How common is hyponatremia in patients with Covid-19 and what’s its significance?  

Hyponatremia has been reported between 20% and 35% of patients hospitalized for Covid-19, 1-5 with low serum sodium levels on admission often associated with progression to severe illness, mechanical ventilation, increased length of stay and death.1,2,4,5

A 2023 retrospective multicenter study involving over 2,600 hospitalized Covid-19 patients (between February 2020 and August 2022) found hyponatremia in 34.2%: Mild (Na 131-134 mmol/L) 25.1%, moderate (Na 126-130 mmol/L) 7.5% and severe (<126 mmol/L) 1.8%.3 There was a significant association between male sex at birth, hypertension, chronic kidney disease, immunosuppressives, thiazide diuretics and hyponatremia.3

Similarly, another retrospective study of hospitalized Covid-19 patients found an association between hyponatremia and several common chronic diseases, such as diabetes, hypertension, ischemic heart disease, chronic liver disease and chronic kidney disease.4 It’s important to note that since older age has also been found to be a risk factor for hyponatremia in Covid-19, the independent contribution of these conditions to hyponatremia is unclear.3

As with many other infectious diseases, the mechanism of hyponatremia in patients with Covid-19 likely has multiple causes, including hypovolemia, syndrome of inappropriate anti-diuretic hormone secretion (SIADH), diuretic use and corticosteroid deficiency, particularly in the critically ill. 1-4  

Interestingly, a study performed early in the pandemic (March 2020) found that the majority (57%)  of hospitalized Covid-19 patients with hyponatremic were euvolemic and that the administration of isotonic saline to such patients was independently associated with increased hospital mortality (cause unclear).2 The authors suggested closer attention to the volume status of Covid-19 patients with hyponatremia (eg, through closer attention to the jugular venous pressure on physical exam) before considering treatment with isotonic saline.

Last, Covid-19 may be associated with hyponatremia during the post-discharge period as well.  An intriguing 2024 study found nearly 25% of patients with Covid-19 developed hyponatremia (<135 mmol/L) during the 1-year follow-up period after discharge with most not reported to have hyponatremia during their index hospitalization.5 In the same study, hyponatremia was associated with older age, male sex, diabetes, hypertension, heart failure, previous invasive ventilatory support and increased rate of readmission.5

Bonus Pearl: Did you know that there is an inverse relationship between interleukin-6, a key pro-inflammatory cytokine, and plasma sodium levels in Covid-19 and that this association may be stronger than that of other viral or bacterial respiratory infections?2  

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References

  1. Ayus JC, Klantar-Zadeh K, Tantisattamo E, et al. Is hyponatremia a novel marker of inflammation in patients with Covid-19? Nephrol Dial Transplant 2023;38:1921-24. Is hyponatremia a novel marker of inflammation in patients with COVID-19? – PubMed (nih.gov)
  2. Pazos-Guerra M, Ruiz-Sanchez JG, Perez-Candel X, et al. Inappropriate therapy of euvolemic hyponatremia, the most frequent type of hyponatremia in SARS-CoV-2 infection, is associated with increased mortality in COVID-19 patients. Front Endocrinol 2023; 14:1227058. Inappropriate therapy of euvolemic hyponatremia, the most frequent type of hyponatremia in SARS-CoV-2 infection, is associated with increased mortality in COVID-19 patients – PubMed (nih.gov)
  3. De Haan L, ten Wolde, Beudel M, et al. What is the aetiology of dynatreaemia in COVID-19 and how is this related to outcomes in patients admitted during earlier and later COVID-19 waves? A multicentre, restrospective observational study in 11 Dutch hospitals. BMJ Open 2023;13:e075232. Original research: What is the aetiology of dysnatraemia in COVID-19 and how is this related to outcomes in patients admitted during earlier and later COVID-19 waves? A multicentre, retrospective observational study in 11 Dutch hospitals – PMC (nih.gov)
  4. Rehman F, Rehan ST, Rind BJ, et al. Hyponatremia causing factors and its association with disease severity and length of stay in Covid-19 patients: A retrospective study from tertiary care hospital. Medicine 2023; 102:45(e35920) Hyponatremia causing factors and its association with disease severity and length of stay in COVID-19 patients: A retrospective study from tertiary care hospital – PubMed (nih.gov)
  5. Biagetti B, Sanchez-Montalva A, Puig-Perez A, et al. Hyponatremia after COVID-19 is frequent in the first year and increases re-admissions. Scientific Reports 2024:14:595. Hyponatremia after COVID-19 is frequent in the first year and increases re-admissions – PubMed (nih.gov)

