40HYPERTENSIVE END ORGAN DAMAGE IN AN ELDERLY COHORT OF TANZANIANS

Abstract

Background: Hypertension - a leading cause of morbidity and mortality - is a growing issue in Sub-Saharan Africa. Prevalence is high in the elderly population of Northern Tanzania but, surprisingly, not linked to increased mortality. Little evidence is available on the physiological effects of hypertension in Africans. Aim(s): Establish the prevalence of hypertensive end organ damage (EOD) in an elderly cohort of Tanzanians. It was hypothesized that rates of EOD would be surprisingly low amongst this population of survivors. Method(s): 412 participants (age 376) from two villages in Northern Tanzania were followed up from a 2010 hypertension study. Interview established demographics, medical history and assessed cognition. Examination included blood pressure (BP) measurement, ankle-brachial pressure index (ABPI), lying-standing BP, electrocardiogram and dip-stick urinalysis. Prevalence of self-reported visual loss, stroke, peripheral arterial disease (PAD), orthostatic hypotension, left ventricular hypertrophy (LVH), proteinuria and arterial stiffness was reported and correlated with hypertension status and severity. Result(s): Of 246 participants assessed (59.7%, 53.3% female), 69.1% were hypertensive (BP > 140/90 mmHg). Treatment and control levels were low (30.6% and 7.7% respectively). Overall prevalence of EOD was as follows: self-reported visual loss - 58.9%, PAD - 28.0%, orthostatic hypotension - 24.4%, proteinuria - 15%, LVH- 13.8%, stroke - 5.3%. Hypertension was significantly associated with PAD (p = 0.003), proteinuria (p = 0.046) and LVH (p = 0.026). Interestingly, hypertensives were noted to have lower rates of arterial stiffness (p = 0.130) and cognitive decline (p = 0.131). Conclusion(s): Contrary to the hypothesis, prevalence of EOD in this cohort of elderly Africans is similar to elderly cohorts in developed countries. A beneficial effect of hypertension on arterial calcification and cognition cannot be ruled out. This may go some way to explaining why previous studies have found no increased mortality risk amongst hypertensives in this population, and requires further exploration.