Prevalence and Determinants of Masked Hypertension Among Black Nigerians Compared With a Reference Population.

Hitherto, diagnosis of hypertension in sub-Saharan Africa was largely based on conventional office blood pressure (BP). Data on the prevalence of masked hypertension (MH) in this region is scarce. Among individuals with normal office BP (<140/90 mm Hg), we compared the prevalence and determinants of MH diagnosed with self-monitored home blood pressure (≥135/85 mm Hg) among 293 Nigerians with a reference population consisting of 3615 subjects enrolled in the International Database on Home Blood Pressure in Relation to Cardiovascular Outcomes. In the reference population, the prevalence of MH was 14.6% overall and 11.1% and 39.6% in untreated and treated participants, respectively. Among Nigerians, the prevalence standardized to the sex and age distribution of the reference population was similar with rates of 14.4%, 8.6%, and 34.6%, respectively. The mutually adjusted odds ratios of having MH in Nigerians were 2.34 (95% confidence interval, 1.39-3.94) for a 10-year higher age, 1.92 (1.11-3.31) and 1.70 (1.14-2.53) for 10- or 5-mm Hg increments in systolic or diastolic office BP, and 3.05 (1.08-8.55) for being on antihypertensive therapy. The corresponding estimates in the reference population were similar with odds ratios of 1.80 (1.62-2.01), 1.64 (1.45-1.87), 1.13 (1.05-1.22), and 2.84 (2.21-3.64), respectively. In conclusion, MH is as common in Nigerians as in other populations with older age and higher levels of office BP being major risk factors. A significant proportion of true hypertensive subjects therefore remains undetected based on office BP, which is particularly relevant in sub-Saharan Africa, where hypertension is now a major cause of death.

Oscillometric and auscultatory blood pressure measurement in the assessment of blood pressure and target organ damage.

OBJECTIVE: The objective of this study was to elucidate the usefulness of both the oscillometric blood pressure (OBP) and auscultatory blood pressure (ABP) measurement technique in the assessment of blood pressure (BP) and target organ damage in the general population. METHODS: We studied a sample of the Finnish adult population aged 25-74 years. Four hundred and eighty-four study participants underwent a health examination including measurements of 24-h urine albumin, echocardiographic variables of the left ventricle, intima media thickness and pulse wave velocity. OBP and ABP were measured simultaneously four times by beginning the OBP measurements in random order from the right or left arm and by switching the devices between hands after two measurements. RESULTS: The mean OBP was 126.7/77.4 mmHg and the mean ABP was 124.5/78.0 mmHg. Systolic difference between OBP compared with ABP was large in men. Male sex, higher arm circumference and lower systolic BP were independent determinants explaining the greater difference between systolic OBP compared with ABP. Diabetes, higher arm circumference and higher pulse wave velocity were independent determinants explaining greater difference between diastolic OBP compared with ABP. The correlations of target organ damage between OBP and ABP were equally good. CONCLUSION: At population level OBP and ABP measurements yielded similar results in relation to BP level and the indicators of target organ damage, probably due to the simultaneous and controlled measurement protocol, and to the sample of participants from the general population. It is, however, recommendable to use either OBP or ABP measurements for individual patients to avoid unnecessary interdevice variability.