COVID-19 and diabetes mellitus: implications for prognosis and clinical management

ABSTRACT

Introduction

COVID-19 is a novel coronavirus that emerged from Wuhan, China in December 2019, and within 3 months became a global pandemic.

Areas covered

PubMed search of published data on COVID-19, respiratory infections, and diabetes mellitus (DM). DM associates with impairments of both cellular and humoral immunity. Early emergent global data reveal that severity of clinical outcome from COVID-19 infection (including hospitalization and admission to Intensive Care Unit [ICU]), associate with co-morbidities, prominently DM. The key principles of management of COVID-19 in patients with DM include ongoing focused outpatient management (remotely where necessary) and maintenance of good glycemic control.

Expert opinion

We will remember the dawn of the third decade of the twenty-first century as a time when the world changed, the true scale and impact of which is hard for us to imagine. Like a phoenix from the ashes though, COVID-19 provides us with a great learning opportunity to renew insights into ourselves as individuals, our clinical teams, and the optimized provision of care for our patients. COVID-19 has re-shaped and re-focused our collective societal values, with a sea-changed shift from materialistic to human-centric, from self-centredness to altruism, ultimately for the betterment of patient care and the whole of society.

KEYWORDS:

• COVID-19
• diabetes mellitus
• respiratory infection
• immunity
• glycemia

Article highlights

• The first description of COVID-19 was amongst a cluster of patients suffering from pneumonia in Wuhan, China [1]. Within 3 months, COVID-19 became a global pandemic. In the early stages of the global pandemic, the numbers of new reported cases of COVID-19 doubled every 7.4 days, with a basic reproductive number estimated at 2.2 (95% CI 1.4 to 3.9) [3].

• Diabetes mellitus (DM) increases the risk of both susceptibility to, and severity of respiratory infections generally, including gram-negative bacteria, Staphylococcus aureus, fungi (an example being candidiasis) [9], and Mycobacterium tuberculosis (TB).

• DM is a known risk factor for adverse outcomes from coronavirus-related infections causing respiratory disease, including Severe Acute Respiratory Syndrome coronavirus (SARS-CoV) that occurred in 2002 [11,17,18], and the Middle East Respiratory Syndrome coronavirus (MERS-CoV) that emerged in Saudi Arabia in 2012 [11,19]. Epidemiological data reveal DM as the primary co-morbidity that associated with severe or lethal MERS-CoV infection [20].

• Much compelling evidence from the literature from both human- and rodent-based studies support the notion that DM associates with impairment of both cellular- and humoral-based immunity. Severity of hyperglycemia is commensurate with some measures of immune dysfunction, such as humoral immunity [30].

• Global data (including from China, Italy, and the US) reveal DM as an important and predominant risk factor for COVID-19.

• Based on the experiences of SARS-CoV in Taiwan [17], by maintaining close attention to outpatient preventive management of DM we may limit hospital admissions of our patients with DM, even at a time that post-dates the current pandemic. To optimize outpatient management, we should develop alternate means of health-care administration, such as telehealth, wearable technologies, and remote patient monitoring [41]. We should also strive for good glycemic control and stability in our patients with DM, both as a preventive measure and in the management of patients with DM who are already infected with COVID-19 (especially during insulin infusions), to optimize clinical outcome.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.