An Epidemiological Investigation Of Risk Factors For Hypertension In Windhoek, Khomas Region, Namibia

ABSTRACT

Hypertension is a major and preventable risk factor for cardiovascular diseases Khomas region has a hypertension prevalence of 57%, which is the highest in Namibia. Cardiovascular diseases related mortality is the highest among adults in Namibia. No analytical studies have been done to determine risk factors for hypertension in Namibia. We conducted a study to determine lifestyle and socio-demographic factors associated with hypertension in Khomas region. We conducted an un-matched 1:1 case-control study in Khomas region. Anthropometric measurements and a questionnaire were administered to both cases and controls. A case was defined as any primary hypertension patient 18 to 60 years reporting to the selected health facility. A control was defined as any person aged 18 to 60 years residing in the same neighbourhood as the selected cases. Cases were selected using consecutive sampling from four selected health facilities. Community controls were selected using simple random sampling. Bivariate analysis was conducted to determine the odds ratios and 95% confidence level. Factors which were significant at p-value less than 0.05 were retained in multiple logistic regression model to determine significant associations. A total of 131 cases and 131 community controls were interviewed. The mean (±SD) age of the participants was 39.8 (±13.5) years. Overall, 184 (70.2%) of participants were female. Central obesity was found to be associated with hypertension (OR=3.42, 95% CI=1.99 – 5.87, P = 0.001) at the bivariate level. The multivariate analysis found that older age (OR = 1.08, 95% CI= 1.05 – 1.13, P = 0.001), attaining tertiary education (OR = 0.28, 95% CI= 0.08 – 0.92, P = 0.04) were found to be protective against hypertension, while BMI ≥ 25 (OR = 2.29, 95% CI: 1.06 – 4.96, P = 0.03) was significantly associated with hypertension. Being Overweight/obesity and primary education are major risk factors for hypertension in Khomas region. Interventions targeted at reducing obesity in the general population are needed to curb the increase of hypertension.