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Biomedical subjects

A Dornhorst

Publications and source records attributed to A Dornhorst.

At least 19 recordsLinked to original sources
PubMed2005

Veganism and its relationship with insulin resistance and intramyocellular lipid.

OBJECTIVE: To test the hypothesis that dietary factors in the vegan diet lead to improved insulin sensitivity and lower intramyocellular lipid (IMCL) storage. DESIGN: Case-control study. SETTING: Imperial College School of Medicine, Hammersmith Hospital Campus, London, UK. SUBJECTS: A total of 24 vegans and 25 omnivores participated in this study; three vegan subjects could not be matched therefore the matched results are shown for 21 vegans and 25 omnivores. The subjects were matched for gender, age and body mass index (BMI). INTERVENTIONS: Full anthropometry, 7-day dietary assessment and physical activity levels were obtained. Insulin sensitivity (%S) and beta-cell function (%B) were determined using the homeostatic model assessment (HOMA). IMCL levels were determined using in vivo proton magnetic resonance spectroscopy; total body fat content was assessed by bioelectrical impedance. RESULTS: There was no difference between the groups in sex, age, BMI, waist measurement, percentage body fat, activity levels and energy intake. Vegans had a significantly lower systolic blood pressure (-11.0 mmHg, CI -20.6 to -1.3, P=0.027) and higher dietary intake of carbohydrate (10.7%, CI 6.8-14.5, P<0.001), nonstarch polysaccharides (20.7 g, CI 15.8-25.6, P<0.001) and polyunsaturated fat (2.8%, CI 1.0-4.6, P=0.003), with a significantly lower glycaemic index (-3.7, CI -6.7 to -0.7, P=0.01). Also, vegans had lower fasting plasma triacylglycerol (-0.7 mmol/l, CI -0.9 to -0.4, P<0.001) and glucose (-0.4 mmol/l, CI -0.7 to -0.09, P=0.05) concentrations. There was no significant difference in HOMA %S but there was with HOMA %B (32.1%, CI 10.3-53.9, P=0.005), while IMCL levels were significantly lower in the soleus muscle (-9.7, CI -16.2 to -3.3, P=0.01). CONCLUSION: Vegans have a food intake and a biochemical profile that will be expected to be cardioprotective, with lower IMCL accumulation and beta-cell protective.

Adipose Tissue↗
PubMed2005

Improving hospital doctors' working lives: online questionnaire survey of all grades.

BACKGROUND: In 2001, the Department of Health produced the Improving Working Lives (IWL) for Doctors document. This is the first national survey which asks hospital doctors what changes are needed to improve their working lives. METHODS: An online questionnaire was run over a period of six weeks and was open to all doctors of all grades. Doctors were asked to choose their top five factors from a list of 35 diverse choices or to provide alternatives in free text. Demographic data were also collected. RESULTS: 1603 hospital doctors working in the UK completed the online questionnaire. Improved secretarial or managerial support was the first IWL choice for consultants, with different aspects of clinical and non-clinical support representing their top four choices. Junior hospital doctors and staff and associate specialist grades (staff grades, associate specialists, and clinical assistants) identified improved support for education and training as their first choice, while among the female specialist registrars, it was improved support for childcare. Greater opportunities to develop new skills was an important issue for doctors in the surgical specialties and improved access to mentoring was important for all junior doctors, staff and associate specialist grades, and doctors from black and ethnic minority groups. CONCLUSIONS: Hospital doctors in the UK need more support to improve their working lives. The principle needs are better secretarial and managerial support for consultants; education, training, and mentoring for junior doctors and staff and associate specialist grades; and improved opportunities to develop new skills for those in surgical specialties. Support with childcare is an important issue for female specialist registrars. The Department of Health, NHS trusts, deaneries, and Royal Colleges need to endorse policies that promote a training and working environment that will improve working lives for all hospital doctors, ensuring that appropriate and continuing support is available from the time doctors enter the new foundation programmes and proposed run-through grades, to their time spent as consultants in today's NHS.

