Biomedical subjects

C Berne

Publications and source records attributed to C Berne.

At least 19 recordsLinked to original sources

PubMed2006

The influence of glucose self-monitoring on glycaemic control in patients with diabetes mellitus in Sudan.

OBJECTIVE: To investigate the influence of self-monitoring of glucose on the glycaemic control in Sudanese diabetic subjects. SUBJECTS AND METHODS: A group of 193 consecutive type 2 and type 1 diabetic subjects (95 men, 98 women) were studied. In 104 subjects with type 2 diabetes fasting blood glucose was measured using a glucose meter and blood was obtained for serum glucose measurement in the laboratory. In the remaining 89 diabetic subjects random blood glucose was measured using the same glucose meter and a whole blood sample was drawn for laboratory assessment of HbA1c. Data on self-monitoring and other clinical and personal characteristics were recorded. RESULTS: More than 75% of either type 1 and type 2 diabetic patients never self-monitored blood or urine glucose. In type 2 diabetic subjects self-monitoring of blood or urine glucose was not related to glycaemic control. In type 1 diabetic subjects, however, self-monitoring of blood glucose was significantly associated with better glycaemic control, as assessed by HbA1c (P=0.02) and blood glucose at clinic visits (P< or =0.0001), and similar associations were found for urine glucose self-monitoring (P=0.04 and 0.02) respectively. Neither glycaemic control nor glucose self-monitoring was associated with education level. CONCLUSIONS: Self-monitoring of blood glucose was not found to be associated to better glycaemic control in Sudanese subjects with type 2 diabetes. In contrast, self-monitoring of both blood and urine glucose was significantly associated with glycaemic control in subjects with type 1 diabetes. Self-monitoring of urine glucose could be useful where measurement of blood glucose is not available or affordable.

Adult↗

PubMed2005

Current status of clinical islet transplantation.

Islet transplantation is currently being explored as a treatment for patients with type 1 diabetes. At present, the number of patients becoming insulin-independent is rapidly increasing world-wide applying the transplantation protocol originally described by the group in Edmonton. A hallmark in this procedure is repeated infusions of islets obtained from 2 to 4 donors until normoglycemia is achieved. In order to establish islet transplantation as a widely accepted treatment modality, and make tolerance induction regimes applicable, it is essential that the donor:recipient ratio is brought down to 1:1. A conceivable strategy to achieve this goal in clinical islet transplantation is discussed.

Animals↗

PubMed2005

Insulin sensitivity, proinsulin and insulin as predictors of coronary heart disease. A population-based 10-year, follow-up study in 70-year old men using the euglycaemic insulin clamp.

AIMS/HYPOTHESIS: The association between CHD and insulin sensitivity (Si) measured by the euglycaemic insulin clamp has not been examined previously. Earlier studies found a relationship between CHD and elevated plasma insulin, an analysis that may have been confounded by co-determination of proinsulin, which has evolved as a stronger predictor of CHD. The aim was to determine the longitudinal relationships between Si, intact proinsulin, 32-33 split proinsulin, specific insulin and subsequent CHD. METHODS: This was a population-based cohort study of 815 men in Uppsala, Sweden, aged 70 years at baseline with a follow-up of up to 10 years. Baseline insulin sensitivity was determined by euglycaemic insulin clamp. Fasting proinsulin, 32-33 split proinsulin and specific insulin concentrations were analysed using specific two-site immunometric assays. CHD was taken as diagnosed, if stated (in the event of death) on the Cause of Death Registry, or for subjects hospitalised for the first time with CHD, if CHD was recorded in the Hospital-Discharge Registry. The associations were analysed using Cox's proportional hazards, presented as hazard ratios (HRs) with their 95% CIs for a one-SD increase in the predictor. RESULTS: In multivariate analysis, Si (HR:0.80, CI:0.65-0.97) adjusted for serum cholesterol, systolic blood pressure, fasting plasma glucose, BMI and smoking predicted CHD. Intact proinsulin (HR:1.18, CI:1.01-1.38), adjusted as the model above, predicted CHD, whereas 32-33 split proinsulin (HR:1.13, CI:0.95-1.35) or specific insulin (HR:1.07, CI:0.89-1.30) did not. CONCLUSIONS/INTERPRETATION: Insulin resistance measured by the euglycaemic insulin clamp predicts subsequent CHD in elderly men. Proinsulin provides a better prediction of CHD than insulin.

