About PARCAM Project
CONTRIBUTION OF INTESTINAL PARASITE INFECTIONS IN THE RISK OF DEVELOPING CARDIO-METABOLIC DISEASES IN RURAL AND URBAN AREAS OF GABON : A PILOT STUDY
Non communicable diseases (NCDs) and Infectious diseases (IDs), such as malaria and intestinal parasites are highly prevalent in sub-Saharan Africa. Their dual burden, associated risk factors and impact are poorly studied in Central Africa.
The ParCaM study will estimate and compare the frequency of cardio-metabolic diseases risk factors (CMDRF), including metabolic syndrome, hypertension, and inflammatory biomarkers in individuals with or without intestinal parasite infection (IPIs). Differences between specific age groups, type of parasitism (protozoa, helminths) and geographical (urban versus rural) areas will be emphasized. In addition, risk groups will be identified.
A two phase prospective and analytical study will be conducted in two urban (Libreville and Melen) and two rural (Koulamoutou and Bitam) cities in Gabon. Phase 1 will be a cross-sectional survey during which young adults aged between 18 and 49 years will be randomly included in the 4 sites. A standardized World Health Organization STEPwise NCDs surveillance questionnaire will be used to obtain demographic characteristics, lifestyle and risk factors. Blood pressure, height, weight, BMI and waist circumference will be measured. A parasitological analysis will identify intestinal protozoa, soil-transmitted helminths including urinary and intestinal schistosomiasis. Clinical chemistry and immunological tests will allow to identify the metabolic syndrome (which involves glucose, insulin, lipids levels) and the chronic inflammation biomarkers (IL-6, TNF-, sCD14, hsCRP). The Framingham score will determine the 10-year cardiovascular risk at the beginning and the end of the follow-up. In the Phase 2, selected participants will be included in 18-month prospective cohort study to estimate the frequency of occurrence of any CMD event or risk factor. Statistical analysis will include the estimation of the prevalence of IPIs and logistic regression analysis to assess the association between the presence of IPIs and CMDRF. Covariates such as study area, age, sex, area of residency and type of parasitism will be introduced within the model.
The prevalence of IPIs and CMDRF will be described globally and according to the study area (urban and rural areas). Also, the impact of IPIs on the occurrence of CMDRF will be estimated adjusted to the westernized or rural life style. The results of this study will emphasize the need of collaborative multi-country assessment of NCD and neglected infectious diseases burden estimation and co-management, as well as their prevention through the reduction of risk factors in urban, but also in remote areas.
Inflammatory response and dysbiosis due to IPIs lead to dyslipidemia, type 2 diabetes and their cardiovascular (CVD) consequences. This will be translated into higher frequency of these CMD risk factors (CMDRF) in participants chronically or repeatedly infected when compared to uninfected participants. As exposition to IPI and type of parasitism are different between urban and rural areas, biomarkers of CMDRF will show different patterns according to the urbanisation. Precisely, we hypothesise that there will be more metabolic syndrome, more inflammation (as measured by IL-6, TNF-α, hsCRP) and more monocyte activation (as measured by sCD14) in chronically or repeatedly parasite-infected than in uninfected participants with difference according to urbanisation.
The primary outcome will be the frequency or incidence of CMD risk factors (defined as presence of any of the following conditions: metabolic syndrome, high level of inflammatory and monocyte activation markers, High Framingham score) in parasitic-infected and non-infected individuals in urban versus rural areas.
Socio-demographic variables, as well as household characterisation and lifestyle will be considered as exposures and potential confounders.
The secondary outcomes will be the estimation and comparison of the following events between IPI-infected versus IPI-uninfected participants as follows:
During the cross-sectional study
- Prevalence, intensity, and distribution of IPIs (STH and Protozoa) and schistosomiasis
- Prevalence and distribution of biomarkers of metabolic syndrome, diabetes and CVD between rural and urban inhabitants
- Prevalence of high Framingham risk score according to study area
- Global frequency of CMDRF
- Prevalence of pre-diabetes/diabetes
- Prevalence of dyslipidaemia
- Prevalence of cardiovascular disturbance.
During the prospective cohort study
- Incidence of IPIs in urban and rural areas
- Prevalence of new CMDRF in urban and rural areas at the end of the cohort study
- Evolution of Framingham score globally and according to the type of parasitism and study area
- Evolution of the levels of inflammatory biomarkers in participants from urban and rural areas
- Incidence of CMDRF, including metabolic syndrome, chronic inflammation and high blood pressure in the general population and between groups.