Previous studies have suggested that blockade of the renin–angiotensin system may prevent diabetes in people with cardiovascular disease or hypertension. In a double-blind, randomized clinical trial with a 2-by-2 factorial design, we randomly assigned 5269 participants without cardiovascular disease but with impaired fasting glucose levels (after an 8-hour fast) or impaired glucose tolerance to receive ramipril (up to 15 mg per day) or placebo (and rosiglitazone or placebo) and followed them for a median of 3 years. We studied the effects of ramipril on the development of diabetes or death, whichever came first (the primary outcome), and on secondary outcomes, including regression to normoglycemia. The incidence of the primary outcome did not differ significantly between the ramipril group (18.1%) and the placebo group (19.5%; hazard ratio for the ramipril group, 0.91; 95% confidence interval [CI], 0.81 to 1.03; P=0.15). Participants receiving ramipril were more likely to have regression to normoglycemia than those receiving placebo (hazard ratio, 1.16; 95% CI, 1.07 to 1.27; P=0.001). At the end of the study, the median fasting plasma glucose level was not significantly lower in the ramipril group (102.7 mg per deciliter [5.70 mmol per liter]) than in the placebo group (103.4 mg per deciliter [5.74 mmol per liter], P=0.07), though plasma glucose levels 2 hours after an oral glucose load were significantly lower in the ramipril group (135.1 mg per deciliter [7.50 mmol per liter] vs. 140.5 mg per deciliter [7.80 mmol per liter], P=0.01). Among persons with impaired fasting glucose levels or impaired glucose tolerance, the use of ramipril for 3 years does not significantly reduce the incidence of diabetes or death but does significantly increase regression to normoglycemia. (ClinicalTrials.gov number, NCT00095654.)
Aims: In patients with cardiovascular disease, epicardial adipose tissue (EAT) is characterized by insulin resistance, high pro-inflammatory chemokines and low differentiation ability. Since dapagliflozin reduces body fat and cardiovascular events in diabetic patients, we wanted to know its effect on EAT and subcutaneous adipose tissue (SAT). Methods and results: Adipose samples were obtained from 52 patients undergoing heart surgery. Sodium-glucose cotransporter 2 (SGLT2) expression was determined by real time PCR (n = 20), Western blot and immunohistochemistry. Fat explants (n = 21) were treated with dapagliflozin and/or insulin. Glucose, free fatty acid, adipokines levels (by array) were measured in their secretomes which were tested on human coronary endothelial cells by wound healing assays. The effect of dapagliflozin effect on levels of glucose transporters in EAT explants was analysed by Western blot. Glucose uptake was also measured by fluorescence glucose (6NBDG) of differentiated stromal vascular cells from fat pads (n = 11). Finally, dapagliflozin-induced adipocytes differentiation was analysed by AdipoRed staining and perilipin levels. Results revealed SGLT2 expression in EAT. Dapagliflozin increased glucose uptake (20.95 ± 4.4 mg/dL vs. 12.97 ± 4.1 mg/dL; p < 0.001) and glucose transporter type 4 (2.09 ± 0.3 fold change; p < 0.01) in EAT. Moreover, dapagliflozin reduced the secretion levels of chemokines and benefited wound healing in endothelial cells (0.21 ± 0.05 vs. 0.38 ± 0.08 open wound; p < 0.05). Finally, the chronic treatment with dapagliflozin improved the differentiation of SVC, confirmed by adipoRed staining (539 ± 142 a.u. vs. 473 ± 136 a.u.; p < 0.01) and perilipin expression levels (121 ± 10 vs. 84 ± 11 a.u.). Conclusions: Dapagliflozin increased glucose uptake, reduced the secretion of pro-inflammatory chemokines (with a beneficial effect on the healing of human coronary artery endothelial cells) and improved the differentiation of EAT cells. These results suggest a new protective pathway for this drug on EAT from patients with cardiovascular disease.
1 July 2010 in American Journal of Physiology-Heart and Circulatory Physiology
Epicardial adipose tissue (EAT) is an endocrine organ adjacent to coronary arteries and myocardium without anatomy barriers. Locally produced adipokines may reflect or affect to cardiovascular physiology and pathology. Our aim was to study the protein expression profiles of EAT and subcutaneous adipose tissue (SAT) to identify local candidate molecules characterizing EAT in patients with cardiovascular disease. EAT and SAT samples were collected from 55 patients undergoing heart surgery. Proteins from these tissues were separated by two-dimensional (2D) gel electrophoresis, and differences between them were identified by MALDI-TOF/TOF spectra. Differences in protein levels were further investigated by real-time RT-PCR and Western blots, and production of reactive oxygen species (ROS) in EAT and SAT was evaluated by nitroblue tetrazolium chloride assays. ROS production was higher in EAT than SAT. We have found mRNA differences for catalase, glutathione S-transferase P, and protein disulfide isomerase, and 2D Western blots additionally showed post-translational differences for phosphoglycerate mutase 1; all four are related to oxidative stress pathways. EAT suffers greater oxidative stress than SAT in patients with cardiovascular diseases and exhibits associated proteomic differences that suggest the possibility of its association with myocardial stress in these patients.