Changes in Glycemic Control and Lipid Profiles Following COVID-19 Infection in Adults with Type 2 Diabetes: A Retrospective Study in Saudi Arabia

Background: The clinical course and mortality risk of COVID-19 in patients with type 2 diabetes (T2D) remain elevated. Understanding its pathogenesis is essential for prognostic and therapeutic strategies. Viral infections can disrupt host glucose and lipid metabolism. This study evaluated changes in glycemic and lipid parameters following COVID-19 infection in T2D patients. Methods: A retrospective analysis was conducted on T2D patients who tested positive for COVID-19 between April 2020 and December 2021. Laboratory results before and after infection were compared to assess changes in glycemic and lipid markers. Results: The study included 969 patients with T2D; 56.7% were female, and the median age was 58 years (IQR: 49–67). Hypertension, asthma, and chronic kidney disease were present in 51.5%, 14.2%, and 7.2% of patients, respectively. Fasting blood glucose did not change significantly from before to after COVID-19 infection [7.9 mmol/L (IQR: 6.2–10.6) vs. 7.8 mmol/L (IQR: 6.2–10.2)], nor did HbA1c [7.6% (IQR: 6.7–9.1) vs. 7.6% (IQR: 6.5–9.2)]. In contrast, modest but statistically significant reductions were observed in triglycerides [1.47 mmol/L (IQR: 1.13–2.00) vs. 1.44 mmol/L (IQR: 1.08–1.94)], total cholesterol [4.3 mmol/L (IQR: 3.67–5.03) vs. 4.1 mmol/L (IQR: 3.55–4.93)], and LDL cholesterol [2.7 mmol/L (IQR: 2.11–3.45) vs. 2.5 mmol/L (IQR: 1.98–3.23)]. HDL cholesterol remained unchanged [1.0 mmol/L (IQR: 0.90–1.21) vs. 1.0 mmol/L (IQR: 0.89–1.22)]. Conclusions: COVID-19 infection was not associated with significant long-term changes in glycemic control among patients with T2D, as fasting blood glucose and HbA1c levels remained broadly stable after infection. In contrast, significant reductions were observed in total cholesterol, LDL cholesterol, and triglyceride levels, while HDL cholesterol remained unchanged. These findings indicate that changes following COVID-19 infection were more apparent in lipid parameters than in glycemic markers.