Adiponectin levels and its relation with insulin secretion and insulin sensitivity in a group of sub-Saharan African women with polycystic ovary syndrome.

Low levels of adiponectin have been reported in Polycystic Ovary Syndrome (PCOS). In sub-Saharan Africa, little data are available on the topic. We aimed to investigate the levels of adiponectin and its relation with insulin secretion and insulin sensitivity in women with PCOS in Yaoundé, Cameroon. A comparative cross-sectional study was conducted in 32 women presenting PCOS and 32 controls matched for age and Body Mass Index. For each participant, adiponectin levels were measured. We estimated insulin sensitivity using Homeostasis model index (HOMA-IR) and insulin secretion with C-peptide levels. Women with PCOS had higher insulin secretion levels than controls (C-peptide: 4.98 ± 3.83 vs 3.25 ± 1.62 mUI/l; p = 0.02). Also, the HOMA-IR index was higher compared to that of women without PCOS (1.15 ± 0.90 vs 0.77 ± 0.38; p = 0.03) suggesting greater insulin resistance. The median [25th-75th percentile] values of adiponectin concentrations were similar between the two groups (22.68 [21.72-23.41] μg/ml vs 22.03 [21.40-22.93] μg/ml; p = 0.1). There was no association between insulin sensitivity and adiponectin levels in the PCOS group. PCOS is not associated with changes in adiponectin in a population of sub-Saharan African women. Further studies are needed to shed more light on this condition

Erratum to: Investigation of the association between the TCF7L2 rs7903146 (C/T) gene polymorphism and obesity in a Cameroonian population: a pilot study

Upon publication of the original article [1], it was noticed that the author\u2019s name \u201cJean Jacques Noubiap\u201d was incorrectly given as \u201cJean Jacques N. Noubiap\u201d. This has now been acknowledged and corrected in this erratum

Investigation of the association between the TCF7L2 rs7903146 (C/T) gene polymorphism and obesity in a Cameroonian population: a pilot study

Objective: This study aimed at investigating the association between the rs7903146 (C/T) polymorphism of the TCF7L2 gene with obesity in a Cameroonian population. Method: This was a case-control pilot study including 61 obese and 61 non-obese Cameroonian adults. Anthropometric indices of obesity, blood pressure, fasting blood glucose, and blood lipids were measured. The rs7903146 (C/T) polymorphism of the TCF7L2 gene was genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), and genotypes were correlated with clinical and biological parameters. Results: The T allele was predominant in the study population with a frequency of 93%. No statistically significant difference was however observed between the genotypic (p = 0.50) and allelic frequencies (p = 0.58) of obese and non-obese subjects. Comparison of clinical and biochemical parameters of C allele carriers (CX = CC + CT) with those of TT genotype showed that there was no significant difference between the lipid profile of these two groups. Conclusion: The rs7903146 (C/T) polymorphism of the TCF7L2 gene might not be associated with obesity in the Cameroonian population

Genetic polymorphisms of organic cation transporters 1 (OCT1) and responses to metformin therapy in individuals with type 2 diabetes mellitus : a systematic review protocol

CITATION: Mato, E. P. M. et al. 2018. Genetic polymorphisms of organic cation transporters 1 (OCT1) and responses to metformin therapy in individuals with type 2 diabetes mellitus : a systematic review protocol. Systematic Reviews, 7:105, doi:10.1186/s13643-018-0773-y.The original publication is available at https://systematicreviewsjournal.biomedcentral.comBackground: Metformin is one of the most commonly used drugs for type 2 diabetes mellitus (T2DM). Despite its efficacy and safety, metformin is frequently associated with highly variable glycemic responses, which is hypothesized to be the result of genetic variations in its transport by organic cation transporters (OCTs). This systematic review aims to highlight and summarize the overall effects of OCT1 polymorphisms on therapeutic responses to metformin and to evaluate their potential role in terms of interethnic differences with metformin responses. Methods/design: We will systematically review observational studies reporting on the genetic association between OCT1 polymorphisms and metformin responses in T2DM patients. A comprehensive search strategy formulated with the help of a librarian will be used to search MEDLINE via PubMed, Embase, and CINAHL for relevant studies published between January 1990 and July 2017. Two review authors will independently screen titles and abstracts in duplicate, extract data, and assess the risk of bias with discrepancies resolved by discussion or arbitration of a third review author. Mined data will be grouped according to OCT1 polymorphisms, and their effects on therapeutic responses to metformin will be narratively synthesized. If sufficient numbers of homogeneous studies are scored, meta-analyses will be performed to obtain pooled effect estimates. Funnel plots analysis and Egger’s test will be used to assess publication bias. This study will be reported according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. Discussion: This review will summarize the genetic effects of OCT1 polymorphisms associated with variabilities in glycemic responses to metformin. The findings of this study could help to develop genetic tests that could predict a person’s response to metformin treatment and create personalized drugs with greater efficacy and safety. Systematic review registration: Registration number: PROSPERO, CRD42017079978https://systematicreviewsjournal.biomedcentral.com/articles/10.1186/s13643-018-0773-yPublisher's versio

