Project : YODA

The Young-Onset Diabetes in Sub-Saharan Africa (YODA) project is a landmark research initiative dedicated to decoding the unique biological and clinical characteristics of Type 1 Diabetes (T1D) in the African context. While global T1D guidelines are often based on Western populations, evidence suggests that the disease manifests differently in resource-limited settings like Cameroon and Uganda. By analyzing genetic susceptibility, pancreatic beta-cell function, and socioeconomic barriers, YODA bridges the knowledge gap between clinical research and patient survival. This project not only redefines our understanding of the African T1D phenotype but also advocates for sustainable access to insulin and life-saving diagnostic markers like C-peptide.

The characteristics of type 1 diabetes (T1D) in Africa, particularly sub-Saharan Africa, are not well understood. Most previous studies suggest that T1D in this region may differ from the classic form of the disease described in Western literature. Diagnosing T1D accurately in Africa is challenging due to the high prevalence of atypical forms of diabetes and limited resources.

Key differences from the Western phenotype include:

• The peak age of onset appears to be later, often after 18 to 20 years.
• Studies have reported lower rates of islet autoantibodies, ranging from 20% to 60%, among African people with T1D.
• Some research indicates a much higher level of retained endogenous insulin secretion, along with lower rates of genetic susceptibility to T1D and associated HLA haplotypes.
• The HLA DR3 haplotype seems to be more common than the HLA DR4 haplotype among people with T1D in sub-Saharan Africa.

Previous T1D studies in this region have been limited by small sample sizes and diverse methodologies. There is a lack of robust studies conducted soon after the onset of diabetes. Large-scale, prospective studies with standardized methods are essential to gain a deeper understanding of the T1D phenotype in sub-Saharan Africa.

The study was designed with three primary goals:

• Survival Analysis: To determine how endogenous insulin secretion and access to treatment influence survival rates for T1D patients in Cameroon.

• Phenotypic Characterization: To define the specific clinical and biological traits of T1D within the Cameroonian population.

• Cohort Establishment: To create a prospective research cohort that supports future efforts in optimizing diabetes care across Sub-Saharan Africa.

This is a multicenter cross-sectional study conducted in Cameroon and Uganda, with a planned total recruitment of 300 participants in Cameroon. Participants underwent a medical examination with assessment of socioeconomic status and determination of circulating postprandial C-peptide concentrations, islet autoantibodies and genetic susceptibility to type 1 diabetes. Next, a subset of 100 participants underwent a mixed meal tolerance test to assess pancreatic beta cell secretion. Finally, follow-up of type 1 diabetic patients at Changing Diabetes in Children (CDiC) clinics across the country assessed their survival.

As part of this project, we conducted a study to examine the mortality and low C-peptide levels in children and young adults with T1D in Cameroon. Among 313 participants, there were 23 deaths recorded over a period of 53 months. The primary causes of death were hypoglycemia (30.4%) and diabetic ketoacidosis (21.8%).

Nearly half of these deaths occurred outside of a hospital, which highlights the limited access to healthcare and insufficient follow-up.

A significant finding was that 73.9% of the deceased had very low C-peptide levels (less than 200 pmol/L), indicating a severe insulin deficiency and a high risk of complications. Furthermore, many of the deaths were among patients who were no longer enrolled in the free insulin provision program.

These results emphasize the critical need to improve diabetes education, ensure sustainable access to insulin, and use C-peptide as a prognostic marker to improve the survival of young T1D patients in resource-limited settings.

Funding

Katte, J., Mcdonald, T.J., Sobngwi, E., & Jones, A.G. (2023). The phenotype of type 1 diabetes in sub-Saharan Africa. Frontiers in Public Health, 11. [read more]

Katte, J., Squires, S., Dehayem, M.Y., Balungi, P.A., Padoa, C.J., Sengupta, D., Fatumo, S.A., Piloya, T., Nyangabyaki-Twesigye, C., Bahendeka, S.K., Majaliwa, E., Muze, K.C., Ramaiya, K.L., Sap, S., Motala, A.A., Pirie, F.J., Rheeder, P., van Dyk, J.C., Mbanya, J.C., Shields, B.M., Shah, A.S., Pihoker, C., Divers, J., Patel, K.A., Oram, R.A., Dabelea, D., Hattersley, A.T., McDonald, T.J., Crowther, N.J., Nyirenda, M., Sobngwi, E., & Jones, A.G. (2025). Non-autoimmune, insulin-deficient diabetes in children and young adults in Africa: evidence from the Young-Onset Diabetes in sub-Saharan Africa (YODA) cross-sectional study. The lancet. Diabetes & endocrinology. [read more]