Impact of rest on office blood pressure in patients with hypertension and diabetes at the national obesity centre of Yaounde: a cross-sectional study in Sub-Saharan Africa

Sylvain Raoul Simeni Njonnou, Aimée Tiodoung Timnou, Martine Claude Etoa Etoga, Ahmadou Musa Jingi, Jerome Boombhi, Chris Nadège Nganou-Ngnindjo, Ba Hamadou, Liliane Mfeukeu-Kuate, Sylvie Ndongo Amougou, Marie-Josiane Ntsama Essomba, Odette Kengni Kebiwo, Mesmin Dehayem Yefou, Gloria Ashuntantang, Eugène Sobngwi


Background: Hypertension is the most important cardiovascular risk factor. Enhancing the accuracy of blood pressure (BP) measurement would be helpful for controlling hypertension. The importance of rest before measuring BP in the office is known, but the magnitude of the change in BP with the duration of rest is not known. We aim to evaluate the magnitude of the fall in BP after a prolonged rest in diabetic and hypertensive patients and identify the associated factors.
Methods: We carried out a cross-sectional study between January and February 2016 at the National Obesity Centre of Yaoundé. Were included all consenting patients with diabetes and hypertension, of both sexes, aged ≥18 years. Sitting BP was measured after resting for 15 minutes (BP15), 30 minutes (BP30), and 45 minutes (BP45). All the BP were measured by the same investigator using an electronic BP device. BP <140/90 mmHg defined a good control.
Results: We included 80 (53 women) participants with mean age of 62.4±8.4 years. Mean BP15 was 152.3±26.3 for systolic BP (SBP) and 88.5±15.1 mmHg for diastolic BP (DBP). Compared to BP15, there was a significant reduction of 8.3 (−6.5%) mmHg (P<0.001) for SBP30 and 3.1 (−3.9%) mmHg (P=0.001) for DBP30. Also, SBP45 and DBP45 were respectively 13.5 (−9.4%) mmHg (P<0.001) and 5.5 (−6.6%) mm Hg (P<0.001) lower than BP15 (P=0.001). BP45 reclassified 6.3% and 16.3% as poor control at BP30 and BP15 respectively. ACEI were associated with a reduction of SBP at 30 and 45 minutes. Renin Angiotensin Aldosterone System Blockers were associated with reduction of SBP between 15 and 30 minutes.
Conclusions: Resting for 45 minutes rather than the recommended 5 to 10 minutes reduce SBP/DBP of 8.3/3.1 mmHg at 30 and 13.5/5.5 mmHg at 45 minutes and may improve the reliability of the office blood pressure values.