Microvascular complications of diabetes include retinopathy (DR), diabetic kidney disease (DKD), and neuropathy (DN), which play a crucial role in diabetes management, as they significantly impair the functionality of the patient and remain major causes of morbidity despite advances in glycaemic control. The aim of this review was to summarize multi-omics findings in DR, DKD, and DN. Multi-omics studies consist of genomic, epigenomic, transcriptomic, proteomic, and metabolomic research. These studies provided comprehensive insights into the complex mechanisms underlying microvascular complications of diabetes, such as inflammation, angiogenesis, and apoptosis in the retina, kidneys, and nervous system. They also enabled the search for emerging diagnostic, prognostic, and therapeutic biomarkers. Moreover, changes in microRNA levels were found to differentiate patients with non-proliferative and proliferative DR. In addition, different proteins and metabolites concentrations were noticed in diabetes macular oedema and tractional retinal detachment—serious complications of DR. Specific molecular signatures, such as miR-146a and miR-27 dysregulation, changes in levels of HLA-DRA, AGER, and HSPA1A proteins, and alterations in tyrosine, alanine, 2,4-dihydroxybutanoic acid, ribonic acid, myoinositol, ribitol, 3,4-dihydroxybutanoic acid, valine, glycine, and 2-hydroxyisovaleric acid, were found to be characteristic for all microvascular complications of diabetes. In the future, more studies in multi-omics are expected to help improve precision medicine approaches to treating diabetes, allowing for personalized prediction, prevention, and treatment of microvascular complications.

Alström (ALMS) and Bardet-Biedl syndromes (BBS) are rare ciliopathies characterized by obesity and hyperglycemia that lead to type 2 diabetes, but also other disorders, including neurodegeneration. However, isolated clinical manifestations can be observed in carriers of heterozygous mutations in the ALMS1 and BBS genes. Recently, the influence of oral bacteria on the presence of obesity, type 2 diabetes, and neurodegenerative processes has been widely discussed. The purpose of the research project was to analyze the profile of the microbiome in the oral cavity by sequencing the 16S rRNA gene in ALMS/BBS patients and carriers of causative variants in these genes. Oral mucosal swabs were taken from 8 ALMS/BBS patients, 24 family members, 20 obese patients, and 29 healthy individuals. Streptococcus (30.7%), Haemophilus (18.9%), and Prevotella (11%) were the most common bacteria in the study group. Comparison between groups showed a higher abundance of Prevotella, Enterococcus, Eikenella, Capnocytophaga, Parvimonas, Selenomonas, and Corynobacterium, and a lower abundance of Lactobacillus in the study group compared to other groups. The specific profile of the oral microbiome found in patients with variants in the ALMS1 and BBS genes may enable the identification of the modulatory role of the oral microbiome in these disorders and point to new directions for additional therapy for these patients and heterozygous family members in the future.

Background: Intense exercise leads to neutrophil extracellular traps (NETs) formation, which triggers cell disintegration. NET, as well as other processes of apoptosis, necrosis, and spontaneous secretion, result in increased levels of cell-free DNA (cf-DNA) in the circulation. An increment of cf-DNA is also observed in autoimmune diseases, such as type 1 diabetes mellitus (T1DM). Repeated exhaustive exercises are an impulse for physiological adaptation; therefore, in this case–control study, we compared the exercise-induced increase in cf-DNA in men with T1DM and healthy controls to determine the development of the tolerance to exercise. Methods: Volunteers performed a treadmill run to exhaustion at a speed matching 70% of their personal VO2 max at three consecutive visits, separated by a 72 h resting period. Blood was collected before and after exercise for the determination of plasma cell-free nuclear and mitochondrial DNA (cf n-DNA, cf mt-DNA) by real-time PCR, blood cell count and metabolic markers. Results: Each bout of exhaustive exercise induced a great elevation of cf n-DNA levels. An increase in cf mt-DNA was observed after each run. However, the significance of the increase was noted only after the second bout in T1DM participants (p < 0.02). Changes in cf-DNA concentration were transient and returned to baseline values during 72 h of resting. The exercise-induced increment in circulating cf n-DNA and cf mt-DNA was not significantly different between the studied groups (p > 0.05). Conclusions: Cf-DNA appears to be a sensitive marker of inflammation, with a lower post-exercise increase in individuals with T1DM than in healthy men.

