The phenotype of type 1 diabetes in sub-Saharan Africa

This is the final version. Available from Frontiers Media via the DOI in this record. The phenotype of type 1 diabetes in Africa, especially sub-Saharan Africa, is poorly understood. Most previously conducted studies have suggested that type 1 diabetes may have a different phenotype from the classical form of the disease described in western literature. Making an accurate diagnosis of type 1 diabetes in Africa is challenging, given the predominance of atypical diabetes forms and limited resources. The peak age of onset of type 1 diabetes in sub-Saharan Africa seems to occur after 18-20 years. Multiple studies have reported lower rates of islet autoantibodies ranging from 20 to 60% amongst people with type 1 diabetes in African populations, lower than that reported in other populations. Some studies have reported much higher levels of retained endogenous insulin secretion than in type 1 diabetes elsewhere, with lower rates of type 1 diabetes genetic susceptibility and HLA haplotypes. The HLA DR3 appears to be the most predominant HLA haplotype amongst people with type 1 diabetes in sub-Saharan Africa than the HLA DR4 haplotype. Some type 1 diabetes studies in sub-Saharan Africa have been limited by small sample sizes and diverse methods employed. Robust studies close to diabetes onset are sparse. Large prospective studies with well-standardized methodologies in people at or close to diabetes diagnosis in different population groups will be paramount to provide further insight into the phenotype of type 1 diabetes in sub-Saharan Africa.National Institute for Health Research (NIHR

Gestational diabetes mellitus in Cameroon: prevalence, risk factors and screening strategies

Copyright \ua9 2024 Sobngwi, Sobngwi-Tambekou, Katte, Echouffo-Tcheugui, Balti, Kengne, Fezeu, Ditah, Tchatchoua, Dehayem, Unwin, Rankin, Mbanya and Bell.Background: The burden of gestational diabetes (GDM) and the optimal screening strategies in African populations are yet to be determined. We assessed the prevalence of GDM and the performance of various screening tests in a Cameroonian population. Methods: We carried out a cross-sectional study involving the screening of 983 women at 24-28 weeks of pregnancy for GDM using serial tests, including fasting plasma (FPG), random blood glucose (RBG), a 1-hour 50g glucose challenge test (GCT), and standard 2-hour oral glucose tolerance test (OGTT). GDM was defined using the World Health Organization (WHO 1999), International Association of Diabetes and Pregnancy Special Group (IADPSG 2010), and National Institute for Health Care Excellence (NICE 2015) criteria. GDM correlates were assessed using logistic regressions, and c-statistics were used to assess the performance of screening strategies. Findings: GDM prevalence was 5\ub79%, 17\ub77%, and 11\ub70% using WHO, IADPSG, and NICE criteria, respectively. Previous stillbirth [odds ratio: 3\ub714, 95%CI: 1\ub727-7\ub776)] was the main correlate of GDM. The optimal cut-points to diagnose WHO-defined GDM were 5\ub79 mmol/L for RPG (c-statistic 0\ub762) and 7\ub71 mmol/L for 1-hour 50g GCT (c-statistic 0\ub776). The same cut-off value for RPG was applicable for IADPSG-diagnosed GDM while the threshold was 6\ub75 mmol/L (c-statistic 0\ub761) for NICE-diagnosed GDM. The optimal cut-off of 1-hour 50g GCT was similar for IADPSG and NICE-diagnosed GDM. WHO-defined GDM was always confirmed by another diagnosis strategy while IADPSG and GCT independently identified at least 66\ub79 and 41\ub70% of the cases. Interpretation: GDM is common among Cameroonian women. Effective detection of GDM in under-resourced settings may require simpler algorithms including the initial use of FPG, which could substantially increase screening yield

