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Dive into the research topics where Brett I. Shand is active.

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Featured researches published by Brett I. Shand.


Diabetes, Obesity and Metabolism | 2003

Plasma adiponectin in overweight, nondiabetic individuals with or without insulin resistance

Brett I. Shand; Russell S. Scott; Peter A. Elder; Peter M. George

Aim:  Adiponectin is a protein produced exclusively by adipocytes with putative insulin‐sensitizing and anti‐atherogenic properties. This cross‐sectional study investigated the relationship between plasma adiponectin and a range of anthropometric, glycaemic, lipid and inflammatory parameters in overweight and obese subjects expressing characteristics of the metabolic syndrome.


Clinical Chemistry and Laboratory Medicine | 2006

Biovariability of plasma adiponectin.

Brett I. Shand; Peter A. Elder; Russell S. Scott; Chris Frampton; Jinny Willis

Abstract Background: Adiponectin is a cytokine produced by adipose tissue with insulin sensitising and anti-atherosclerotic effects. Low plasma adiponectin levels are used as a marker of the metabolic syndrome and incipient type 2 diabetes. Methods: We carried out a series of studies to determine the short- and long-term variability of plasma adiponectin levels, including diurnal and post-prandial changes. These investigations also included examining the effect of frozen storage on plasma adiponectin levels. Results: A nested study in 10 overweight subjects with the metabolic syndrome and 10 age- and sex-matched controls showed intra-subject variation in adiponectin levels over a 30-day period of 12.2% and 18.8%, respectively, equivalent to reference change values of 1.7 and 3.6μg/mL. In non-obese subjects, plasma adiponectin levels varied minimally over a 15-month period (baseline, 8.3±2.9μg/mL vs. +15months, 8.2±3.0μg/mL, p=0.95) and showed only minor diurnal and post-prandial changes (pre-meal, 8.2±3.0μg/mL vs. 3h post-prandial, 8.3±3.1μg/mL, p=0.60). The adiponectin assay had an intra-assay variation of 8.8%, with storage at −30°C for 33months or three cycles of freezing and thawing having no discernible effect on adiponectin levels. Conclusions: These results demonstrate that plasma adiponectin levels have relatively low biovariability and that adiponectin can be sampled fasting or non-fasting to provide a reliable marker of insulin resistance and incipient type 2 diabetes. Clin Chem Lab Med 2006;44:1264–8.


Diabetes and Vascular Disease Research | 2008

Adiponectin attenuates endothelial dysfunction induced by oxidised low-density lipoproteins

Stuart D. Plant; Brett I. Shand; Peter A. Elder; Russell S. Scott

We investigated whether the adipocytokine, adiponectin, protected the endothelium against damage induced by oxidised low-density lipoprotein cholesterol (oxLDL). Human umbilical vein endothelial cells were cultured with either 200 or 350 μg/ml oxLDL, with or without adiponectin purified from human serum (12 μg/ml). Cellular oxidative status was assessed by measuring reactive oxygen species (ROS), peroxynitrite and glutathione (GSH) levels, while cell function was evaluated by measuring nitric oxide (NO) levels and immunohistochemical examination of proteins in the adherens cell junction. At a concentration of 200 μg/ml, oxLDL induced a small increase in ROS and peroxynitrite levels, a two-fold increase in GSH levels and no changes in NO levels or localisation of proteins in the adherens junction. However, 350 μg/ml of oxLDL induced a marked increase in ROS and peroxynitrite levels, a four-fold reduction in GSH levels and a significant decrease in NO levels and disruption of the adherens junctions. Addition of adiponectin to the cultures resulted in maintenance of normal ROS, peroxynitrite and GSH levels, with no change in either NO levels or protein localisation in the adherens junction. This study demonstrates that adiponectin protects against endothelial dysfunction and cellular disruption induced by oxLDL, with this effect being due, in part, to maintenance of intracellular GSH levels.


Australian and New Zealand Journal of Psychiatry | 2009

Comparison of insulin resistance, metabolic syndrome and adiponectin in overweight bipolar patients taking sodium valproate and controls.

