Connections between body composition and dysregulation of islet α- and ß-cells in type 2 diabetes.

BACKGROUND: Accompanying islet α- and ß-cell dysregulation in type 2 diabetes (T2D) at the microscopic scale, alterations in body composition at the macroscopic scale may affect the pathogenesis of T2D. However, the connections between body composition and islet α-cell and ß-cell functions in T2D have not been thoroughly explored. METHODS: For this cross-sectional study, we recruited a total of 729 Chinese Han patients with T2D in a consecutive manner. Dual-energy X-ray absorptiometry (DXA) was used to measure body composition, which included total bone-free mass, total fat and lean mass, trunk fat and lean mass and limb fat and lean mass. Every patient underwent an oral glucose tolerance test to simultaneously detect glucose, C-peptide and glucagon. The indices of islet α-cell function included fasting glucagon levels and the area under the curve of glucagon after a challenge (AUCglucagon), while the indices of ß-cell function included the insulin sensitivity index derived from C-peptide (ISIC-peptide) and the area under the curve of C-peptide after a challenge (AUCC-peptide). RESULTS: Among all patients, fat mass, especially trunk fat mass, was significantly correlated with ISIC-peptide and AUCC-peptide levels (r = - 0.330 and 0.317, respectively, p < 0.001), while lean mass, especially limb lean mass, was significantly correlated with fasting glucagon and AUCglucagon levels (r = - 0.196 and - 0.214, respectively, p < 0.001). Moreover, after adjusting for other relevant variables via multivariate linear regression analysis, increased trunk fat mass was independently associated with decreased ISIC-peptide (ß = - 0.247, t = - 3.628, p < 0.001, partial R2 = 10.9%) and increased AUCC-peptide (ß = 0.229, t = 3.581, p < 0.001, partial R2 = 8.2%), while decreased limb lean mass was independently associated with increased fasting glucagon (ß = - 0.226, t = - 2.127, p = 0.034, partial R2 = 3.8%) and increased AUCglucagon (ß = - 0.218, t = - 2.050, p = 0.041, partial R2 = 2.3%). Additionally, when separate analyses were performed with the same concept for both sexes, we found that increased trunk fat mass was still independently associated with decreased ISIC-peptide and increased AUCC-peptide, while decreased limb lean mass was still independently associated with increased fasting glucagon and AUCglucagon. CONCLUSIONS: Increased trunk fat mass may partly account for decreased insulin sensitivity and increased insulin secretion, while decreased limb lean mass may be connected to increased fasting glucagon and postprandial glucagon secretion.

Corrigendum: The association between normal serum sodium levels and bone turnover in patients with type 2 diabetes.

[This corrects the article DOI: 10.3389/fendo.2022.927223.].

The association between normal serum sodium levels and bone turnover in patients with type 2 diabetes.

Background: Sodium is a critically important component of bones, and hyponatremia has firmly been established as a risk factor associated with the incidence of fragility fractures. However, researches have also revealed that lower serum sodium are linked to reductions in muscle mass and a higher risk of cardiovascular disease even when these levels are within the normal range. Accordingly, this study was developed to examine the relationships between normal serum sodium concentrations and bone turnover in patients with type 2 diabetes (T2D). Methods: Patients with T2D were enrolled in the present study from January 2021 to April 2022. All patients underwent analyses of serum sodium levels, oral glucose tolerance testing (OGTT), bone turnover markers (BTMs), and dual-energy X-ray absorptiometry (DXA) scanning. BTMs included bone formation markers osteocalcin (OC) and N-terminal propeptide of type-I procollagen (PINP), and bone resorption marker C-terminal telopeptide (CTx). Patients were stratified into three subgroups based on the tertiles of their serum sodium concentrations. Results: In total, 372 patients with T2D and sodium levels in the normal range were enrolled in this study. Serum OC and PINP levels were increased from subgroup with the low sodium tertile to that with the high sodium tertile (p for trend < 0.05), whereas CTx level was comparable among the subgroups. A positive correlation was detected between serum sodium levels and both lnOC (r = 0.210, p < 0.001) and lnPINP (r = 0.196, p < 0.001), with these relationships remaining significant even following adjustment for age, sex, body mass index (BMI), and HbA1c. Only after adjusting for these four factors a positive correlation was detected between serum sodium levels and CTx levels (r = 0.108, p < 0.05). Linear regression analyses revealed that following adjustment for potential covariates, serum sodium level was and positively significantly associated with lnOC level (ß = 0.134, t = 2.281, p < 0.05) and PINP level (ß = 0.179, t = 3.023, p < 0.01). Conclusion: These results highlight a significant association between low-normal serum sodium levels and low bone turnover.

Increased levels of serum adenosine deaminase and increased risk of diabetic peripheral neuropathy in type 2 diabetes.

