Nutrition, immunity, infection and metabolic health in Ecuador

This thesis is a compilation of several articles with as subject nutrition, immunity, infection and metabolic health in Ecuador. Focus is in particular on

1. The association of zinc deficiency with immune functioning and with infections in children and aged (generally over 60 years) under-privileged Ecuadorian urban populations

2. The prevalence of metabolic syndrome and its association with micronutrient deficiencies in aged under-privileged Ecuadorian urban populations.

The investigations are based on studies carried out at both the community level and in hospitals.

More specifically the following aims for the studies presented in this thesis were:

1. To know the prevalence of micronutrient, and in particular zinc deficiency in younger and older Ecuadorian populations.

2. To perform limited studies on the immunological consequences of micronutrient and in particular zinc deficiency. For that purpose we determined in the older subjects as described in chapters 6 and 7 the following immune tests: a). DTH skin tests with some recall antigens b). Ex vivo IL-2 production in cultured mononuclear cells c). Ex vivo INF-γ production in cultured mononuclear cells

3. To study the prevalence of respiratory infections in both children and older subjects and its association with zinc deficiency.

4. To study the effects of zinc supplementation on the prevention of respiratory symptoms in young children, and determine the lowest efficacious zinc dose to prevent acute infections in young children.

5. To study the effects of zinc supplementation as an adjunct to the standard treatment of severe pneumonia in hospitalized children.

6. To study the prevalence of the MetS in an older Ecuadorian population and to determine its association with micronutrient deficiencies.

7. To determine whether infiltration of the gastric mucosa by mononuclear and polymorphonuclear cells (PMNs) in H. pylori infected adults was associated with lower zinc tissue concentrations to try to relate active gastritis to zinc deficiency.