Investigating the relationship between dietary acid load and risk of diabetes; a meta-analysis

Introduction: Diabetes is the most common endocrine disease that annually causes four million deaths in the world. It is not just a disease, however a series of metabolic disorders caused by defects in insulin secretion, insulin action, or both. Considering the importance of diet in the incidence and complications of diabetes, this study aimed to investigate the relationship between the dietary acid load with diabetes, which has recently been considered. Methods: This meta-analysis was first performed as a systematic review by searching in Google Scholar, Science Direct, PubMed, Wiley, Directory of Open Access Journals (DOAJ), Springer, Cochrane, ProQuest, and Scopus, as well as domestic databases including Magiran, SID, Irandoc, and Google Scholar. A total of 1511 articles were found that after reviewing and excluding irrelevant articles, five were included in the study. Results: In the present study, a significantly high heterogeneity was observed (I2 = 61.5, P = 0.01). A random effect model was used and the studies were weighted using the inverse-variance method. The odds ratio (OR) obtained from the meta-analysis was 1.17 (1.12-1.22). Examination of publication bias showed that the studies were symmetrically distributed in the funnel plot. Egger’s and Begg’s tests were also performed that showed no evidence for the existence of publication bias [Egger’s test (P ≥ 0.79) and Begg’s test (P ≥ 0.69)]. Conclusion: The results of the present meta-analysis showed a significant relationship between dietary acid load and the incidence of diabetes. This result is similar to most studies on the subject, except for one study, which was limited to the elderly male population. The number of studies in the present meta-analysis was low due to the limited number of research in this field.