The coronavirus disease 2019 (COVID19) pandemic continues to represent a substantial public health concern. It can rapidly progress to severe disease, with poor prognosis and a high mortality risk. An early diagnosis and specific prognostic tools can help healthcare providers to start interventions promptly, understand the likely prognosis and to identify and treat timely individuals likely to develop severe disease with enhanced mortality risk. Here we focused on an impressive set of systematic reviews and meta-analyses that were performed since the start of the COVID19 pandemic and summarized their results related to the levels of hematologic, inflammatory, immunologic biomarkers as well as markers of cardiac, respiratory, hepatic, gastrointestinal and renal systems and their association with the disease progression, severity and mortality. The evidence outlines the significance of specific biomarkers, including inflammatory and immunological parameters (C-reactive protein, procalcitonin, interleukin-6), hematological (lymphocytes count, neutrophil-to-lymphocyte ratio, D-dimer, ferritin, red blood cell distribution width), cardiac (troponin, CK-MB, myoglobin), liver (AST, ALT, total bilirubin, albumin) and lung injury (Krebs von den Lungen-6) that can be used as prognostic biomarkers to aid the identification of high-risk patients and the prediction of serious outcomes, including mortality, in COVID19. Thus, these parameters should be used as essential tools for an early risk stratification and adequate intervention in improving disease outcomes in COVID19 patients.

Abstract Studies published earlier this year demonstrated the association of the solute carrier SLC6A20 gene with the risk and severity of COVID-19. The SLC6A20 protein product (Sodium-dependent Imino Transporter 1 (SIT1)) is involved in the transport of amino acids, including glycine. Here we summarized the results of recent studies demonstrating the interaction of SIT1 with the ACE2 receptor for SARS-CoV-2 as well as an observed association of SLC6A20 with the risk and traits of Type 2 diabetes (T2D). Recently, it was also proposed that SLC6A20 represents the novel regulator of glycine levels and that glycine has beneficial effects against the proinflammatory cytokine secretion induced by SARS-CoV-2 infection. Ivermectin, as a partial agonist of glycine-gated chloride channels, was also recently suggested to interfere with the COVID-19 cytokine storm by inducing the activation of glycine receptors. Furthermore, plasma glycine levels are found to be decreased in diabetic patients. Thus, further clinical trials are warranted to confirm the potential favorable effects of targeting the SIT1 transporter and glycine levels in the treatment of COVID-19, particularly for the severe case of disease associated with hyperglycemia, inflammation, and T2D. These findings suggest that SIT1 may potentially represent one of the missing pieces in the complex puzzle observed between these two pandemic diseases and the potential novel target for their efficient treatment.

Recent evidence shows that COVID-19 patients with existing metabolic disorders, such as diabetes and metabolic syndrome, are exposed to a high risk of morbidity and mortality. At the same time, in order to manage the pandemic, the health authorities around the world are advising people to stay at home. This results in decreased physical activity and an increased consumption of an unhealthy diet, which often leads to an increase in body weight, risk for diabetes, insulin resistance, and metabolic syndrome, and thus, paradoxically, to a high risk of morbidity and mortality due to COVID-19 complications. Here we summarize the evidence demonstrating that the promotion of a healthy life style, including physical activity and a dietary intake of natural polyphenols present in coffee and tea, has the potential to improve the prevention and management of insulin resistance and diabetes in the time of COVID-19 pandemic. Particularly, it would be pertinent to evaluate further the potential positive effects of coffee beverages, rich in natural polyphenols, as an adjuvant therapy for COVID-19, which appear not to be studied sufficiently.

The response to metformin, the most commonly used drug for the treatment of type 2 diabetes (T2D), is highly variable. The common variant rs7903146 C>T within the transcription factor 7 like 2 gene (TCF7L2) is the strongest genetic risk factor associated with T2D to date. In this study we explored the effects of TCF7L2 rs7903146 genotype on metformin response in T2D. The study included 86 newly diagnosed patients with T2D, incident users of metformin. Levels of fasting glucose, insulin, HbA1c, total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides, and anthropometric parameters were measured prior to metformin therapy, and 6 and 12 months after the treatment. Genotyping of TCF7L2 rs7903146 was performed by the Sequenom MassARRAY® iPLEX® platform. At baseline, the diabetes risk allele (T) showed an association with lower triglyceride levels (p = 0.037). After 12 months of metformin treatment, the T allele was associated with 25.9% lower fasting insulin levels (95% CI 10.9-38.3%, p = 0.002) and 29.1% lower HOMA-IR index (95% CI 10.1-44.1%, p = 0.005), after adjustment for baseline values. Moreover, the T allele was associated with 6.7% lower fasting glucose levels (95% CI 1.1-12.0%, p = 0.021), adjusted for baseline glucose and baseline HOMA-%B levels, after 6 months of metformin treatment. This effect was more pronounced in TT carriers who had 16.8% lower fasting glucose levels (95% CI 7.0-25.6%, p = 0.002) compared to the patients with CC genotype. Our results suggest that TCF7L2 rs7903146 variant affects markers of insulin resistance and glycemic response to metformin in newly diagnosed patients with T2D within the first year of metformin treatment.

Summary Background FTO, a gene recently discovered in genomewide associated studies for type 2 diabetes mellitus (T2D), play an important role in the management of energy homeostasis, nucleic acid demethylation and regulation of body fat mass by lipolysis. The aim of this study was to analyze the association of FTO rs8050136 A>C genetic variant with clinical and biochemical parameters of T2D in the population of West Balkan region (Bosnians and Herzegovinians and Kosovars). Methods The study included 638 patients with T2D and prediabetes and 360 healthy controls of both genders, aged from 40 to 65 years. Patients were recruited at the Clinical Centre University of Sarajevo, University Hospital of Clinical Centre in Banja Luka, General Hospital in Tešanj and Health Centre in Prizren. Genotyping of analyzed FTO polymorphism rs8050136 A>C was performed by qPCR allelic discrimination. Results Genotype frequencies of the analyzed polymorphism were comparable between patients with T2D, prediabetic patients, and healthy population. Logistic regression analyses didn’t show significant association of FTO rs8050136 A allele with increased risk of T2D. However, risk A allele was significantly associated with higher levels of HbA1c, insulin, HOMA-IR index, diastolic blood pressure, and inflammatory markers (fibrinogen and leukocytes) as well as showed tendency of association with increased values of obesity markers (BMI, waist and hip circumference). Conclusions Results of our study showed a significant association of FTO genetic variant rs8050136 A>C with the major markers of insulin resistance, obesity and inflammation, opening new avenues for solving many unclear questions in the pathogenesis of T2D.