Prevalence, awareness and management of type 2 diabetes mellitus in Mwanza City, Tanzania

A THESIS SUBMITTED IN FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY OF SOKOINE UNIVERSITY OF AGRICULTURE. MOROGORO, TANZANIA.

Type 2 diabetes mellitus (T2DM) is a metabolic disease caused by either inadequate insulin produced by beta cells of the pancreas or inability of body cells to respond to insulin produced. Prevalence of this disease is increasing rapidly around the world. This study was conducted to assess the prevalence, awareness and management of T2DM among adults in Mwanza City, Tanzania. A multistage random sampling technique was employed to obtain representative subjects. A total of 288 males and 352 females’ respondents were included in this study. For each subject, anthropometric measurements of height, weight, waist and hip circumference were performed, total body fat mass, and blood pressure were measured using standard procedures. In addition, random blood glucose testing was employed to identify subjects at risk. Subjects with random glucose level of or above 200 mg/dl were subjected to fasting blood glucose testing on the succeeding day. Subjects were confirmed to have T2DM if they had fasting blood glucose level of or above 126 mg/dl. Information about causes, lifestyle behaviors, risk factors and management of T2DM were collected using pre-tested structured questionnaire. Overall, prevalence of T2DM was 11.9% and the prevalence was higher among females (7.2%) than among males (4.7%). T2DM and Impaired Fasting Glucose (IFG) were found to be higher in females than in males and tended to increase with age. Prevalence of T2DM was shown to be higher in 41-60 years and less in 60 and above years. Awareness of the causes of diabetes was very low with only 17% of the respondents having correct knowledge about the causes of T2DM. Over half (54.2%) of the respondents were not aware of the age most affected by the disease. Moreover, 45.5% of the respondents did not know how to manage the disease through diet, physical exercises and medication. Independent associations were found between T2DM and risk factors such as age (OR 3.88, 95% CI 2.16-6.95) heredity (positive first degree relative) (OR 1.34; 95% CI; 1.10-1.64) alcohol intake (OR 1.23; 95% CI: 1.02-1.48) smoking, (OR 3.86; CI: 2.57-5.78) and hypertension (OR 0.096; 95% CI: 1.954-18.251). Prevalence of overweight in the studied population was 10.5% in males and 18.1% in females. Most females (60.8%) had waist-hip ratio of ≥ 0.85. Results revealed further that, the biggest amount of serving of fruits and vegetables was 250g whereby only 19% of the respondents consumed that amount per day. Prevalence of hypertension was high in 41-50 year age group (10.2%), while the overall prevalence of hypertension was 34.1%. The prevalence of hypertension was 16.7 and 17.3% in females and males, respectively. The relative risk of developing T2DM if one had hypertension was 4.052 (95% CI: 2.55-6.433, p=0.06). The relative risk for developing T2DM by having first class relative with the disease was 2.11 (95% CI: 1.4-3.1). One year follow up after nutrition education intervention showed improvements in metabolic, anthropometric and cardiovascular outcomes. The most notable improvement was the glycemic control. Results revealed that, fasting blood glucose levels decreased gradually from the baseline up to the 12 months endline. There was significant (p ≤0.05) difference in the blood glucose levels during several clinic visits. There was 34% decrease in blood sugar levels during the intervention from the baseline survey up to 12 months. Fasting blood glucose after 3 months of intervention was higher (p≤0.05) than after 6 months and after 12 months. There was 7.3% decrease in average weight (4.2kg) from baseline to 12 months post intervention. Mean BMI was decreasing gradually with time of intervention. Mean BMI (28.6±5.6) in the first visit was significantly higher (p≤0.05) than in the subsequent visits. There was an average decrease of 8.8% in the BMI from baseline to 12 months’ endline. No differences (p>0.05) in systolic blood pressure were observed among subjects though there was a decrease in the average levels from baseline to 12 months post- intervention. In diastolic blood pressure there was significant variation (p≤0.05) among subjects from the baseline to 3 months, 6 months and 12 months post-intervention. Mean diastolic blood pressure decreased by 6.3% for the entire intervention period. Waist-hip ratios among subjects decreased insignificantly (p>0.05) from the baseline up to 12 months after intervention. For dietary management of type 2 diabetes mellitus, glycemic indices (GI) of commonly consumed staple foods namely cassava flour, undehuled maize flour, sorghum flour, millet flour and plantains (Matoke) were determined. Cassava diet had the lowest glycemic value (49.8) followed by maize meal (51), while cooked plantains (Matoke) (57.85) and finger millet meal (60.92) had medium GI values. Sorghum meal had the highest GI (65.71). Based on the GIs values, cassava and whole maize meals were recommended as the most suitable staples for the management of type 2 diabetes mellitus. Moreover, finger millet, sorghum and plantains meals can be consumed but moderately. It was concluded from the studies that Health Ministry and other health practitioners should ensure that public education on T2DM is emphasized and routine measurement of blood glucose levels is recommended among adults. Furthermore, health practitioners and the government have to ensure policies are placed to intervene, and modify lifestyle behaviors at young ages so as to reduce the risks of developing T2DM. For proper management of T2DM, policy makers have to ensure that services and proper medicine for patients with T2DM are accessible throughout the primary health care delivery facilities in the country. Moreover, policy makers should identify patients with low income who would receive treatment and medication at subsidized rates to ensure that no patient would skip the management regime for the treatment of T2DM.