Background: Increased serum adenosine deaminase (ADA) levels have been shown to be involved in metabolic abnormalities and immune disequilibrium, which may in turn contribute to inflammatory diseases. This study aimed to determine whether increased serum ADA levels are related to diabetic peripheral neuropathy (DPN) in patients with type 2 diabetes (T2D). Methods: This study was part of a series exploring the potential risks for DPN. All patients received DPN assessment based on neuropathic symptoms, neuropathic signs, and nerve conduction studies to calculate the composite Z score of nerve latency, amplitude and conduction velocity (NCV). DPN was confirmed by both at least a presentation of neuropathic symptoms/signs and an abnormal nerve conduction index. Serum ADA levels were also synchronously detected. Results: A total of 384 eligible patients with T2D were recruited for this study, and 24.5% (n=94) were determined to have DPN. Increases in serum ADA levels were closely associated with increases in composite Z score of latency (ß=0.263, t=5.273, p<0.001) and decreases in composite Z score of amplitude (ß=-0.126, t=-2.352, p=0.019) and NCV (ß=-0.201, t=-3.841, p<0.001) after adjusting for other clinical covariates. Moreover, each 5 U/L increase in serum ADA levels was associated with a 1.781-fold increased adjusted odds ratio of having DPN (95% confidence interval: 1.271-2.495). Furthermore, the optimal cut-off value of serum ADA levels to discriminate DPN was ≥14.2 U/L (sensitivity=59.57%, specificity=75.52% and Youden index=0.351) after analysis by receiver operating characteristic curve. Conclusions: Increased serum ADA levels may be a potential risk factor for DPN in patients with T2D.

High-normal serum carcinoembryonic antigen levels and increased risk of diabetic peripheral neuropathy in type 2 diabetes.

BACKGROUND: Increased serum carcinoembryonic antigen (CEA) levels are reported to be associated with various metabolic and inflammatory diseases. This study assessed whether high-normal serum CEA is related to diabetic peripheral neuropathy (DPN) in patients with type 2 diabetes (T2D). METHODS: All subjects received DPN assessment based on neuropathic symptoms, neuropathic signs, and nerve conduction studies to calculate composite Z scores of nerve latency, amplitude and conduction velocity (NCV). DPN was confirmed by both at least a presentation of neuropathic symptoms/signs and an abnormal nerve conduction index. Serum CEA levels and other clinical indices were also synchronously detected. Multivariable linear regression analyses were used to determine the independent effects of serum CEA levels on nerve conduction indices, multivariable logistic regression analyses were used to determine the independent impact of CEA levels on the risk of DPN, and receiver operating characteristic (ROC) curve analysis was used to assess the diagnostic capability of CEA levels to discriminate DPN. RESULTS: We ultimately recruited 402 eligible subjects with normal ranges of serum CEA for this study, and 25.4% (n = 102) were determined to have DPN. After adjusting for other clinical covariates, serum CEA levels were independently associated with the composite Z score for latency (ß = 0.132, t = 2.330, p = 0.021), amplitude (ß = - 0.164, t = - 2.838, p = 0.005) and NCV (ß = - 0.210, t = - 3.662, p < 0.001). Moreover, the prevalence of DPN in the first, second, third and fourth quartiles of CEA level was 12.9%, 19.0%, 29.4% and 40.4%, respectively (p for trend < 0.001); the corresponding adjusted odds ratios and 95% CIs for DPN in CEA quartiles were 1, 1.47 (0.45-4.82), 1.72 (0.54-5.53) and 4.58 (1.39-15.06), respectively. Furthermore, the optimal cut-off value of high-normal serum CEA to discriminate DPN was ≥ 2.66 ng/mL, with a Youden index of 0.28, sensitivity of 66.67% and specificity of 61.00%. CONCLUSIONS: Increased serum CEA levels within the normal range are closely linked to dysfunction of peripheral nerve conduction and the risk of DPN, and high-normal serum CEA levels are a potential risk factor for DPN in T2D.

Increased plasma D-dimer levels may be a promising indicator for diabetic peripheral neuropathy in type 2 diabetes.

