297
views
0
recommends
+1 Recommend
1 collections
    2
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      The role of Toxoplasma gondii as a possible inflammatory agent in the pathogenesis of type 2 diabetes mellitus in humans

      review-article

      Read this article at

      ScienceOpenPublisher
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Type 2 diabetes mellitus (T2DM) continues to be a major challenge for public health authorities worldwide. While potential causes such as obesity, physical inactivity, and dietary patterns have been proposed to explain the growing epidemic, there may also be unidentified environmental determinants. An emerging field of research is starting to examine the association of infectious and environmental pathogens with diabetes. In particular, the potential of these pathogens to cause low-grade inflammation that facilitates the risk and development of T2DM. An understudied pathogen of potential interest is the protozoan parasite Toxoplasma gondii (T. gondii). There is limited clinical evidence supporting the association between chronic T. gondii infection and the development of many disorders, including T2DM, in both animals and humans. This review (1) addresses the existing knowledge of the role of T. gondii in the inflammation process leading to T2DM, (2) examines the current studies describing the relationship between T. gondii and T2DM, and (3) makes recommendations for future studies to determine the role of T. gondii in the pathogenesis of T2DM. We believe that T. gondii may be an important target for T2DM intervention, and propose a new field of study, “toxoplasmic type 2 diabetes.”

          Most cited references214

          • Record: found
          • Abstract: found
          • Article: not found

          Inflammatory cytokines and the risk to develop type 2 diabetes: results of the prospective population-based European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam Study.

          A subclinical inflammatory reaction has been shown to precede the onset of type 2 (non-insulin-dependent) diabetes. We therefore examined prospectively the effects of the central inflammatory cytokines interleukin (IL)-1beta, IL-6, and tumor necrosis factor-alpha (TNF-alpha) on the development of type 2 diabetes. We designed a nested case-control study within the prospective population-based European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam study including 27,548 individuals. Case subjects were defined to be those who were free of type 2 diabetes at baseline and subsequently developed type 2 diabetes during a 2.3-year follow-up period. A total of 192 cases of incident type 2 diabetes were identified and matched with 384 non-disease-developing control subjects. IL-6 and TNF-alpha levels were found to be elevated in participants with incident type 2 diabetes, whereas IL-1beta plasma levels did not differ between the groups. Analysis of single cytokines revealed IL-6 as an independent predictor of type 2 diabetes after adjustment for age, sex, BMI, waist-to-hip ratio (WHR), sports, smoking status, educational attainment, alcohol consumption, and HbA(1c) (4th vs. the 1st quartile: odds ratio [OR] 2.6, 95% CI 1.2-5.5). The association between TNF-alpha and future type 2 diabetes was no longer significant after adjustment for BMI or WHR. Interestingly, combined analysis of the cytokines revealed a significant interaction between IL-1beta and IL-6. In the fully adjusted model, participants with detectable levels of IL-1beta and elevated levels of IL-6 had an independently increased risk to develop type 2 diabetes (3.3, 1.7-6.8), whereas individuals with increased concentrations of IL-6 but undetectable levels of IL-1beta had no significantly increased risk, both compared with the low-level reference group. These results were confirmed in an analysis including only individuals with HbA(1c) <5.8% at baseline. Our data suggest that the pattern of circulating inflammatory cytokines modifies the risk for type 2 diabetes. In particular, a combined elevation of IL-1beta and IL-6, rather than the isolated elevation of IL-6 alone, independently increases the risk of type 2 diabetes. These data strongly support the hypothesis that a subclinical inflammatory reaction has a role in the pathogenesis of type 2 diabetes.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Toxoplasmosis snapshots: global status of Toxoplasma gondii seroprevalence and implications for pregnancy and congenital toxoplasmosis.

