Cardiac Rehabilitation in German Speaking Countries of Europe-Evidence-Based Guidelines from Germany, Austria and Switzerland LLKardReha-DACH-Part 2.

BACKGROUND: Scientific guidelines have been developed to update and harmonize exercise based cardiac rehabilitation (ebCR) in German speaking countries. Key recommendations for ebCR indications have recently been published in part 1 of this journal. The present part 2 updates the evidence with respect to contents and delivery of ebCR in clinical practice, focusing on exercise training (ET), psychological interventions (PI), patient education (PE). In addition, special patients' groups and new developments, such as telemedical (Tele) or home-based ebCR, are discussed as well. METHODS: Generation of evidence and search of literature have been described in part 1. RESULTS: Well documented evidence confirms the prognostic significance of ET in patients with coronary artery disease. Positive clinical effects of ET are described in patients with congestive heart failure, heart valve surgery or intervention, adults with congenital heart disease, and peripheral arterial disease. Specific recommendations for risk stratification and adequate exercise prescription for continuous-, interval-, and strength training are given in detail. PI when added to ebCR did not show significant positive effects in general. There was a positive trend towards reduction in depressive symptoms for "distress management" and "lifestyle changes". PE is able to increase patients' knowledge and motivation, as well as behavior changes, regarding physical activity, dietary habits, and smoking cessation. The evidence for distinct ebCR programs in special patients' groups is less clear. Studies on Tele-CR predominantly included low-risk patients. Hence, it is questionable, whether clinical results derived from studies in conventional ebCR may be transferred to Tele-CR. CONCLUSIONS: ET is the cornerstone of ebCR. Additional PI should be included, adjusted to the needs of the individual patient. PE is able to promote patients self-management, empowerment, and motivation. Diversity-sensitive structures should be established to interact with the needs of special patient groups and gender issues. Tele-CR should be further investigated as a valuable tool to implement ebCR more widely and effectively.

Type 1 diabetes in older adults: Comparing treatments and chronic complications in the United States T1D Exchange and the German/Austrian DPV registries.

AIMS: Compare characteristics, therapies and clinical outcomes in older adults with type 1 diabetes in the United States T1D Exchange (T1DX) and German/Austrian Diabetes Patienten Verlaufsdokumentation (DPV) registries. METHODS: Cross-sectional study of adults ≥60years old with type 1 diabetes seen in 2011-2012 in the T1DX (n=1283) and DPV (n=2014) registries. Wilcoxon rank-sum test was used for continuous variables and chi-square test for categorical variables. Adjusted analyses used generalized linear models. RESULTS: Individuals in both registries were similar in body mass index (mean 27kg/m2), percent with obesity (25%) and gender (48% male). In T1DX there was longer diabetes duration (32.3 vs. 28.8years), greater use of antihypertensive medications (including ACE-I and ARBs; 85% vs. 62%), statins (68% vs. 40%), aspirin (77% vs. 21%), insulin pumps (58% vs. 18%), and less smoking (7% vs. 10%); lower adjusted mean LDL-cholesterol (84 vs. 109mg/dL), and lower adjusted mean systolic and diastolic blood pressures (128 vs. 136 and 68 vs. 74mmHg); fewer myocardial infarctions (6% vs. 9% [99% CI of difference, 1% to 5%]), strokes (2% vs. 8% [3% to 7%]), microvascular complications including microalbuminuria (17% vs. 44% [22% to 32%]) but increased depression (16.1% vs. 8.7%). Adjusted mean HbA1c levels were similar (7.5%, 58mmol/mol). CONCLUSIONS: Differences between the registries included greater use of antihypertensives, statins and insulin pumps, and fewer chronic complications in the T1DX. Further research is needed to better understand the role of intensive therapy in improving outcomes in older adults with type 1 diabetes.

Insulin inhibits caspase-3 activity in human renal tubular epithelial cells via the PI3-kinase/Akt pathway.

