The incidence of type 2 diabetes is growing rapidly, not only in developed countries but also worldwide. We chose to study type 2 diabetes in West Africa, where diabetes is less common than in the U.

A total of 2,570 apparently healthy human immunodeficiency virus-negative adults from the six geopolitical zones in the country were enrolled in our study in 2006. The samples were assayed using the Cyflow technique. Data were analyzed using the Statistical Package for Social Scientists (SPSS). The majority (64%) of the participants had CD4 counts within the range of 501 to 1,000 cells/l. The reference range for CD4 was 365 to 1,571 cells/l, while the reference range for CD8 was 145 to 884 cells/l.In Nigeria, although country-specific reference ranges for some hematological measures have been determined (3,5,6), national data for CD4 reference values are still not available. Prior to a few recent monocenter studies carried out among defined populations of healthy Nigerians (2, 13), CD4 reference range values from literature based on studies in western countries were largely employed for clinical decision making.However, as the access to treatment increased in Nigeria, it became critically necessary to determine on a national level the reference values for CD4 cell counts and the factors that may affect it. This was necessary to inform the clinicians of the required minimal range for the initiation of antiretroviral therapy, and also for accurate monitoring of responses to therapy and other treatment outcomes.The national study reported in this document was a multicenter study conducted among healthy human immunodeficiency virus (HIV)-negative adult Nigerians, in eight sites across the six geopolitical zones of the country. Therefore, the objective of this study was to establish the normal reference values of CD4 and CD8, as well as CD4/CD8 lymphocyte ratios, indigenous to Nigeria.This project was carried out as a cross-sectional study among apparently healthy Nigerians aged 18 years and older who tested HIV negative at voluntary counseling and testing site sites. Exclusion criteria included pregnancy, sickle cell anemia, or clinical illness.A 5-ml sample of blood was collected from each participant by venipuncture into a Vacutainer EDTA bottle. These samples were retested using the Genie II kit (Bio-Rad), which is a rapid HIV serology test kit. Only samples that were confirmed negative were assayed for CD4 and CD8 cell counts concurrently using the Cyflow technique, with an instrument known as the Cyflow counter (Partec). This instrument is for counting and analyzing particles and cells. The first step in the measurement of cells is staining with a fluorescent dye. The fluorescent molecules are taken up by the cells. The cells are individually illuminated by light of a defined wavelength. The light activates the fluorescent molecules so that they emit light of a characteristic color (wavelength). This fluorescent light is filtered out, and its intensity is measured by a ploidy analyzer for each single cell. The fluorescence light intensity emitted by a labeled cell is proportional to its CD4 or CD8 content. For cell counting or concentration determination, the sample volume detector measures exactly 0.2 ml of th...

BackgroundContext-specific evidence of the spectrum of type 2 diabetes (T2D) burden is essential for setting priorities and designing interventions to reduce associated morbidity and mortality. However, there are currently limited data on the burden of T2D complications and comorbidity in sub-Saharan Africa (SSA).MethodsT2D complications and comorbidities were assessed in 2,784 participants with diabetes enrolled from tertiary health centres and contextualised in 3,209 individuals without diabetes in Nigeria, Ghana and Kenya. T2D complications and comorbidities evaluated included cardiometabolic, ocular, neurological and renal characteristics.FindingsThe most common complications/comorbidities among the T2D participants were hypertension (71%; 95% CI 69–73), hyperlipidaemia (34%; 95% CI 32–36), and obesity (27%; 95% CI 25–29). Additionally, the prevalence of cataracts was 32% (95% CI 30–35), diabetic retinopathy 15% (95% CI 13–17), impaired renal function 13% (95% CI 12–15), and erectile dysfunction (in men) 35% (95% CI 32–38). T2D population-attributable fraction for these comorbidities ranged between 6 and 64%.InterpretationThe burden of diabetes complications and comorbidity is substantial in SSA highlighting the urgent need for innovative public health strategies that prioritise promotion of healthy lifestyles for prevention and early detection of T2D. Also needed are strategies to strengthen health care system capacities to provide treatment and care for diabetes complications.

Genome analysis of diverse human populations has contributed to the identification of novel genomic loci for diseases of major clinical and public health impact. Here, we report a genome-wide analysis of type 2 diabetes (T2D) in sub-Saharan Africans, an understudied ancestral group. We analyze ~18 million autosomal SNPs in 5,231 individuals from Nigeria, Ghana and Kenya. We identify a previously-unreported genome-wide significant locus: ZRANB3 (Zinc Finger RANBP2-Type Containing 3, lead SNP p = 2.831 × 10 −9 ). Knockdown or genomic knockout of the zebrafish ortholog results in reduction in pancreatic β-cell number which we demonstrate to be due to increased apoptosis in islets. siRNA transfection of murine Zranb3 in MIN6 β-cells results in impaired insulin secretion in response to high glucose, implicating Zranb3 in β-cell functional response to high glucose conditions. We also show transferability in our study of 32 established T2D loci. Our findings advance understanding of the genetics of T2D in non-European ancestry populations.

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