ABSTRACT
BACKGROUND: Amount and quality of dietary fat modifies glucose tolerance. Omega 3 Fatty Acids (n-3F A) are polyunsaturated fats, mainly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) found primarily in fish and they have a positive effect on glucose tolerance. OBJECTIVE: To compare risk of type 2 diabetes mellitus (T2DM), as demonstrated thourough impaired glucose tolerance (IGT), and n-3FA intake among two rural populations. DESIGN: A descriptive, cross-sectional comparative study. SETTING: Bondo District (Luo Community) and Kericho District (Kipsigis Community) of the Lake Victoria basin of Kenya. SUBJECTS: Sample of 150 individuals, aged above 18 years was randomly selected from each of the two communities. INTERVENTIONS: Impaired glucose tolerance (IGT) was measured according to World Health Organisation diagnostic criteria. The intake of n-3FA was determined using a 24 hour dietary recall and food frequency schedule. Data was analysed using SPSS and Pearson Correlation Coefficient was used to test correlation between n-3FA consumption and IGT. The inter-group comparisons were done using the t-test and analysis of variance. RESULTS: The prevalence of IGT was 11.8% among the Kipsigis and 4.8% among the Luo (P<0.001). The mean EPA and DHA intake was found to be 0.29 g/day and 0.34 g/day respectively among the Luo and 0.01 g/day and 0.01 g/day among the Kipsigis (P<0.001). The relationship between 2 hour post-prandial glucose level and consumption of DHA was (r=-0.111, p<0.05), EPA (r=-0.123, p<0.05), polyunsaturated fatty acids (r=-0.128, p<0.05) and saturated fats (r=-0.002, p=0.973). CONCLUSION: The levels of IGT were significantly lower (P<0.001) among the Luo, than among the Kipsigis. There was also evidence of significant inverse relationship between IGT and consumption of n-3FA and polyunsaturated fatty acids (PUFA) but no association between saturated fats intake and IGT. The saturated fat ingested did not affect the level of post-prandial glucose. The Luo who consumed higher n-3FA amounts, recorded lower levels of IGT than the Kipsigis who had significantly lower consumption. RECOMMENDATIONS: Effective screening methods should be used at the existing health units to determine risk factors of type 2 diabetes mellitus like IGT among patients. This could help in advising them accordingly on lifestyle changes, especially concerning diet and beneficial fats.