Apoptotic mechanisms in proximal renal tubular epithelial cells (PTEC) are crucial in the pathogenesis of acute kidney injury. We investigated whether insulin alters anti-apoptotic signalling in human PTEC. Cells were deprived of insulin for 0, 24 or 48 h and then stimulated with insulin for 0 or 5 min. Apoptosis was induced by camptothecin incubation. Insulin receptor kinase (IR-kinase) activity, phosphorylation of insulin receptor substrate-1 (IRS-1), IRS-1-associated PI3-kinase (p85), Ser(273)-phosphorylation of Akt and caspase-3 activity (C3-activity) were determined. Insulin stimulation increased the activity of IR-kinase, IRS-1 phosphorylation, p85 association with IRS-1 and Ser(273)-phosphorylation of Akt by at least 250%, respectively and decreased the C3-activity by 45% (p < 0.01, respectively). Deprivation of insulin for 24 and 48 h reduced basal and insulin-stimulated IR-kinase activity, IRS-1 phosphorylation, p85 association with IRS-1 and Ser(273)-phosphorylation of Akt by 30-40% and increased C3-activity by 15-20% (p < 0.01, respectively). Incubation with camptothecin increased C3-activity by 250-300% (p < 0.001). Subsequent insulin stimulation reversed the camptothecin induced increase of C3-activity. Our data indicate that apoptosis in PTEC is regulated by the insulin dependent PI3-kinase/Akt pathway. The enhancement of tubular-specific cell survival signals might represent a potential therapeutic tool for the protection of renal function in acute kidney injury.

Calpain inhibition impairs glycogen syntheses in HepG2 hepatoma cells without altering insulin signaling.

Calpains are a family of non-lysosomal cytoplasmatic cysteine proteases. Since calpain 10 (CAPN10), a member of the calpain family of proteases, has been found to represent a putative diabetes susceptibility gene, it was argued that calpains may be involved in the development of type 2 diabetes. The functional role of calpains in insulin signaling and/or insulin action is, however, not clear. We investigated the effects of the calpains 1 and 2 inhibitor PD151746 on insulin signaling and insulin action in human hepatoma G2 cells (HepG2). HepG2 cells were incubated without (-PD) or with (+PD) 5.33 micromol/l PD151746 for different times and then stimulated with 100 nmol/l insulin for 0 (t(0)), 5 (t(5)), 15 (t(15)), 30 (t(30)), 45 (t(45)), and 60 (t(60)) min. After solubilization of the cells, insulin receptor kinase activity, tyrosine phosphorylation of insulin receptor substrate-1 (IRS-1), IRS-1-associated phosphatidylinositol-3 kinase (PI3-kinase), PI3-kinase activity, Thr(308) phosphorlyation of Akt, amount of protein tyrosine phosphatase-epsilon (PTPepsilon), and glycogen synthase activity were determined. Incubation with PD151746 resulted in a significant reduction of insulin-stimulated glycogen synthesis compared with cells not pre-incubated with the calpain inhibitor (-PD: t(0), 4.90 +/- 1.20%; t(5), 5.90 +/- 1.02%; t(15), 5.29 +/- 0.95%; t(30), 5.60 +/- 1.10%; t(45), 5.52 +/- 0.90%; t(60), 5.67 +/- 0.97%;+PD: t(0), 4.56 +/- 1.10%; t(5), 6.16 +/- 1.05%; t(15), 7.52 +/- 1.09%; t(30), 7.68 +/- 1.10%; t(45), 8.28 +/- 0.89%; t(60), 7.69 +/- 0.98%; P < 0.05). Incubation with PD151746 significantly increased the protein amount of PTPepsilon in the cells after 12 h (-PD: t(1), 0.85 +/- 0.18 RU (Relative unit); t(8), 0.87 +/- 0.18 RU; t(12), 0.9 +/- 0.13 RU; +PD: t(1), 0.92 +/- 0.21 RU; t(8), 1.1 +/- 0.15 RU; t(12), 1.34 +/- 0.16 RU; P < 0.05). Calpain inhibition with PD151746 had no effect on the insulin stimulation of the investigated insulin signaling parameters. These results in HepG2 cells suggest that calpains play a role in the hepatic regulation of insulin-stimulated glycogen synthesis independent of the PI3-kinase/Akt signaling pathway.