Background: WFS1-spectrum disorders are caused by a mutation in the WFS1 gene. The term includes a wide range of rare disorders, from the most severe Wolfram syndrome with autosomal recessive inheritance to milder clinical manifestations with a single causative variant in the WFS1 gene, such as Wolfram-like syndrome, low-frequency sensorineural hearing loss (LFSNHL), isolated diabetes mellitus (DM), nonsyndromic optic atrophy (OA), and isolated congenital cataracts. Methods: The aim of this study was to evaluate genotype–phenotype correlations in Polish patients with WFS1-spectrum disorders. The study group constituted 22 patients (10 F; 12 M), including 10 patients (3 F; 7 M) referred to the Outpatient Clinic for Rare Diseases in Children and Adolescents and Diabetogenetics between 2019 and 2024 with clinical symptoms suggestive of WFS1-spectrum disorders, and 12 of their first-degree relatives (7 F; 5 M) from 10 families in Poland. Molecular testing was performed using tNGS (Targeted Next Generation Sequencing; Illumina) and analyzed for variants in the WFS1 gene. Results: Thirteen different variants in the WFS1 gene were found in 22 individuals (10 patients and family members), including the identification of two new variants (c.1535T>C and c.2485C>G). All patients had hyperglycemia or DM, hearing impairment, OA, or a combination of these symptoms. Four patients in the study group were diagnosed with Wolfram syndrome and all were compound heterozygotes for variants in the WFS1 gene. Conclusions: The evaluation of molecular characteristics in combination with clinical symptoms broadens the understanding of WFS1-spectrum disorders and allows more accurate management and prognosis for patients with this diagnosis.

Background/Objectives: Transient neonatal diabetes mellitus (TNDM) is a form of neonatal diabetes mellitus (NDM) arising in the first weeks of life and remitting in infancy. Epigenetic aberrations at the imprinted 6q24 locus (overexpression of PLAGL1/HYMAI) are the most common causes of TNDM. The aim of this study was a retrospective clinical and genetic analysis of a Polish pediatric cohort, emphasizing the role of methylation-specific MLPA (MS-MLPA) in the diagnosis of TNDM. Methods: We conducted a retrospective analysis of the medical records of 22 patients with diabetes diagnosed at 1 year of age. The molecular studies included an analysis of the NDM gene panel by a targeted NGS and MS-MLPA for the 6q24 imprinting region. Results: 6q24-TNDM was confirmed in five patients, with a median age of diabetes remission of 4 months (IQR: 3–6 months). The MS-MLPA identified paternal UPD6 or isolated maternal hypomethylation of PLAGL1 in three patients, and two had a paternal 6q24 duplication. Conclusions: In our group, changes in the 6q24 region were confirmed in 22.7% of NDM patients, indicating the usefulness of the MS-MLPA technique in the diagnosis and detection of imprinting defects. We acknowledge key limitations, including diagnostic delays and incomplete parental testing, which precluded trio-based confirmation of paternal UPD6 versus epimutation in some cases; future diagnostic workflows should incorporate an early trio-based SNP array or STR confirmation. A methylation analysis should be included early in the NDM genetic diagnosis process to provide genetic counseling and monitor patients for diabetes recurrence.

Highlights: • Integrated oral microbiome–metabolome profiling in ALMS/BBS • Disease-specific oral microbial restructuring beyond obesity • Distinct saliva and GCF microbiome–metabolome networks • Organic, amino acid, and carbohydrate metabolism are associated with oral taxa • Multi-omics reveals functional host–microbiome interactions