Background. Irisin, an exercise-induced myokine and adipocytokine, has been reported to decrease in type 2 diabetic patients. Recently, several research studies indicated that circulating levels were correlated with bone mineral density (BMD). To evaluate bone metabolism, bone turnover markers (BTMs) should be included. However, with respect to newly diagnosed T2DM patients, the relevance of their irisin levels to their BTMs and BMD remains unclear. The investigation of serum irisin levels in patients who have been newly diagnosed with type 2 diabetes and illumination of the relationship between serum irisin levels and those two indices of BMD and BTMs mentioned above are the intention of this cross-sectional study. Methods. 66 new-onset type 2 diabetic patients (T2DM group), together with 82 control subjects (NGT group), were recruited in this study. Serum irisin concentrations and BTMs (including osteocalcin (OC), procollagen type 1 N-terminal propeptide (P1NP), and β-C-terminal telopeptides of type I collagen (β-CTX)) were determined by the enzyme-linked immunosorbent assay (ELISA). Glucose, lipid profile, and insulin were considered as measuring indicators as well. Dual-energy X-ray absorptiometry (DXA) was utilized to evaluate the indicator of BMD. Serum irisin, BTMs, and BMD were compared between diabetic patients and healthy individuals. Pearson and Spearman correlation analyses were applied as well to assess correlations between irisin and BTMs and BMD. Multiple stepwise regression analysis was conducted to identify the independent factors of irisin. ROC curve analyses were carried out for serum irisin prediction for osteoporosis/osteopenia (OP). Results. The serum levels of irisin, procollagen type 1, intact N-terminal propeptide (P1NP), and osteocalcin (OC) were evidently lower in T2DM subjects than in NGT subjects (10.90 ± 1.88 vs .11.69 ± 2.06 ng/mL, < 0.05; 36.42(25.68,51.70) vs. 44.52(35.73,58.05)ng/ml, < 0.05; 16.15(12.40,21.66) vs. 18.70(15.56, 23.22)ng/ml, < 0.05). Among patients with T2DM, the circulating irisin level of those with OP was lower than that of normal BMD (9.98 ± 2.09 vs. 11.39 ± 1.57 ng/ml, < 0.01); irisin had a negative correlation with β-C-terminal telopeptides of type I collagen (β-CTX) (r = −0.496, < 0.001) and came back unrelated to Lumbar BMD; Lumbar BMD was negatively relevant to OC (r = −0.274, < 0.05) and β-CTX (r = −0.410, < 0.01). Multiple linear regression analyses of stepwise models implied that TG, LDL-C, and β-CTX were independently associated with serum irisin concentrations ( < 0.01 or < 0.05). Conclusion. Serum irisin level was declined in patients with type 2 diabetes diagnosed in the near term and had a certain association with bone turnover markers. It is suggested to consider irisin as a potential biomarker of bone metabolic disorder in T2DM patients with the initial diagnosis.

Introduction: Sirtuin 1, a class III histone deacetylase, plays a critical role in the pathophysiology of both diabetes mellitus and bone metabolism by promoting osteoblast differentiation and inhibiting osteoclast maturation. However, its exact impact on bone mineral density (BMD) and bone metabolism in type 2 diabetes mellitus (T2DM) remains unclear. This study investigates the relationship between Sirtuin 1 levels, BMD, and bone metabolism in newly diagnosed T2DM patients, specifically examining alterations in Sirtuin 1 levels in those with concomitant osteoporosis or osteopenia.Methods: A total of 69 newly diagnosed T2DM patients and 82 control subjects with normal glucose tolerance (NGT) were enrolled. Serum Sirtuin 1 levels and bone turnover markers, including osteocalcin (OC), procollagen type 1 N-terminal propeptide (P1NP), and β-C-terminal telopeptide of type I collagen (β-CTX), were measured using enzyme-linked immunosorbent assay (ELISA). BMD was assessed via dual-energy X-ray absorptiometry (DXA). Comparisons of these parameters were made between the T2DM and NGT groups.Results: T2DM patients were further categorized into a normal BMD group (DMn) and an osteopenia or osteoporosis group (DMo), and differences in Sirtuin 1 levels between these subgroups were analyzed. Risk factors for osteoporosis/osteopenia in T2DM patients were also evaluated. Serum Sirtuin 1 levels were found to be significantly diminished in the T2DM group relative to the control group (P < 0.05), with no significant differences in lumbar spine BMD, OC, 25(OH)D, and β-CTX between groups (P > 0.05). Osteoporosis incidence was higher in T2DM subjects compared to controls (34.8% vs. 18.3%, P = 0.026). Subgroup analysis revealed that SIRT1 levels in T2DM patients with osteoporosis or osteopenia exhibited a significant reduction compared to those with normal BMD (P < 0.05). Logistic regression indicated that Sirtuin 1, age, HDL-C, P1NP, and β-CTX were independent risk factors for osteoporosis in T2DM patients.Discussion: In conclusion, decreased serum Sirtuin 1 levels are associated with bone turnover markers in T2DM patients and may serve as an independent risk factor and potential biomarker for diagnosing bone metabolism disorders in newly diagnosed T2DM patients.

