Target organ damage among hypertensive adults in rural Nigeria: a cross-sectional study

To study the prevalence of target organ damage (TOD) in hypertensive adults in a general population in rural Nigeria, to assess determinants of TOD and the contribution of TOD screening to assess eligibility for antihypertensive treatment.

All adults diagnosed with hypertension (n=387) and a random sample (n=540) out of all nonhypertensive adults, classified during a household survey in 2009, had a blood pressure measurement and were invited for TOD (myocardial infarction, left ventricular hypertrophy, angina pectoris, kidney disease) screening in 2011.

Participation in TOD screening was 51% (n=196) in respondents with hypertension and 33% (n=179) in those without hypertension. TOD prevalence in hypertensive and nonhypertensive adults was 32 and 15%, respectively. Hypertension severity was a strong determinant for TOD [grade 1 odds ratio (OR) 2.66, 95% confidence interval (CI)1.04-6.84; grade 2 OR 3.82, 95% CI 1.41-10.36]. Out of 196 hypertensive patients, 151 were untreated, of whom all grade 2 hypertensive patients (n=71) were eligible for treatment. Screening revealed TOD in 19 out of 80 grade 1 hypertensive respondents (24%), therefore also classifying them as eligible for treatment. TOD screening hypertensive nonrespondents had more severe hypertension than hypertensive respondents, which may have resulted in an underestimation of the true prevalence of TOD among adults with hypertension.

A high prevalence of 32% TOD in hypertensive adults in rural Nigeria was observed. Almost a quarter of respondents with grade 1 hypertension were eligible for antihypertensive treatment based on TOD screening findings. As TOD screening is mostly unavailable in sub-Saharan Africa, we propose antihypertensive treatment for all patients with hypertension.