Does Hypertension Put You at a Higher Risk for Infection or Death From Covid-19?

Early news reports of fatalities in China from coronavirus strongly implied that hypertension was an independent risk factor for severe disease and death.

Bloomberg and many other seemingly reliable news sources relied on one Chinese doctor’s anecdotal statements along with a Lancet article to make this claim:

“A top Chinese intensive care doctor told Bloomberg that of 170 patients who died in January in Wuhan, nearly half had hypertension, and anecdotally he said that he and other doctors have noticed hypertension is prevalent in those who die.”

However the actual Lancet report on 191 patients published March 11, 2020 , entitled Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study did not find hypertension or heart disease to be an independent risk factor for severe respiratory disease or death.

Of the 191 patients, 137 were discharged and 54 died in hospital. 91 (48%) patients had a comorbidity, with hypertension being the most common (58 [30%] patients), followed by diabetes (36 [19%] patients) and coronary heart disease (15 [8%] patients).

Although patients with hypertension were more likely to die than those without hypertension this does not prove hypertension is an independent risk factor

Age was by far the most significant risk  factor and the older patients also had more hypertension. When all variables were factored into an analysis, hypertension and heart disease were not significantly related to death:

Multivariable regression showed increasing odds of in-hospital death associated with older age (odds ratio 1·10, 95% CI 1·03–1·17, per year increase; p=0·0043), higher Sequential Organ Failure Assessment (SOFA) score (5·65, 2·61–12·23; p<0·0001), and d-dimer greater than 1 μg/mL (18·42, 2·64–128·55; p=0·0033) on admission

Heart disease and hypertension were not significant factors after accounting for age.

Nephrology Journal Club (NephJC) has an excellent discussion (frequently updated and well-reference)  on this topic here. After looking at all current publications in this area they agree with me that the current data do not support the idea that hypertension is an independent risk factor for either getting SARS-CoV2 or having a more serious illness from it.

Among the patients with COVID-19, it seems the prevalence of prior h/o HT is higher in those who develop severe disease than those who do not. Same applies for development of ARDS or death – but mostly in unadjusted analysis. See table below for more. The last two rows are the best quality data so far, and suggest the association between COVID-19 severity and hypertension is attenuated after adjustment.

updated HT table.JPG

Sources: Guan et al, NEJM; Huang et al, Lancet; Wang et al, JAMA; Zhang et al, Allergy; Zhou et al, Lancet; Wu et al, JAMA IM; Italian report (PDF); Chen et al, BMJ; Shi et al, JAMA Cardiol; McMichael et al, NEJM; Guo et al, JAMA Cardiol; Bean et al, MedRxiv 2020; Petrilli et al, MedRXiv 2020

As can be seen, most of the studies except the last two, did not adjust for age. Even age-stratified association of hypertension would have been a more useful way to see these data to understand this issue a bit better. We hope more data in coming days will clarify this relationship. Unlike what we stated earlier, the Zhou et al study did not adjust for hypertension.

Source: AHA website , using NHANES data

Source: AHA website, using NHANES data

As can be seen above, hypertension in the general population closely associates with increasing age, hence any association with hypertension may merely represent confounding due to age, and should be interpreted after careful analysis.

The Question Is Definitively Answered

The speed at which data and studies are being published on Covid-19 is so rapid that a study has been published since I began writing this post which I feel definitively answers my title question.
Using observational data on 8910 hospitalized patients in 169 hospitals in Asia, Europe, and North America, investigators examined cardiovascular factors that were associated with in-hospital death.
Surprisingly, in this database, although the average age of the 515 nonsurvivors was 56 years versus 49 years for the 8195 survivors, there was no difference in the prevalence of hypertension. In fact survivors had a slightly higher prevalence of hypertension (26.4% versus 25.2%) despite being younger than the nonsurvivors.
A multivariable logistic-regression model identified age>65 years, coronary artery disease, heart failure, arrhythmia, COPD and current smoking as independently associated with in-hospital death.
nejmoa2007621_f1
Hypertension was not independently associated with in-hospital death.
Interestingly, patients receiving ACE inhibitors and statins were substantially less likely to die.
In Summary
  1. Hypertension does not put you at a higher risk of serious illness or death due to Covid-19.
  2. As discussed in previous posts (see here and here), there is no reason to stop taking your ACE inhibitor or angiotensin receptor blocker (ARB) blood pressure medication during this pandemic. (Also don’t start demanding you be put on an ACE inhibitor-the protective association seen in one study does not prove causality, we need randomized trials to show drugs safety and effectiveness!)
  3. Be very skeptical of early anecdotal reports and small trials rushed to publication (especially “preprints” which have not been peer-reviewed) during Covid-19. The poorly substantiated claims that hypertension was a major risk factor for death and that ACE inhibitors increased patient’s risk during Covid-19 have proven false. As better data emerges regarding hydroxychloroquine, despite enthusiastic anecdotal reports from some physicians, this drug has not been proven safe and/or effective for Covid-19 treatment.