Type 1 diabetes in sub-Saharan Africa: understanding aetiology and survival

Type 1 diabetes is a chronic autoimmune disease characterised by severe endogenous insulin deficiency resulting from the progressive destruction of insulin-secreting beta cells of the pancreatic islets. The detection of one or more circulating islet autoantibodies is fundamental in confirming the diagnosis of the condition. Type 1 diabetes has been poorly characterised in Africa, especially in sub-Saharan Africa, due to the lack of robust observational data. Previous studies conducted amongst young people in sub-Saharan Africa have reported an atypical phenotype suggesting a non-autoimmune aetiology. Whether this is true is uncertain as many of these previous studies were limited by small sample sizes and the use of non-standardised methods. Examining the phenotype and aetiology of type 1 diabetes in African populations will be fundamental in providing insights into the progression of the disease and strategies for prevention and treatment. Furthermore, type 1 diabetes is historically associated with high mortality in the African continent. The mortality is thought to be highest amongst young children and those close to diabetes diagnosis. Whether high mortality introduces a survival bias with the possible enrichment of a particular phenotype of diabetes has not been previously studied. The aim of this thesis is to examine the phenotype and aetiology of diabetes amongst young people with a clinician diagnosis of type 1 diabetes in sub-Saharan Africa. The thesis also seeks to investigate the association between the phenotype of diabetes and survival in sub-Saharan Africa. In Chapter 1, we present an overview of type 1 diabetes and review current evidence on the phenotype of type 1 diabetes in sub-Saharan Africa. We also describe the datasets and clinical studies used in the subsequent chapters of this thesis. In Chapter 2, we describe the clinical utility of the urinary C-peptide to creatinine ratio in assessing endogenous insulin secretion in patients with diabetes in Cameroon and demonstrate that the use of home meal stimulation may not be appropriate in this setting. In Chapter 3, we describe the performance of home-collected dried blood spot C-peptide measurements in assessing endogenous insulin secretion in people with young-onset diabetes in Cameroon. We show that simple dried blood spot C-peptide measurements provide a robust method of assessing endogenous insulin secretion in this population. In Chapter 4, we examine the phenotype and markers of type 1 diabetes aetiology in people with a clinician diagnosis of type 1 diabetes in Cameroon. We show that most young people diagnosed with type 1 diabetes likely have atypical non-autoimmune diabetes and do not have features suggestive of autoimmune type 1 or type 2 diabetes. In Chapter 5, we examine the mortality rate within a group of children and adolescents with a clinician diagnosis of type 1 diabetes in Cameroon. We demonstrate that mortality was substantially high and mainly associated with place of care and education. Chapter 6 presents an overview of the main findings, conclusions, limitations, and perspectives for future research generated by this thesis

Mortality amongst children and adolescents with type 1 diabetes in sub-Saharan Africa: The case study of the Changing Diabetes in Children program in Cameroon.

This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record Data availability statement: The data that support the findings of this study are available from the corresponding author upon reasonable request.INTRODUCTION: Type 1 diabetes in Africa has been associated with high mortality attributed mainly to poor insulin access. Free insulin provision programs for people with type 1 diabetes have been introduced across Africa recently. We aimed to determine the mortality rate and associated factors in a cohort of children and adolescents with type 1 diabetes who receive free insulin treatment in sub-Saharan Africa. METHODS: We conducted a retrospective analysis using the Changing Diabetes in Children (CDiC) medical records in Cameroon between 2011 and 2015. RESULTS: The overall mortality rate was 33.0 per 1000 person-years (95% CI 25.2-43.2). Most deaths (71.7%) occurred outside of the hospital setting, and the cause of death was known only in 13/53 (24.5%). Mortality was substantially higher in CDiC participants followed up in regional clinics compared to the main urban CDiC clinic in Yaounde; 41 per 1000 years (95% CI 30.8-56.0) versus 17.5 per 1000 years (95% CI 9.4-32.5), and in those with no formal education compared to those who had some level of education; 68.0 per 1000 years (95% CI 45.1-102.2) versus 23.6 per 1000 years (95% CI 16.5-33.8). In Cox proportional multivariable analysis, urban place of care (HR = 0.23, 95% CI 0.09-0.57; p = 0.002) and formal education (HR = 0.42, 95% CI 0.22-0.79; p = 0.007) were independently associated with mortality. CONCLUSION: Despite free insulin provision, mortality remains high in children and adolescents with type 1 diabetes in Cameroon and is substantially higher in rural settings and those with no formal education.National Institute for Health Research (NIHR