The Relationship between Type II Diabetes and Selected Modifiable Lifestyle Factors: A Case-Control Study at the Out-Patient Department of the St. Mary's Mission Hospital, Langata, Nairobi.
Type 2 diabetes is a chronic non-communicable disease that is associated with high levels of morbidity, mortality and economic burden both at individual and national levels. However it is also a highly preventable disease with research indicating that up to 80% of all cases of this disease can be prevented through lifestyle modification. Obesity, alcohol intake, cigarette smoking, physical inactivity and low fiber diet have been linked by many studies to type 2 diabetes as modifiable risk factors (WHO, 2010). Primary prevention of type 2 diabetes would involve parallel public health programs, in respect to each of the modifiable lifestyle factors, aimed at modifying these factors in the general population. Since such programs would require substantial resources, prioritization would be imperative especially in resource-poor countries to ensure that resources are allocated to each of these programs commensurate or proportionate to their expected impact in terms of reduction of type 2 diabetes in the general population. This requires scientific studies to establish how strongly each of these modifiable lifestyle factors is a risk factor for type 2 diabetes. This study therefore sought to find out the relationship between each of the five modifiable lifestyle factors and having type 2 diabetes. The study was a matched case- control study at the out-patient department at the St Mary’s Mission Hospital, Langata in Nairobi. The dependent variable was the presence of type II diabetes while the predictor variables were Body Mass Index (BMI), number of pack-years smoked, type of diet, level of physical activity and the level of alcohol consumption with the possible confounding variables being age, sex, level of education and work status. The sample size was 132 cases with one control for each case. A case was defined as any patient who was seen at the diabetic clinic at the hospital, was newly diagnosed with type 2 diabetes as per the WHO criteria and gave fully informed written consent for inclusion into the study. A control was defined as any adult out- patient who was seen at the general out-patient clinic at the hospital for any disease other than diabetes, hypertension, cancer, chronic respiratory disease or any chronic cardio- vascular or cerebro-vascular disease, who matched a particular case for age and gender and who gave a fully informed written consent for inclusion into the study. Cases were selected as they become available while controls were purposively selected to match specific cases selected on that day. The data was analyzed using the Statistical Package for the Social Sciences (SPSS) version 17. Logistic regression analysis was done to check for and adjust for any confounding and interactions between the predictor variables. This study found out that alcohol consumption and being over-weight or obese had strong dose-response relationships with having type 2 diabetes. Physical activity had dose- response relationship with having type 2 diabetes that was of borderline significance. Smoking and amount of fiber in diet were found not to have any significant relationships with having type 2 diabetes. The recommendations from the study included strict enforcement of the regulations set out in the Alcoholic Drinks Control Act, 2010 and the development and conduction of continuous public awareness campaigns on the health hazards of alcohol consumption. Other recommendations include formulation of policies that encourage use of public and non-motorized transport, promote physical activity among members of the public and promote consumption of wholesome indigenous foods while discouraging the consumption of fast foods and limiting the amount of unhealthy ingredients in the foods. The study also recommended that in view of the contradicting findings of this study vis- à-vis previous studies, more studies be done on the relationship between type 2 diabetes and smoking with larger sample size so as to increase the power to detect any relationship.