Brown Adipose Tissue Activation Is Inversely Related to Central Obesity and Metabolic Parameters in Adult Human

Background: Recent studies have shown that adult human possess active brown adipose tissue (BAT), which might be important in affecting obesity. However, the supporting evidence on the relationship between BAT and central obesity and metabolic profile in large population based studies is sparse. Methodology/Principal Findings We studied 4011 (2688 males and 1323 females) tumor-free Chinese adults aged 18-89 for BAT activities, visceral/subcutaneous fat areas (VFA/SFA), waist circumferences (WC) and metabolic parameters. We found that the prevalence of BAT was around 2.7% in our study participants, with a significant sexual difference (5.5% in the females vs. 1.3% in the males; p<0.0001). BAT detection was increased in low temperature and declined in elderly subjects. The BAT positive subjects had lower BMI (P<0.0001), less SFA (P<0.01), VFA (P<0.0001), WC (P<0.0001), lower fasting glucose and triglyceride levels (both P<0.01) and increased HDL cholesterol concentrations (P<0.0001), compared with the BAT negative subjects. Robust logistic regression revealed that after adjustment for covariates (including age, sex, BMI, VFA, SFA and WC), age and BMI in the males (0.92 [95%CI, 0.88-0.96] and 0.84 [95% CI, 0.75-0.96], both P ≤0.008) while age and VFA in the females (0.87 [95%CI, 0.83-0.91] and 0.98 [95%CI, 0.97-0.99], respectively, P<0.05) were independently associated with detectable BAT. Conclusions/Significance: Our data suggest that decreased amount of active BAT might be associated with accumulation of visceral fat content and unfavorable metabolic outcomes

Acute Response of Peripheral Blood Cell to Autologous Hematopoietic Stem Cell Transplantation in Type 1 Diabetic Patient

Autologous nonmyeloablative hematopoietic stem cell transplantation (AHST) was the first therapeutic approach that can improve β cell function in type 1 diabetic (T1D) patients. This study was designed to investigate the potential mechanisms involved.We applied AHST to nine T1D patients diagnosed within six months and analyzed the acute responses in peripheral blood for lymphocyte subpopulation as well as for genomic expression profiling at the six-month follow-up.We found six patients obtained insulin free (IF group) and three remained insulin dependent (ID group); C-peptide production was significantly higher in IF group compared to ID group. The acute responses in lymphocytes at six-month follow-up include declined CD3(+)CD4(+), CD3(+)CD8(+) T cell population and recovered B cell, NK cell population in both groups but with no significant differences between the two groups; most immune-related genes and pathways were up-regulated in peripheral blood mononuclear cell (PBMC) of both groups while none of transcription factors for immune regulatory component were significantly changed; the IF group demonstrated more AHST-modified genetic events than the ID group and distinct pattern of top pathways, co-expression network as well as 'hub' genes (eg, TCF7 and GZMA) were associated with each group.AHST could improve the islet function in newly diagnosed T1D patients and elimination of the islet specific autoreactive T cells might be one of the mechanisms involved; T1D patients responded differently to AHST possibly due to the distinct transcriptional events occurring in PBMC.ClinicalTrials.gov NCT00807651

Brown Adipose Tissue in Humans Is Activated by Elevated Plasma Catecholamines Levels and Is Inversely Related to Central Obesity

BACKGROUND: Recent studies have shown that adult human possess active brown adipose tissue (BAT), which might be important in controlling obesity. It is known that ß-adrenoceptor-UCP1 system regulates BAT in rodent, but its influence in adult humans remains to be shown. The present study is to determine whether BAT activity can be independently stimulated by elevated catecholamines levels in adult human, and whether it is associated with their adiposity. METHODOLOGY/PRINCIPAL FINDINGS: We studied 14 patients with pheochromocytoma and 14 normal subjects who had performed both ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) and plasma total metanephrine (TMN) measurements during 2007-2010. The BAT detection rate and the mean BAT activity were significantly higher in patients with elevated TMN levels (Group A: 6/8 and 6.7±2.1 SUVmean· g/ml) than patients with normal TMN concentrations (Group B: 0/6 and 0.4±0.04 SUVmean· g/ml) and normal subjects (Group C: 0/14 and 0.4±0.03 SUVmean·g/ml). BAT activities were positively correlated with TMN levels (R = 0.83, p<0.0001) and were inversely related to body mass index (R = -0.47, p = 0.010), visceral fat areas (R = -0.39, p = 0.044), visceral/total fat areas (R = -0.52, p = 0.0043) and waist circumferences (R = -0.43, p = 0.019). Robust regression revealed that TMN (R = 0.81, p<0.0001) and waist circumferences (R = -0.009, p = 0.009) were the two independent predictors of BAT activities. CONCLUSIONS/SIGNIFICANCE: Brown adipose tissue activity in adult human can be activated by elevated plasma TMN levels, such as in the case of patients with pheochromocytoma, and is negatively associated with central adiposity

