Is the vitamin D status of patients with COVID-19 associated with reduced mortality? A systematic review and meta-analysis

ABSTRACT To conduct a systematic review and meta-analysis of studies assessing the association between serum vitamin D status and mortality in patients with COVID- 19. We searched PubMed and Embase for studies addressing the association of serum vitamin D levels and COVID-19 mortality published until April 24, 2022. Risk ratios (RRs) and 95% confidence interval (CIs) were pooled using fixed or random effects models. The risk of bias was assessed using the Newcastle-Ottawa Scale. The meta-analysis included 21 studies that measured serum vitamin D levels close to the date of admission, of which 2 were case- control and 19 were cohort studies. Vitamin D deficiency was associated with COVID-19 mortality in the overall analysis but not when the analysis was adjusted to vitamin D cutoff levels < 10 or < 12 ng/mL (RR 1.60, 95% CI 0.93-2.27, I2 60.2%). Similarly, analyses including only studies that adjusted measures of effect for confounders showed no association between vitamin D status and death. However, when the analysis included studies without adjustments for confounding factors, the RR was 1.51 (95% CI 1.28-1.74, I2 0.0%), suggesting that confounders may have led to many observational studies incorrectly estimating the association between vitamin D status and mortality in patients with COVID-19. Deficient vitamin D levels were not associated with increased mortality rate in patients with COVID-19 when the analysis included studies with adjustments for confounders. Randomized clinical trials are needed to assess this association.

Acute kidney injury associated with dengue virus infection: a review / Injúria renal aguda associada à infecção pelo vírus da dengue: uma revisão

Abstract Acute kidney injury (AKI) is one of the least studied complications of dengue, but it carries high mortality rates and prolonged hospital stay. Due to the severity of this complication, the risk of developing chronic kidney disease (CKD) and the increasing number of dengue cases reported worldwide, particularly in the tropical and subtropical regions of Africa, Southeast Asia and South America, including Brazil, we embarked on this narrative review, aimed to update the epidemiology of AKI associated with dengue, elucidate the main pathophysiological mechanisms of AKI caused by the dengue virus infection, as well as discuss useful information on the prevention and management of AKI in patients with dengue.

Resumo A injúria renal aguda (IRA) é uma das complicações da dengue menos estudadas, mas que acarreta altas taxas de mortalidade e prolongamento do tempo de internação. Devido à gravidade dessa complicação, ao risco de desenvolvimento de doença renal crônica (DRC) e ao número crescente de casos de dengue relatados no mundo, particularmente nas regiões tropicais e subtropicais da África, Sudeste Asiático e América do Sul, incluindo o Brasil, foi proposta esta revisão narrativa que objetivou atualizar a epidemiologia da IRA associada à dengue, elucidar os principais mecanismos fisiopatológicos da IRA causada pela infecção do vírus da dengue, assim como discutir informações úteis sobre a prevenção e o manejo da IRA em pacientes com dengue.