Aim: This review aims to explore the pathophysiological mechanisms by which SARS-- CoV-2 affects lipid metabolism and the metabolome in patients with Type 2 Diabetes Mellitus (T2DM). It compares these alterations with those observed in non-diabetic individuals and proposes strategies to mitigate potential long-term metabolic complications. Methods: A narrative review was conducted using PubMed, Scopus, and Google Scholar to identify studies published between 2004 and 2025 concerning adult T2DM patients during or after COVID-19 infection. The analysis focused on lipid profiles, including total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and triglycerides, along with hemoglobin A1C levels and COVID-19 severity. Search terms included: (Post-COVID-19) AND (Diabetes Mellitus Type 2), ((Post-COVID-19) AND (Diabetes Mellitus Type 2)) AND (Lipid Profile), ((- COVID-19) AND (Lipid Profile)) AND (Diabetes Mellitus Type 2), (Post-COVID-19) AND (Lipid Metabolism), (COVID-19) AND (Lipid Metabolism), (Post-COVID-19) AND (Metabolome), (COVID-19) AND (Metabolome). Results: Post-COVID-19, patients with T2DM exhibit persistent disturbances in lipid metabolism and broader metabolic pathways. SARS-CoV-2 infection amplifies metabolic dysregulation, leading to decreased levels of total cholesterol, HDL, and LDL, while triglyceride levels remain variable. Mechanistically, the virus disrupts lipid homeostasis by upregulating genes such as CD36 and peroxisome proliferator-activated receptor gamma (PPAR-γ) and by altering amino acid metabolism, particularly within the tryptophan-kynurenine and glutamine pathways. Discussion: Enhanced oxidative stress and lipid peroxidation contribute to systemic inflammation and endothelial dysfunction. Furthermore, glycemic control worsens due to increased insulin resistance and pancreatic interactions involving angiotensin-converting enzyme 2 (ACE2). Conclusion: COVID-19 significantly alters lipid metabolism and the metabolomic profile in individuals with T2DM. Longitudinal studies are warranted to clarify the duration and clinical impact of these changes and to develop personalized therapeutic strategies for this high-risk population.

Background: Chronic kidney disease (CKD) affects up to 40% of individuals with diabetes mellitus. Given the fact that CKD in diabetics may result from various non-diabetic renal disorders, kidney biopsy remains essential in cases with atypical clinical presentation. The aim of this study was to assess the prevalence of diabetic nephropathy (DN) and other non-diabetic kidney diseases (NDKD) among diabetic patients who underwent renal biopsy. We also tried to find clinical and laboratory markers predicting the presence of DN in renal tissue. Methods: A retrospective analysis of all native renal biopsies in diabetic patients performed between 2010 and 2024 in one European nephrology center. Results: The cohort included 115 diabetic patients. DN was diagnosed in 43.5% individuals. Among NDKD cases, vasculitis (8.7%), membranous nephropathy (7.8%), and amyloidosis (7.8%) were most frequent. Compared with the NDKD group, patients with DN were younger, had a longer duration of DM, more often required insulin therapy, more frequently demonstrated diabetic retinopathy (DR) and nephrotic syndrome, and exhibited higher HbA1c levels. In multivariable logistic regression, younger age, need for insulin therapy, and presence of DR were the strongest predictors of DN. Conclusions: NDKD is common among DM patients. Patient’s younger age, the need for insulin therapy, and the presence of DR are strong predictive markers for diabetic nephropathy. Renal biopsy remains the most accurate method for diagnosis and should be considered in every case of suspected NDKD.