Hypertension prevalence and age-related changes of blood-pressure in semi-nomadic and urban Oromos of Ethiopia

We evaluated the prevalence of hypertension and the age-related behaviour of systolic blood pressure (SBP) and diastolic blood pressure (DBP) in a wide sample of male and female Ethiopian Oromos living in rural or pre-industrial urbanized settings. Blood pressure (BP) was measured in the sitting position after 5 min rest in 5277 Oromos. In the group, 4928 were semi-nomadic shepherds, while 349 came from a town of 60,000 inhabitants where they were involved in low-technology jobs. The first subgroup was composed of 2482 men and 2446 women. All subjects were divided into 3 age groups: 15–44, 45–64, and 65 years. Body weight (BW) and the Quetelet index (QI) were matched to BP levels using Pearson's method. In semi-nomadic men, SBP was 121.4±8.4 mmHg versus 132.4±10.4 mmHg in urban men (p<0.001). In women, SBP was 120.5±7.9 mmHg versus 128.1±10.1 mmHg (p<0.001). The prevalence of hypertension was 0.40% in the semi-nomadic and 3.15% in the urban population. In the latter, significant increases in BW and QI were found, which were significantly correlated to both SBP and DBP. In semi-nomadic men, a 5.33% increase in SBP and a 5.22% in DBP was found between age groups 1 and 2 (p<0.001 in both). In urban men the increase was 4.77% and 3.41% respectively (p<0.001). In both male populations no difference in SBP and DBP was observed between age groups 2 and 3. In semi-nomadic women however, a progressive rise in SBP (4.84% between age groups 1 and 2,p<0.001; 1.86% between groups 2 and 3,p<0.001) and DBP (4.26% between age groups 1 and 2,p<0.001; 2.72% between groups 2 and 3,p<0.001) was present. Similar differences in SBP and DBP were evident between urban women of age groups 1 and 2. Due to social reasons, women for group 3 were not available in the urban setting. In conclusion, this study shows a very low prevalence of hypertension in a semi-nomadic group and about an 8-fold increase in the urban population. SBP and DBP are significantly higher in the urban setting and in both men and women the increase is related to BW. Moreover, SBP and DBP progressively increase with age in women but not in men.