Endocrine Abstracts

Introduction: The prevalence of diabetes mellitus (DM) in patients with coronavirus disease (COVID)-19 varies widely, depending on population characteristics, country, age and disease severity. Moreover, pre-existing DM seems to double the risk of both critical COVID-19 and mortality.

Aim: To evaluate incidence and mortality risk of COVID-19 in a large diabetic population in Northern Italy.

Methods: A retrospective, observational, big data cohort study was carried out, including subjects with type 1 and type 2 DM living in the Province of Modena, submitted to at least one swab for SARS-CoV-2 between March 2020 and March 2021. Data were extracted from the Hospital data warehouse.

Results: 9553 diabetic patients were enrolled (age 68.8+14.1 years). COVID-19 was detected in 2302 patients (24.1%) with death in 8.9% of cases. No differences in COVID-19 prevalence were detected considering sex. Mean age (67.6+13.7 vs 69.8+14.1 years) was significantly lower in infected than uninfected patients and COVID-19 was more frequent in youngest people, according to quartile of age (P<0.001) and retirement age of 65 years (P<0.001). Moreover, DM duration was lower in infected than uninfected patients (11.2+6.6 vs 11.8+6.7 years, P<0.001), but higher HbA1c was found in infected compared to uninfected patients (58.7+16.7 vs 56.7+15.9 mmol/mol, P<0.001). Accordingly, COVID-19 was less frequent in patients treated with anti-diabetic drugs compared to those not treated (P<0.001). Logistic analysis confirms these results and identifies 3 risk factors for COVID-19: age (odds ratio-OR 1.013, 95% confidence interval-CI:1.008-1.017), DM duration (OR 1.007, 95%CI:1.001-1.013), and HbA1c (OR 1.009, 95%CI:1.002-1.016). As regards COVID-19 mortality, logistic analysis demonstrated that death was predicted by DM duration (OR 1.010, 95%CI: 1.005-1.015) and HbA1c (OR 1.005, 95%CI:1.002-1.009). Three ROC analyses were generated setting death as test variable, showing that the worse prognosis could be predicted by DM duration longer than 10.9 years (AUC=0.639, 95%CI:0.601–0.676) and age older than 74.4 years (AUC=0.797, 95%CI:0.767–0.827).

Conclsion: Our big data analysis confirms the correlation between COVID-19 mortality and DM. In particular, although COVID-19 was more frequently detected in youngest patients, a poor glycemic control worsens outcomes, confirming the importance of strict glyco-metabolic control, especially in older diabetic people with long DM duration. Thus, diabetic patients should undergo careful monitoring of blood glucose. In particular, patients with DM and COVID-19 should be followed carefully when older than 74 years and with long DM duration.