Genetic polymorphisms of organic cation transporters 1 (OCT1) and responses to metformin therapy in individuals with type 2 diabetes mellitus: a systematic review protocol

Abstract Background Metformin is one of the most commonly used drugs for type 2 diabetes mellitus (T2DM). Despite its efficacy and safety, metformin is frequently associated with highly variable glycemic responses, which is hypothesized to be the result of genetic variations in its transport by organic cation transporters (OCTs). This systematic review aims to highlight and summarize the overall effects of OCT1 polymorphisms on therapeutic responses to metformin and to evaluate their potential role in terms of interethnic differences with metformin responses. Methods/design We will systematically review observational studies reporting on the genetic association between OCT1 polymorphisms and metformin responses in T2DM patients. A comprehensive search strategy formulated with the help of a librarian will be used to search MEDLINE via PubMed, Embase, and CINAHL for relevant studies published between January 1990 and July 2017. Two review authors will independently screen titles and abstracts in duplicate, extract data, and assess the risk of bias with discrepancies resolved by discussion or arbitration of a third review author. Mined data will be grouped according to OCT1 polymorphisms, and their effects on therapeutic responses to metformin will be narratively synthesized. If sufficient numbers of homogeneous studies are scored, meta-analyses will be performed to obtain pooled effect estimates. Funnel plots analysis and Egger’s test will be used to assess publication bias. This study will be reported according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. Discussion This review will summarize the genetic effects of OCT1 polymorphisms associated with variabilities in glycemic responses to metformin. The findings of this study could help to develop genetic tests that could predict a person’s response to metformin treatment and create personalized drugs with greater efficacy and safety. Systematic review registration Registration number: PROSPERO, CRD4201707997

Genetic determinants of dyslipidemia in African-based populations: a systematic review

Identification of genetic/genomic factors contributing to dyslipidemia is of great interest to prevention and reduction of the onset and burden of cardiovascular diseases in Africa. This systematic review summarizes available data on genetic variants associated with dyslipidemia in populations within Africa. A PubMed and EMBASE database search was conducted to identify all studies published until June 2018 on genetic susceptibility to dyslipidemia in African-based populations, excluding familial hypercholesterolemia. All studies on genetic predispositions of dyslipidemia and respecting the preestablished inclusion criteria were included in this systematic review. Because of high heterogeneity, the data were summarized narratively. Twenty-two studies investigated mostly the targeted genetic variants. A total of 51 polymorphisms in 28 susceptibility genes to dyslipidemia have been associated with a particular trait in the African populations, and through variable effects. Most polymorphisms investigated in Northern Africa seemed to have consistent effects on increasing the level of low-density lipoprotein cholesterol (LDL-C), total cholesterol, and triglycerides in patients with diabetes, myocardial infarction, coronary artery disease, and metabolic syndrome. By contrast, only Ser447Ter and C49620T variants were associated with increased LDL-C in sub-Saharan Africa. Despite few studies available in this context in the literature, certain genetic variants were consistently associated with dyslipidemia especially in Northern Africa as highlighted in this analysis. Further data, particularly from genome-wide association studies, would help establish an African-specific reference for genetic susceptibility markers of dyslipidemia.Jean Jacques Noubiap, Edith Pascale M. Mato, Magellan Guewo-Fokeng, Arnaud D. Kaze, Houssam Boulenouar, and Ambroise Wonka

Additional file 1: of Genetic polymorphisms of organic cation transporters 1 (OCT1) and responses to metformin therapy in individuals with type 2 diabetes mellitus: a systematic review protocol

PRISMA-P 2015 checklist. (DOC 82 kb

Association between the rs12255372 variant of the TCF7L2 gene and obesity in a Cameroonian population Obesity

10.1186/s13104-015-1661-3BMC Research Notes81717

Contribution of the TCF7L2 rs7903146 (C/T) gene polymorphism to the susceptibility to type 2 diabetes mellitus in Cameroon

10.1186/s40200-015-0148-zJournal of Diabetes and Metabolic Disorders14126