Changes to insulin sensitivity in glucose clearance systems and redox following dietary supplementation with a novel cysteine-rich protein: A pilot randomized controlled trial in humans with type-2 diabetes.

We recently developed a novel keratin-derived protein (KDP) rich in cysteine, glycine, and arginine, with the potential to alter tissue redox status and insulin sensitivity. The KDP was tested in 35 human adults with type-2 diabetes mellitus (T2DM) in a 14-wk randomised controlled pilot trial comprising three 2×20 g supplemental protein/day arms: KDP-whey (KDPWHE), whey (WHEY), non-protein isocaloric control (CON), with standardised exercise. Outcomes were measured morning fasted and following insulin-stimulation (80 mU/m2/min hyperinsulinaemic-isoglycaemic clamp). With KDPWHE supplementation there was good and very-good evidence for moderate-sized increases in insulin-stimulated glucose clearance rate (GCR; 26%; 90% confidence limits, CL 2%, 49%) and skeletal-muscle microvascular blood flow (46%; 16%, 83%), respectively, and good evidence for increased insulin-stimulated sarcoplasmic GLUT4 translocation (18%; 0%, 39%) vs CON. In contrast, WHEY did not effect GCR (-2%; -25%, 21%) and attenuated HbA1c lowering (14%; 5%, 24%) vs CON. KDPWHE effects on basal glutathione in erythrocytes and skeletal muscle were unclear, but in muscle there was very-good evidence for large increases in oxidised peroxiredoxin isoform 2 (oxiPRX2) (19%; 2.2%, 35%) and good evidence for lower GPx1 concentrations (-40%; -4.3%, -63%) vs CON; insulin stimulation, however, attenuated the basal oxiPRX2 response (4%; -16%, 24%), and increased GPx1 (39%; -5%, 101%) and SOD1 (26%; -3%, 60%) protein expression. Effects of KDPWHE on oxiPRX3 and NRF2 content, phosphorylation of capillary eNOS and insulin-signalling proteins upstream of GLUT4 translocation AktSer437 and AS160Thr642 were inconclusive, but there was good evidence for increased IRSSer312 (41%; 3%, 95%), insulin-stimulated NFκB-DNA binding (46%; 3.4%, 105%), and basal PAK-1Thr423/2Thr402 phosphorylation (143%; 66%, 257%) vs WHEY. Our findings provide good evidence to suggest that dietary supplementation with a novel edible keratin protein in humans with T2DM may increase glucose clearance and modify skeletal-muscle tissue redox and insulin sensitivity within systems involving peroxiredoxins, antioxidant expression, and glucose uptake.

Physiological measures in participants with chronic fatigue syndrome, multiple sclerosis and healthy controls following repeated exercise: a pilot study.

PURPOSE: To compare physiological responses of chronic fatigue syndrome (CFS/ME), multiple sclerosis (MS) and healthy controls (HC) following a 24-h repeated exercise test. METHODS: Ten CFS, seven MS and 17 age- and gender-matched healthy controls (10, CFS HC; and seven, MS HC) were recruited. Each participant completed a maximal incremental cycle exercise test on day 1 and again 24 h later. Heart rate (HR), blood pressure (BP), rating of perceived exertion (RPE), oxygen consumption (V˙O2), carbon dioxide production and workload (WL) were recorded. Data analysis investigated these responses at anaerobic threshold (AT) and peak work rate (PWR). RESULTS: On day 2, both CFS and MS had significantly reduced max workload compared to HC. On day 2, significant differences were apparent in WL between CFS and CFS HC (93 ± 37 W, 132 ± 42 W, P<0·042). CFS workload decreased on day 2, alongside a decrease in HR but with an increase in V˙O2 (ml  kg  min-1 ). This was in comparison with an increase in WL, HR and V˙O2 for CFS HC. MS demonstrated a decreased WL compared to MS HC on both days of the study (D1 81 ± 30 W, 116 ±30 W; D2 84 ± 29 W, 118 ± 36 W); however, patients with MS were able to achieve a higher WL on day 2 alongside MS HC. CONCLUSION: These results suggest that exercise exhibits a different physiological response in MS and CFS/ME, demonstrating repeated cardiovascular exercise testing as a valid measure for differentiating between fatigue conditions.

The CO2-SFE crude lipid extract and the free fatty acid extract from Perna canaliculus have anti-inflammatory effects on adjuvant-induced arthritis in rats.