Jane L. Elmslie; Richard J. Porter; Peter R. Joyce; Penelope J. Hunt; Brett I. Shand; Russell S. Scott

Objective: Metabolic abnormalities in patients with bipolar disorder may be secondary to obesity, aspects of the disorder or its treatment. To investigate this further, the purpose the present study was to compare insulin resistance, components of the metabolic syndrome and adiponectin levels in a group of overweight bipolar patients taking sodium valproate and a group of non-psychiatric control subjects. Methods: Data were collected from 60 overweight bipolar patients who had experienced clinically significant weight gain thought to be related to sodium valproate treatment and from 60 control subjects without psychiatric illness matched for age, gender, body mass index and ethnicity. Results: The frequency of the metabolic syndrome was high in both groups (50% and 32%, respectively), although not significantly different between groups (p = 0.06). Similar frequencies of insulin resistance (HOMA-IR), abdominal obesity, hypertriglyceridaemia, hypertension and fasting hyperglycaemia were found in both groups. High-density lipoprotein cholesterol levels were lower in patients (p = 0.006), while adiponectin was unexpectedly higher than in control subjects (9.6±5.9 µg mL−1 vs 7.4±4.3 µg mL−1, p = 0.03). The frequencies of insulin resistance (HOMA-IR), the metabolic syndrome and its individual components were not significantly different in patients taking atypical antipsychotic medication and patients not on these medications. Conclusions: Frequencies of insulin resistance and the metabolic syndrome were similar in bipolar patients taking sodium valproate and matched control subjects, but dyslipidaemia was more frequent. Adiponectin levels were higher in patients. Further research is required to clarify the reasons for these findings.


Nephron | 2000

A Controlled Trial of the Effect of Folate Supplements on Homocysteine, Lipids and Hemorheology in End-Stage Renal Disease

David O. McGregor; Brett I. Shand; Kelvin L. Lynn

Elevated plasma homocysteine (Hcy), dyslipidemia and hemorheological abnormalities all occur commonly in end-stage renal disease (ESRD) and are recognized risk factors for arteriosclerosis. To study the effect of folate supplementation on these factors we conducted a randomized controlled trial. Thirteen hemodialysis (HD) and 8 continuous ambulatory peritoneal dialysis (CAPD) patients received either 5 mg folic acid daily or placebo for 3 months. After 1 and 3 months, fasting blood samples were taken for Hcy, lipid profile, blood and plasma viscosity, red blood cell (RBC) osmotic fragility, plasma fibrinogen concentration and in vivo platelet aggregability. At baseline, the CAPD patients had a higher mean plasma fibrinogen concentration than the HD patients and they also tended to have higher mean plasma viscosity. Folate-treated patients showed marked increases in RBC folate and an average decrease in plasma Hcy concentration of 33%. Mean total cholesterol, LDL cholesterol and triglyceride concentrations decreased significantly in the CAPD patients who took folate. Folate had no significant effect on hemorheology. In conclusion, folate supplements in ESRD reduce plasma Hcy concentrations and may improve lipid profiles. In our patients, hemorheological abnormalities were more marked in patients on CAPD than in those on HD and were not improved by folate supplementation.


Clinical Biochemistry | 2008

Plasma retinol-binding protein is not a marker of insulin resistance in overweight subjects: A three year longitudinal study

John G. Lewis; Brett I. Shand; C. M. Frampton; Peter A. Elder; Russell S. Scott

OBJECTIVES This longitudinal study investigated whether or not plasma retinol-binding protein (RBP), recently referred to as RBP4, was a marker of insulin resistance in overweight subjects. METHODS We measured anthropometric markers as well as RBP, fasting glucose and insulin in 206 overweight subjects and repeated these measurements 36 months later. Subjects were grouped according to fasting plasma glucose concentration at baseline and 36 months. RESULTS Subjects (n=51) with a normal basal fasting glucose (<5.6 mmol/L) who developed impaired fasting glucose (IFG) 3 years later (>or=5.6 mmol/L) showed a highly significant increase in both fasting insulin and insulin resistance, but importantly no change in plasma RBP. This group had a significant increase in body mass index (BMI). Subjects (n=101) with a normal fasting glucose at both baseline (<5.6 mmol/L) and 36 months showed no significant change in fasting insulin, insulin resistance, RBP or BMI. The remaining subjects had impaired basal fasting glucose and were not analysed on a group-wise basis. Overall, RBP correlated significantly, but inversely, with anthropometric measures, but not with fasting glucose, insulin or insulin resistance. CONCLUSIONS This is the first report of a long-term longitudinal study on RBP and the major finding is that subjects who developed insulin resistance showed no change in plasma RBP. On the basis of our results we consider that RBP cannot be construed as a marker of insulin resistance in overweight humans.


