Exploring the relationship between diabetes mellitus and environmental fluoride contamination in selected areas of Tanzania

Prevalence of Diabetes Mellitus in Tanzania is on the increase. Some few studies have linked fluoride contamination with possibilities of having effects on the insulin production resulting to Diabetes Mellitus. This has not been fully explored in Tanzania. Therefore, this study was undertaken to examine any relationship between fluoride levels in human blood serum and Diabetes Mellitus status of individuals in specific two wards of Tanzania. Cross sectional survey was conducted to explore the relationship between Diabetes Mellitus and fluoride in human blood serum whereby, two locations with different characteristics of environmental fluoride contamination in water sources were investigated. These areas were Ngarenanyuki ward (fluoride endemic area) in Arusha region and Mlandizi ward (non-endemic area) in Pwani region. The survey was conducted where 300 individuals (participants) were sampled from the study locations and consent for fasting blood sugar levels test, whereby, 97 individuals among them consent for both fasting blood sugar test and fluoride levels in blood serum determination. The prevalence of Diabetes Mellitus through fasting blood sugar test was 8.3%. High Diabetes prevalence was recorded at Mlandizi ward compared to Ngarenanyuki ward, though the difference was not significantly different (p = 0.144). Serum fluoride > 0.0 6 mg/l was significantly high in Ngarenanyuki (79%) compared to Mlandizi (21%) (P < 0.001). However, the current study did not establish any association between Fasting Blood Sugar tests and fluoride levels in blood serum (Pearson`s correlation coefficient analysis, r = - 0.0632; P < 0.663). Further work to include other cofounders is therefore recommended in order to understand broadly the influence of fluoride in Diabetes prevalence in fluoride endemic areas.