The anti-inflammatory (AI) activity of a supercritical fluid extract (CO(2)-SFE) of tartaric acid-stabilised Perna canaliculus mussel powder, and of the free fatty acid (FFA) class separated from the CO(2)-SFE extract by column chromatography, was investigated in the rat adjuvant arthritis model. Administration of the CO(2)-SFE extract (100 mg/kg BW/day s.c.) for 15 days post-adjuvant inoculation significantly reduced rear paw swelling by 34% and the deterioration in total body condition by 52% in arthritic rats, compared to vehicle controls. These observations were accompanied by a decreased serum ceruloplasmin oxidase activity, and reduced inflammatory response of the spleen. The mussel FFA extract given at one third of the dose (30 mg/kg BW/day s.c.) and for a shorter treatment period (5 days during the inflammatory phase) achieved an even greater AI activity, and was equipotent to piroxicam (2 mg/kg BW/day s.c.). Preliminary toxicology assessment using both arthritic and non-arthritic (healthy) rats revealed no significant differences between the mussel treatment groups and respective vehicle controls in either organ weights, tissue histology or selected biochemical parameters. These results indicate the CO(2)-SFE crude lipid extract and its FFA components from stabilised P. canaliculus mussel powder contain biologically significant AI activity in vivo, with no apparent adverse side effects.

Randomized controlled trial of supervised exercise to evaluate changes in cardiac function in patients with peripheral atherosclerotic disease.

INTRODUCTION: Peripheral atherosclerotic disease (PAD) is a condition characterized by low functional capacity which is associated with impaired free living, ambulation and low exercise tolerance. The purpose of this randomized controlled study was to evaluate whether changes in maximal walking time are associated with adaptations in cardiovascular function following supervised exercise. METHODS: After ethics approval, 28 patients (63 +/- 11 years) completed a graded treadmill test (2 min stages, 3.2 km h(-1), with gradient increasing 2% every 2 min) until they reached level three or four on the claudication pain scale. Peak oxygen consumption was assessed on a breath-by-breath basis, by online expiratory gas analysis. Following a 40-min recovery period, peak cardiac output was measured using the non-invasive carbon dioxide rebreathing method described by Defares (J Appl Physiol, 13, 1958, 159). Peak cardiac power output was then computed using the equation described by Cooke et al. (Heart, 1998, 79, 289). Patients were randomly assigned to one of two groups: supervised, who exercised at the hospital twice weekly for 12 weeks or control, who received normal treatment which included encouragement to walk regularly. RESULTS: After 12 weeks, there were no significant changes in body mass, peak oxygen consumption, peak cardiac output, peak heart rate, peak cardiac power output, respiratory exchange ratio or rating of perceived exertion in both the supervised and control group. There was a significant improvement (91%) in maximal walking distance following the supervised exercise programme. Although patients' peak cardiovascular measurements were unchanged, the patients in the supervised exercise group were able to complete a higher workload at the end of the 12 weeks of exercise, for the equivalent demands on the circulation system. CONCLUSIONS: The findings from this study suggest that a short-term period of supervised exercise training results in an improved walking time in patients with limiting claudication because of PAD. It also demonstrated that the cardiovascular system becomes more efficient in meeting the demands of exercise. It is recommended that individuals with PAD should undertake exercise as a form of treatment.

The temporal relationship between erectile dysfunction and cardiovascular disease.

BACKGROUND: Erectile dysfunction (ED) and cardiovascular disease (CVD) share similar risk factors, and ED may be a marker of CVD progression. The study assessed: (i) the temporal relationship between ED and CVD and (ii) the UK incidence of ED, in patients with CVD and an age-matched control group. DESIGN: After ethics approval, 207 patients (CVD group) attending cardiovascular rehabilitation programmes and 165 age-matched subjects (control group), from GP practices across the UK, completed up to four questionnaires [ED details, The International Index of Erectile Function (IIEF) (before and after a cardiovascular event) and ED related Quality of Life]. A health professional also completed a medical details questionnaire. RESULTS: Erectile dysfunction was reported by 66% of individuals with CVD, with a mean duration of 5 +/- 5.3 years. The control group was significantly different (p < 0.05) in both incidence (37%) and mean duration (6.6 +/- 6.8 years). Only 53% of the CVD group and 43% of the control group had discussed their symptoms of ED with a health professional. The IIEF demonstrated that ED became significantly worse (p < 0.05) after a cardiovascular event, changing from moderate to severe (13-10). CONCLUSIONS: From these data, it is now evident that ED may precede a cardiovascular event by as much as 5 years. In almost half of the men with ED, there were missed opportunities to undertake a CVD risk assessment and provide an intervention, because the men did not acknowledge the problem. Men with ED should be specifically targeted for CVD preventative strategies in terms of lifestyle changes, and appropriate pharmacological treatments.

Novel anti-inflammatory omega-3 PUFAs from the New Zealand green-lipped mussel, Perna canaliculus.