Skeptically Yours,

-ACP

 

10 thoughts on “Does Hypertension Put You at a Higher Risk for Infection or Death From Covid-19?”

  1. The label of hypertension is not an independent risk factor. That does not mean that hypertension is not a risk factor.

    1. David,
      An interesting distinction. I could change the title to Does the label of hypertension ….or does the diagnosis of hypertension….
      Those with the diagnosis of hypertension can have high, low or normal BP depending on treatment, etc.
      Are you aware of any data that indicates presenting with a high BP is a risk factor?

      1. Extending David’s query a bit: Is having blood pressure readings well above the defining threshold for “hypertension” – while on the spot in the COVID-19 ICU – not a risk factor, whether or not there was a previous diagnosis of hypertension or treatment for it? Normal healthy BP will elevate under the stress of COVID and the like, right?
        Trying to avoid semantics here, Boss. 🙂

        1. This is from the NephJC article.
          It is also not clear how hypertension was coded – we can speculate that it might be based on use of hypertension medications rather than actual BP measurement. We do have data on actual BP from two studies:

          In one study by (Huang et al, Lancet), the median systolic BP, on admission, in the 13 patients with COVID-19 who required ICU care later was 145 mm Hg compared to 122 in the 22 patients who did not. The patients needing ICU care were similar in age to those who did not need ICU care (median age 49 years)

          In another study (Chen et al, BMJ) the median arterial BP, on admission, was 137 mm Hg among those who died compared to 125 mm Hg amongst those who survived. In this study, the patients who died were older (median age 68 years) than those who survived (median age 51 years)

          Without better adjusted or stratified data, it is hard to say what this represents.

  2. Great point on not rushing to judgement before the PEER reviewed data comes out. One thing that has been really interesting regarding this crisis has been the identification of novel clinical applications of existing RX’s for treatment of COVID. I realize this a common occurrence, but I have never witnessed it play out. Two points to that, I am surprised at how some medical and science professionals are so quick to jump on the bandwagon of efficacy for a drug based on anecdotal or low grade data or just flat out speculation. I am not sure if its because of the nature of the situation (people are dying so let’s give it try) vs wishful thinking (maybe we found a cure) or something more nefarious like a financial gain/COI.

    The other point is correlation doesn’t equal causation. I just read a lengthy article on vitamin D and how low levels correlated to higher mortality rates with respect to covid. This in turn has led some people to believe by increasing their vitamin D levels through supplements that this will function as a prophylaxis to getting covid or lessening its severity. Although this is an interesting finding that certainly warrants more investigation, it should be met with a wait and see approach so that we can get a better handle on why that is.

    We are living in interesting times, if there is one thing I hope can come from this crisis is that therapy trials can be developed quickly with randomization and that good quality data can be mined and accurately interpreted to elucidate what works and what doesn’t.

  3. Observationally speaking, having a decent Vit D level – We have less problems DownUnder here – is just sensible, and the fact that D- deficiency does your immune system no favours is not hard to swallow.
    But ‘hypertension’, well, is it not related to Insulin Resistance ?

    There would be few worse places in USA than NYC for large % of Insulin Resistant population. Obesity which usually (but not always) co-exists with IR adds the risk from … fat… generating some chemicals which discomboboulate the immune system… not a great idea when fighting off a nasty invader !
    Can you think of a better time to consider re-visiting with the Standard American Processed foods Diet ?

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