Major Ethnic Differences Seen in Early-Onset Type 2 Diabetes

TOPLINE:
There are major phenotypic differences in early-onset (diagnosed at < 40 years) type 2 diabetes (T2D) between adult Black Ugandans and White Europeans with recently diagnosed diabetes.
Obesity is central to the pathogenesis of early-onset T2D in White Europeans, but is insignificant in adult Ugandans.
Pancreatic beta-cell dysfunction appears to explain the early onset of T2D in the Ugandan population.
METHODOLOGY: 
In the Uganda Diabetes Phenotype (UDIP) study cohort of 500 adult Ugandans and the UK StartRight study cohort of 714 White Europeans with recently diagnosed islet autoantibody-negative T2D, phenotypic characteristics were compared in people with early-onset vs late-onset (diagnosed at ≥ 40 years) T2D.
There were 113 White Europeans and 134 Black Ugandans with early-onset T2D.
TAKEAWAY:
In the White European group, those with early vs late onset were more often female (52.2% vs 39.1%; P = .01), had higher body mass index (BMI; 36.7 kg/m2 vs 33.0 kg/m2; P < .001), larger waist circumference (112.4 cm vs 108.8 cm; P = .06), and higher frequency of obesity (82.3% vs 63.4%; P < .001).
In contrast, among the Ugandan participants, those with early vs late T2D onset had lower waist circumference (93.1 cm vs 97.4 cm; P = .006), but there were no differences in the proportion of females (53.0% vs 57.9% female; P = .32), obesity (32.6% vs 35.2%; P = .48), or BMI (27.3 kg/m2 vs 27.9 kg/m2; P = .29).
In both ethnic groups, those with early-onset T2D had non-significantly higher genetic risk scores for T2D compared with late onset (P = .09 for Ugandan and P = .08 for White Europeans).
IN PRACTICE:
“An in-depth understanding of the phenotype of early-onset T2D in Black African and White European populations is important and has significant clinical and therapeutic implications. Because of these phenotypic differences, the therapeutic and preventive strategies for early-onset T2D should be tailored to ethnicity and population,” the authors wrote.
SOURCE:
Conducted by Davis Kibirige, MD, PhD, of Non-Communicable Diseases Theme, Medical Research Council/Uganda Virus Research Institute and London School of Hygiene and Tropical Medicine Uganda Research Unit, Entebbe, Uganda, and Department of Medicine, Uganda Martyrs Hospital Lubaga, Kampala, Uganda, and colleagues, the study was published online August 29, 2024, in BMJ Open Diabetes Research & Care.
LIMITATIONS:
Designs differed between the two studies. Ugandan participants were recruited only from seven secondary hospitals, whereas StartRight recruited from combined primary and secondary healthcare.
DISCLOSURES:
The UDIP study was supported by the UK Medical Research Council and the UK Department for International Development, and the National Institute for Health and Care Research (NIHR). The StartRight study was funded by the NIHR and Diabetes UK. Genetic analysis for the StartRight study was funded by the European Foundation for the Study of Diabetes. Jean-Claude Katte is supported by the NIHR Exeter Biomedical Research Centre.
 
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