Immune response after autologous hematopoietic stem cell transplantation in type 1 diabetes mellitus

Abstract Background This study explored the details of the immune response after autologous hematopoietic stem cell transplantation (AHSCT) treatment in type 1 diabetes mellitus. Methods Peripheral blood mononuclear cells (PBMCs) from 18 patients with type 1 diabetes mellitus were taken at baseline and 12 months after AHSCT or insulin-only therapy. The lymphocyte proliferation, mRNA expression and secretion of pro-inflammatory and anti-inflammatory cytokines belonging to T-helper type 1 (Th1), T-helper type 17 (Th17) and regulatory T (Treg) cells in PBMC culture supernatants were assessed. Results Compared with patients receiving insulin-only treatment, the patients receiving AHSCT treatment showed better residual C-peptide secretion, lower anti-GAD titers and less exogenous insulin dosages after 12 months of follow-up. AHSCT treatment was associated with significantly reduced Th1 and Th17 cell proportions as well as decreased IFN-γ, IL-2, IL-12p40 and IL-17A levels in the PBMC culture supernatants (all P < 0.05). Although there was no significant Treg cell expansion after AHSCT treatment, we observed increased IL-10, TGF-β and Foxp3 mRNA expression and increased TGF-β levels. However, we found no significant changes in the T-cell subpopulations after insulin treatment, except for higher IL-12p40 mRNA expression and a lower proportion of Treg cells. Conclusions AHSCT treatment was associated with decreased expansion and function of Th1 and Th17 cells, which may explain the better therapeutic effect of AHSCT compared with the traditional intensive insulin therapy. Trial registration Clinicaltrials.gov NCT00807651 . Registered 18 December 2008

Plasma bile acid changes in type 2 diabetes correlated with insulin secretion in two-step hyperglycemic clamp

Background: Bile acids (BAs) conduct crucial signals in human metabolism. Correlations between changes in plasma BA concentrations, insulin secretion defects, and progression of type 2 diabetes mellitus (T2DM) in humans have not been sufficiently investigated. This study explored the trajectories of changes in human plasma BA concentrations and their association with insulin secretion dynamics during a two-step hyperglycemic clamp. Methods: Eleven healthy subjects with normal glucose tolerance (NGT) and 33 drug-naive T2DM subjects were enrolled in the study. The two-step hyperglycemic clamp consisted of a classic clamp as Step 1 with fasting, followed by a Step 2 clamp after ingestion of a carbohydrate meal, illustrating basal and incretin-amplified insulin responses to glucose. Plasma BA were assayed using liquid chromatography-tandem mass spectrometry. Nine T2DM subjects were followed-up, and the two-step clamp was repeated after 3 months sulfonylurea treatment. Results: Ursodeoxycholic acid (UDCA) was lower and lithocholic acid (LCA) and taurocholic acid (TCA) were higher in T2DM compared with NGT subjects. The dynamics of plasma UDCA concentrations and the UDCA/LCA ratio was positively correlated with insulin secretion in T2DM subjects and were corrected after treatment. Moreover, fasting ratios of UDCA/LCA and unconjugated/conjugated BAs were correlated with the first phase of insulin secretion in T2DM subjects. Conclusion: The abnormal BA composition in T2DM subjects and its correlation with insulin secretion during the clamp suggest an interaction between BA signals and insulin secretion capacity, and the potential to use fasting plasma BA composition indices to predict and evaluate the progression and prognosis of T2DM

Visit-to-visit HbA1c variability is associated with aortic stiffness progression in participants with type 2 diabetes