 

Disclosures/Disclaimers: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Mercy Hospital-St. Louis, Massachusetts General Hospital, Harvard Catalyst, Harvard University, their affiliate academic healthcare centers, or its contributors. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

How common is hyponatremia in patients with Covid-19 and what’s its significance?  

Should I consider treating my patient with heart failure with an SGLT2 inhibitor?

Absolutely! Although sodium glucose cotransporter 2 (SGLT2) inhibitors are often used for their antidiabetic properties, more recently they have been shown to have extraordinary benefits in patients with heart failure.

 In 2015, a large randomized controlled trial, EMPA-REG OUTCOME, showed that empagliflozin significantly lowered overall death, death from cardiovascular events, and hospitalizations for heart failure in patients who had type II diabetes (T2DM) and cardiovascular disease1.

Later, 2 other randomized controlled trials showed that patients with heart failure with reduced ejection fractions (HFrEF), irrespective of a diagnosis of T2DM, had lower rates of death from cardiovascular causes and better heart failure outcomes when treated with SGLT2 inhibitors2,3.

In 2021, the EMPEROR Preserved trial showed that SGLT2 inhibitors provide significant clinical benefit for patients with heart failure with preserved ejection fraction (HFpEF), irrespective of the presence of T2DM4. In addition, multiple studies have shown substantial benefit to starting SGLT2 inhibitors during or shortly after a hospitalization for heart failure.5,6,7

 The effectiveness of SGLT2 inhibitors in heart failure is also reflected in the updated guidelines from the American College of Cardiology/American Heart Association8  that recommend  use of SGLT2 inhibitors in patients with chronic symptomatic HFrEF.  In addition,  the guidelines state that SGLT2 inhibitors can be beneficial in decreasing heart failure hospitalizations and cardiovascular mortality for patients mildly reduced ejection fraction and those with HFpEF.

 Potential mechanisms of action of SGLT2 inhibitors in heart failure include reduction in myocardial oxidative stress, decrease cardiac preload and afterload, increase endothelial function, decrease arterial stiffness, and increase muscle free fatty acid uptake which leads to increased availability of ketones during times of stress.9 

So the data to date suggest that we should consider SGLT2 inhibitors as part of our armamentarium for treatment of heart failure unless, of course, there are contraindications, including pregnancy/risk of pregnancy, breastfeeding, eGFR <30mL/min/1.73 m2, symptoms of hypotension, systolic blood pressure <95mmHg, or a known allergic/other adverse reactions. 10

Bonus Pearl: Did you know that SGLT 2 inhibitors are derived from phlorizin, a naturally occurring phenol glycoside first isolated back in 1835 from the bark of apple tree in 1835? 11

