UP Professor Paul Rheeder Co-Authors Lancet Study on Novel Non-Autoimmune Diabetes Variant in Africa

Breakthrough in Understanding Youth-Onset Diabetes in Sub-Saharan Africa

The landmark Young-Onset Diabetes in sub-Saharan Africa (YODA) study has unveiled a previously unrecognized subtype of diabetes affecting children and young adults across the continent. Published in the prestigious The Lancet Diabetes & Endocrinology on July 21, 2025, this cross-sectional research challenges long-held assumptions about type 1 diabetes (T1D) diagnosis and management in resource-limited settings. Led by an international team, the study analyzed nearly 900 participants from Cameroon, Uganda, and South Africa, revealing that approximately 65% of those clinically diagnosed with T1D lack the hallmark islet autoantibodies and exhibit low genetic risk scores typically associated with autoimmune T1D.

This non-autoimmune, insulin-deficient diabetes subtype presents with severe beta-cell failure, requiring lifelong insulin therapy, yet does not fit neatly into traditional type 2 diabetes (T2D) categories due to the young age at onset and absence of obesity. The findings underscore the heterogeneity of diabetes in Africa, where environmental factors like infections, nutrition, or genetics may play pivotal roles. For South African higher education institutions, this discovery highlights the critical contributions of local academics in global health research.

The YODA Study: Methodology and Scope

The YODA project represents the largest investigation to date into young-onset diabetes in sub-Saharan Africa. Researchers recruited 1,072 insulin-treated individuals under 30 years old with a body mass index (BMI) below 30 kg/m² from outpatient clinics in three countries. After exclusions for incomplete data, 894 participants were analyzed, ensuring a robust sample reflective of real-world clinical presentations.

Key assessments included:

• Islet autoantibodies (GADA, IA-2A, ZnT8A) via enzyme-linked immunosorbent assay (ELISA), with positivity thresholds calibrated against local controls.
• Genetic risk scores (GRS) for T1D using 67 single nucleotide polymorphisms (SNPs), compared to African ancestry databases like the Uganda Genome Resource and AWI-Gen.
• Random plasma C-peptide levels to gauge endogenous insulin production, defining severe deficiency as below 200 pmol/L.

Comparisons were drawn with the U.S.-based SEARCH for Diabetes in Youth study, involving Black and White participants, to contextualize findings globally. Statistical methods employed chi-squared tests and Mann-Whitney U for group differences, confirming significant distinctions (p < 0.0001 for GRS between autoantibody-positive and negative groups).

Key Findings: A Tale of Two Diabetes Subtypes

The study delineated two distinct profiles among African youth:

• Autoimmune T1D (34.9%, n=312): Positive for autoantibodies (primarily GADA at 28.8%), elevated T1D GRS (mean 11.76), and profound insulin deficiency (82.7% C-peptide <200 pmol/L). This mirrors classic T1D seen worldwide.
• Non-Autoimmune Insulin-Deficient Diabetes (65.1%, n=582): Autoantibody-negative, lower T1D GRS (9.66), yet 65.9% had severe C-peptide deficiency. No enrichment in T2D GRS, ruling out misclassified T2D. Prevalent even in recent-onset cases (<20 years duration: 55.1%).

Interestingly, 15.1% of Black U.S. T1D patients shared this profile, versus 9.3% Whites, hinting at ancestry-linked factors. No classic malnutrition diabetes in adulthood (MDA) signatures like stunting or rural predominance were evident, prompting exploration of novel etiologies such as viral triggers or metabolic insults.

Professor Paul Rheeder's Pivotal Role at University of Pretoria

Professor Paul Rheeder, from UP's Department of Internal Medicine at Steve Biko Academic Hospital and Director of the UP Diabetes Research Centre, played a key role in the South African cohort. His longstanding expertise in diabetes epidemiology and management in low-resource settings was instrumental. Collaborating with peers from the University of the Witwatersrand (Wits) and University of KwaZulu-Natal (UKZN), Rheeder helped recruit patients and interpret data reflective of South Africa's diverse population.

