Response to Ravnskov: The advice to cease cholesterol lowering therapy during Covid-19 infection is not supported by RCTs and could even be misused in lay media
According to Ravnskov (1), based on an observational study by Hu et al (2), cholesterol lowering treatment should be ceased in patients with a life-threatening Covid-19 infection. We argue that such advice should not be based on observational studies which have the inherent problem of several forms of bias and confounding that could explain the observed higher mortality from infectious diseases in subjects with low serum cholesterol.
Total and low-density have now (2) been shown to be significantly lower during severe Covid-19 infection, but as demonstrated previously low cholesterol levels are good markers of infectious disease severity (3). Importantly, this observation does not show causality, since low cholesterol levels may in fact be the result of (the severity of) the disease itself, as has been shown as early as 1952 by Dutch researchers (4).
The physical and emotional stress that accompany severe infection also influence cholesterol levels (5).
Taken together, since data from randomized clinical trials are lacking to support the conclusion of Ravnskov, the advice to cease cholesterol lowering therapy should be strongly discouraged, except in the setting of a well designed, controlled and preferably randomized study. More importantly, such strong recommendations could easily be misused by lay- and social media and result in discontinuation of cholesterol lowering therapies in high risk groups for cardiovascular events. We fear that this could worsen the outcome for this group of patients who already underuse the cardiovascular services due to COVID19-anxiety.
1. Ravnskov, U. Cholesterol-lowering treatment may worsen the outcome of a Covid-19 infection. BMJ 2020;368:m1182
2. Hu, X, Chen D, Wu L, He G, Ye W. Low Serum Cholesterol level among patients with COVID-19 infection in Wenzhou, China (February 21, 2020). Available at SSRN: https://ssrn.com/abstract=3544826
3. Gustavo Lima, W, Alves Souza, N, Antunes Fernandes, SO, Nascimento Cardoso, V, Piassi Godói, I. Serum Lipid Profile as a Predictor of Dengue Severity: A Systematic Review and Meta-Analysis. Rev Med Virol . 2019 Sep;29(5):e2056. doi: 10.1002/rmv.2056. Epub 2019 Jun 6.
4. Groen, J., Tjiang, B. K., Kamminga, C. E., and Willebrands, A. F. (1952), Voeding, 13, 556
5. Gordon, H. The regulation of the human serum-cholesterol level. Postgrad Med J. 1959 Apr;35(402):186-96
Competing interests: No competing interests