Endothelial dysfunction (ED) contributes to the pathologic process underlying macrovascular complications, a common complication of type 2 diabetes mellitus (T2DM). Soluble endoglin (sEng) shed from the extracellular domain of the entire endoglin molecule blocks endothelial protection mediated by transforming growth factor-beta 1 (TGF-β1). The reactive hyperemia index (RHI), which is determined by reactive hyperemia peripheral arterial tonometry (RH-PAT), is a new index with which to evaluate ED. This study determined the changes in serum sEng levels in newly-diagnosed (untreated) T2DM patients and the correlation with the RHI. The T2DM group included 34 newly-diagnosed T2DM patients, while the control group included 53 healthy adults. The clinical data from the two groups were evaluated retrospectively. The intima-media thickness (IMT) of the common carotid artery (CCA) and the ankle-brachial index (ABI) of both legs were used to assess structural vascular changes. The serum sEng level was determined using an ELISA kit. Endothelial function was assessed using RH-PAT and the RHI was computed. The serum sEng level in the T2DM group was significantly greater than the control group, although the RHI was significantly lower in the T2DM group (p < 0.05). The serum sEng level was negatively correlated with the RHI in T2DM patents (r = 0.354, p = 0.041). The serum sEng level, CCA-IMT, and ABI were not significantly correlated with T2DM (p > 0.05). In summary, among newly-diagnosed T2DM patients, the serum sEng levels were inversely correlated with the RHI, and an elevated sEng level may be associated with ED.

Objective: This study explores the correlations between visceral adiposity index, fatty liver indices and thyroid dysfunction in type 2 diabetes mellitus patients. Methods: This cross-sectional investigation was carried out between January 2021 and December 2022, encompassing 131 adult out-patients. Patients with other endocrine diseases, severe hepatic or renal insufficiency, or recent use of thyroid-affecting medications were excluded. Clinical and laboratory data, including body mass index, waist circumference, lipid profiles, liver function markers, and thyroid function tests, were collected. Results: Blood tests showed hepatic injury markers, alanine aminotransferase, aspartate aminotransferase, and adverse lipid profiles, elevated triglycerides, reduced high-density lipoprotein, significantly increased across fatty liver indices quartiles (P < 0.05), reflecting hepatocellular injury. Waist circumference and body mass index also increased significantly with higher fatty liver indices quartiles. Similarly, visceral adiposity index showed strong correlations with metabolic parameters, including elevated alanine aminotransferase, aspartate aminotransferase, and triglycerides levels (P < 0.05). Regarding thyroid function, TSH levels increased to some extent (P = 0.068), suggesting a potential link between fatty liver and hypothyroidism. Conclusion: This study highlights the significant role of visceral fat accumulation and liver fat deposition in contributing to insulin resistance and metabolic imbalances among individuals with type 2 diabetes. Clinicians and public health departments should promote early identification and intervention of visceral fat accumulation and fatty liver as tools to prevent metabolic syndrome and related diseases.

In the present study, we investigate the effect of reduced cystathionine-gamma-lyase (CSE) expression in high glucose induced metalloproteinasesl4 (MMP14) expression in adipocytes and visceral adipose tissues. Diabetic mice were prepared by injections of STZ and the expression of CSE, MMP14 in visceral adipose tissues were determined. Adipocytes were differentiated from 3T3-L1 cells and treated with high glucose (HG), H2S slow-releasing compound GYY4137 or transfected with CSE siRNA. Then the expression of CSE, MMP14 were determined by western blotting. CSE knockout mice were generated by crossing CSE+/- heterozygous mice and given intraperitoneally (i.p.) injections of GYY4137, and then the expression of CSE and MMP14 in visceral adipose tissues were determined by quantitative real-time PCR and western blotting. The following results were obtained from the study. In adipose tissues of diabetic mice, the mRNA and protein expression of MMP14 increased while the mRNA and protein expression of CSE decreased. In 313-1,1 adipocytes, both HG-DMEM and CSE siRNA transfection increased the mRNA and protein of MMP14. The addition of GYY4137 inhibited HG-induced upregulation of MMP14 expression. In CSE knockout mice, the mRNA and protein expression of MMP14 in adipose tissues increased, which could be inhibited by i.p. injections of GYY4137. In conclusion, high glucose increased the expression of MMP14 in adipocytes and visceral adipose tissues through inhibiting the expression of CSE.