Diabetes-related acute metabolic emergencies in COVID-19 patients: a systematic review and meta-analysis.

AIMS: COVID-19 is associated with diabetic ketoacidosis (DKA), hyperglycaemic hyperosmolar state (HHS) and euglycaemic DKA (EDKA); however, evidence regarding parameters affecting outcome and mortality rates is scarce. METHODS: A systematic literature review was conducted using EMBASE, PubMed/Medline, and Google Scholar from January 2020 to 7 January 2021 to identify all studies describing clinical profile, outcome and mortality rates regarding DKA, HHS, DKA/HHS and EDKA cases in COVID-19 patients. The appropriate Joanna Briggs Institute tools were used for quality assessment; quality of evidence was approached using GRADE. Univariate and multivariate analyses were used to assess correlations between clinical characteristics and outcome based on case reports. Combined mortality rates (CMR) were estimated from data reported in case report series, cross-sectional studies, and meta-analyses. The protocol was submitted to PROSPERO (ID: 229356/230737). RESULTS: From 312 identified publications, 44 were qualitatively and quantitatively analyzed. Critical COVID-19 necessitating ICU (P = 3 × 10-8), DKA/HHS presence (P = 0.021), and AKI (P = 0.037) were independently correlated with death. Increased COVID-19 severity (P = 0.003), elevated lactates (P < 0.001), augmented anion gap (P < 0.001), and AKI (P = 0.002) were associated with DKA/HHS. SGLT-2i were linked with EDKA (P = 0.004) and negatively associated with AKI (P = 0.023). CMR was 27.1% (95% CI 11.2-46.9%) with considerable heterogeneity (I 2 = 67%). CONCLUSION: Acute diabetes-related metabolic emergencies in COVID-19 patients lead to increased mortality; key determinants are critical COVID-19 illness, coexistence of DKA/HHS and AKI. Previous SGLT-2i treatment, though associated with EDKA, might preserve renal function in COVID-19 patients. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13340-021-00502-9.

Acute and repeated exposure with the nitric oxide (NO) donor sodium nitroprusside (SNP) differentially modulate responses in a rat model of anxiety.

The nitric oxide (NO) donor sodium nitroprusside (SNP) actually is under investigation for the treatment of schizophrenia. That anxiety disorders are noted to occur commonly in schizophrenia patients is known. Contradictory results were reported however, concerning the effects of SNP in animal models of anxiety disorders. The present study investigated the effects of acute and repeated administration of SNP on anxiety-like behaviour in rats assessed in the light/dark test. The effects of SNP on motility in a locomotor activity chamber were also investigated in rats. Acute administration of 1 mg/kg SNP 30 but not 60 min before testing induced anxiolytic-like behaviour which cannot be attributed to changes in locomotor activity. Conversely, a single injection of 3 mg/kg SNP at 30 min before testing depressed rats' general activity, while at 60 min this dose did not influence performance of animals either in the light/dark or in the motor activity test. Repeated application of SNP (1 and 3 mg/kg, for 5 consecutive days) did not alter rodents' performance in the above described behavioural paradigms. The present results suggest that the effects exerted by SNP in the light/dark test in rats are dose, time and treatment schedule-dependent. The current findings propose also a narrow therapeutic window for SNP in this animal model of anxiety.

The nitric oxide donor sodium nitroprusside attenuates recognition memory deficits and social withdrawal produced by the NMDA receptor antagonist ketamine and induces anxiolytic-like behaviour in rats.

RATIONALE: Experimental evidence indicates that the non-competitive N-methyl-D-aspartate (NMDA) receptor antagonist ketamine impairs cognition and can mimic certain aspects of positive and negative symptoms of schizophrenia in rodents. Nitric oxide (NO) is considered as an intracellular messenger in the brain, and its abnormalities have been linked to schizophrenia. OBJECTIVES: The present study was designed to investigate the ability of the NO donor sodium nitroprusside (SNP) to counteract schizophrenia-like behavioural deficits produced by ketamine in rats. METHODS: The ability of SNP to reverse ketamine-induced memory deficits and social withdrawal were assessed using the novel object recognition task (NORT) and the social interaction test, respectively. Furthermore, since anxiety disorders are noted to occur commonly in schizophrenics, the effects of SNP on anxiety-like behaviour were examined using the light/dark test. Locomotor activity was also assessed as an independent measure of the potential motoric effects of this NO donor. RESULTS: SNP (0.3 and 1 mg/kg) reversed ketamine (3 mg/kg)-induced short-term recognition memory deficits. SNP (1 mg/kg) counteracted the ketamine (8 mg/kg)-induced social isolation in the social interaction test. The anxiolytic-like effects in the light/dark test of SNP (1 mg/kg) cannot be attributed to changes in locomotor activity. CONCLUSIONS: Our findings illustrate a functional interaction between the nitrergic and glutamatergic system that may be of relevance for schizophrenia-like behavioural deficits. The data also suggest a role of NO in anxiety.