            Toxoplasma gondii's importance for humans refers mainly to primary infection during pregnancy, resulting in abortion/stillbirth or congenital toxoplasmosis. The authors sought to evaluate the current global status of T. gondii seroprevalence and its correlations with risk factors, environmental and socioeconomic parameters. Literature published during the last decade on toxoplasmosis seroprevalence, in women who were pregnant or of childbearing age, was retrieved. A total of 99 studies were eligible; a further 36 studies offered seroprevalence data from regions/countries for which no data on pregnancy/childbearing age were available. Foci of high prevalence exist in Latin America, parts of Eastern/Central Europe, the Middle East, parts of south-east Asia and Africa. Regional seroprevalence variations relate to individual subpopulations' religious and socioeconomic practices. A trend towards lower seroprevalence is observed in many European countries and the United States of America (USA). There is no obvious climate-related gradient, excluding North and Latin America. Immigration has affected local prevalence in certain countries. We further sought to recognise specific risk factors related to seropositivity; however, such risk factors are not reported systematically. Population awareness may affect recognition of said risks. Global toxoplasmosis seroprevalence is continuingly evolving, subject to regional socioeconomic parameters and population habits. Awareness of these seroprevalence trends, particularly in the case of women of childbearing age, may allow proper public health policies to be enforced, targeting in particular seronegative women of childbearing age in high seroprevalence areas.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Inflammation and activated innate immunity in the pathogenesis of type 2 diabetes.

              There is increasing evidence that an ongoing cytokine-induced acute-phase response (sometimes called low-grade inflammation, but part of a widespread activation of the innate immune system) is closely involved in the pathogenesis of type 2 diabetes and associated complications such as dyslipidemia and atherosclerosis. Elevated circulating inflammatory markers such as C-reactive protein and interleukin-6 predict the development of type 2 diabetes, and several drugs with anti-inflammatory properties lower both acute-phase reactants and glycemia (aspirin and thiazolidinediones) and possibly decrease the risk of developing type 2 diabetes (statins). Among the risk factors for type 2 diabetes, which are also known to be associated with activated innate immunity, are age, inactivity, certain dietary components, smoking, psychological stress, and low birth weight. Activated immunity may be the common antecedent of both type 2 diabetes and atherosclerosis, which probably develop in parallel. Other features of type 2 diabetes, such as fatigue, sleep disturbance, and depression, are likely to be at least partly due to hypercytokinemia and activated innate immunity. Further research is needed to confirm and clarify the role of innate immunity in type 2 diabetes, particularly the extent to which inflammation in type 2 diabetes is a primary abnormality or partly secondary to hyperglycemia, obesity, atherosclerosis, or other common features of the disease.
                Bookmark

                Author and article information

                Journal
                FMCH
                Family Medicine and Community Health
                FMCH
                Compuscript (Ireland )
                2009-8774
                2305-6983
                December 2016
                December 2016
                : 4
                : 4
                : 44-62
                Affiliations
                [1] 1School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
                [2] 2Busselton Population and Medical Research Institute, Busselton, WA, Australia
                [3] 3School of Population Health, University of Western Australia, Nedlands, WA, Australia
                Author notes
                CORRESPONDING AUTHOR: Wei Wang, MD, PhD, FFPH, School of Medical and Health Sciences, Edith Cowan University, 270 Joondalup Drive, Joondalup WA 6027, Australia, Tel.: +61-8-63043717, E-mail: wei.wang@ 123456ecu.edu.au
                Article
                FMCH.2016.0128
                10.15212/FMCH.2016.0128
                297113f6-ba04-4e36-a33e-2b9af599b295
                Copyright © 2016 Family Medicine and Community Health

                This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 Unported License (CC BY-NC 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. See https://creativecommons.org/licenses/by-nc/4.0/.

                History
                : 24 August 2016
                : 18 September 2016
                Categories
                Review

                General medicine,Medicine,Geriatric medicine,Occupational & Environmental medicine,Internal medicine,Health & Social care
                diabetes mellitus, type 2,Etiology,Toxoplasma gondii infection,inflammation,toxoplasmosis

                Comments

                Comment on this article