Attitude of Health Personnel↗
PubMed2004

A prospective randomised trial to determine the efficacy of a low glycaemic index diet given in addition to healthy eating and weight loss advice in patients with coronary heart disease.

OBJECTIVE: Recent epidemiological and prospective trial evidence suggests that consumption of a low glycaemic index (LGI) diet will reduce coronary risk. We hypothesise that introduction of an LGI diet will improve the metabolic profile of patients who have undergone coronary artery bypass grafting. DESIGN: We conducted a randomised parallel group trial comparing a control group (n=29, age 61.8+/-9 y), who received currently advocated healthy eating dietary advice only, to an intervention group, who received healthy eating advice emphasising LGI carbohydrates (n=26, age 63.6+/-9.4 y) over a 12-week period in free-living patients with coronary heart disease. Outcome measures included fasting glucose, insulin, total cholesterol, high-density lipoprotein cholesterol, very low-density lipoprotein cholesterol, low density lipoprotein cholesterol and triglycerides. RESULTS: A significant lower dietary glycaemic index was achieved in the group assigned to an LGI diet compared to the healthy eating control group (71+/-1 vs 81+/-1); fibre intake was also higher in the LGI group (20+/-1 vs 15+/-1 g). All biochemical markers of glucose and lipid metabolism measured were similar after 12 weeks of the LGI diet or control diet. DISCUSSION: The LGI group achieved a significant LGI and a higher dietary fibre intake. However, there was no measurable significant effect of either the LGI diet or the health eating diet on lipid levels; this may have been hidden by concurrent drug therapy.

Adult↗
PubMed2004

Retrospective analysis of the impact of a low glycaemic index diet on hospital stay following coronary artery bypass grafting: a hypothesis.

OBJECTIVE: Glucose tolerance and insulin resistance influence medical outcome in subjects with coronary artery disease, these metabolic parameters also influence general perioperative surgical outcome. We hypothesize that glucose tolerance and insulin resistance can be favourably modified by reducing the glycaemic index of the diet. DESIGN: The present study is a retrospective analysis of a low and high glycaemic index diet on glucose tolerance, insulin resistance and perioperative outcome, as assessed by the length of hospital stay following coronary artery bypass surgery. Thirty-five adults awaiting bypass surgery were randomized, for the 4 weeks prior to surgery, to either a low glycaemic index diet (17 subjects) or high glycaemic index diet (18 subjects). Glucose and insulin responses during a 75 g oral glucose tolerance test were assessed before and after dietary intervention and insulin-mediated glucose uptake was assessed in isolated adipocytes obtained at surgery. RESULTS: The patients who consumed a low glycaemic diet had improved glucose tolerance and significantly greater in vitro adipocyte insulin sensitivity at the time of surgery compared with the high glycaemic diet group (78.87 +/- 10.64% versus 41.11 +/- 7%, respectively). The total length of stay in the patients on the low glycaemic diet was less than patients consuming the high glycaemic diet (7.06 +/- 0.38 days versus 9.53 +/- 1.44 days, P < 0.5). CONCLUSION: This study provides further support that carbohydrate and fat metabolism influence cardiac outcome and provides new evidence that dietary modification prior to coronary artery bypass surgery can shorten hospital stay.

Adipocytes↗
PubMed2002

Lack of effect of oral vitamin C on blood pressure, oxidative stress and endothelial function in Type II diabetes.

