Electrolyte imbalances as poor prognostic markers in COVID-19: a systemic review and meta-analysis

PURPOSE

Serum electrolyte imbalances are highly prevalent in COVID-19 patients. However, their associations with COVID-19 outcomes are inconsistent, and of unknown prognostic value. We aim to systematically clarify the associations and prognostic accuracy of electrolyte imbalances (sodium, calcium, potassium, magnesium, chloride and phosphate) in predicting poor COVID-19 clinical outcome.

METHODS

PubMed, Embase and Cochrane Library were searched. Odds of poor clinical outcome (a composite of mortality, intensive-care unit (ICU) admission, need for respiratory support and acute respiratory distress syndrome) were pooled using mixed-effects models. The associated prognostic sensitivity, positive and negative likelihood ratios (LR + , LR-) and predictive values (PPV, NPV; assuming 25% pre-test probability), and area under the curve (AUC) were computed.

RESULTS

We included 28 observational studies from 953 records with low to moderate risk-of-bias. Hyponatremia (OR = 2.08, 95% CI = 1.48-2.94, I² = 93%, N = 8), hypernatremia (OR = 4.32, 95% CI = 3.17-5.88, I² = 45%, N = 7) and hypocalcemia (OR = 3.31, 95% CI = 2.24-4.88, I² = 25%, N = 6) were associated with poor COVID-19 outcome. These associations remained significant on adjustment for covariates such as demographics and comorbidities. Hypernatremia was 97% specific in predicting poor outcome (LR + 4.0, PPV = 55%, AUC = 0.80) despite no differences in CRP and IL-6 levels between hypernatremic and normonatremic patients. Hypocalcemia was 76% sensitive in predicting poor outcome (LR- 0.44, NPV = 87%, AUC = 0.71). Overall quality of evidence ranged from very low to moderate.

CONCLUSION

Hyponatremia, hypernatremia and hypocalcemia are associated with poor COVID-19 clinical outcome. Hypernatremia is 97% specific for a poor outcome, and the association is independent of inflammatory marker levels. Further studies should evaluate if correcting these imbalances help improve clinical outcome.

The efficacy of adjuvant radioactive iodine after reoperation in patients with persistent or recurrent differentiated thyroid cancer: a systematic review

OBJECTIVE

The effectiveness of adjuvant radioiodine (RAI) after reoperation in patients with persistent or recurrent differentiated thyroid cancer (DTC) is controversial. Although various organizations recognize that strong evidence for the use of RAI is lacking, they continue to recommend the use of adjuvant RAI therapy for select groups of patients. This is concerning as RAI therapy has potential side effects such as gastrointestinal symptoms, bone marrow suppression, and gonadal damage.

METHODS

Four electronic databases were systematically searched for randomized trials or observational studies that examined the outcomes of adjuvant RAI after reoperation for recurrent DTC, among patients of any age. The baseline characteristics, treatment response, disease progression, and overall survival of these studies were synthesized and reported. A meta-analysis of the use of RAI on progression-free survival was also performed.

RESULTS

Six observational studies, comprising a combined cohort of 437 patients who underwent reoperation, were included from 1212 records. Adjuvant RAI after reoperation in recurrent DTC was not associated with longer progression-free or overall survival. There was also no association of RAI with excellent structural or biochemical treatment response, lower thyroglobulin levels, nor a lower rate of second recurrence or distant metastases.

CONCLUSIONS

Adjuvant RAI after reoperation in recurrent DTC was not associated with improved cancer or treatment-related outcomes. However, as the included studies were of inadequate quality, there is an urgent need for randomized trials and well-analyzed cohort studies. Physicians should exercise clinical judgment to prescribe adjuvant RAI for only selected, high-risk patients.

The impact of sodium-glucose cotransporter inhibitors on blood pressure: a meta-analysis and metaregression of 111 randomized-controlled trials

OBJECTIVE

Multiple trials on sodium-glucose cotransporter (SGLT) inhibitors have been performed recently demonstrating blood pressure (BP) reduction benefits in both diabetic and nondiabetic patients. Hence, we conducted a systematic review and meta-analysis to determine the effect of different SGLT inhibitors on BP in both patients with and without diabetes mellitus.

METHODS

Four electronic databases (PubMed, Embase, Cochrane, and SCOPUS) were searched on 4 November 2021 for articles published from 1 January 2000 up to 21 November 2021, for studies evaluating the BP effects of SGLT inhibitors. Pair-wise meta-analysis and random effects metaregression models were utilized.

RESULTS

In total, 111 studies examining SBP (108 studies, 104 304 patients) and/or DBP (82 studies, 74 719 patients) were included. In patients with diabetes, the random effects model demonstrated SGLT inhibitor produced a mean reduction in SBPs of -3.46 mmHg (95% confidence interval: -3.83, -3.09) compared with placebo. There were no statistically significant changes in BP among patients without diabetes. Drug response relationship was not observed in SGLT inhibitors and BP, except for Canagliflozin and DBP.

CONCLUSION

Sodium-glucose cotransporter 2 inhibitors and combined sodium-glucose cotransporter 1/2 inhibitors produced small reductions in BP in patients with diabetes.

SGLT inhibitors on weight and body mass: A meta-analysis of 116 randomized-controlled trials

OBJECTIVE

Multiple trials have demonstrated the metabolic effects of sodium/glucose cotransporter 2 (SGLT2) inhibitors in patients regardless of diabetes status, and recent trials have been conducted on the combined sodium/glucose cotransporter 1 and sodium/glucose cotransporter 2 (SGLT1/SGLT2) inhibitors. Therefore, a meta-analysis was conducted to investigate the weight reduction effects and dose-response relationship of SGLT inhibitors and to assess the relative efficacy of SGLT1/SGLT2 inhibitors.

METHODS

Four electronic databases (PubMed, Embase, Cochrane, and Scopus) were searched on November 21, 2020, for articles published from January 1, 2000, up to November 21, 2020.

RESULTS

In total, 116 randomized-controlled trials were included, with a combined cohort of 98,497 patients. Overall, patients had a mean weight reduction of -1.79 kg (95% CI: -1.93 to -1.66, p < 0.001) compared with placebo. This effect was observed across diabetes status, duration of follow-up, various comorbidities, and all SGLT drug types. Mean BMI changes were -0.71 kg/m² (95% CI: -0.94 to -0.47, p < 0.001) compared with placebo. Canagliflozin, empagliflozin, sotagliflozin, and licogliflozin showed a dose-response relationship for mean weight change. Compared with SGLT2 inhibitors, SGLT1/SGLT2 inhibitors had a significantly larger reduction in weight.

CONCLUSIONS

SGLT inhibitors demonstrated weight reduction benefits in this meta-analysis. Further studies are needed to clarify their role in weight management.