Fasting insulin sensitivity indices are not better than routine clinical variables at predicting insulin sensitivity among Black Africans: a clamp study in sub-Saharan Africans

BACKGROUND: We aimed to evaluate the predictive utility of common fasting insulin sensitivity indices, and non-laboratory surrogates [BMI, waist circumference (WC) and waist-to-height ratio (WHtR)] in sub-Saharan Africans without diabetes. METHODS: We measured fasting glucose and insulin, and glucose uptake during 80/mU/m2/min euglycemic clamp in 87 Cameroonians (51 men) aged (SD) 34.6 (11.4) years. We derived insulin sensitivity indices including HOMA-IR, quantitative insulin sensitivity check index (QUICKI), fasting insulin resistance index (FIRI) and glucose-to-insulin ratio (GIR). Indices and clinical predictors were compared to clamp using correlation tests, robust linear regressions and agreement of classification by sex-specific thirds. RESULTS: The mean insulin sensitivity was M =10.5+/-3.2mg/kg/min. Classification across thirds of insulin sensitivity by clamp matched with non-laboratory surrogates in 30-48% of participants, and with fasting indices in 27-51%, with kappa statistics ranging from 0.10 to 0.26. Fasting indices correlated significantly with clamp (/r/=0.23-0.30), with GIR performing less well than fasting insulin and HOMA-IR (both p <0.02). BMI, WC and WHtR were equal or superior to fasting indices (/r/=0.38-0.43). Combinations of fasting indices and clinical predictors explained 25-27% of variation in clamp values. CONCLUSION: Fasting insulin sensitivity indices are modest predictors of insulin sensitivity measured by euglycemic clamp, and do not perform better than clinical surrogates in this population

Association between depression, glycaemic control and the prevalence of diabetic retinopathy in a diabetic population in Cameroon

Purpose: The prevalence of diabetes mellitus is increasing especially in low- and middle- income countries in which 75% of the world’s diabetic population reside. The macro- and microvascular complications of diabetes such as diabetic retinopathy are also set to increase in these populations. The relationship between depression and glycaemic control has been established in high- income countries, but evidence from low- and middle-income countries is scarce. This research aimed to determine an association between depression and glycaemic control and record the prevalence of diabetic retinopathy in a diabetic population in Cameroon. Methods: Analysis of cross-sectional data from the ‘Improving access to HbA1c measurements in sub-Saharan Africa’ study was used. Primary data were collected from six diabetic care facilities in Yaoundé, Cameroon. Participants were aged ≥ 18 years with at least a 6-month history of diabetes. Depression was assessed using the Centre for Epidemiological Studies Depression Scale (CES-D). A CES-D score ≥ 16 was used to identify the presence of clinically significant depressive symptoms. Data on glycaemic control were measured using HbA1c measurements at baseline. The presence of diabetic retinopathy was established through ophthalmoscopy and angiography using the Early Treatment Diabetic Retinopathy Study classification. Results: A total of 261 participants were included in the study, and information on depressive symptoms at baseline (CES-D score) were available for 240 participants. The results of the data analysis found that 60% of the study participants had clinically significant depressive symptoms (CES-D > 16). A weak non-significant positive correlation was found between CES-D score and HbA1c level (p = 0.46, r = 0.05) using the Pearson’s correlation co-efficient. Gender and attendance to a patient support group were significantly associated with the presence of clinically significant depressive symptoms. Poor glycaemic control (HbA1c > 7%) was found in 72.8% of the population. Educational level and insulin use were significantly associated with glycaemic control. The prevalence of diabetic retinopathy was 27.2% (23.4% non-proliferative, 2.5% pre- proliferative and 3.2% proliferative), and the prevalence of diabetic maculopathy was 10.0%. Conclusion: The study found that a large proportion of diabetic patients may be experiencing depressive symptoms for which they are currently not receiving treatment or support. We also found a large proportion to have poor glycaemic control that is known to worsen the vascular complications of diabetes. In light of the increasing epidemic of type 2 diabetes in sub-Saharan Africa, it is important that the recognition of depressive symptoms becomes integrated into future healthcare policies in the nations of sub-Saharan Africa. This research suggests that individuals experiencing depressive symptoms may be more likely to engage in patient support groups. These groups can be beneficial in providing patients with diabetes valuable information, which could lead to better glycaemic control

Effect of male circumcision on the prevalence of high-risk human papillomavirus in young men: results of a randomized controlled trial conducted in Orange Farm, South Africa.

International audienceBACKGROUND: A causal association links high-risk human papillomavirus (HR-HPV) and cervical cancer, which is a major public health problem. The objective of the present study was to investigate the association between male circumcision (MC) and the prevalence of HR-HPV among young men. METHODS: We used data from a MC trial conducted in Orange Farm, South Africa, among men aged 18-24 years. Urethral swab samples were collected during a period of 262 consecutive days from participants in the intervention (circumcised) and control (uncircumcised) groups who were reporting for a scheduled follow-up visit. Swab samples were analyzed using polymerase chain reaction. HR-HPV prevalence rate ratios (PRRs) were assessed using univariate and multivariate log Poisson regression. RESULTS: In an intention-to-treat analysis, the prevalences of HR-HPV among the intervention and control groups were 14.8% (94/637) and 22.3% (140/627), respectively, with a PRR of 0.66 (0.51-0.86) (P = .002). Controlling for propensity score and confounders (ethnic group, age, education, sexual behavior [including condom use], marital status, and human immunodeficiency virus status) had no effect on the results. CONCLUSIONS: This is the first randomized controlled trial to show a reduction in the prevalence of urethral HR-HPV infection after MC. This finding explains why women with circumcised partners are at a lower risk of cervical cancer than other women

Effect of HSV-2 serostatus on acquisition of HIV by young men: results of a longitudinal study in Orange Farm, South Africa.