Type II diabetes is characterized by increased oxidative stress, endothelial dysfunction and hypertension. We investigated whether short-term treatment with oral vitamin C reduces oxidative stress and improves endothelial function and blood pressure in subjects with Type II diabetes. Subjects ( n =35) received vitamin C (1.5 g daily in three doses) or matching placebo for 3 weeks in a randomized, double-blind, parallel-group design. Plasma concentrations of 8-epi-prostaglandin F(2alpha) (8-epi-PGF(2alpha)), a non-enzymically derived oxidation product of arachidonic acid, were used as a marker of oxidative stress. Endothelial function was assessed by measuring forearm blood flow responses to brachial artery infusion of the endothelium-dependent vasodilator acetylcholine (with nitroprusside as an endothelium-independent control) and by the pulse wave responses to systemic albuterol (endothelium-dependent vasodilator) and glyceryl trinitrate (endothelium-independent vasodilator). Plasma concentrations of vitamin C increased from 58+/-6 to 122+/-10 micromol/l after vitamin C, but 8-epi-PGF(2alpha) levels (baseline, 95+/-4 pg/l; after treatment, 99+/-5 pg/l), blood pressure (baseline, 141+/-5/80+/-2 mmHg; after treatment, 141+/-5/81+/-3 mmHg) and endothelial function, as assessed by the systemic vasodilator response to albuterol and by the forearm blood flow response to acetylcholine, were not significantly different from baseline or placebo. Thus treatment with vitamin C (1.5 g daily) for 3 weeks does not significantly improve oxidative stress, blood pressure or endothelial function in patients with Type II diabetes.

Acetylcholine↗
PubMed2002

The principles of dietary management of gestational diabetes: reflection on current evidence.

BACKGROUND: Gestational diabetes (GDM) is the commonest metabolic disorder of pregnancy. Most women with GDM are treated with nutritional management alone. There are conflicting guidelines surrounding its dietary management and this has resulted in a lack of conformity to the dietary advice currently prescribed. There is also conflicting opinions to the effectiveness of dietary management of GDM on pregnancy outcomes. The aim of this review was to examine the scientific evidence for the optimal nutritional management of GDM. METHODS: A Medline search of all English papers published between 1995 and 2001 that cross-referenced GDM with diet was under taken. Because of the poor quality of many of these papers, literature prior to 1995 known to the authors and considered relevant to the review were also included. RESULTS: The evidence base in this area is of poor quality. One systematic review based on randomized control trials failed to show any benefit from dietary intervention in GDM. However, that review did not include informative clinical and observational studies that are not classified as randomized controlled trials. Overall current evidence points to the effectiveness of dietary advice as a means of improving maternal hyperglycaemia and reducing the risk of accelerated foetal growth. The evidence surrounding energy restriction, carbohydrate and fat manipulation in GDM remains controversial. CONCLUSIONS: Current but limited evidence supports dietary alterations to reduce rates of accelerated foetal growth. There is a clear need for good quality randomized control trials in this area.

Diabetes Mellitus↗
PubMed2002

Intensive lifestyle intervention combined with the choice of pharmacotherapy improves weight loss and cardiac risk factors in the obese.

BACKGROUND: Obesity is on the increase yet within the National Health Service (NHS) treatment approaches differ greatly and service is patchy. Our aim was to compare current practice within a general dietetic clinic with a new clinic developed specifically for patients of higher morbidity risk. METHODS: Locally referred patients to the dietitians from within or without Hammersmith Hospitals NHS Trust of higher morbidity risk were invited to attend a new Lifestyle Clinic. Treatment was of a contractual nature and included more time with the dietitian, the offer of pharmacotherapy if appropriate and an emphasis on achieving a realistic weight loss of 10% within a 6-month period. Cognitive behavioural strategies were utilized focusing on achieving changes in dietary intake and physical activity levels. RESULTS: A total of 103 patients have been enrolled of whom 34 have been discharged before completion of the clinic programme. Twenty-six patients have completed (18 started pharmocotherapy with Orlistat and eight remained on lifestyle advice only), with the remainder still attending the Lifestyle Clinic. The results for these 26 patients demonstrate clinically significant benefits with regard to exercise tolerance 390.8 +/- 37.5 m vs. 473 +/- 46.6 m (P < 0.001), waist measurement 121.5 +/- 4.4 cm vs. 110.9 +/- 3.6 cm (P < 0.001), and total cholesterol : HDL ratio 1.17 +/- 0.05 mmol L-1 vs. 1.27 +/- 0.07 mmol L-1 (P < 0.05). A weight loss comparison with historical data collected in the general dietetic clinic achieves a 7.8 +/- 0.7 kg reduction in weight (with pharmocotherapy 8.96 +/- 0.98 kg, with lifestyle only 5.23 +/- 0.657) vs. 1.7 +/- 0.4 kg (P < 0.05). CONCLUSION: Lifestyle clinics facilitate beneficial lifestyle changes which impact positively on morbidity risk factors demonstrating an improvement on current service offered within the NHS. There is an obvious resource implication of offering an intensive management package. There is need for a randomized control trial with analysis to evaluate whether there is cost benefit from this type of intervention.

