Helminth infections and type 2 diabetes mellitus in Indonesia. Integrating parasitological, immunological and metabolic studies

Projectleiders: Jan Smit, Leiden Universitair Medisch Centrum en Taniawati Supali, University of Indonesia

Cardiovascular diseases are no longer a problem only for rich Western countries: 80% of deaths from these diseases are now estimated to occur in developing countries. Type 2 diabetes mellitus (DM2) is a significant risk factor for cardiovascular diseases and is closely associated with a Western lifestyle. In Asia, there is currently a rapidly growing epidemic of DM2. By 2030, India, China, and Indonesia are likely to be among the countries with the highest occurrence of DM2. This epidemic is a major burden on the healthcare system and prevention is therefore of great importance. Developing prevention programmes requires a knowledge of all the factors that are relevant to the development of DM2. Rapid economic development in Asia is leading to major changes in infrastructure, technology, and the food supply which are associated with excess food intake and a lack of physical exercise, thus leading to an increase in DM2. Along with the disappearance of traditional lifestyles, the disappearance or reduction of infectious diseases also plays a role. Besides changes in eating patterns and physical activity, inflammatory processes also play a major role in the development of DM2. It is therefore plausible that the effects of changing infection pressure on the immune system also play a role in the development of DM2 in developing countries.

Population research in Flores Photo: Jan Smit

In an earlier study on the Indonesian island of Flores, our group discovered that parasitic infections (worm infections) reduce the activity of the immune system and that people who were suffering from such infections had a more favourable blood sugar profile than those who were not. In the current programme, we intend investigating the relationship between worm infections and DM2 and the underlying mechanisms. To that end, an interdisciplinary research programme has been set up involving researchers engaged in clinical and basic research, social medicine, and statistics. The hypothesis that worm infections reduce the likelihood of people developing DM2 will be investigated in a controlled study in which inhabitants of the island of Flores will be treated with anti-worm medication or control medication. The study will investigate the effect of the disappearance of worm infections on blood sugar metabolism and the immunological mechanisms that play a role. All relevant lifestyle and socio-cultural factors will also be studied. In order to determine the mechanism, studies will also be carried out on laboratory models of worm infections and DM2. Given the variety and complexity of the data collected, methods will also be developed for analysing that data and integrating it into a model that will describe the contribution of worm infections together with all other relevant factors in the development of DM2. The intention of the programme is to develop instruments for use by policy-makers engaged in constructing DM2 prevention programmes in Indonesia.