Contributed by Yisrael Wallach, MD, St. Louis, Missouri

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References

  1. Zinman, B., Wanner, C., Lachin, J. M., Fitchett, D., Bluhmki, E., Hantel, S., … & Inzucchi, S. E. (2015). Empagliflozin, cardiovascular outcomes, and mortality in type 2 diabetes. New England Journal of Medicine, 373(22), 2117-2128. https://pubmed.ncbi.nlm.nih.gov/26378978/
  2. McMurray, J. J., Solomon, S. D., Inzucchi, S. E., Køber, L., Kosiborod, M. N., Martinez, F. A., … & Langkilde, A. M. (2019). Dapagliflozin in patients with heart failure and reduced ejection fraction. New England Journal of Medicine, 381(21), 1995-2008. https://pubmed.ncbi.nlm.nih.gov/31535829/
  3. Packer, M., Anker, S. D., Butler, J., Filippatos, G., Pocock, S. J., Carson, P., … & Zannad, F. (2020). Cardiovascular and renal outcomes with empagliflozin in heart failure. New England Journal of Medicine, 383(15), 1413-1424. https://pubmed.ncbi.nlm.nih.gov/32865377/
  4. Anker, S. D., Butler, J., Filippatos, G., Ferreira, J. P., Bocchi, E., Böhm, M., … & Packer, M. (2021). Empagliflozin in heart failure with a preserved ejection fraction. New England Journal of Medicine, 385(16), 1451-1461. https://pubmed.ncbi.nlm.nih.gov/34449189/
  5. Cunningham, J. W., Vaduganathan, M., Claggett, B. L., Kulac, I. J., Desai, A. S., Jhund, P. S., … & Solomon, S. D. (2022). Dapagliflozin in Patients Recently Hospitalized With Heart Failure and Mildly Reduced or Preserved Ejection Fraction. Journal of the American College of Cardiology. https://pubmed.ncbi.nlm.nih.gov/36041912/
  6. Voors, A. A., Angermann, C. E., Teerlink, J. R., Collins, S. P., Kosiborod, M., Biegus, J., … & Ponikowski, P. (2022). The SGLT2 inhibitor empagliflozin in patients hospitalized for acute heart failure: a multinational randomized trial. Nature medicine, 28(3), 568-574. https://pubmed.ncbi.nlm.nih.gov/35228754/
  7. Bhatt, D. L., Szarek, M., Steg, P. G., Cannon, C. P., Leiter, L. A., McGuire, D. K., … & Pitt, B. (2021). Sotagliflozin in patients with diabetes and recent worsening heart failure. New England Journal of Medicine, 384(2), 117-128. https://pubmed.ncbi.nlm.nih.gov/33200892/
  8. Heidenreich, P. A., Bozkurt, B., Aguilar, D., Allen, L. A., Byun, J. J., Colvin, M. M., … & Yancy, C. W. (2022). 2022 AHA/ACC/HFSA guideline for the management of heart failure: Executive summary: a report of the American College of Cardiology/American heart association joint Committee on clinical practice guidelines. Journal of the American College of Cardiology, 79(17), 1757-1780. https://pubmed.ncbi.nlm.nih.gov/35379504/
  9. Muscoli, S., Barillà, F., Tajmir, R., Meloni, M., Della Morte, D., Bellia, A., … & Andreadi, A. (2022). The New Role of SGLT2 Inhibitors in the Management of Heart Failure: Current Evidence and Future Perspective. Pharmaceutics, 14(8), 1730. https://pubmed.ncbi.nlm.nih.gov/36015359/
  10. Aktaa, S., Abdin, A., Arbelo, E., Burri, H., Vernooy, K., Blomström-Lundqvist, C., … & Gale, C. P. (2022). European Society of Cardiology Quality Indicators for the care and outcomes of cardiac pacing: developed by the Working Group for Cardiac Pacing Quality Indicators in collaboration with the European Heart Rhythm Association of the European Society of Cardiology. EP Europace, 24(1), 165-172. https://pubmed.ncbi.nlm.nih.gov/34455442/
  11. Petersen, C. (1835). Analyse des phloridzins. Annalen der pharmacie, 15(2), 178-178. 

Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Mercy Hospital-St. Louis, Massachusetts General Hospital, Harvard Catalyst, Harvard University, their affiliate academic healthcare centers, or its contributors. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

 

 

Should I consider treating my patient with heart failure with an SGLT2 inhibitor?