[Effects of various HIV protease inhibitors on function of rat insulinoma cells].

OBJECTIVE: To investigate the effects of various HIV protease inhibitors on the function of pancreatic beta-cells. METHODS: Rat insulinoma INS-1 cells were incubated with different concentrations of ritonavir or amprenavir for 48 h and stimulated with 20 mmol/L D-glucose for 30 min. The rate of insulin release was measured in the supernatant by ELISA, normalized to cellular DNA contents. Cells were counted with trypan blue and MTT test were determined to evaluate the effect of protease inhibitors on cell viability. RESULT: Ritonavir treatment significantly decreased baseline insulin release and glucose-stimulated insulin release in a dose-dependent manner (r=-0.861, -0.839, both P<0.01). For 10 micromol/L of ritonavir, the decrease rate of baseline insulin secretion and glucose-stimulated insulin secretion was 46% and 47%, respectively. Amprenavir had no effect on the rate of insulin release. CONCLUSION: Various HIV protease inhibitors present different effect on the insulin release of pancreatic beta-cells.

Simvastatin acutely reduces myocardial reperfusion injury in vivo by activating the phosphatidylinositide 3-kinase/Akt pathway.

Long-term pretreatment with statins reduces myocardial injury after acute ischemia and reperfusion by increasing the expression of endothelial nitric oxide synthase (eNOS). We hypothesized that statins may act rapidly enough to protect the myocardium from ischemia/reperfusion injury when given right at the beginning of the reperfusion period and tried to delineate the role of PI 3-kinase/Akt pathway in early eNOS activation. Activated simvastatin was given intravenously 3 minutes before starting the reperfusion after temporary coronary artery occlusion (CAO) in anaesthetized rats. Simvastatin significantly increased myocardial PI 3-kinase activity, AktSer473, and eNOSSer1177 phosphorylation and reduced infarct size by 42%. Infarct size reduction as well as activation of PI 3-kinase/Akt/eNOS pathway were not observed in rats co-treated with the PI 3-kinase inhibitor wortmannin. Contribution of eNOS was further delineated using the NOS inhibitor L-NAME, which could completely block cardioprotection by the statin. In summary, simvastatin acutely reduces the extent of myocardial necrosis in normocholesterolemic rats in an NO- dependent manner by activating the PI 3-kinase/Akt pathway. This is the first study demonstrating short-term cardioprotective effects of simvastatin in an in vivo model of ischemia/reperfusion.

[Impairment of IRS-2 signaling in rat insulinoma INS-1 cells by nelfinavir].

OBJECTIVE: To investigate whether HIV-1 protease inhibitor nelfinavir alters the insulin stimulated phosphorylation of insulin signaling parameters in rat insulinoma INS-1 cells. METHODS: INS-1 cells were incubated with nelfinavir for 48 h and stimulated with 100 nmol/L insulin for 2 min. Immunoprecipitation and Western blot analysis of the insulin stimulated insulin receptor substrate (IRS)-1,-2 and Akt-Thr(308) phosphorylation were performed on cell lysates. Cytotoxic effects of nelfinavir were measured by cell count with trypan blue and MTT reduction test. RESULT: Nelfinavir decreased insulin stimulated phosphorylation of IRS-2 and Akt-Thr(308) in a dose-dependent manner; for 10 micromol/L of nelfinavir, the decrease was 52% and 55%, respectively. CONCLUSION: Treatment with nelfinavir might impair IRS-2-mediated signaling in pancreatic beta cells.