The association of Intron 4 VNTR and Glu298Asp polymorphisms of the nitric oxide synthetase 3 gene and vasculogenic erectile dysfunction in Turkish men

Genes Predisposing to Erectile Dysfunction and Management: A Review

Background: The burden of erectile dysfunction (ED) is rising worldwide due to unresponsiveness of some affected individuals to existing drugs and treatment strategies. Fortunately, improvement in biological techniques has led to the understanding that some cases of the disorder may have a genetic etiology, which, when fully understood, may lead to improved treatment.

Objective: This review articulated established ED candidate genes and pathophysiology to assist researchers and medical practitioners to formulate effective drugs and treatment procedures.

Methods: The Google search engine was used to retrieve relevant information on the topic from reputable academic databases, including PubMed, Medline, Google Scholar, Scopus, and SpringerLink.

Results: The search discovered 10 ED candidate genes, which are SIM1, SLC6A4, 5-HTTLPR, TGFB1, DAT1, MC4R, NOS3, GNB3, AR, and MTHFR. Polymorphisms or mutations in these genes may disrupt erectile activities of the hypothalamus, neurotransmitters such as dopamine, serotonin, and nitric oxide as well as relaxation of penile tissues. Clinical presentations of ED include loss of erection, weak vaginal penetration, premature ejaculation, and anejaculation. Each gene has a distinct mechanism, which, if targeted in the affected may reverse the disorder or reduce the effects.

Conclusion: Some cases of ED are genetic, which, when fully understood, may give an insight into new treatment procedures or improve on the current ones. Medical practitioners are advised to formulate treatment procedures that target the affected gene (s) in individuals.

Gene Polymorphisms Affecting Erectile Dysfunction

INTRODUCTION

Erectile dysfunction (ED) is usually developed from psychological, neurological, hormonal, and vascular pathologies or a combination of these factors. However, the possible genetic polymorphisms that might underlie this disorder were not thoroughly investigated.

OBJECTIVES

This review article aimed to assess the possible involvement of gene polymorphisms in men with ED.

METHODS

A systematic review was conducted until January 2020 based on a search of all relevant articles in many electronic sites such as PubMed, Medline Medical Subject Headings, Science Direct, Scopus, Cochrane Library, EMBASE, CINAHL, and Egyptian Knowledge Bank databases with no language restriction. Keywords used to assess the outcome and estimates for relevant associations were sexual health, genes, erectile dysfunction, polymorphisms, and cavernous tissues.

RESULTS

Many genetic studies were carried out to inspect the contribution of different encoded genotypes and ED. Overall, 50 studies were reviewed and were classified as per the type of gene polymorphisms. These studies have investigated 10,174 men with ED compared with 6,891 healthy men as controls. 35 studies were case-controlled, 13 cross-sectional cohort studies, one retrospective study, and one genome-wide association study. So far, the most relevant gene polymorphisms linked with men with ED included endothelial nitric oxide synthase (eNOS), angiotensin-converting enzyme (ACE), androgen receptor (AR) CAG repeat, G-protein β3 (GNB3) subunit, methylenetetrahydrofolate reductase (MTHFR), vascular endothelial growth factor (VEGF), TGFB1, proprotein convertase subtilisin/kexin type 9 (PCSK9), ARG1, DRD2, DRD4, DDAH, and HNF4A genes. Both PROGINS and IGFBP-3 polymorphisms were investigated in only one study each but with irrelevant significance.

CONCLUSIONS

Although several genetic studies exposed the association between different genotypes and men with ED with varied outcomes, such a relationship should not be overlooked. Therefore, more studies should be encouraged to elucidate the exact role, if any, for such association. Mostafa T, Taymour M. Gene Polymorphisms Affecting Erectile Dysfunction. Sex Med 2020;8:561-572.

Management of an emergency tooth extraction in diabetic patients on the dental chair

BACKGROUND AND OBJECTIVE

Approximately 75% of diabetic patients in Saudi Arabia had poor glycaemic control. A high proportion of these patients will attend dental surgery clinics for treatment. Therefore, dentists should be well-prepared to control any complications they might arise on the dental chair during the dental procedures. Management of the associated risk factors is important to limit disease complications and improve the health of patients with diabetes.The objectives of this review were to determine the maximum acceptable level of blood glucose for tooth removal in diabetics, show a systematic technique for the management of patients with diabetes on the dental chair. By using PRISMA guidelines, analysis of the published articles and reports across the world is considered one of the most appropriate available methods to obtain strong evidence about the acceptable levels of blood glucose where teeth extraction can be done safely.

RESULTS

A total of 1080 studies were retrieved using the search strategy. After screening 185 titles, abstracts and 85 full-text articles, 36 studies were included. The outcome of this systematic review revealed that fasting blood glucose level of 240 mg/dl is a critical point for any dental treatment because the warning signs of diabetes start coming out. Maximum acceptable levels of blood glucose for removal of teeth in diabetics are 180 mg/dl (before meal) and 234 mg/dl (2 h after a meal). High blood glucose levels reduce the secretion of nitric oxide (powerful vasodilator) in the body which leads to poor circulation and slow-healing socket. Uncontrolled diabetics are at high risk of infection because of the high ketone levels in the blood.

CONCLUSION

Fasting blood glucose level of 180 mg/dl is a cut-off point for any selective dental extraction. However, Random blood glucose level of 234 mg/dl (13 mmol/l) is a cut-off point for an emergency tooth extraction. Tightly controlled diabetic patients (blood glucose level below 70 mg/dl) are susceptible to hypoglycemia.