Dysglycemia after COVID-19 pneumonia: a six-month cohort study

Aim: The aim of this study was to understand whether the dysglycemia associated with SARS-CoV-2 infection persists or reverts when the viral infection resolves. Methods: We analyzed fasting blood glucose (FBG) after hospital discharge in a cohort of 621 adult cases with suspected COVID-19 pneumonia. Results: At admission, 18.8% of the patients in our cohort had pre-existing diabetes, 9.3% fasting glucose in the diabetes range without a prior diagnosis (DFG), 26% impaired fasting glucose (IFG), 44.9% normal fasting glucose (NFG), while 2% had no FBG available. FBG categories were similarly distributed in the 71 patients without confirmed COVID-19 pneumonia. During follow-up (median time 6 month) FBG was available for 321 out of the 453 (70.9%) surviving patients and showed a trend to a marginal increase [from 97 (87–116) to 100 (92–114) mg/dL; p = 0.071]. Transitions between FBG categories were analyzed in subjects without pre-existing diabetes (265 out of 321). We identified three groups: (i) patients who maintained or improved FBG during follow-up [Group A, n = 185; from 100 (86–109) to 94 (88–99) mg/dL; p < 0.001]; (ii) patients who moved from the NFG to IFG category [Group B, n = 66: from 89 (85–96) to 106 (102–113) mg/dl; p < 0.001]; (iii) patients who maintained or reached DFG during follow-up [Group C, n = 14: from 114 (94–138) to 134 (126–143) mg/dl; p = 0.035]. Male sex and ICU admission during the hospitalization were more prevalent in Group C compared to Group A or B. Conclusions: Six months after the SARS-CoV-2 infection DFG was evident in only few patients who experienced severe COVID-19 pneumonia.