Prevalence and Determinants of Masked Hypertension in Nigeria: The REMAH Study.

BACKGROUND: Estimating the burden of hypertension in Nigeria hitherto relied on clinic blood pressure (BP) measurement alone. This excludes individuals with masked hypertension (MH), i.e., normotensive clinic but hypertensive out-of-clinic BP. METHODS: In a nationally representative sample of adult Nigerians, we obtained clinic BP using auscultatory method and out-of-clinic BP by self-measured home BP with semi-automated oscillometric device. Clinic BP was average of 5 consecutive measurements and home BP was average of 3 days duplicate morning and evening readings. MH was clinic BP <140 mm Hg systolic and 90 mm Hg diastolic and home BP ≥135 mm Hg systolic and/or 85 mm Hg diastolic. RESULTS: Among 933 participants, the prevalence of sustained hypertension, MH, and white-coat hypertension was 28.3%, 7.9%, and 11.9%, respectively. Among subjects whose clinic BP were in the normotensive range (n = 558), the prevalence of MH was 13%; 12% among untreated and 27% among treated individuals. The mutually adjusted odds ratios of having MH among all participants with normotensive clinic BP were 1.33 (95% confidence interval, 1.10-1.60) for a 10-year higher age, 1.59 (1.09-2.40) for a 10 mm Hg increment in systolic clinic BP, and 1.16 (1.08-1.28) for a 10 mg/dl higher random blood glucose. The corresponding estimates in the untreated population were 1.24 (1.03-1.51), 1.56 (1.04-2.44), and 1.16 (1.08-1.29), respectively. CONCLUSIONS: MH is common in Nigeria and increasing age, clinic systolic BP, and random blood glucose are the risk factors.

Urinary sodium excretion and its association with blood pressure in Nigeria: A nationwide population survey.

Assessment of level of salt intake in a population is the first step toward planning strategies aimed at salt reduction. As a surrogate of salt intake, we measured a single 24-hour urine sodium (uNa) of free-living 2503 adults in a nationally representative sample of Nigerians drawn from 12 rural and urban communities; and evaluated the community-level association of uNa with blood pressure (BP). Overall, the median (interquartile range (IQR)) of uNa was 99 (105) mmol, ranging from 23.8 (32.4) in rural north-central to 172.8 (131.0) mmol in urban northwestern region. Daily uNa was significantly higher (p < .001) in men compared to women (107.1 vs 93.9 mmol); and urban compared to rural dwellers (114.9 vs 86.0mmol). About one-half of participants excreted uNa in excess of recommended daily maximum value (86mmol). In a model adjusted for age, sex, body mass index (BMI), level of education, place of residence, and use of antihypertensive medication; being a man (odds ratio, OR 1.69, 95% confidence Interval CI, 1.21-2.37, p = .002) and being < 60 years of age (OR 1.74, 95% CI 1.23-2.45, p = .002), were associated with excreting higher than recommended uNa. In a fully adjusted model of the community-level analysis, urinary sodium, potassium, and sodium-to-potassium ratio each showed no significant independent association with both systolic and diastolic BPs. Among adult Nigerians, the median daily uNa excretion was 99 mmol and it had no significant association with blood pressure indices.

Prevalence, Awareness, Treatment and Control of Hypertension in Nigeria: Data from a Nationwide Survey 2017.

Background: Previous studies that evaluated the prevalence, awareness and treatment of hypertension in Nigeria were either localized to some specific regions of the country or non-standardized thereby making evaluation of trend in hypertension care difficult. Methods: We used the World Health Organization (WHO) STEPwise approach to chronic disease risk factor surveillance to evaluate in a nationally representative sample of 4192 adult Nigerians selected from a rural and an urban community in one state in each of the six geo-political zones of the country. Results: The overall age-standardized prevalence of hypertension was 38.1% and this varied across the geo-political zones as follows: North-Central, 20.9%; North-East, 27.5%; North-West, 26.8%; South-East, 52.8%; South-South, 44.6%; and South-West, 42.1%. Prevalence rate did not differ significantly (p > 0.05) according to place of residence; 39.2% versus 37.5 %; urban vs rural. Prevalence of hypertension increased from 6.8% among subjects less than 30 years to 63.0% among those aged 70 years and above. Awareness was better (62.2% vs. 56.6%; P = 0.0272); treatment rate significantly higher (40.9 % vs. 30.8%; P < 0.0001) and control similar (14 vs. 10.8%) among urban compared to rural residents. Women were more aware of (63.3% vs. 52.8%; P < 0.0001); had similar (P > 0.05) treatment (36.7 vs. 34.3%) and control (33.9% vs. 35.5%) rates of hypertension compared to men. Conclusion: Our results suggest a large burden of hypertension in Nigeria and a closing up of the rural-urban gap previously reported. This calls for a change in public health policies anchored on a primary health care system to address the emerging disease burden occasioned by hypertension.

Removing the mask on hypertension (REMAH) study: Design; quality of blood pressure phenotypes and characteristics of the first 490 participants.

Purpose: Previous studies that evaluated the prevalence of hypertension in Nigeria were either clinic based, non-standardized or did not include out-of-clinic blood pressure (BP) measurement. Materials and Methods: We selected a rural and an urban community in one state in each of the 6 geopolitical zones of Nigeria. Five consecutive BP of adults older than 18 years were measured in the clinic following which, each participant was provided with a home BP device to obtain duplicate morning and evening BP for 3 days. Result: Out of 556 invited from Anambra State, South-East Nigeria, 490 (88%) consented. Overall, more women participated in both rural (115 vs 61, p < .0001) and urban (213 vs 101; p < .0001) sites. About 35.9% of participants had their home BP monitored. Of the 4890 clinic BP readings, 29.8%, 16.3%, 16.6%, 16.4% and 20.8% ended in 0,2,4,6 and 8 digits respectively. Only 0.8% ended in odd numbers. Of the identical BP readings,5 (0.20%), 6 (0.25%), 56 (2.30%) and 316 (12.9%) SBP and 8 (0.33%), 17 (0.70%), 93 (3.80%), 319 (13.1%) DBP had no difference in five, four, three and two values of the five consecutive readings. Conclusion: REMAH is feasible and the quality of BP will ensure that the final results are robust.