J-shaped association between fasting blood glucose levels and COVID-19 severity in patients without diabetes

Abstract

Aims: Coronavirus disease 2019 (COVID-19) has become a recognized worldwide pandemic. Researchers now know that mortality from COVID-19 can be reduced through early prevention measures. This retrospective, multi-centered study of 293 COVID-19 patients without diabetes explores the association between fasting blood glucose (FBG) levels and the risk of COVID-19 disease progression, with the goal of providing clinical evidence for glycemic targets in patients.

Methods: The multivariate stepwise binary logistic regression analysis was used to test the dose-response effects of FBG levels on the risk of severe and critical condition in COVID-19 patients.

Results: FBG levels were plotted in quintiles with set at <4.74, 4.74-5.21, 5.21-5.78, 5.78-7.05, and ≧7.05 mmol/L. The constituent ratio of severe or critical cases in each FBG quintile was 20.7%, 1.7%, 13.8%, 27.1%, and 67.2%, respectively (P < 0.0001). When the second quintile was used as the reference, the adjusted odds ratios (AORs) (95%CI) for the risk of severe/critical condition in COVID-19 was 25.33 (2.77, 231.64), 1.00 (Reference), 3.13 (0.33, 29.67), 10.59 (1.23, 91.24), 38.93 (4.36, 347.48) per FBG quintile respectively (P < 0.001).

Conclusions: We provide evidence of J-shaped associations between FBG and risk of severe and critical condition in non-diabetes patients with COVID-19, with nadir at 4.74-5.78 mmol/L.

Keywords: Coronavirus disease 2019 (COVID-19); Fasting blood glucose; Glycemic target; Hyperglycemia; Hypoglycemia.

Fig. 1

Flow diagram presenting inclusion and exclusion criteria for subjects in this study.

Fig. 2

The constituent ratio of severe and critical cases in confirmed COVID-19 patients across fasting blood glucose (FBG) quintiles. The constituent ratio of severe and critical cases in each FBG quintile (<4.74, 4.74–5.21, 5.21–5.78, 5.78–7.05, and ≧ 7.05 mmol/L) was 20.7%, 1.7%, 13.8%, 27.1%, and 67.2%, respectively. White bar = cumulatively mild and moderate cases. Black bar = cumulatively severe and critical cases. ns: no significant difference.

Fig. 3

Adjusted dose–response curves by fasting blood glucose (FBG) quintiles for severe and critical condition of COVID-19 patients. Odds ratios of severe and critical condition in COVID-19 patients according to FBG quintiles (<4.74, 4.74–5.21, 5.21–5.78, 5.78–7.05, and ≧ 7.05 mmol/L) were estimated using the median value for each quintile (4.50, 5.02, 5.50, 6.21, and 9.05 mmol/L, respectively). Model 1 (solid black curve) included FBG quintile. Model 2 (black dashed curve) included FBG quintile, age, gender, and body mass index (BMI). Model 3 (black dotted curve) was additionally adjusted for lactate dehydrogenase (LDH), aspartate aminotransferase (AST), and high-density lipoprotein (HDL) levels.