Diabetes, Metabolic Syndrome and Risk of Malaria in Cameroon

Risk of Malaria and Other Parasitic Infections in Individuals With Type 2 Diabetes With or Without Metabolic Syndrome in Cameroon.

Non-communicable diseases (NCDs) such as diabetes are increasing in countries where malaria transmission is common. This study aims to investigate the relationship between NCDs and parasitic infections in Cameroon. The investigators will assess the risk of malaria, as well as other parasitic diseases, in a prospectively followed group of adults with diabetes, compared with those without diabetes. Malaria parasites and intestinal worms will be tested using blood and stool collected at four time points during a one-year follow-up. In addition, this project will investigate how natural protection against malaria is affected by diabetes and other risk factors for heart diseases.

Study Overview

• Status: Completed
• Conditions: Diabetes Mellitus; Metabolic Syndrome; Malaria; Endemic

Detailed Description

Studies have suggested that diabetes could be associated with both increased risk of and protection from infection with certain protozoans and helminths. A study from Ghana demonstrated an increased risk of asymptomatic malaria in individuals with type 2 diabetes, compared to healthy subjects. On the contrary, a Chinese study found a lower prevalence of diabetes and metabolic syndrome among adults previously exposed to Schistosoma. In sub-Saharan Africa, endemic to these parasitic infections, limited is known on their interaction with diabetes and metabolic syndrome. Findings from this study can inform policy to better integrate public health measures to improve the care of individuals with chronic non-communicable diseases such as diabetes and metabolic syndrome living at risk of malaria and other parasitic infections and prevent them from complications.

This study aims to investigate whether diabetes with/without metabolic syndrome affects the risk of malaria and antibody-mediated immunity to malaria in adults, and if this risk is specific to malaria or also observed in other parasitic infections.

This will be a prospective cohort study conducted at the Limbe Regional Hospital and Global Health Systems Laboratory in the Southwest Region of Cameroon. This cohort will comprise two groups of participants: the exposed group comprised of patients with type 2 diabetes (T2DM), and an unexposed group made of individuals without diabetes. Participants will be aged 21 years and above and must provide written informed consent to be part of the cohort. For every patient with diabetes included in the study, a participant without diabetes matched for sex and age (±5 years) and living in the same neighborhood will be identified and involved in the study. All participants will be assessed at the beginning, and every third months after the initiation into the cohort, and up to 4 times in 1 year. During each study encounter, participants will be tested for malaria through microscopy rapid diagnostic testing (RDT), and PCR to detect low-level parasitemia and confirm the plasmodium species. Also, stool analysis and urine microscopy will be performed, together with serological markers to enable the detection of helminths. At each visit, a full blood count, lipid profile, fasting plasma glucose, hemoglobin electrophoresis, creatinine for kidney function, HIV, and glycated hemoglobin tests will be done. The blood pressure, weight and height, and waist circumference will be measured at each encounter to aid in determining metabolic syndrome. Stored plasma samples will be analyzed on a panel of antigens using ELISA and a Luminex assay to measure the antibody response to malaria.

Data will be analyzed using STATA. Descriptive statistics will be performed to determine the incidence of parasites using the Kaplan-Meyer method, and between-group comparisons of proportions done using the Chi-Squared tests or Fisher´s exact tests, and continuous data using the t-test. The risk of asymptomatic parasitemia in the exposed and the unexposed groups will be estimated using Cox proportional hazards regression. Age, sex, BMI, and additional patient characteristics such as socioeconomic factors, HIV status, and hemoglobinopathies will be included in a multivariable model to adjust for confounding. Stratified analyses and interaction terms will be used to evaluate if metabolic syndrome modifies the risk. Age and sex-stratified analysis will also be performed.

• Study Type: Observational
• Enrollment (Actual): 406

Contacts and Locations

Study Locations

• Cameroon
  • Limbe, Cameroon
    • Limbe Regional Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

Adult patients with type 2 diabetes identified at the outpatient diabetes clinic of Limbe Regional Hospital will be invited to the study. Community comparators matched on age and sex will be identified in the patients' family or in the home community to control for exposure to similar malaria transmission.

Description

Inclusion Criteria: Age 21 years and above with diagnosis of type 2 diabetes -

Exclusion Criteria: pregnancy

-

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Type 2 diabetes; Individuals with type 2 diabetes followed by the diabetes clinic at Limbe hospital
Diabetes free; Community controls without diabetes, referred by the patients with diabetes. The unexposed individuals referred should have approximately the same age, be of same sex and health cathment area as the exposed individual

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
asymptomatic malaria	malaria parasites detected by RDT/microscopy/PCR	1 year follow up

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
symptomatic malaria	any symptomatic malaria detected during the study period , defined as symptoms such as fever, headache, body ache and positive microscopy and/or RDT	1 year follow up

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
schistosoma infection	detected schistosoma eggs in stool or urine by microscopy r PCR	1 year follow up
strongyloides infection	Ab against S ratti detected by ELISA	1 year follow up

Collaborators and Investigators

• Sponsor: Karolinska Institutet
• Collaborators: European Foundation for the Study of Diabetes; University of Dschang
• Investigators: Principal Investigator: Katja Wyss, PhD MD, Karolinska Institutet

Study record dates

Study Major Dates

• Study Start (Actual): September 21, 2023
• Primary Completion (Actual): March 19, 2025
• Study Completion (Actual): March 19, 2025

Study Registration Dates

• First Submitted: February 19, 2024
• First Submitted That Met QC Criteria: February 19, 2024
• First Posted (Actual): February 26, 2024

Study Record Updates

• Last Update Posted (Estimated): September 3, 2025
• Last Update Submitted That Met QC Criteria: August 26, 2025
• Last Verified: August 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Vector Borne Diseases; Mosquito-Borne Diseases; Endocrine System Diseases; Neoplasms; Metabolic Diseases; Immune System Diseases; Infections; Virus Diseases; Neoplasms by Histologic Type; Glucose Metabolism Disorders; Protozoan Infections; Parasitic Diseases; DNA Virus Infections; Lymphatic Diseases; Lymphoproliferative Disorders; Immunoproliferative Disorders; Lymphoma, Non-Hodgkin; Insulin Resistance; Hyperinsulinism; Lymphoma, B-Cell; Lymphoma; Epstein-Barr Virus Infections; Herpesviridae Infections; Tumor Virus Infections; Nutritional and Metabolic Diseases; Hemic and Lymphatic Diseases; Malaria; Metabolic Syndrome; Diabetes Mellitus; Burkitt Lymphoma
• Other Study ID Numbers: 2023/08/1545

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No