Cardiovascular disease risk factors among school attending adolescents in rural Nigeria

Thesis (PhD)--Stellenbosch University, 2016.ENGLISH ABSTRACT: Background: The prevalence of Cardiovascular Disease (CVD) is increasing in Nigeria, particularly hypertensive heart disease among the working class population. Unfortunately, resources for effective management of CVD at acute stage are sparse and expensive for the average Nigerian making preventive measure the best option for Nigeria. CVD risk factors have been identified in adolescents in many countries but information on CVD risk factors among Nigerian adolescents, especially rural adolescents, are sparse. This study aimed to develop culturally appropriate lifestyle CVD risk factors questionnaire for adolescents in Nigeria and to investigate CVD risk factors and its associates among 15-18 years school attending adolescents in rural Nigeria. Methods: The study was conducted in rural south west Nigeria, one of the six geopolitical zones of Nigeria. The people living in this area are Yoruba speaking population of Nigeria. The study was conducted in four phases. Phase 1: development of a composite lifestyle CVD risk factors questionnaire through systematic review, expert panel and target population. Phase 2: Cross cultural validation of composite measure developed to facilitate its use among rural adolescents. Phase 3: Pilot study to assess the logistics of the study and to test the reliability of the newly developed questionnaire. Phase 4: investigation into CVD risk factors among adolescents. CVD risk factors such as smoking, alcohol, Physical inactivity, and poor diet using the newly developed questionnaire were assessed. Blood pressure, BMI and waist hip ratio were also assessed using standardized protocol. Data was analyzed qualitatively and quantitatively. Content validation of the questionnaire was done qualitatively using expert consensus and adolescents’ feedback. Reliability was tested using ICC (Intraclass Correlation), Kappa and paired t test. CVD risk factors data was analyzed descriptively first, then with Pearson correlation and multiple regressions to determine associations among risk factors at 95% confidence interval (0.05 level of significance). Result: European countries showed high prevalence of smoking among adolescents in the systematic review. The prevalence of dyslipidemia ranged from 2.5% of total cholesterol (TC) in rural Iran adolescents to 48.9% high Triglyceride (TG) in rural Mexican adolescents. Overweight and obesity prevalence ranged from 0.6% prevalence in an age (10 y) of a study to 48.7%. Studies from the United States showed a decreasing trend in pre hypertension and hypertension, overweight and obesity. The newly developed composite lifestyle CVD risk factors questionnaire for adolescents had moderate to good reliability. Intraclass correlation (ICC) ranged from 0.3 - 0.7 and 0.3-0.8 in English and Yoruba versions’ subscales respectively. Kappa statistics showed moderate to strong agreement in priority questions in English and Yoruba versions. Investigation into the CVD risk factors showed high prevalence and clustering of CVD risk factors; 7.1% adolescents were smokers, 10.2% drank excessive alcohol, 27.9% had low physical activity level, 59.8% consumed high cholesterol diet, 6.1%, consumed low vegetable 8.1% consume low fruit 65.5% had high salt intake, 33.1% had pre hypertension ( systolic), 5.5% had pre hypertension (diastolic) 3.2% had hypertension (systolic) 0.8% had hypertension (diastolic). Smoking and drinking were significantly higher in males and physical activity was significantly higher in females. Smoking and drinking were significantly associated in both males and females and the odd of drinking and smoking was more elevated in girls. Systolic pre- hypertension was associated with age and high BMI in boys and was associated with only high BMI in girls. Conclusion: Nigerian rural adolescents are at risk of future adult CVD. There is an urgent need to put measures in place to prevent future epidemic of CVD in adulthood. CVD prevention program for boys and girls should be tailored to address gender specific CVD risk factors.AFRIKAANSE OPSOMMING: Nie beskikbaar nie