Background: Increased plasma D-dimer levels have been reported to be associated with a range of adverse health outcomes. This study aimed to determine whether plasma D-dimer is connected to diabetic peripheral neuropathy (DPN) in patients with type 2 diabetes (T2D). Methods: This study was part of a series exploring the potential risks for DPN. All patients were questioned for neurologic symptoms, examined for neurologic signs, and received nerve conduction studies to collect nerve action potential onset latency, amplitude, and nerve conduction velocity (NCV). Composite Z scores of latency, amplitude, and NCV were calculated. DPN was confirmed as both at least a neurologic symptom/sign and an abnormality of nerve conduction studies. Coagulation function indices, such as plasma D-dimer levels, were also synchronously detected. Results: We finally recruited 393 eligible patients for this study, of whom 24.7% (n = 97) were determined to have DPN. The plasma D-dimer level was found to be closely associated with the composite Z score of latency, amplitude, and NCV after adjusting for other coagulation function indices and clinical covariates (latency: ß = 0.134, t = 2.299, p = 0.022; amplitude: ß = -0.138, t = -2.286, p = 0.023; NCV: ß = -0.139, t = -2.433, p = 0.016). Moreover, the prevalence of DPN in the first, second, third, and fourth quartiles (Q1, Q2, Q3, and Q4) of the D-dimer level was 15.2%, 15.9%, 26.4%, and 42.7%, respectively (p for trend < 0.001). The corresponding adjusted odds ratios and 95% CIs for DPN in D-dimer quartiles were 1, 0.79 (0.21-2.99), 1.75 (0.49-6.26), and 5.17 (1.38-19.42), respectively. Furthermore, the optimal cutoff value of the plasma D-dimer level to discriminate DPN was ≥0.22 mg/L (sensitivity = 67.01%, specificity = 58.78%, and Youden index = 0.26) after analysis by the receiver operating characteristic curve. Conclusions: Increased plasma D-dimer levels may be a promising indicator for DPN in patients with T2D.

The Positive Relationship Between the Low-Density Lipoprotein Cholesterol/Apoprotein B Ratio and Bone Turnover Markers in Patients With Type 2 Diabetes.

Background: Dyslipidemia may contribute to low bone turnover in patients with type 2 diabetes (T2D) through mediating oxidative stress and atherosclerosis. The low-density lipoprotein cholesterol/apoprotein B (LDL-C/Apo B) ratio is a surrogate marker of small and density low-density lipoprotein cholesterol (sd-LDL-C), a most harmful group of LDL-Cs. The present study aimed to investigate the association between the LDL-C/Apo B ratio and bone turnover in patients with T2D. Methods: This study was a cross-sectional study enrolled patients with T2D from January 2021 to December 2021. Each participant was assessed for lipid profiles, bone turnover markers (BTMs), lumbar spine (L1-L4) and hip dual-energy X-ray absorptiometry (DXA) scans. Osteoporosis was diagnosed as a T-score lower than or equal to -2.5 at the spine or hip. Results: A total of 335 patients with T2D were enrolled in the study, and the LDL-C/Apo B ratio ranged from 0.78 to 4.00. Along with the LDL-C/Apo B ratio tertile ascending, osteocalcin (OC), C-terminal telopeptide (CTx) and N-terminal propeptide of type-I procollagen (PINP) levels gradually increased (all p < 0.05). There were no differences in lumbar spine and hip T-score, proportion of osteoporosis (all p > 0.05) among the three subgroups. The LDL-C/Apo B ratio was positively correlated with lnOC (r = 0.244, p < 0.001), lnCTx (r = 0.226, p < 0.01) and lnPINP (r = 0.211, p < 0.001). These significant positive correlations persisted even when divided into male and female subgroups. Furthermore, three multiple linear regression analyses were constructed to investigate the independent association of the LDL-C/Apo B ratio with the BTMs levels. After adjusting for other clinical parameters, the LDL-C/Apo B ratio was still significantly associated with OC level (ß = 0.199, t = 3.348, p < 0.01), CTx level (ß = 0.238, t = 4.084, p < 0.001) and PINP level (ß = 0.162, t = 2.741, p < 0.01). Conclusion: The LDL-C/Apo B ratio was significantly and positively associated with BTMs in patients with T2D. In clinical practice, more attention should be paid to the patients with T2D whose LDL-C/Apo B ratio is relatively low for the purpose of maintaining bone health.

Association of serum stromal cell-derived factor 1 levels with EZSCAN score and its derived indicators in patients with type 2 diabetes.

Background: The aim of the study was to explore whether plasma stromal cell-derived factor 1 (SDF-1) levels are associated with the EZSCAN score and its derived indicators in patients with type 2 diabetes (T2D). Methods: From July 2020 to December 2020, a total of 253 patients with T2D were consecutively recruited. Serum SDF-1 levels were measured by sandwich ELISA. EZSCAN test was applied to evaluate the sudomotor function of each patient, and based on the results, EZSCAN score, cardiac autonomic neuropathy risk score (CANRS) and cardiovascular risk score (CVDRS) were calculated by particular algorithms. In addition, other relevant clinical data were also collected. Results: With increasing tertiles of serum SDF-1 levels, the CANRS and CVDRS significantly increased (both Pfor trend <0.001), while the EZSCAN score significantly decreased (Pfor trend <0.001). Moreover, serum SDF-1 levels were significantly and positively correlated with the CANRS and CVDRS (r = 0.496 and 0.510, respectively, both P < 0.001), and negatively correlated with the EZSCAN score (r = -0.391, P < 0.001). Furthermore, multivariate linear regression analyses were constructed, and after adjusting for other clinical covariates, serum SDF-1 levels were independently responsible for EZSCAN score (ß = -0.273, t = -3.679, P < 0.001), CANRS (ß = 0.334, t = 5.110, P < 0.001) and CVDRS (ß = 0.191, t = 4.983, P = 0.003). Conclusions: SDF-1 levels in serum were independently associated with the EZSCAN score and its derived indicators, such as CANRS and CVDRS in patients with T2D.

