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 nonstandardized 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%; NorthEast , 27.5%; NorthWest , 26.8%; SouthEast , 52.8%; South-South, 44.6%; and SouthWest , 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.

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. | 2267 ODILI et aL.

Abstract-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.

BACKGROUNDThe association of electrocardiographic left ventricular hypertrophy (ECG-LVH) with blood pressure (BP) in Blacks living in sub-Saharan Africa remains poorly documented.METHODSIn 225 Black Nigerians and 729 White Flemish, we analyzed QRS voltages and voltage-duration products and 12 criteria diagnostic of ECG-LVH in relation to office BP (mean of 5 consecutive readings) and home BP (duplicate morning and evening readings averaged over 1 week).RESULTSIn multivariable analyses, QRS voltage and voltage-duration indexes were generally higher in Blacks than Whites. By using any of 12 criteria, ECG-LVH was more prevalent among Black than White men (54.4% vs. 36.0%) with no ethnic difference among women (17.1%). Precordial voltages and voltage-duration products increased with office and home systolic BP (SBP), and increases were up to 3-fold steeper in Blacks. In Blacks vs. Whites, increases in the Sokolow–Lyon voltage associated with a 10-mm Hg higher SBP were 0.18 mV (95% confidence interval [CI], 0.09–0.26) vs. 0.06 mV (0.02–0.09) and 0.17 mV (0.07–0.28) vs. 0.11 mV (CI, 0.07–0.15) for office and home BP, respectively, with a significant ethnic gradient (P < 0.05). The risk of ECG-LVH increased more with office and home BP in Blacks than Whites.CONCLUSIONSAssociations of ECG voltages and voltage-duration products and risk of ECG-LVH with BP are steeper in Black Nigerians compared with a White reference population. In resource-poor settings of sub-Saharan Africa, the ECG in combination with office and home BP is an essential instrument in risk stratification across the entire BP range.