Background: Growth differentiation factor-15 (GDF-15) is a stress-responsive cytokine associated with inflammation, metabolic dysfunction, and cardiovascular disease. Its role as a biomarker of microvascular complications in type 2 diabetes (T2D) remains incompletely defined. Objective: To evaluate circulating GDF-15 levels and their association with microvascular complications in patients with T2D. Methods: This cross-sectional study included 160 participants divided into three groups: T2D (n = 93), obesity without carbohydrate disorders (n = 36), and healthy controls (n = 31). Microvascular complications (neuropathy, nephropathy, retinopathy) were assessed. Multivariable logistic regression and receiver operating characteristic (ROC) analysis were performed. Results: GDF-15 levels were significantly higher in T2D compared with non-diabetic individuals (267.5 ± 168.9 vs. 118.3 ± 55.5 pg/mL, p < 0.001). Higher GDF-15 was associated with neuropathy (odds ratio (OR) 1.985; 95% confidence interval (CI) 1.431–2.753) and nephropathy (OR 1.673; 95% CI 1.243–2.254) in unadjusted models. After adjustment, only nephropathy remained independently associated (OR 1.405; 95% CI 1.026–1.923). ROC analysis showed moderate discriminative ability for nephropathy (area under the curve (AUC) = 0.763). Conclusions: Circulating GDF-15 levels are significantly elevated in patients with T2D and are associated with microvascular complications, with the strongest independent association observed for diabetic nephropathy. These findings suggest that GDF-15 may represent a promising biomarker reflecting metabolic stress and risk of diabetic complications.

Background/Objectives: Angiopoietin-like proteins 4 and 8 (ANGPTL4 and ANGPTL8) are key regulators of lipid metabolism and inflammatory processes, with a potential role in the pathogenesis of type 2 diabetes mellitus (T2DM) and its complications. This monocentric observational study evaluated serum levels of ANGPTL4 and ANGPTL8 in 160 participants (93 patients with T2DM and 67 controls without carbohydrate disturbances) and their associations with peripheral and cardiac autonomic neuropathy. Methods: This is a monocentric, cross-sectional, observational study conducted at the Endocrinology and Metabolic Disorders Clinic of Alexandrovska Hospital in Sofia, involving 160 participants and approved by the Ethics Committee of Medical University–Sofia, with all subjects providing written informed consent in accordance with the Declaration of Helsinki. The main methods included detailed clinical and anthropometric assessments, diagnosis of peripheral neuropathy via the Neuropathy Disability Score (NDS), evaluation of cardiac autonomic neuropathy using heart rate variability analysis and Ewing cardiovascular reflex tests, comprehensive laboratory investigations with fasting blood samples, measurement of serum ANGPTL4 and ANGPTL8 levels by ELISA kits, and statistical analysis performed with IBM SPSS version 25, using parametric and non-parametric tests, correlations, logistic regression, and ROC curves. Results: ANGPTL4 levels were significantly lower in patients with T2DM (12.6 ± 23.1 ng/mL vs. 21.5 ± 29.3 ng/mL; p = 0.033). In a multivariate model, higher values remained associated with lower odds of T2DM (OR per 1 SD = 0.634; p = 0.0424). ANGPTL8 demonstrated moderate discriminatory ability for cardiac autonomic neuropathy (AUC = 0.678; p = 0.007) in unadjusted analysis, but the association did not persist after covariate adjustment. ANGPTL4 showed inverse correlations with body weight, basal metabolic rate, and GGT. Conclusions: The results support the role of ANGPTL4 as a potential biomarker in metabolic disturbances and complications in T2DM, while ANGPTL8 remains mainly insignificant after correction for potential confounding factors.

Berardinelli–Seip syndrome, also known as congenital generalized lipodystrophy (CGL), is a rare genetic disorder characterized by lipoatrophy, acromegaloid features, hyperinsulinemia, hypertriglyceridemia, and hepatic steatosis. With estimated prevalence 1 in every 10,000,000 births, CGL challenges medical specialists to seek better ways for early diagnosis of the disease. Despite its rarity, the condition is associated with severe metabolic and cardiovascular complications, leading to significant morbidity and reduced life expectancy. Advances in molecular genetics have identified mutations in AGPAT2, BSCL2, CAV1, and PTRF, which provide important insights into adipose tissue biology and systemic metabolism. Early recognition and genetic confirmation are crucial to initiate timely interventions, including lifestyle modification, insulin sensitizers, and lipid-lowering therapies including metreleptin therapy in indicated cases. Two illustrative cases are presented, reflecting our experience with the clinical variability, genetic findings, and therapeutic strategies in CGL as well as highlighting the importance of comprehensive care and emerging therapies. Keywords: Berardinelli–Seip syndrome congenital generalized lipodystrophy CGL BSCL AGPAT2 gene diabetes mellitus hypertriglyceridemia