Increased serum cystatin C levels and responses of pancreatic α- and ß-cells in type 2 diabetes.

Background: Increased serum cystatin C (CysC) can predict the onset of type 2 diabetes (T2D). Meanwhile, impaired pancreatic α- and ß-cell functions get involved in the pathophysiological processes of T2D. So this study was to explore the relationships between serum CysC levels and pancreatic α- and ß-cell functions in T2D. Methods: In this cross-sectional observational study, a total of 2634 patients with T2D were consecutively recruited. Each recruited patient received a serum CysC test and oral glucose tolerance test for synchronous detection of serum C-peptide and plasma glucagon. As components of pancreatic ß-cell function, insulin secretion and sensitivity indices were evaluated by C-peptide area under the curve (AUC-CP) and C-peptide-substituted Matsuda's index (Matsuda-CP), respectively. Fasting glucagon (F-GLA) and post-challenge glucagon calculated by glucagon area under the curve (AUC-GLA) were used to assess pancreatic α-cell function. These skewed indices and were further natural log-transformed (ln). Results: With quartiles of serum CysC levels ascending, AUC-CP, F-GLA and AUC-GLA were increased, while Matsuda-CP was decreased (P for trend <0.001). Moreover, serum CysC levels were positively related to lnAUC-CP, lnF-GLA and lnAUC-GLA (r= 0.241, 0.131 and 0.208, respectively, P < 0.001), and inversely related to lnMatsuda-CP (r= -0.195, P < 0.001). Furthermore, after controlling for other relevant variables via multivariable linear regression analysis, serum CysC levels were identified to account for lnAUC-CP (ß= 0.178, t= 10.518, P < 0.001), lnMatsuda-CP (ß= -0.137, t= -7.118, P < 0.001), lnF-GLA (ß= 0.049, t= 2.263, P = 0.024) and lnAUC-GLA (ß= 0.121, t= 5.730, P < 0.001). Conclusions: Increased serum CysC levels may be partly responsible for increased insulin secretion from ß-cells, decreased systemic insulin sensitivity, and elevated fasting and postprandial glucagon secretion from α-cells in T2D.

Sedentary lifestyle and body composition in type 2 diabetes.

BACKGROUND: Body composition alterations may participate in the pathophysiological processes of type 2 diabetes (T2D). A sedentary lifestyle may be responsible for alterations of body composition and adverse consequences, but on which body composition of patients with T2D and to what extent the sedentary lifestyle has an effect have been poorly investigated. METHODS: We recruited 402 patients with T2D for this cross-sectional study. All patients received questionnaires to evaluate sedentary time and were further divided into three subgroups: low sedentary time (LST, < 4 h, n = 109), middle sedentary time (MST, 4-8 h, n = 129) and high sedentary time (HST, > 8 h, n = 164). Each patient underwent a dual energy X-ray absorptiometry (DXA) scan to detect body composition, which included body fat percentage (B-FAT), trunk fat percentage (T-FAT), appendicular skeletal muscle index (ASMI), lumbar spine bone mineral density (BMD) (LS-BMD), femoral neck BMD (FN-BMD), hip BMD (H-BMD) and total BMD (T-BMD). Other relevant clinical data were also collected. RESULTS: With increasing sedentary time (from the LST to HST group), B-FAT and T-FAT were notably increased, while ASMI, LS-BMD, FN-BMD, H-BMD and T-BMD were decreased (p for trend < 0.01). After adjustment for other relevant clinical factors and with the LST group as the reference, the adjusted mean changes [B (95% CI)] in B-FAT, T-FAT, ASMI, LS-BMD, FN-BMD, H-BMD and T-BMD in the HST group were 2.011(1.014 to 3.008)%, 1.951(0.705 to 3.197)%, - 0.377(- 0.531 to - 0.223) kg/m2, - 0.083(- 0.124 to - 0.042) g/cm2, - 0.051(- 0.079 to - 0.024) g/cm2, - 0.059(- 0.087 to - 0.031) g/cm2 and - 0.060(- 0.088 to - 0.033) g/cm2, p < 0.01, respectively. CONCLUSIONS: A sedentary lifestyle may independently account for increases in trunk and body fat percentage and decreases in appendicular skeletal muscle mass and BMD of the lumbar spine, femoral neck, hip and total body in patients with T2D.

Plasma 1,5-anhydro-D-glucitol is associated with peripheral nerve function and diabetic peripheral neuropathy in patients with type 2 diabetes and mild-to-moderate hyperglycemia.

