Non-communicable diseases, an `epidemic in slow motion', have been projected to be a leading cause of morbidity and mortality in Nigeria by 2030.30,31 The surveillance of NCD risk factors is one of the key strategies advocated to tackle these emerging public health concerns, particularly in low and middle income countries. Therefore, this study investigated prevalence of NCD and its association with behavioral risk factors in the busy surburb of the Ijegun- Isheri Osun in Lagos State, Nigeria. We found that most of the participants were aged 40 years and above, more than half were female, and majority were married.
Tobacco use, the leading cause of morbidity and mortality globally that claims about 6 million lives annually, was also prevalent in this study.32,33 This finding corroborates with reports in other literature where prevalence of tobacco use of was found to be 34.4% in India 43.2% in Bangladesh.34 It is known that unhealthy lifestyle habits are prevalent in urban cities and industrial hubs in Nigeria.35,36 Conversely, low prevalence rates have been reported among the working class in some other parts of Nigeria.31,37,38 The contrast in findings could be as a result of formal civil servants being the focus of previous studies as against this study whose participants were general community residents and traders. The sex differences in smoking in this study is in keeping with similar reports in other parts of the country where more males smoked cigarettes than females. This can be attributed to the risk-taking behaviours of men. There was a significant association between increasing age and smoking, which was similar to other existing literature19. Similarly previous health reports conclude that majority of adult smokers initiated the habit of smoking before the age of 18 years, a finding which supports calls for the extension of the focus for tobacco control programs to young adults in order to curtail the habit of smoking as people get older.39,40
Alcohol consumption and harmful use of alcohol were reported in more than half of our study population as 32.8% and 34.4% respectively. Approximately 2.3 million die each year from the harmful use of alcohol, accounting for about 3.8% of all deaths in the world. More than half of these deaths occur from NCDs including cancers, cardiovascular disease and liver cirrhosis.32 A prevalence of 26.9% for alcohol consumption has been reported in urban communities in Ibadan.22 The differences in our findings and that of the earlier studies could be due to differences in study populations and the prevailing lifestyles present in these different communities. Another reason for inconsistent results with the available literature could be due to differences in assessment methods. Previous studies used self-constructed instrument while this study used standard and pretested questionnaire (WHO Stepwise protocol).41
In our study, physical activity was high (52.9%), which was consistent with previous studies in Ibadan and Abuja, Nigeria which have reported physical activity of 53.6% and 49% respectively among drivers.4243 The similarity in the outcome could be due to driving being the occupation of majority of residents in Iseri-Osun - the study setting of this study. This is especially in keeping with the higher physical activity observed in males. Also, majority of the female respondents in this study were traders who usually sit in their shops throughout the day as reported also in a study in Tejuosho market in Lagos.16 Moreover, Lagos is a boisterous city and residents have to engage in demanding jobs and travel long distance daily in search of their daily means of sustenance. However, lower prevalence of physical activity (37.8%) among civil servants in Ibadan have been reported.44,45 The differences in the findings could be due to different instruments used for the assessment of physical exercise. Previous studies reported an underestimated level of physical inactivity in their study because of the subjective method of assessment in the use of self-reported questionnaires (International Physical Activity Questionnaire).46 Meanwhile, this study used WHO recommendation to classify participants into physical activity categories.47,48 One plausible reason for high percentage of physical activity in this study was because most participants were young adults with an average age of 38 years. Also, most of them were employed, even though their occupation were not disclosed but leaving home for work place every day might require walking among most participants. Still, workplace interventions that encourage more physical activity at work should be encouraged in the community.
Raised blood pressure, the major risk factor for cardiovascular diseases, which include coronary heart disease, cerebrovascular disease, peripheral vascular disease etc., has become a global concern. This is because CVDs are the leading cause of death globally with an estimated 17.5 million deaths yearly, occurring mostly in low-and-middle income countries.32 This fact was buttressed in this study where about a third had hypertension, which supports previous findings in other researches in Nigeria.43,49This is also in keeping with the landmark meta-analysis by Adeloye et al.50 who reported prevalence of 30.6% in urban communities in Nigeria. Increasing age has been shown to be a risk factor for raised blood pressure.43,49 Participants aged 60 years or above were about nine times more likely to be hypertensive compared to those in age group below 60 years. As a result of aging, changes occurring within the cardiovascular system like thickening of the arterial wall. Thus, the heart does more work in pushing blood against the thickened arterial wall leading to an increase in arterial blood pressure.44,51However, our study did not show any significant gender difference in the occurrence of hypertension. Similarly, there was no significant association between gender and high blood pressure in similar settings although a systematic review on the current prevalence and pattern of hypertension in Nigeria, higher significant prevalence of hypertension was reported among males compared to females44,45,52,53. Being employed and having dyslipidaemia were other predictors of hypertension in this study. Dyslipidaemia contributes to atherosclerosis through endothelial dysfunction, inflammation and insulin resistance. Employed individuals living in Lagos generally are exposed to daily stress that is characteristic industrial capitals.
The low prevalence of diabetes in this study is similar to the finding by Ajayi et al.42, Oguoma et al.54 and Sani et al.55 but lower than the reports by Oluyombo et al56. in Ekiti and Agaba et al57. However, Odugbemi et al.16 have reported much lower prevalence of diabetes in Tejuosho market in Lagos. It appears that diabetes prevalence is much higher in Nigeria compared to her neighbouring sub-Saharan countries.58
Dyslipidaemia was prevalent in almost half of the respondents. In addition, age and the lifestyle risk factors predicted those with dyslipidaemia. Dyslipidaemia usually co-exists with obesity and both are important in the pathway to hypertension and atherosclerotic vascular disease. Ogunbode et al.59 have coined a mnemonic termed “WASHED” for NCD lifestyle modification and health education in those with obesity in primary care settings. “WASHED” stands for weight control, alcohol reduction, smoking cessation, health promotion, exercise and diet. We have shown in our study the important role of smoking and physical activity as dominant risk factors of dyslipidaemia. We believe that health promotion and education in the community and primary care settings geared towards smoking cessation, increased physical activity and healthy diet would play critical roles in stemming the tide of atherosclerotic vascular diseases in Nigeria. This will require concerted efforts by stakeholders and policy makers if Nigeria is to achieve the 2025 voluntary targets of the Global NCD Action Plan.57
This study is an important contribution to the surveillance of NCD risk factors in Nigeria as most of the observations were based on validated tools than self-reported information. Even though it is not a nationally representative survey, an assessment of one community in one of the largest cities in Nigeria can give a minuscular view of the drivers of NCDs within the larger population until the time when nationally representative surveys would be conducted in Nigeria. Although, obesity is one of the four metabolic risk factors of NCDs, it was not assessed in this study However, we have measured blood cholesterol levels which are more important in the pathophysiologic pathway to cardiovascular diseases.60,61 Cross tabulation of behavioural risk factors by socio-demographic factors was not computed which makes it difficult to observe the categories of participants that constitute more in one habit or the other. We perhaps underestimated the level of physical inactivity in our study because of the subjective method of assessment in the use of self-reported questionnaires. For future studies, using more objective means of assessing physical activity like pedometers and accelerometers could give better result.
In conclusion, we have shown the prevalence of common NCDs and their risk factors in a representative community in Nigeria’s most busy city. Many of these risk factors are modifiable and this underscores the importance of health promotion and education in reducing the burden of NCDs in Nigeria. Larger surveys of these nature are needed for policy formulation. We plan to conduct more surveys across Nigeria’s 6 socio-political regions in the future.