December 1, 2015Open Access
Risk factors of hypertension among adults aged 35–64 years living in an urban slum Nairobi, Kenya
Key Result
The age-standardized prevalence of hypertension was 29.4%, with obesity significantly increasing the odds of hypertension (AOR 1.8) among adults in a Kenyan urban slum.
Study Design
Type
Cross-Sectional (n=1,528)
Structured PICO
P
Population
1,528 adults aged 35-64 years living in an urban slum in Nairobi, Kenya, were assessed to determine the prevalence and risk factors of hypertension.
O
Outcome
Prevalence of hypertension and associated risk factors
Hypertension affects nearly one-third of adults in a Kenyan urban slum, driven by risk factors such as obesity, wealth index, and physical inactivity.
Main Result
Odds Ratio: 1.8 (95% CI 1.1–3.1)
Absolute Event Rate: 36% vs 21.9%
Limitations
- Recall bias due to self-reported behavioral risk factors
- Potential under-reporting of discouraged behaviors such as alcohol and tobacco consumption
- Blood pressure based on average of two measurements at a single visit
- Cross-sectional design precludes establishing causality
Abstract
BACKGROUND: Hypertension is an emerging public health problem in Sub Saharan Africa (SSA) and urbanization is considered to favor its emergence. Given a paucity of information on hypertension and associated risk factors among urban slum dwellers in SSA, we aimed to characterize the distribution of risk factors for hypertension and investigate their association with hypertension in an urban slum in Kenya. METHODS: We conducted a community based cross-sectional survey among adults 35 years and older living in Kibera slum Nairobi, Kenya. Trained interviewers collected data on socio demographic characteristics and self reported health behaviours using modified World Health Organization stepwise surveillance questionnaire for chronic disease risk factors. Anthropometric and blood pressure measurements were performed following standard procedures. Multiple logistic regression was used for analysis and odds ratios with 95 % confidence intervals were calculated to identify risk factors associated with hypertension. RESULT: A total of 1528 adults were surveyed with a mean age of 46.7 years. The age-standardized prevalence of hypertension was 29.4 % (95 % CI 27.0-31.7). Among the 418 participants classified as hypertensive, over one third (39.0 %) were unaware they had hypertension. Prevalence of current smoking and alcohol consumption was 8.5 and 13.1 % respectively. Over one quarter 26.2 % participants were classified as overweight (Body Mass Index BMI ≥25 to ≤29.9 kg/m(2)), and 17 % classified as obese (BMI ≥30 kg/m(2)). Overweight, obesity, current smoking, some level of education, highest wealth index, moderate physical activity, older age and being widowed were each independently associated with hypertension. When fit in a multivariable logistic regression model, being a widow AOR = 1.7; (95 % CI, 1.1-2.6), belonging to the highest wealth index AOR = 1.6; (95 % CI, 1.1-2.5), obesity AOR = 1.8; 95 % CI, 1.1-3.1) and moderate physical activity AOR = 1.9; (95 % CI, 1.2-3.0), all remained significantly associated with hypertension. CONCLUSION: Hypertension in the slum is a public health problem affecting at least one in three adults aged 35-64 years. Age, marital status, wealth index, physical inactivity and body mass index are important risk factors associated with hypertension. Prevention measures targeting the modifiable risk factors associated with hypertension are warranted to curb hypertension and its progressive effects.