BACKGROUND: Plasma 1,5-anhydro-D-glucitol (1,5-AG) may be a easily accessible marker for glycemic variability under mild-to-moderate hyperglycemia. The present study was to investigate the association of 1,5-AG with peripheral nerve function and diabetic peripheral neuropathy (DPN) in patients with T2D and mild-to-moderate hyperglycemia. METHODS: We recruited 574 T2D patients with mild-to-moderate hyperglycemia (HbA1c < 8.0%) for this cross-sectional study, with plasma 1,5-AG synchronously detected. All patients were questioned for neurologic symptoms, examined for neurologic signs and screened for peripheral nerve function. Nerve function included the latency, amplitude and nerve conduction velocity (NCV) of limbs nerves (median, ulnar nerve, common peroneal, superficial peroneal, tibial and sural nerve). Besides, composite Z-score of latency, amplitude and NCV were calculated. DPN was identified as both at least a neurologic symptom/sign and an abnormality of peripheral nerve function. RESULTS: Among the recruited patients, 23.9% (n = 137) were identified to be with DPN, and the prevalence of DPN decreased from 36.6%, 24.5%, 21.2%, 13.3% from first (Q1), second (Q2), and third (Q3) to fourth quartile (Q4) of 1,5-AG. Moreover, multivariable linear regression analysis showed 1,5-AG was associated with composite Z-score of nerve latency (ß = - 0.18, t = - 3.84, p < 0.001), amplitude(ß = 0.26, t = 5.35, p < 0.001) and NCV (ß = 0.24, t = 5.61, p < 0.001), respectively. Furthermore, compared to Q4 of 1,5-AG as reference, the adjusted odds ratios and 95% CIs for DPN of Q3, Q2, and Q1 were 1.29(0.59-2.81), 1.85(0.87-3.97), and 2.72(1.16-6.34), respectively. Additionally, receiver operating characteristic analysis revealed that optimal cutoff value of 1,5-AG to indicate DPN was ≤ 30.8 µmol/L, with sensitivity of 56.20% and specificity of 66.36%. CONCLUSIONS: Low plasma 1,5-AG is closely associated with impaired peripheral nerve function and DPN in T2D patients under mild-to-moderate hyperglycemia.

Association of sleep quality with glycemic variability assessed by flash glucose monitoring in patients with type 2 diabetes.

BACKGROUND: Deterioration of sleep quality has been reported to contribute to the incidence of diabetes and may be responsible for glycemic status in diabetes. The present study explored the relationship between sleep quality and glycemic variability in patients with type 2 diabetes (T2D). METHODS: We recruited 111 patients with T2D for this cross-sectional study. Each patient underwent flash glucose monitoring for 14 days to obtain glycemic variability parameters, such as standard deviation of glucose (SD), coefficient of variation of glucose (CV), mean amplitude of glycemic excursions (MAGE), mean of daily differences (MODD), and time in glucose range of 3.9-10 mmol/L (TIR3.9-10). After 14 days of flash glucose monitoring, each patient received a questionnaire on the Pittsburgh Sleep Quality Index (PSQI) to evaluate subjective sleep quality. HbA1c was also collected to assess average glucose. RESULTS: HbA1c was comparable among the subgroups of PSQI score tertiles. Across ascending tertiles of PSQI scores, SD, CV and MAGE were increased, while TIR3.9-10 was decreased (p for trend < 0.05), but not MODD (p for trend = 0.090). Moreover, PSQI scores were positively correlated with SD, CV, MODD and MAGE (r = 0.322, 0.361, 0.308 and 0.354, respectively, p < 0.001) and were inversely correlated with TIR3.9-10 (r = - 0.386, p < 0.001). After adjusting for other relevant data by multivariate linear regression analyses, PSQI scores were independently responsible for SD (ß = 0.251, t = 2.112, p = 0.041), CV (ß = 0.286, t = 2.207, p = 0.033), MAGE (ß = 0.323, t = 2.489, p = 0.018), and TIR3.9-10 (ß = - 0.401, t = - 3.930, p < 0.001) but not for MODD (ß = 0.188, t = 1.374, p = 0.177). CONCLUSIONS: Increased glycemic variability assessed by flash glucose monitoring was closely associated with poor subjective sleep quality evaluated by the PSQI in patients with T2D.

The association between serum adenosine deaminase levels and Graves' disease.