Abstract Background Glycemic variability plays an important role in the development of cardiovascular disease (CVD). This study aims to determine whether long-term visit-to-visit glycemic variability is associated with aortic stiffness progression in participants with type 2 diabetes (T2D). Methods Prospective data were obtained from 2115 T2D participants in the National Metabolic Management Center (MMC) from June 2017 to December 2022. Two brachial-ankle pulse wave velocity (ba-PWV) measurements were performed to assess aortic stiffness over a mean follow-up period of 2.6 years. A multivariate latent class growth mixed model was applied to identify trajectories of blood glucose. Logistic regression models were used to determine the odds ratio (OR) for aortic stiffness associated with glycemic variability evaluated by the coefficient of variation (CV), variability independent of the mean (VIM), average real variability (ARV), and successive variation (SV) of blood glucose. Results Four distinct trajectories of glycated hemoglobin (HbA1c) or fasting blood glucose (FBG) were identified. In the U-shape class of HbA1c and FBG, the adjusted ORs were 2.17 and 1.21 for having increased/persistently high ba-PWV, respectively. Additionally, HbA1c variability (CV, VIM, SV) was significantly associated with aortic stiffness progression, with ORs ranging from 1.20 to 1.24. Cross-tabulation analysis indicated that the third tertile of the HbA1c mean and VIM conferred a 78% (95% confidence interval [CI] 1.23–2.58) higher odds of aortic stiffness progression. Sensitivity analysis demonstrated that the SD of HbA1c and the highest HbA1c variability score (HVS) were significantly associated with the adverse outcomes independent of the mean of HbA1c during the follow-up. Conclusions Long-term visit-to-visit HbA1c variability was independently associated with aortic stiffness progression, suggesting that HbA1c variability was a strong predictor of subclinical atherosclerosis in T2D participants

Saxagliptin alters bile acid profiles and yields metabolic benefits in drug-naive overweight or obese type 2 diabetes patient

Background The aim of the present study was to investigate the metabolic benefits of saxagliptin and its effects on serum bile acids (BAs) in normal weight and overweight/obese drug-naive type 2 diabetes (T2D) patients. Methods In all, 282 drug-naive T2D patients (123 normal weight [NW], with body mass index [BMI] between 19.0 and = 25.0 kg/m(2)) were enrolled in the study and treated with saxagliptin 5 mg daily for 24 weeks. Serum BAs were assayed by liquid chromatography with tandem mass spectrometry. Results At 24 weeks, HbA1c was significantly reduced in both groups, but the HbA1c levels were lower in the OW/OB than NW group. Moreover, significant decreases were seen at 24 weeks in C-reactive protein (CRP), aspartate aminotransferase, alanine aminotransferase, waist circumference, and systolic blood pressure in the OW/OB group. Interestingly, cholic acid, glycocholic acid, glycochenodeoxycholic acid, glycodeoxycholic acid (GDCA), and glycoursodeoxycholic acid (GUDCA) were increased in both groups after treatment, whereas chenodeoxycholic acid and deoxycholic acid (DCA) were specifically increased in the OW/OB group. Increased DCA and GDCA concentrations were significantly associated with decreased HbA1c or fasting blood glucose and CRP levels, whereas increased GDCA and GUDCA concentrations were associated with decreased waist circumference in the OW/OB group during treatment. In the NW group, increased GUDCA concentrations were significantly associated with a decrease in HbA1c. Conclusions Type 2 diabetes patients with OW/OB exhibited greater improvement in glycemic control and additional metabolic benefits after saxagliptin treatment. Saxagliptin significantly increased the BA pool, and DCA and GDCA were associated with metabolic improvements in OW/OB T2D patients

The unadjusted and adjusted ORs and 95% CI from the logistic regressions predicting the likelihood of positive BAT in the subgroup with low outdoor temperature (<20°C).

<p>Data are odds ratios, 95% confidence interval. The backward multivariate logistic regression analysis was used to evaluate the ORs for positive BAT:</p><p>*P<0.0001,</p><p>^†P<0.001,</p><p>^‡P<0.05.</p><p>WC, Waist Circumferences; SFA, subcutaneous fat areas; VFA, visceral fat areas</p><p>The unadjusted and adjusted ORs and 95% CI from the logistic regressions predicting the likelihood of positive BAT in the subgroup with low outdoor temperature (<20°C).</p