from BP registered during t he episode of headache (mean+/-SD systolic BP: 137.0 +/- 17.3 vs 139.4 +/- 21.1; P = .13; diastolic BP: 83.3 +/- 12.8 vs 85.0 +/- 18.2; P = .30). Bloo d pressure values registered during the episode of headache and in the hour s before and after the episode were not different from each other. Analysis restricted to 8 patients with migraine-like headache showed a similar patt ern. Conclusions: In patients with mild hypertension, there is no association be tween the occurrence of headache and variation of BP. Health professionals must discourage patients with hypertension from believing that they can rel y on the presence of such a symptom to know about their BP levels.