BACKGROUND: Adenosine deaminase (ADA) is essential for the differentiation and maturation of lymphocytes, while lymphocytes infiltration in thyroid tissue is a vital pathological feature of Graves' disease (GD). The aim of the present study was to compare the concentration of ADA between healthy controls (HC) and patients with GD, and evaluate the association between ADA and GD. METHODS: A total of 112 GD patients and 77 matched HC were enrolled in this study. Each participant was examined for thyroid hormones and autoantibodies, ADA concentration, and thyroid ultrasonography. RESULTS: Serum ADA levels in GD patients were significantly higher than that in HC subgroup (P < 0.001). In GD patients, serum ADA levels were positively associated with serum-free triiodothyronine (FT3), free thyroxine (FT4), thyroid peroxidase antibody (TPOAb), thyroid-stimulating hormone receptor antibody (TRAb) levels, and total thyroid gland volume (thyroid VolT) and negatively associated with serum thyroid-stimulating hormone receptor (TSH) levels (all P < 0.05). There were no similar correlations in the HC subgroup. Multiple linear regression analysis suggested that serum TSH, FT3, and ADA levels played an important role in serum TRAb levels. CONCLUSIONS: Our results demonstrated that serum ADA levels were closely associated with GD.

The relationship between adenosine deaminase and heart rate-corrected QT interval in type 2 diabetic patients.

BACKGROUND: Prolonged heart rate-corrected QT (QTc) interval may reflect poor prognosis of patients with type 2 diabetes (T2D). Serum adenosine deaminase (ADA) levels are related to hyperglycemia, insulin resistance (IR) and inflammation, which may participate in diabetic complications. We investigated the association of serum ADA levels with prolonged QTc interval in a large-scale sample of patients with T2D. METHODS: In this cross-sectional study, a total of 492 patients with T2D were recruited. Serum ADA levels were determined by venous blood during fasting. QTc interval was estimated from resting 12-lead ECGs, and prolonged QTc interval was defined as QTc > 440 ms. RESULTS: In this study, the prevalence of prolonged QTc interval was 22.8%. Serum ADA levels were positively associated with QTc interval (r = 0.324, P < 0.0001). The proportion of participants with prolonged QTc interval increased significantly from 9.2% in the first tertile (T1) to 24.7% in the second tertile (T2) and 39.0% in the third tertile (T3) of ADA (P for trend < 0.001). After adjusting for other possible risk factors by multiple linear regression analysis, serum ADA level was still significantly associated with QTc interval (ß = 0.217, t = 3.400, P < 0.01). Multivariate logistic regression analysis showed that female (OR 5.084, CI 2.379-10.864, P < 0.001), insulin-sensitizers treatment (OR 4.229, CI 1.290-13.860, P = 0.017) and ADA (OR 1.212, CI 1.094-1.343, P < 0.001) were independent contributors to prolonged QTc interval. CONCLUSIONS: Serum ADA levels were independently associated with prolonged QTc interval in patients with T2D.

Serum fatty acid-binding protein 4 levels and responses of pancreatic islet ß-cells and α-cells in patients with type 2 diabetes.

BACKGROUND: Serum fatty acid-binding protein 4 (FABP4), as an intracellular lipid chaperone and adipokine, was reported to be related to the incidence of type 2 diabetes (T2D) and diabetic complications, but its association with pancreatic islet ß-cell and α-cell functions has not been fully elucidated. So the present study was to investigate the serum FABP4 levels and responses of islet ß-cells and α-cells in patients with T2D. METHODS: 115 patients with T2D and 89 healthy controls (HC), who received serum FABP4 levels test, were recruited to participate in this study. Moreover, 75-g oral glucose tolerance test (OGTT) was performed in T2D patients to evaluate islet ß-cell and α-cell functions. Systemic insulin sensitivity and overall insulin secretion of islet ß-cell function were assessed by Matsuda index using C peptide (ISIM-cp) and ratio of the area under the C peptide curve to the glucose curve (AUCcp/glu) during OGTT, respectively. Fasting glucagon (Gluca0min) and postchallenge glucagon assessed by the area under the glucagon curve (AUCgluca) were determined during OGTT to evaluate islet α-cell function. And other various clinical variables were also measured in all participants. Skewed variables were natural log-transformed (ln), such as lnFABP4. RESULTS: The serum FABP4 levels in T2D patients were significantly higher than those in HC (p < 0.05). And after partially adjusting for fasting plasma glucose, serum lnFABP4 levels were negatively correlated with lnISIM-cp (r = - 0.332, p < 0.001) and positively correlated with lnAUCcp/glu (r = 0.324, p < 0.001), lnGluca0min (r = 0.200, p = 0.040) and lnAUCgluca (r = 0.311, p < 0.001), respectively, in patients with T2D. Furthermore, when multiple linear regression analyses were applied to adjust for other various clinical variables, serum lnFABP4 levels were found to remain associated with lnISIM-cp (ß = - 0.296, t = - 2.900, p = 0.005), lnAUCcp/glu (ß = 0.223, t = 2.038, p = 0.046), lnGluca0min (ß = 0.272, t = 2.330, p = 0.024) and lnAUCgluca (ß = 0.341, t = 3.065, p = 0.004), respectively. CONCLUSION: Increased serum FABP4 levels were closely associated with blunted insulin sensitivity, increased insulin secretion, and elevated fasting and postchallenge glucagon levels in patients with T2D.

