The association between Toxoplasma gondii and type 2 diabetes mellitus: a systematic review and meta-analysis of human case-control studies
Aus Molan, Kazunori Nosaka, Michael Hunter, Wei Wang
Abstract
Abstract Objectives An emerging field of research is examining the association of infectious and environmental pathogens with type 2 diabetes mellitus (T2DM). An understudied pathogen of interest is the protozoan parasite Toxoplasma gondii ( T. gondii ). The objective of this study was to investigate the possible correlation between T. gondii infection and T2DM. We conducted a systematic review and meta-analysis on the currently available T. gondii seroprevalence data from case-control studies looking at subjects with T2DM in comparison to healthy controls to estimate the risk of T2DM. Methods Ten electronic databases were searched using specific Medical Subject Headings terms without language or date restrictions. Fixed and random effects models were used to determine odds ratios with statistical significance being set at 5.0%. Results Ten publications reporting T. gondii seroprevalence from 4072 subjects met the eligibility criteria. Seven of these studies reported a significant association between T. gondii infection and T2DM ( p < 0.05). The overall weighted prevalence of T. gondii infection in subjects with T2DM was 47.8% (range 6.4–65.1%) in comparison to 25.9% (range 3.2–59.0%) of healthy controls ( p < 0.001). The common odds ratio, calculated using a random effects model, was 2.32 (95% CI 1.66–3.24, p < 0.001). Conclusions T. gondii infection should continue to be regarded as a possible contributing factor in T2DM disease development. Further studies that include inflammatory biomarker analysis are warranted to determine the specific role of this parasite in the pathogenesis of T2DM.