Cleaner Data Confirm COVID-19 Link to Diabetes, Hypertension


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Further refinement of data from patients hospitalized worldwide for COVID-19 disease showed a 12% prevalence rate of patients with diabetes in this population and a 17% prevalence rate for hypertension.

These are lower rates than previously reported for COVID-19 patients with either of these two comorbidities, yet the findings still document important epidemiologic links between diabetes, hypertension, and COVID-19, said the study’s authors.

A meta-analysis of data from 15,794 patients hospitalized because of COVID-19 disease that was drawn from 65 carefully curated reports published from December 1, 2019, to April 6, 2020, also showed that, among the hospitalized COVID-19 patients with diabetes (either type 1 or type 2), the rate of patients who required ICU admission was 96% higher than among those without diabetes and mortality was 2.78-fold higher, both statistically significant differences.

The rate of ICU admissions among those hospitalized with COVID-19 who also had hypertension was 2.95-fold above those without hypertension, and mortality was 2.39-fold higher, also statistically significant differences, reported a team of researchers in the recently published report.

The new meta-analysis was notable for the extra effort investigators employed to eliminate duplicated patients from their database of COVID-19 patients included in various published reports, a potential source of bias that likely introduced errors into prior meta-analyses that used similar data. “We found an overwhelming proportion of studies at high risk of data repetition,” the report said.

Virtually all of the included studies were retrospective case studies, nearly two-thirds had data from a single center, and 71% of the studies included only patients in China.

“We developed a method to identify reports that had a high risk for repetitions” of included patients, said Fady Hannah-Shmouni, MD, a senior author of the study. “We also used methods to minimize bias, we excluded certain patients populations, and we applied a uniform definition of COVID-19 disease severity,” specifically patients who died or needed ICU admission, because the definitions used originally by many of the reports were very heterogeneous, said Dr. Hannah-Shmouni, principal investigator for Endocrine, Genetics, and Hypertension at the National Institute of Child Health and Human Development.

Despite the effort to eliminate case duplications, the analysis remains subject to additional confounders, in part because of a lack of comprehensive patient information on factors such as smoking, body mass index, socioeconomic status, and the specific type of diabetes or hypertension a patient had.

“Even with these limitations, we were able to show that the prevalence of hypertension and diabetes is elevated in patients with COVID-19, that patients with diabetes have increased risk for both death and ICU admissions, and that there is the potential for reverse causality in the reporting of hypertension as a risk factor for COVID-19,” Dr. Hannah-Shmouni said in an interview. “We believe the explosion of data that associated hypertension and COVID-19 may be partially the result of reverse causality.”

One possible example of this reverse causality is the overlap between hypertension and age as potential risk factors for COVID-19 disease or increased infection severity. People “older than 80 frequently develop severe disease if infected with the novel coronavirus, and 80% of people older than 80 have hypertension, so it’s not surprising that hypertension is highly prevalent among hospitalized COVID-19 patients,” but this “does not imply a causal relationship between hypertension and severe COVID-19; the risk of hypertension probably depends on older age,” noted Ernesto L. Schiffrin, MD, a coauthor of the study, as well as professor of medicine at McGill University and director of the Hypertension and Vascular Research Unit at the Lady Davis Institute for Medical Research, both in Montreal.

“My current opinion, on the basis of the totality of data, is that hypertension does not worsen [COVID-19] outcomes, but patients who are elderly, obese, diabetic, or immunocompromised are susceptible to more severe COVID-19 and worse outcomes,” said Dr. Schiffrin in an interview.

The new findings show “there is certainly an interplay between the virus, diabetes, and hypertension and other risk factors,” and while still limited by biases, the new findings “get closer” to correctly estimating the COVID-19 risks associated with these comorbidities,” Dr. Hannah-Shmouni said.

The connections identified between COVID-19, diabetes, and hypertension mean that patients with these chronic diseases should receive education about their COVID-19 risks and should have adequate access to the drugs and supplies they need to control blood pressure and hyperglycemia.

Patients with diabetes also need to be current on vaccinations to reduce their risk for pneumonia. And recognition of the heightened COVID-19 risk for people with these comorbidities is important among people who work in relevant government agencies, health care workers, and patient advocacy groups, he added.

The study received no commercial funding. Dr. Hannah-Shmouni and Dr. Schiffrin had no disclosures.

SOURCE: Barrera FJ et al. J Endocn Soc. 2020 July 21. doi: 10.1210/jendso/bvaa102.

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