The relationship between insulin sensitivity and serum antithrombin 3 activity in patients with type 2 diabetes.

BACKGROUND: Antithrombin 3 (AT3) is a physiological inhibitor of thrombin, and serum AT3 activity was found to decrease at the status of type 2 diabetes (T2D). T2D was presented with an increased risk of thrombotic complications at the background of impaired insulin sensitivity. The aim of this study was to investigate the relationship between insulin sensitivity indices and serum AT3 activity in patients with T2D. METHODS: We conducted a cross-sectional study in patients with T2D who consented to participate in the study at the Endocrinology Department of Affiliated 2 Hospital of Nantong University from January 2015 to June 2018. All patients received serum AT3 activity test and 75 g oral glucose tolerance test (OGTT). Basal and systemic insulin sensitivity were assessed by homeostasis model assessment of insulin resistance (HOMA-IR) and Matsuda index (ISIMatsuda), respectively, from the OGTT. And other relevant clinical data were also collected. RESULTS: Total of 1612 patients with T2D were enrolled in the study, with a mean age of 58.67 ± 13.09 years and a median diabetes duration of 6 years (interquartile range, 1-10 years). Across ascending quartiles of serum AT3 activity, HOMA-IR progressively decreased, while ISIMatsuda progressively increased (all P for trend < 0.001). Moreover, serum AT3 activity was negatively correlated with HOMA-IR (r = -0.189, P < 0.001) and positively correlated with ISIMatsuda (r = 0.221, P < 0.001). After adjusting for other metabolic risk factors, hemostatic parameters and glucose-lowering therapies by multivariate linear regression analysis, HOMA-IR (ß = -0.185, t = -5.960, P < 0.001) and ISIMatsuda (ß = 0.197, t = 6.632, P < 0.001) remained independently associated with the serum AT3 activity in patients with T2D, respectively. CONCLUSIONS: Reduced basal and systemic insulin sensitivity are associated with decreased serum AT3 activity in patients with T2D.

Inverse relationship between serum adenosine deaminase levels and islet beta cell function in patients with type 2 diabetes.

OBJECTIVE: Type 2 diabetes (T2D) is a chronic low-grade inflammatory disease, which characterized by islet beta cell dysfunction. Serum adenosine deaminase (ADA) is an important enzyme that regulates the biological activity of insulin, and its levels are greatly increased in inflammatory diseases with insulin resistance. The present study was designed to explore the relationship between serum ADA levels and islet beta cell function in patients with T2D. METHODS: This cross-sectional study recruited 1573 patients with T2D from the Endocrinology Department of the Affiliated Hospital 2 of Nantong University between 2015 and 2018. All participants were received serum ADA test and oral glucose tolerance test (OGTT). Insulin sensitivity index (assessed by Matsuda index using C-peptide, ISIM-cp), insulin secretion index (assessed by ratio of area under the C-peptide curve to glucose curve, AUCcp/glu) and islet beta cell function (assessed by insulin secretion-sensitivity index 2 using C-peptide, ISSI2cp) were derived from OGTT. And other clinical parameters, such as HbA1c, were also collected. RESULTS: It was showed that HbA1c was significantly increased, while ISIM-cp, AUCcp/glu and ISSI2cp significantly decreased, across ascending quartiles of serum ADA levels. Moreover, serum ADA levels were negatively correlated with ISSI2cp (r = - 0.267, p < 0.001). Furthermore, after adjusting for other clinical parameters by multiple linear regression analysis, serum ADA levels were still independently associated with ISSI2cp (ß = - 0.125, t = - 5.397, p < 0.001, adjusted R2 = 0.459). CONCLUSIONS: Serum ADA levels are independently associated with islet beta cell function in patients with T2D.

Serum stromal cell-derived factor-1 levels are associated with diabetic kidney disease in type 2 diabetic patients.

The present study was designed to explore whether serum stromal cell-derived factor-1 (SDF-1) levels were associated with diabetic kidney disease (DKD). Serum SDF-1 levels were measured by sandwich ELISA. Patients with an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 or a urinary albumin-to-creatinine ratio (UACR) ≥30 mg/g for 3 months were identified as having DKD. Among the recruited type 2 diabetic patients, 18.71% (n = 32) were found to have DKD, and the serum SDF-1 levels of these patients were higher than those of patients without DKD (p < 0.05). Serum SDF-1 levels were positively correlated with cystatin C levels, the UACR and DKD incidence (r = 0.330, 0.183 and 0.186, respectively, p < 0.05) and inversely related to eGFR (r = -0.368, p < 0.001). After adjusting for other clinical covariates by multivariate logistic regression analyses, serum SDF-1 levels were found to be an independent contributor to DKD, and the odds ratio (95% confidence interval) was 1.438 (1.041-1.986). Furthermore, receiver operating characteristic analysis revealed that the optimal SDF-1 cutoff value for indicating DKD was 5.609 ng/mL (its corresponding sensitivity was 82.00%, and specificity was 46.90%). Our results demonstrated that serum SDF-1 levels were closely associated with DKD and could be considered a potent indicator for DKD in patients with T2D.