Adolescent↗
PubMed2001

Insulinotropic meglitinide analogues.

The loss of early-phase insulin secretion is an important and early event in the natural history of type 2 diabetes. Because a normal pattern of insulin secretion is essential for the effective control of postprandial metabolism, a rational basis for the development of agents that target early-phase insulin release exists. Conventional oral hypoglycaemic agents do not target, or adequately control, postprandial glycaemia. The emergence of new classes of oral agent with a more specific mode of action provides, for the first time, an opportunity to restore early-phase insulin release. One such drug class is the meglitinide analogues (repaglinide, nateglinide, and mitiglinide). These drugs are ideally suited for combination use with metformin. They could also prove effective in combination with a thiazolidinedione, a drug class that targets insulin resistance. Exogenous insulin is frequently required in the late management of type 2 diabetes. However, one hope for newer combinations of diabetic drugs is that the functional life of the beta cell can be extended, thereby delaying the need for insulin injections.

Adult↗
PubMed2001

Glycaemic control and plasma lipoproteins in menopausal women with Type 2 diabetes treated with oral and transdermal combined hormone replacement therapy.

AIMS: To compare the effect of a fixed combination of an oestrogen (17-beta oestradiol) with a cyclical progestagen (norethisterone) on glycaemic control, plasma lipoproteins and haemostatic factors in women with Type 2 diabetes. METHODS: Oral and transdermal hormone replacement therapy (HRT) were compared to no HRT treatment in 33 postmenopausal women with Type 2 diabetes, in a 12-week randomised prospective open parallel group study. RESULTS: In the 11 women who received 12 weeks of oral HRT, there was a significant fall in total cholesterol (5.9+/-1.0 (S.D.) to 4.7+/-1.0 mmol l(-1), P=0.005), low density lipoprotein cholesterol (3.44+/-0.89 to 2.77+/-0.92 mmol l(-1), P=0.005) and triglyceride values (median (range)), (2.46 (0.96-5.52) to 2.29 (1.00-3.87) mmol l(-1), P<0.05). Oral HRT improved glycated haemoglobin (HbA(1c)) (7.4+/-1.4 to 6.8+/-1.2%, P< or =0.005). Oral HRT additionally reduced the cell adhesion factor E-selectin (82+/-33 to 60+/-20 microg l(-1), P<0.01) and factor VII (143+/-25 to 109+/-24% pooled plasma activity, P<0.01). No improvement in any of these parameters, except E-selectin (65+/-19 to 58+/-18 microg l(-1), P<0.01), occurred in the nine women receiving transdermal HRT, and no improvement occurred in the 13 controls randomised to no treatment. CONCLUSION: In women with Type 2 diabetes, cyclical oestrogen and progestagen taken orally for 12 weeks significantly improved glycaemic control and lipoprotein concentrations. These metabolic benefits were not apparent when a similar HRT preparation was administered transdermally.

Administration, Cutaneous↗
PubMed2000

The relevance of the glycaemic index to our understanding of dietary carbohydrates.

AIMS: To review the evidence for the importance of glycaemic index of dietary carbohydrate in disease prevention and control. METHODS: A critical appraisal of the literature published in English between and cited on Medline between January 1966 and October 1999. RESULTS: Using basic, intervention and epidemiological studies from experienced teams, evidence that the glycaemic index of diet may influence outcome in terms of cardiovascular risk, risk of metabolic syndrome diseases and pregnancy was found. CONCLUSIONS: Consideration of glycaemic indices in making dietary recommendations may be expected to produce additional health benefit.

Blood Glucose↗
PubMed2000

The glycaemic index of a range of gluten-free foods.

