Dynamics in the Prevalence of Insulin Resistance between 2005 and 2023 in Type 2 Diabetics in South Kivu in the East of the Democratic Republic of Congo: Cross-Sectional Studies

Aim: Sub-Saharan Africa is undergoing an epidemiological transition responsible for a change in the metabolic profile in favour of insulin resistance. The aim of this study was to assess the dynamics of the prevalence of insulin resistance and associated risk factors in diabetic patients in the Democratic Republic of Congo between 2005 and 2023. Method: We measured fasting blood glucose and insulin levels and looked for metabolic syndrome parameters (2009 criteria) in type 2 diabetes patients in 2005-2008 (n = 176) and in 2018-2023 (n = 303). The HOMA model was used to measure insulin sensitivity and islet β-cell secretory function. Results: Between 2005 and 2013, the trend was towards an increase in the prevalence of insulin resistance (from 13.1% to 50.8%;p Conclusion: This present study shows an increase in insulin resistance in Congolese urban areas and a persistence of atypical diabetes mellitus in Congolese rural areas, confirming the particularity of the pathophysiology of the disease in African areas currently influenced by the epidemiological transition. Further studies using an appropriate methodology are required.

Vitamin D, Parathyroid Hormone, Insulin Sensitivity and Islet β-Cell Secretory Function in Diabetic Patients from South Kivu in the Democratic Republic of Congo: Cross-Sectional Study

Background: The role of vitamin D and parathyroid hormone in the metabolic profile of type 2 diabetes mellitus in sub-Saharan Africa has not been adequately assessed. The aim of this study was to determine the prevalence of low vitamin D level and secondary hyperparathyroidism and their association with insulin sensitivity and β-cell secretory function among Congolese type 2 diabetics. Methodology: Fasting glycaemia, fasting insulin, 25OH D3 and human parathyroid hormone (hPTH) were measured in one hundred and eighty-four type 2 diabetic patients followed as outpatients in South Kivu. Levels of 25OH D3 65 pg/ml defined low vitamin D and elevated parathyroid hormone levels, respectively. The HOMA model was used to measure insulin sensitivity and β-cell secretory function. Results: Medians (IQR) were 25.3 (20.4 - 32.4) ng/ml for 25OH D3 and 53.7 (38.4 - 115.7) pg/ml for hPTH. 58.7% of diabetics had insulin resistance, 126 (68.5%) had low vitamin D and 80 (43.5%) had hyperparathyroidism. In multivariate analysis, hPTH (partial r = −0.28;p = 0.0002) and 25OH D3 (partial r = 0.16;p = 0.03) showed an independent association with insulin sensitivity after adjustment for body mass index and waist circumference. Finally, hPTH (partial r = 0.27;p = 0.0002) was the sole determinant of β-cell secretory function. Conclusions: This study confirms the high prevalence of low vitamin D level and secondary hyperparathyroidism and their association with insulin resistance and impaired islet β-cell secretory function among Congolese with type 2 diabetes mellitus. Vitamin D and calcium supplementation should be envisaged for cases of deficiency in this region.

Association between Metabolic Syndrome Components and Serum High-Sensitivity C-Reactive Protein or Interleukin-6 Levels among Congolese Adults

Metabolic syndrome (MetS) and its components have been linked to elevated serum levels of inflammatory biomarkers such as C-reactive protein, interleukin-6, interleukin-1β and tumor necrosis factor alpha. The aim of our study was to address the association between MetS components with serum hs-CRP and IL-6 levels among Congolese adults. A total of 357 participants (aged 30 - 87 years) were included in this cross-sectional study. Anthropometrics were collected and fasting blood sampled for assessment of fasting blood glycaemia (FBG), lipids and inflammatory parameters using commercially available assays. NCEP-ATPIII criteria were used to define MetS. The Median (IQR) hs-CRP and IL-6 levels were higher in participants with MetS than in those without ([7 (4, 14) versus 6 (4, 8)] mg/L;p = 0.092 and [23.8 (20.9, 27.6) versus 22.3 (19.5, 25.0)] pg/mL;p = 0.002). hs-CRP and IL-6 levels were significantly higher in females with MetS than in those without, but not in males. Among participants, only TG was correlated with hs-CRP (r = 0.149, p = 0.007), and a significant correlation was observed between TG (r = 0.116, p = 0.037), FBG (r = 0.208, p = 0.000), HDL-C (r = −0.119, p = 0.034) and SBP (r = 0.143, p = 0.010) and IL-6. In males, hs-CRP levels were positively correlated with TG (0.316;p = 0.000), negatively with HDL-C (r = −0.290, p = 0.0022), without such correlations in females. In Ames, IL-6 levels were positively correlated with FBG (r = 0.202;p = 0.035), and negatively with HDL-C (r = −0.249, p = 0.009). Significant correlations between IL-6 levels and FBG (r = 0.214;p = 0.000) or SBP (r = 0.227, p = 0.000) were observed in females. Logistic regression analysis was carried out to identify the relationship between MetS components and hs-CRP or IL-6. Values of area under receiver-operating characteristic (ROC) curves suggest potential use of serum hs-CRP (AUC = 0.675) and IL-6 (AUC = 0.656) as diagnostic biomarkers of MetS. Combination of hs-CRP and IL-6 improved diagnosis accuracy, yielding a 0.698 ROC curve area. MetS components are associated with hs-CRP and IL-6 levels among adults Congolese. Combining the two biomarkers hs-CRP and IL-6 improves Mets diagnostic accuracy compared to hs-CRP or IL-6 alone.

Prevalence and Risk Factors of Diabetes Mellitus in the Adult Population of Porto-Novo (Benin)

Introduction: The aim of this study was to determine the prevalence and risk factors of diabetes mellitus in the adult population of Porto-Novo. Methods: A cross-sectional study with random sampling, stratified cluster, was used. Fasting blood glucose was measured in capillary blood (Accu-Chek Active). Diabetes mellitus was defined as fasting glucose ≥ 1.26 g/L, and fasting hyperglycemia in non-diabetic fasting glucose ≥ 1.10 and < 1.26 g/L. Results: The survey involved 240 individuals. The sex ratio was 0.48. The mean age was 46 ± 13 years (range 25 - 80 years). The prevalence of hyperglycemic patients was 7.9%. The prevalence of diabetes was 6.7%, including 3.3% of unknown diabetes, half of diabetics. The prevalence of fasting hyperglycemia without diabetes was 1.2%. The risk factors for diabetes type 2 onset were a family history of diabetes (p = 0.017), older age (p = 0.003), hypertension (p = 0.005) and abdominal obesity (NCEP: p = 0.044;FID: p = 0.001). Conclusion: These high figures confirm the increasing prevalence of diabetes mellitus in Benin, documented in many developing countries.