American Journal of Cardiology | 1995

Fluvastatin for dyslipoproteinemia,with or without concomitant chronic renal insufficiency

Caroline J. Lintott; Russell S. Scott; Janice M. Bremer; Brett I. Shand

Renal insufficiency is frequently associated with both quantitative and qualitative abnormalities in lipid and hemorheologic profiles. Although this may lead to increased risk of cardiovascular disease, a number of studies have also shown dyslipidemia to be a significant risk factor for the progression of renal insufficiency in human chronic renal disease. This double-blind, placebo-controlled trial aimed to assess the effect of fluvastatin, a synthetic 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, on these parameters in dyslipidemic patients with or without chronic renal insufficiency. After a 6-week placebo run-in, 42 patients who had been previously stratified into 2 groups on the basis of creatinine clearance levels (0.5-1.0 mL/sec or > 1.0-1.5 mL/sec) were randomized to treatment with fluvastatin (40 mg daily) or matching placebo. Significant differences (on analysis of variance with repeated measures) were seen between fluvastatin and placebo treatment groups for changes in total cholesterol (-15% vs 1%, respectively; p < 0.001), low density lipoprotein cholesterol (LDL-C; -21% vs -5%; p < 0.001), very low density lipoprotein cholesterol (-14% vs 14%; p = 0.017), very low density lipoprotein triglycerides (-1% vs 29%; p = 0.014) and total triglycerides (-7% vs 24%; p < 0.001). These effects on cholesterol levels were reflected in a significant decrease in apolipoprotein B levels with fluvastatin therapy (p < 0.001). Apolipoprotein A-I levels increased (p = 0.054) despite no significant change in the levels of high density lipoprotein cholesterol. Response to therapy did not differ between the 2 renal function groups for any of the lipid, lipoprotein, and apolipoprotein variables. Hemorheologic parameters were not altered with fluvastatin therapy, regardless of renal function.(ABSTRACT TRUNCATED AT 250 WORDS)


Diabetes, Obesity and Metabolism | 2004

Plasma sex hormone-binding globulin rather than corticosteroid-binding globulin is a marker of insulin resistance in obese adult males.

John G. Lewis; Brett I. Shand; Peter A. Elder; Russell S. Scott

Aim:  Plasma levels of corticosteroid‐binding globulin (CBG) and sex hormone‐binding globulin (SHBG) may be regulated by insulin. The aim of this study was to test the hypothesis that these steroid‐binding proteins are markers of insulin resistance and obesity in adult patients with the metabolic syndrome.


Diabetes Research and Clinical Practice | 2008

Plasma retinol-binding protein is unlikely to be a useful marker of insulin resistance.

John G. Lewis; Brett I. Shand; Peter A. Elder; Russell S. Scott

To assess whether plasma retinol-binding protein (RBP) is a marker of insulin resistance we measured RBP, insulin and glucose in 285 fasting subjects attending a Lipid Disorders Clinic as outpatients. They were grouped as either subjects without diabetes mellitus and with varying degrees of insulin resistance or subjects with diabetes mellitus according to the WHO criteria. We show that there was no association between plasma RBP and insulin-resistance, insulin, glucose, % body fat, waist circumference or BMI whether analysed together or in groups. We confirm, using the largest study cohort to date, that plasma RBP is unlikely to be a useful marker of insulin resistance.


Free Radical Research | 2006

Comparative effects of enzogenol® and vitamin C supplementation versus vitamin C alone on endothelial function and biochemical markers of oxidative stress and inflammation in chronic smokers

Joanna M. Young; Brett I. Shand; Patrice M. McGregor; Russell S. Scott; Chris Frampton

Chronic smoking is associated with endothelial dysfunction and inflammation, with oxidative stress contributing to both these processes. In this study, we investigated the effect of combined antioxidant treatment with Enzogenol®, a flavonoid extract from the bark of Pinus radiata and vitamin C, over and above vitamin C alone, on endothelial function, plasma markers of inflammation and oxidative stress, blood pressure (BP) and anthropometrics. Forty-four chronic smokers without established cardiovascular disease were assigned randomly to receive either 480 mg Enzogenol® and 60 mg vitamin C, or 60 mg vitamin C alone daily for 12 weeks. Endothelial function in the brachial artery was assessed by flow-mediated vasodilation (FMD). FMD improved in both treatment groups (p < 0.001), with no significant difference between the two groups (p = 0.84). In the group receiving Enzogenol® and vitamin C, protein carbonyl levels were significantly reduced compared to the group taking vitamin C alone (p = 0.03). Enzogenol® and vitamin C resulted in a significant reduction in fibrinogen levels in heavy smokers compared with vitamin C alone (p < 0.009). These findings demonstrated that co-supplementation with Enzogenol® and vitamin C in smokers conferred no additional beneficial effect on macrovascular endothelial function over and above that seen in the vitamin C alone group. However, Enzogenol® did demonstrate additional favourable effects on protein oxidative damage and fibrinogen levels.

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