AIMS: The number of people with both diabetes and coeliac disease is increasing. This study examined the effect of gluten-free, as opposed to gluten-replete carbohydrate containing foods, on post-prandial blood glucose concentrations. METHODS: The glycaemic index of six commonly used gluten-free carbohydrates are reported and compared with published figures for similar non-gluten-free products. RESULTS: The results indicate that the glycaemic index of gluten-free and gluten containing foods are similar. CONCLUSIONS: The inclusion of gluten-free foods in the diet of diabetic individuals with coeliac disease should not compromise glycaemic control.

Blood Glucose↗
PubMed1999

Glycaemic index as a determinant of serum HDL-cholesterol concentration.

BACKGROUND: Diet influences the prevalence of coronary heart disease (CHD). Insulin sensitivity and concentrations of HDL cholesterol, two metabolic predictors of CHD, are also influenced by diet. Dietary carbohydrates with a high glycaemic index cause a high postprandial glucose and insulin response, and are associated with decreased insulin sensitivity and an increased risk of CHD. This study examined whether the glycaemic index of dietary carbohydrates is a determinant of serum HDL-cholesterol concentrations. METHOD: Dietary, anthropometric, and biochemical data from the 1986-87 Survey of British Adults (n=2200) were reanalysed by a multiple regression model, which examined the relation between serum total cholesterol, HDL-cholesterol, and calculated LDL-cholesterol concentrations and various dietary characteristics, including the type of carbohydrate, the glycaemic index, and fat intake. FINDINGS: Among the 1420 participants with complete data, there was a significant negative relation between serum HDL-cholesterol concentration and the glycaemic index of the diet for both men (regression coefficient -0.00724 [95% CI -0.0101 to -0.00434], p=0.02) and women (-0.01326 [-0.0162 to -0.0102], p<0.0001). No other significant relation was found with total cholesterol or LDL-cholesterol concentration or with any other dietary carbohydrate or fat constituent. INTERPRETATION: In a cross-sectional study of middle-aged adults, the glycaemic index of the diet was the only dietary variable significantly related to serum HDL-cholesterol concentration. Thus, the glycaemic index of the diet is a stronger predictor than dietary fat intake of serum HDL-cholesterol concentration.

Adult↗
PubMed1999

Implications of new diagnostic criteria for abnormal glucose homeostasis in women with previous gestational diabetes.

OBJECTIVE: To determine the consequences of applying revised American Diabetes Association (ADA) (1997) and World Health Organization (WHO) (1998) recommendations for the classification of glucose intolerance in women with previous gestational diabetes mellitus (GDM). RESEARCH DESIGN AND METHODS: There were 192 women with previous GDM who took an oral glucose tolerance test (OGTT) 1-86 months after delivery and were classified by WHO (1985), ADA (1997, fasting glucose), and revised WHO (1998) guidelines. RESULTS: Among the 165 women without a preexisting diagnosis of diabetes, WHO-1985 and ADA-1997 provided similar estimates of diabetes prevalence (13.3% vs. 11.5%) but widely differing estimates of impaired glucose homeostasis (31.5% impaired glucose tolerance [IGT] by WHO-1985 vs. 10.9% impaired fasting glucose by ADA-1997 criteria). Overall, 56 women (34%) showed a classification discrepancy between WHO-1985 and ADA-1997 criteria, including 44 with normal fasting glucose by ADA-1997 criteria, but abnormal 2-h glucose by WHO-1985 criteria (40 IGT, 4 diabetes). The cardiovascular risk profile of these women was more favorable than that of 18 women with impaired fasting glucose. WHO-1998 recommendations reproduced ADA-1997 findings when used as a fasting screen, but behaved similarly to WHO-1985 criteria when 2-h glucose values were also analyzed. CONCLUSIONS: All criteria produced similar estimates of diabetes prevalence. However, analyses based on a single fasting glucose screen (and a threshold of 6.1 mmol/l) failed to identify 60% of women with abnormal 2-h glucose levels. Screening women with previous GDM (and by analogy, other groups at high risk of diabetes) with a single fasting glucose has low sensitivity for the detection of abnormal glucose tolerance. Recent guidelines recommending this approach require reevaluation.

Adult↗