The present study has identified in the marine mollusc, Perna canaliculus, an homologous series of novel omega 3 polyunsaturated fatty acids (omega-3 PUFA) with significant anti-inflammatory (AI) activity. The free fatty acid (FFA) class was isolated from a supercritical-CO2 lipid extract of the tartaric acid-stabilised freeze-dried mussel powder by normal phase chromatography, followed by reversed-phase high performance liquid chromatography (RP-HPLC). The RP-HPLC involved separation based on carbon numbers, followed by argentation-HPLC (Ag-HPLC) of the methyl esters based on degree of unsaturation. Identification of the FFA components was performed using gas chromatography (GC) with flame ionisation detection, and individual structures were assigned by GC-mass spectroscopy (GC-MS). Inhibition of leukotriene production by stimulated human neutrophils was used as an in vitro screening method to test the AI activity of the purified PUFAs. A structurally related family of omega-3 PUFAs was identified in the most bioactive fractions, which included C18:4, C19:4, C20:4, and C21:5 PUFA. The C20:4 was the predominant PUFA in the extract, and was a structural isomer of arachidonic acid (AA). The novel compounds may be biologically significant as AI agents, as a result of their in vitro inhibition of lipoxygenase products of the AA pathway.

Anti-cyclooxygenase effects of lipid extracts from the New Zealand green-lipped mussel, Perna canaliculus.

Total lipid extracts of P. canaliculus (a bivalve marine mollusc native to New Zealand, commonly called the green-lipped mussel) and Mytilus edulis (commonly called the common blue mussel) moderately inhibited ovine COX-1 and COX-2 pure enzymes in vitro. The inhibition was increased after the mussel extracts were saponified by KOH hydrolysis. Protease- and protease-lipase-hydrolysed lipid extracts of P. canaliculus exhibited similarly strong COX inhibition as the KOH-hydrolysed extract. Lyprinol(R) (a commercial extract from P. canaliculus) also exhibited strong inhibition of both COX isoforms, an effect that was increased 10-fold upon subsequent hydrolysis. In contrast, fish oil was not as anti-COX active as Lyprinol. The Lyprinol free fatty acid fraction, and to a lesser extent the Lyprinol triglyceride fraction, were the only lipid classes of Lyprinol to exhibit strong inhibition of the COX isoforms. The purified PUFA extracts were all bioactive, potently inhibiting COX-1 and COX-2. Incubation of Lyprinol in the absence of exogenous arachidonic acid (AA) showed the appearance of alternate prostaglandin metabolites, confirming Lyprinol PUFA as a competitive substrate inhibitor of AA metabolism.

Cardiac pumping capability in patients with peripheral vascular disease.

INTRODUCTION: Peripheral vascular disease (PVD) is a condition characterized by atherosclerotic occlusive disease of the lower extremities, low functional capacity and low exercise tolerance. Less empirical data are available concerning the cardiovascular response to maximum exercise tests in patients with PVD. The purpose of this study was to examine cardiovascular variables in patients with peripheral vascular disease. METHODS: Fifty patients (67 +/- 9 years) completed an incremental exercise test (2 min stages, 3.2 km h(-1), with increases of 2% every 2 min) to maximum claudication pain. Maximal oxygen consumption (VO2) was assessed on a breath-by-breath basis by online expiratory gas analysis (CardiO2, Medical Graphics Co.). Blood pressure was recorded at peak exercise. Following a 30-min rest period, patients exercised at the highest level attained during the first test and cardiac output (QT) was measured using the exponential non-invasive rebreathing method. Cardiac power output peak (CPOpeak) in Watts (W), was then computed. RESULTS: Mean +/- SD values were; 13.85 +/- 4.14 ml kg min(-1); maximal walk time 357 +/- 227 s; peak mean arterial pressure 127 +/- 15 mmHg; 9.8 +/- 2.39 (l min(-1)); CPO 2.86 +/- 0.87 W. CONCLUSION: Patients with peripheral vascular disease demonstrate attenuated levels of cardiovascular capacity. This group of patients should be given exercise therapy in order to improve cardiovascular status and ambulatory function.

Validity and reliability of selected commercially available metabolic analyzer systems.

Automated metabolic gas analysis systems have advanced considerably over the past decade. They provide an abundance of information, which is not possible by using the traditional Douglas bag method and have become an essential tool in both physiological monitoring and in the diagnosis of cardiopulmonary disease. The validity and reliability of the different online metabolic analyzer systems are not well known, with relatively few independent studies being published. The purpose of this review was to examine and evaluate current literature regarding the validity and reliability of commercially available metabolic analyzer systems. This review reveals significant differences between the available systems in the way that they capture and process basic respiratory measurements. Online metabolic analyzer systems were found to vary significantly when compared with Douglas bag methods. These variations have the potential to introduce error into the accuracy with which the health of cardiovascular system can be assessed or training loads can be assigned. Compounding this is the fact that many automated systems are a "black box", which makes it easy to generate data without the user having much understanding of how the data were generated. In conclusion automated metabolic analyser systems are a scientifically robust method for the evaluation of cardiopulmonary function. Individual researchers and clinicians must, however, be able to make their own decisions about the level of error that is tolerable for their individual needs. This presents a significant practical challenge in light of the speed with which technical developments in the field occur and we make some suggestions for the formulation of intersystem comparison studies.