Associations of Plasma Glucagon Levels with Estimated Glomerular Filtration Rate, Albuminuria and Diabetic Kidney Disease in Patients with Type 2 Diabetes Mellitus.

BACKGROUND: Type 2 diabetes mellitus (T2DM) is characterized by elevated fasting glucagon and impaired suppression of postprandial glucagon secretion, which may participate in diabetic complications. Therefore, we investigated the associations of plasma glucagon with estimated glomerular filtration rate (eGFR), albuminuria and diabetic kidney disease (DKD) in T2DM patients. METHODS: Fasting glucagon and postchallenge glucagon (assessed by area under the glucagon curve [AUCgla]) levels were determined during oral glucose tolerance tests. Patients with an eGFR <60 mL/min/1.73 m2 and/or a urinary albumin-to-creatinine ratio (UACR) ≥30 mg/g who presented with diabetic retinopathy were identified as having DKD. RESULTS: Of the 2,436 recruited patients, fasting glucagon was correlated with eGFR and UACR (r=-0.112 and r=0.157, respectively; P<0.001), and AUCgla was also correlated with eGFR and UACR (r=-0.267 and r=0.234, respectively; P<0.001). Moreover, 31.7% (n=771) presented with DKD; the prevalence of DKD was 27.3%, 27.6%, 32.5%, and 39.2% in the first (Q1), second (Q2), third (Q3), and fourth quartile (Q4) of fasting glucagon, respectively; and the corresponding prevalence for AUCgla was 25.9%, 22.7%, 33.7%, and 44.4%, respectively. Furthermore, after adjusting for other clinical covariates, the adjusted odds ratios (ORs; 95% confidence intervals) for DKD in Q2, Q3, and Q4 versus Q1 of fasting glucagon were 0.946 (0.697 to 1.284), 1.209 (0.895 to 1.634), and 1.521 (1.129 to 2.049), respectively; the corresponding ORs of AUCgla were 0.825 (0.611 to 1.114), 1.323 (0.989 to 1.769), and 2.066 (1.546 to 2.760), respectively. Additionally, when we restricted our analysis in patients with glycosylated hemoglobin <7.0% (n=471), we found fasting glucagon and AUCgla were still independently associated with DKD. CONCLUSION: Both increased fasting and postchallenge glucagon levels were independently associated with DKD in T2DM patients.

Fasting serum total bile acid levels are associated with insulin sensitivity, islet ß-cell function and glucagon levels in response to glucose challenge in patients with type 2 diabetes.

Type 2 diabetes (T2D) is characterized by islet ß-cell dysfunction and impaired suppression of glucagon secretion of α-cells in response to oral hyperglycaemia. Bile acid (BA) metabolism plays a dominant role in maintaining glucose homeostasis. So we evaluated the association of fasting serum total bile acids (S-TBAs) with insulin sensitivity, islet ß-cell function and glucagon levels in T2D. Total 2,952 T2D patients with fasting S-TBAs in the normal range were recruited and received oral glucose tolerance tests for determination of fasting and postchallenge glucose, C-peptide and glucagon. Fasting and systemic insulin sensitivity were assessed by homeostasis model assessment (HOMA) and Matsuda index using C-peptide, i.e., ISHOMA-cp and ISIM-cp, respectively. Islet ß-cell function was assessed by the insulin-secretion-sensitivity-index-2 using C-peptide (ISSI2cp). The area under the glucagon curve (AUCgla) was used to assess postchallenge glucagon. The results showed ISHOMA-cp, ISIM-cp and ISSI2cp decreased, while AUCgla notably increased, across ascending quartiles of S-TBAs but not fasting glucagon. Moreover, S-TBAs were inversely correlated with ISHOMA-cp, ISIM-cp and ISSI2cp (r = -0.21, -0.15 and -0.25, respectively, p < 0.001) and positively correlated with AUCgla (r = 0.32, p < 0.001) but not with fasting glucagon (r = 0.033, p = 0.070). Furthermore, after adjusting for other clinical covariates by multiple linear regression analyses, the S-TBAs were independently associated with ISHOMA-cp (ß = -0.04, t = -2.82, p = 0.005), ISIM-cp (ß = -0.11, t = -7.05, p < 0.001), ISSI2cp (ß = -0.15, t = -10.26, p < 0.001) and AUCgla (ß = 0.29, t = 19.08, p < 0.001). Increased fasting S-TBAs are associated with blunted fasting and systemic insulin sensitivity, impaired islet ß-cell function and increased glucagon levels in response to glucose challenge in T2D.