International audienceBACKGROUND: The objectives of this study were to assess the impact among young men of herpes simplex virus type 2 (HSV-2) status on the acquisition of human immunodeficiency virus (HIV) and on the protective effect of male circumcision against HIV acquisition. METHODS: We used data collected during a male circumcision trial conducted in Orange Farm, South Africa. We estimated adjusted incidence rate ratios (IRRs) for HIV acquisition, using survival analysis and background characteristics, HSV-2 status, male circumcision status, and sexual behavior as covariates. RESULTS: Compared with subjects who remained HSV-2 negative throughout the study, subjects who were HSV-2 positive at enrollment had an adjusted IRR of 3.3 (95% confidence interval [CI], 1.5-7.4; P=.004), and those who became HSV-2 positive during follow-up had an adjusted IRR of 7.0 (95% CI, 3.9-12.4; P<.001). The population fraction of incident HIV infection attributable to HSV-2 was 27.8% (95% CI, 17.7%-37.2%). Intention-to-treat analysis of the protective effect of male circumcision on HIV acquisition was the same among men with and men without HSV-2 (0.38 vs. 0.37; P=.93). CONCLUSIONS: This study shows that HSV-2 has a substantial impact on HIV acquisition among young South African men. It suggests that HSV-2 infection enhances HIV acquisition and is responsible for approximately 25% of incident cases of HIV infection. However, the protective effect of male circumcision against HIV acquisition appears independent of HSV-2 serostatus. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT00122525

Poor glycemic control in type 2 diabetes in the South of the Sahara: the issue of limited access to an HbA1c test

International audienceBackgroundManagement of type 2 diabetes remains a challenge in Africa. The objective of this study was to evaluate the prevalence and predictors of poor glycemic control in patients with type 2 diabetes living in sub-Saharan.Patients and methodsThis was a cross-sectional study involving 1267 people (61% women) with type 2 diabetes (mean age 58 years) recruited across health facilities in Cameroon and Guinea. Predictors of poor glycemic control (HbA1c ≥7.0% (53 mmol/mol)) were investigated via logistic regressions.ResultsThe mean body mass index was 27.4 ± 5.8 kg/m2, and 74% of patients had poor glycemic control. Predictors of poor glycemic control in multivariable regression models were recruitment in Guinea [odd ratio: 2.91 (95% confidence interval 2.07 to 4.11)], age <65 years [1.40 (1.04 to 1.88)], diabetes duration ≥3 years [2.36 (1.74 to 3.21)], treatment with: oral glucose control agents [3.46 (2.28 to 5.26)], insulin alone or with oral glucose control agents [7.74 (4.70 to 12.74)] and absence of a previous HbA1c measurement in Guinea [2.96 (1.30 to 6.75)].ConclusionPoor control of blood glucose is common in patients with type 2 diabetes in these two countries. Limited access to HbA1c appears to be a key factor associated with poor glycemic control in Guinea, and should be addressed by health policies targeting improvement in the outcomes of diabetes care

Table_1_Gestational diabetes mellitus in Cameroon: prevalence, risk factors and screening strategies.pdf

BackgroundThe 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.MethodsWe 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.FindingsGDM prevalence was 5·9%, 17·7%, and 11·0% using WHO, IADPSG, and NICE criteria, respectively. Previous stillbirth [odds ratio: 3·14, 95%CI: 1·27-7·76)] was the main correlate of GDM. The optimal cut-points to diagnose WHO-defined GDM were 5·9 mmol/L for RPG (c-statistic 0·62) and 7·1 mmol/L for 1-hour 50g GCT (c-statistic 0·76). The same cut-off value for RPG was applicable for IADPSG-diagnosed GDM while the threshold was 6·5 mmol/L (c-statistic 0·61) 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 66·9 and 41·0% of the cases.InterpretationGDM 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.</p

Image_1_Gestational diabetes mellitus in Cameroon: prevalence, risk factors and screening strategies.jpeg

BackgroundThe 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.MethodsWe 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.FindingsGDM prevalence was 5·9%, 17·7%, and 11·0% using WHO, IADPSG, and NICE criteria, respectively. Previous stillbirth [odds ratio: 3·14, 95%CI: 1·27-7·76)] was the main correlate of GDM. The optimal cut-points to diagnose WHO-defined GDM were 5·9 mmol/L for RPG (c-statistic 0·62) and 7·1 mmol/L for 1-hour 50g GCT (c-statistic 0·76). The same cut-off value for RPG was applicable for IADPSG-diagnosed GDM while the threshold was 6·5 mmol/L (c-statistic 0·61) 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 66·9 and 41·0% of the cases.InterpretationGDM 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.</p