Background/Objectives: Diabetic neuropathy (DN) is one of the most common complications of type 2 diabetes mellitus (T2DM), involving complex metabolic, vascular, and epigenetic mechanisms. MicroRNA-210-3p (miR-210-3p), a hypoxia-responsive molecule, has been implicated in various diabetic complications, but its role in DN is not well defined. This study aimed to investigate the relationship between miR-210-3p expression, measured as delta Ct (ΔCt), and the presence and type of diabetic neuropathy, as well as correlations with corneal nerve parameters assessed by corneal confocal microscopy (CCM). Methods: Eighty patients with T2DM were stratified into four groups: no neuropathy, autonomic neuropathy, peripheral neuropathy, and combined neuropathy. Expression of miR-210-3p was quantified using RT-qPCR, and CCM was used to measure corneal nerve fiber density (CNFD), length (CNFL), and branch density (CNBD). Results: ΔCt values were significantly lower in patients with combined neuropathy compared to those without neuropathy, indicating higher miR-210-3p expression. Intermediate values were observed in autonomic and peripheral neuropathy groups. CCM parameters were significantly reduced in patients with DN. ΔCt was inversely correlated with neuropathy severity but positively associated with diabetes duration. Conclusions: These findings suggest that miR-210-3p may serve as a biomarker of nerve damage and cellular stress in diabetes, and that combining gene expression profiling with CCM could improve DN diagnosis and monitoring.

Background/Objectives: DEFA3 and DEFA5 are alpha-defensins, which are small cationic antimicrobial peptides that are part of the innate immune system. DEFA3 encodes human neutrophil peptide-3 (HNP-3), primarily expressed in neutrophils, while DEFA5 encodes human defensin-5 (HD-5), predominantly expressed in Paneth cells of the small intestine. Both defensins show elevated levels in diabetes and are strongly associated with diabetic nephropathy, with the highest concentrations found in patients with this complication. We evaluated serum levels of DEFA3 and DEFA5 in 160 participants (93 patients with T2DM and 67 controls without carbohydrate disturbances) and their associations with diabetic nephropathy, as well as peripheral and cardiac autonomic neuropathy and anthropometric and metabolic parameters. Methods: This was a monocentric, cross-sectional, observational study conducted at the Endocrinology and Metabolic Disorders Clinic of Alexandrovska Hospital in Sofia. Main methods included detailed clinical and anthropometric assessments, diagnosis of peripheral neuropathy via the Neuropathy Disability Score (NDS), evaluation of cardiac autonomic neuropathy using heart rate variability analysis and Ewing cardiovascular reflex tests, comprehensive laboratory investigations with fasting blood samples, and measurement of serum DEFA3 and DEFA5 levels by ELISA kits. Results: Serum DEFA3 and DEFA5 levels did not differ significantly between patients with T2DM and controls without carbohydrate disturbances, nor by sex or menopausal status. Patients with diabetic nephropathy showed significantly higher levels of both DEFA3 (345.7 ± 77.9 pg/mL vs. 299.2 ± 100.3 pg/mL; p = 0.042) and DEFA5 (5.3 ± 10.1 pg/mL vs. 2.9 ± 2.9 pg/mL; p = 0.044). DEFA5 levels were also elevated in participants with increased albumin-to-creatinine ratio (4.9 ± 9.9 pg/mL vs. 2.2 ± 1.5 pg/mL; p = 0.043). No significant differences were observed in patients with peripheral neuropathy, cardiac autonomic neuropathy, retinopathy, or macroangiopathy, although a non-significant trend toward higher values was noted. DEFA3 demonstrated moderate discriminatory ability for diabetic nephropathy (AUC = 0.641; p = 0.037), superior to DEFA5 (AUC = 0.570; p = 0.303). DEFA3 showed multiple weak positive correlations with diabetes duration, body weight, BMI, total and LDL-cholesterol, serum creatinine, and uric acid, while DEFA5 correlated only with total cholesterol. Conclusions: Circulating DEFA3 and DEFA5 are associated with diabetic nephropathy and selected metabolic and renal parameters in patients with type 2 diabetes, with DEFA3 showing moderate discriminatory capacity. The associations were largely attenuated after covariate adjustment, suggesting that these alpha-defensins likely reflect downstream innate immune activation and renal stress rather than acting as independent drivers of complications.

Small fiber neuropathy (SFN) is an early and common manifestation of diabetic polyneuropathy in type 2 diabetes mellitus (T2DM), often presenting with pain, dysesthesia, and autonomic dysfunction. Conventional diagnostic methods primarily assess large nerve fibers and may miss early small fiber damage, while skin biopsy, though considered the reference standard, is invasive. Corneal confocal microscopy (CCM) offers a rapid, noninvasive alternative for visualizing and quantifying small nerve fiber pathology in vivo. This was a monocentric observational study including 80 adults with T2DM (18–75 years), conducted at Alexandrovska Hospital, Sofia. Peripheral neuropathy was evaluated using a modified Neuropathy Disability Score and CCM-derived corneal nerve fiber density (CNFD), length (CNFL), and branching density (CNBD). Autonomic and sudomotor function were assessed by cardiovascular reflex tests and Sudoscan. Additional measures included vibration perception threshold, carotid intima–media thickness, body composition analysis, and laboratory parameters. Autonomic neuropathy was present in 66.7% and peripheral neuropathy in 57.5% of participants. Affected patients were older and had higher BMI and longer diabetes duration; peripheral neuropathy was additionally associated with higher HbA1c. Corneal nerve parameters negatively correlated with diabetes duration, HbA1c, intima–media thickness, and vibration threshold. Patients with diabetic retinopathy showed significantly reduced CNFD and CNFL. ROC analysis demonstrated significant discriminative ability of the HRV index for identifying peripheral neuropathy and of CNFD for detecting sudomotor dysfunction. These findings support CCM as a valuable, noninvasive marker of small fiber damage, closely linked to metabolic control, vascular impairment, and both sensory and autonomic dysfunction in T2DM.