Aged↗

PubMed2005

Orlistat in responding obese type 2 diabetic patients: meta-analysis findings and cost-effectiveness as rationales for reimbursement in Sweden and Switzerland.

OBJECTIVE: The aim of this study is to review the clinical and economic rationale for the reimbursement of orlistat in responding obese patients with type 2 diabetes. METHODS: Data from seven randomized controlled clinical trials of orlistat in overweight and obese patients with type 2 diabetes were pooled. A subgroup analysis involving patients who achieved a response (defined as a weight loss of >/=5% after 12 weeks of treatment) was conducted. The outcomes of the pooled analysis were then used to construct a Markov health economic model covering an 11-y period. The incidences of diabetes-related micro- and macrovascular complications were derived from the United Kingdom Prospective Diabetes Study. The effects of changes in body mass index, and the impact of micro- and macrovascular complications on utilities were derived from published sources. Publicly available cost data were used and are presented here in 2001 Euros. Discounting of 3% was applied. A probabilistic sensitivity analysis was conducted to examine the robustness of results. RESULTS: A total of 1249 patients treated with orlistat and 1230 given placebo were eligible for the intent-to-treat analysis. At the end of the study period, 23% of orlistat patients achieved a weight reduction of >/=5%. These patients showed a mean decrease in HbA1C of 1.16%, a weight reduction of 8.6 kg, a reduction in total cholesterol of 5.3% and a reduction in systolic blood pressure of 5.2 mmHg. The base-case economic analysis revealed costs per quality-adjusted life year gained of euro14 000 in Sweden and euro13 600 in Switzerland. CONCLUSION: The data presented here support the utilization and reimbursement of orlistat in overweight and obese diabetic patients who respond to the treatment.

Anti-Obesity Agents↗

PubMed2005

Glycaemic and insulin responses of six traditional Sudanese carbohydrate-rich meals in subjects with Type 2 diabetes mellitus.

AIMS: The objective of this study was to investigate the influence of six Sudanese traditional carbohydrate-rich meals on glucose and insulin responses and to formulate appropriate dietary guidelines based on glycaemic excursions of traditional foods. METHODS: On six occasions with 1-week intervals, 10 Type 2 diabetic subjects consumed six Sudanese traditional carbohydrate-rich meals. The following meals were tested and also analysed for their composition: wheat gorasa (pancakes), sorghum kisra (flat bread) and sorghum acida (porridge), millet kisra and millet acida and maize acida. Blood samples were collected before and after meal ingestion at 0, 30, 60, 120 and 240 min and analysed for plasma glucose and plasma insulin and incremental areas under the curves (AUC) were calculated. RESULTS: A significant variation in AUC for glucose and insulin responses were found between meals, the over all differences in incremental AUCs between the six meals were significant for both plasma glucose (P = 0.0092) and insulin (P = 0.0001). The 2-h glucose values were 10.5 +/- 2.7 for sorghum flatbread, 9.5 +/- 3.1 for sorghum porridge, 10.3 +/- 3.4 for millet flatbread, 10.6 +/- 3.6 for millet porridge, 11.4 +/- 2.7 for maize porridge and 8.7 +/- 2.4 for the wheat pancakes. The comparison between the AUCs of the meals showed that millet acida (porridge) followed by wheat gorasa (pancakes) displayed significantly lower post-prandial glucose and insulin responses, whereas maize acida induced a higher post-prandial glucose and insulin response. CONCLUSIONS: The comparison of glycaemic and insulin responses to six traditional Sudanese meals show differences of clinical importance, and could form a basis for dietary advice to diabetic subjects in Sudan and countries sharing similar food traditions.

Adult↗

PubMed2005

A randomized study of orlistat in combination with a weight management programme in obese patients with Type 2 diabetes treated with metformin.