"Differentiating between Type 1 and Type 2 diabetes at presentation has always been a challenge," Rheeder noted. "This research shows people could still be Type 1 without antibodies, with critical implications for treatment." His contributions extend UP's legacy in translational research, fostering postgraduate training in molecular diagnostics and endocrinology. For aspiring researchers, opportunities abound at higher-ed-jobs in South African universities like UP.

Diabetes Burden in South Africa: Context and Statistics

South Africa grapples with one of Africa's highest diabetes prevalences, affecting 4.58 million adults (12.7% of 20-79 year-olds in 2019), with 52.4% undiagnosed per IDF Atlas. Type 1 diabetes grows at 6.2% annually versus 4% for T2D. Young-onset cases strain public health systems, where insulin access is limited—only 1 in 4 T1D patients achieve glycemic control.

In the YODA South African arm, the non-autoimmune subtype predominates, mirroring continental trends. A prior study at Life Groenkloof Hospital found 86.1% T1D diagnoses pre-25 years, underscoring urgency. Broader impacts include higher complication rates: retinopathy (30%), nephropathy (20%), exacerbated by poverty and HIV co-epidemics.

UP's Tshwane Insulin Project exemplifies local interventions, improving care in underserved communities through research-driven protocols.

Implications for Clinical Practice and Policy in Africa

Resource constraints preclude routine autoantibody or genetic testing in most African clinics. Rheeder emphasizes reliance on demographics, symptoms, and glucose: "Clinicians must recognize not all insulin-dependent youth diabetes is autoimmune." Misclassification risks suboptimal therapy—non-autoimmune cases may respond to oral agents or prevention targeting triggers.

Policy shifts could include:

• Revised WHO/ADA classification incorporating African subtypes.
• Enhanced insulin supply via universal health coverage like SA's NHI.
• Research funding for etiology (e.g., enteroviruses, malnutrition-modifiers).

Acknowledging ancestry effects, U.S. parallels suggest global relevance for African diaspora health. For more on diabetes career paths, explore higher-ed-career-advice.

Broader Research Landscape and Collaborations

YODA exemplifies pan-African academic synergy, funded by MRC/Wellcome and partners. South African contributions from Wits' Sydney Brenner Institute advanced genetic analyses. UP's Diabetes Research Centre, under Rheeder, integrates clinical trials with public health, publishing on insulin barriers and T2D control.

Related studies: LEADS Center (CU Anschutz) links subtypes to ancestry; prior African data showed 20-60% autoantibody negativity versus 70-95% globally. Future YODA phases target longitudinal tracking and interventions.

South African universities drive diabetes innovation—Wits leads HIV-diabetes intersections, UKZN focuses on ketosis-prone variants. Rate professors like Rheeder on rate-my-professor to support academic excellence.

Challenges and Future Directions

Persistent hurdles: diagnostic delays, insulin shortages (SA imports 90%), high youth mortality (20-50% by adulthood). Non-autoimmune subtype demands etiology probes—viral, epigenetic, or nutritional?

Optimism lies in genomics: African biobanks like AWI-Gen enable precision medicine. UP/Wits train next-gen researchers via PhD programs in endocrinology.

Stakeholder views: IDF Africa praises "game-changer for classification"; SA Diabetes Association calls for antibody testing pilots.

Impact on Higher Education and Research Careers

This publication elevates SA's global profile, attracting funding and talent. UP's involvement showcases interdisciplinary prowess—medicine, genetics, epidemiology. For students, it opens doors in diabetes research, vital amid SA's 24 million regional cases projection by 2045.

Actionable insights: Pursue fellowships at UP's centre; leverage YODA for theses. Explore university-jobs in health sciences or higher-ed-jobs/faculty positions.

Photo by Mbuso Mothiba on Unsplash

Conclusion: Paving the Way for Tailored Diabetes Care

The YODA/Lancet study, bolstered by UP Professor Paul Rheeder's expertise, redefines diabetes in Africa, urging nuanced diagnostics and therapies. As SA universities lead, expect innovations reducing burdens. Aspiring academics, join the fight—check higher-ed-jobs, rate-my-professor, higher-ed-career-advice, and university-jobs for opportunities. Africa's diabetes narrative evolves, promising better futures.