Introduction: There is increasing scientific interest in the possible association between hypovitaminosis D and the risk of SARS-CoV-2 infection severity and/or mortality. Objective: To conduct a metanalysis of the association between 25-hydroxyvitamin D (25(OH)D) concentration and SARS-CoV-2 infection severity or mortality. Material and methods: We searched PubMed, EMBASE, Google scholar and the Cochrane Database of Systematic Reviews for studies published between December 2019 and December 2020. Effect statistics were pooled using random effects models. The quality of included studies was assessed with the Newcastle–Ottawa Scale (NOS). Targeted outcomes: mortality and severity proportions in COVID-19 patients with 25(OH)D deficiency, defined as serum 25(OH)D < 50 nmol/L. Results: In the 23 studies included (n = 2692), the mean age was 60.8 (SD ± 15.9) years and 53.8% were men. Results suggested that vitamin 25(OH)D deficiency was associated with increased risk of severe SARS-CoV-2 disease (RR 2.00; 95% CI 1.47–2.71, 17 studies) and mortality (RR 2.45; 95% CI 1.24–4.84, 13 studies). Only 7/23 studies reported C-reactive protein values, all of which were > 10 mg/L. Conclusions 25(OH)D deficiency seems associated with increased SARS-CoV-2 infection severity and mortality. However, findings do not imply causality, and randomized controlled trials are required, and new studies should be designed to determine if decreased 25(OH)D is an epiphenomenon or consequence of the inflammatory process associated with severe forms of SARS-CoV-2. Meanwhile, the concentration of 25(OH)D could be considered as a negative acute phase reactant and a poor prognosis in COVID-19 infection. Introduction: There is increasing scientific interest in the possible association between hypovitaminosis D and the risk of SARS-CoV-2 infection severity and/or mortality. Objective: To conduct a metanalysis of the association between 25-hydroxyvitamin D (25(OH)D) concentration and SARS-CoV-2 infection severity or mortality. Material and methods: We searched PubMed, EMBASE, Google scholar and the Cochrane Database of Systematic Reviews for studies published between December 2019 and December 2020. Effect statistics were pooled using random effects models. The quality of included studies was assessed with the Newcastle–Ottawa Scale (NOS). Targeted outcomes: mortality and severity proportions in COVID-19 patients with 25(OH)D deficiency, defined as serum 25(OH)D < 50 nmol/L. Results: In the 23 studies included (n = 2692), the mean age was 60.8 (SD ± 15.9) years and 53.8% were men. Results suggested that vitamin 25(OH)D deficiency was associated with increased risk of severe SARS-CoV-2 disease (RR 2.00; 95% CI 1.47–2.71, 17 studies) and mortality (RR 2.45; 95% CI 1.24–4.84, 13 studies). Only 7/23 studies reported C-reactive protein values, all of which were > 10 mg/L. Conclusions 25(OH)D deficiency seems associated with increased SARS-CoV-2 infection severity and mortality. However, findings do not imply causality, and randomized controlled trials are required, and new studies should be designed to determine if decreased 25(OH)D is an epiphenomenon or consequence of the inflammatory process associated with severe forms of SARS-CoV-2. Meanwhile, the concentration of 25(OH)D could be considered as a negative acute phase reactant and a poor prognosis in COVID-19 infection.

Background: Hypertension and type 2 diabetes increase the risk of severe SARS-CoV-2 infection. On the other hand, homozygous ACE deletion polymorphism (DD) has been associated with these two diseases and risk of acute respiratory distress syndrome. The aim of the study was to conduct a meta-analysis of the association between ACE gene I/D polymorphism (DD, II and DI) and severity of SARS-CoV-2 infection in hospitalized patients. Material and methods: We searched PubMed, EMBASE and Google Scholar for studies published between January 2020 and April 2021. We included case-control studies evaluating the association between ACE I/D and severity of SARS-CoV-2 infection in hospitalized patients, were there was sufficient genotype or allele frequency data to calculate IRR (incidence rate ratio) and 95% confidence intervals (CIs). Results: Five studies were included (mean age 58.5 years and 61% men), combining to a total of 786 patients. Four studies were conducted in Caucasians. Overall, patients who had homozygous co-dominance genotype DD were at 47% higher risk of severe COVID-19 compared with II or ID (IRR: 1.47; 95% CI: 1.15–1.89; p = 0.002). Conclusions: The ACE DD genotype may confer a greater risk of severe COVID-19 in hospitalized patients. Further studies including more diverse ethnic groups are necessary to fully establish this association. Background: Hypertension and type 2 diabetes increase the risk of severe SARS-CoV-2 infection. On the other hand, homozygous ACE deletion polymorphism (DD) has been associated with these two diseases and risk of acute respiratory distress syndrome. The aim of the study was to conduct a meta-analysis of the association between ACE gene I/D polymorphism (DD, II and DI) and severity of SARS-CoV-2 infection in hospitalized patients. Material and methods: We searched PubMed, EMBASE and Google Scholar for studies published between January 2020 and April 2021. We included case-control studies evaluating the association between ACE I/D and severity of SARS-CoV-2 infection in hospitalized patients, were there was sufficient genotype or allele frequency data to calculate IRR (incidence rate ratio) and 95% confidence intervals (CIs). Results: Five studies were included (mean age 58.5 years and 61% men), combining to a total of 786 patients. Four studies were conducted in Caucasians. Overall, patients who had homozygous co-dominance genotype DD were at 47% higher risk of severe COVID-19 compared with II or ID (IRR: 1.47; 95% CI: 1.15–1.89; p = 0.002). Conclusions: The ACE DD genotype may confer a greater risk of severe COVID-19 in hospitalized patients. Further studies including more diverse ethnic groups are necessary to fully establish this association.

Background: Anti-hypertensive medications may reduce the incidence of cognitive disorders. This may be due to reasons beyond their pure hypotensive effect. This study aimed to systematically review the association between the use of Angiotensin-Receptor Blockers (ARBs) and the incidence of Alzheimer’s disease (AD). Methods: We systematically searched studies reporting the association between ARB use and the incidence of AD. Results: Ten studies (1 RCT, 2 case-control and 7 cohort studies) met the inclusion criteria. When all observational studies (9) were analyzed, ARB use was associated with a reduced risk of incident AD (HR 0.72, 95% CI: 0.58-0.88, p<0.001). In the only RCT, decrease in the incidence of AD was also significant (HR= 0.31, 95% CI: 0.14-0.68). Conclusion: ARB use may reduce the risk of incident AD. This association does not imply causation and further research is required to clarify potential mechanisms.