AIMS: To assess the effects of orlistat vs. placebo, in combination with a weight management programme, on weight loss and metabolic control in obese patients with Type 2 diabetes. METHODS: Patients treated with either metformin alone or metformin in combination with sulphonylurea were randomized to double-blind treatment with orlistat or placebo (120 mg) three times daily, combined with a mildly reduced calorie diet and a weight management programme for 52 weeks. Changes in body weight, anthropometry, glycaemic control and lipid profile were assessed. RESULTS: After 52 weeks, orlistat-treated patients achieved an almost threefold greater reduction in weight compared with placebo recipients (-5.0% vs. -1.8%; P<0.0001). The decrease in waist circumference was significantly greater with orlistat than placebo (-4.8 cm vs. -2.8 cm; P=0.0022). Orlistat treatment was also associated with significantly greater reductions in haemoglobin A(1c) (-1.1% vs. -0.2%; P<0.0001), fasting plasma glucose (-1.9 mmol/l vs. -0.3 mmol/l; P<0.0001), total cholesterol (-0.2 mmol/l vs. 0.1 mmol/l; P=0.03) and apolipoprotein B (-0.08 g/l vs. 0.01 g/l; P=0.0085) and greater improvements in beta-cell function (P=0.031) and insulin resistance (P=0.001) assessed using the homeostasis model assessment (HOMA). Similar results were obtained for subgroups of patients treated with metformin alone or metformin in combination with sulphonylurea. Orlistat treatment reduced the requirement for anti-diabetic medication more than placebo. CONCLUSIONS: Orlistat, in combination with a reduced calorie diet and a weight management programme, promotes weight loss and clinically relevant improvements in glycaemic control and other cardiovascular risk factors in obese patients with Type 2 diabetes.

Adult↗

PubMed2004

Body composition and bone mineral density in long-standing type 1 diabetes.

OBJECTIVES: To study body composition and bone mineral density (BMD) in adult patients with long-standing type 1 diabetes mellitus. RESEARCH DESIGN AND METHODS: In a population-based study, body composition and BMD were evaluated by dual energy X-ray absorptiometry in 38 patients with type 1 diabetes since childhood, compared with 38 age- and sex-matched controls. The mean age was 43 years (range 33-55 years) and the mean duration of diabetes was 33 years (range 28-37 years). RESULTS: Besides a tendency to a reduced abdominal fat mass in diabetic males, no difference was observed in fat mass, muscle mass, or BMD between the groups. Significant correlations were found between insulin dosage and whole body fat mass in diabetic females and between serum cholesterol levels and abdominal fat mass in diabetic males. CONCLUSION: Patients with long-standing type 1 diabetes with onset in childhood and adolescence seem to show only minor differences in body composition and no difference in BMD compared with closely matched healthy controls.

Absorptiometry, Photon↗

PubMed2004

Normal weight promotes remission and low number of islet antibodies prolong the duration of remission in Type 1 diabetes.

AIM: To identify clinical, immunological and biochemical factors that predict remission, and its duration in a large cohort of young adults with Type 1 diabetes mellitus (DM). METHODS: In Sweden, 362 patients (15-34 years), classified as Type 1 DM were included in a prospective, nation-wide population-based study. All patients were followed at local hospitals for examination of HbA(1c) and insulin dosage over a median period after diagnosis of 5 years. Duration of remission, defined as an insulin maintenance dose </= 0.3 U/kg/24 h and HbA(1c) within the normal range, was analysed in relation to characteristics at diagnosis. RESULTS: Remissions were seen in 43% of the patients with a median duration of 8 months (range 1-73). Sixteen per cent had a remission with a duration > 12 months. Among patients with antibodies (ab(+)), bivariate analysis suggested that adult age, absence of low BMI, high plasma C-peptide concentrations, lack of ketonuria or ketoacidosis at diagnosis and low insulin dose at discharge from hospital were associated with a high possibility of achieving remission. Multiple regression showed that normal weight (BMI of 20-24.9 kg/m(2)) was the only factor that remained significant for the possibility of entering remission. In survival analysis among ab(+) remitters, a low number of islet antibodies, one or two instead of three or four, were associated with a long duration of remissions. CONCLUSION: In islet antibody-positive Type 1 DM, normal body weight was the strongest factor for entering remission, whilst a low number of islet antibodies was of importance for the duration.

Adolescent↗

PubMed2003

Hypoglycaemia induces decreased islet blood perfusion mediated by the central nervous system in normal and Type 2 diabetic GK rats.

AIMS/HYPOTHESIS: The aim of this study was to evaluate the effects of induced hypoglycaemia on pancreatic-islet blood flow in normal rats and in the GK rat, an animal model of Type 2 diabetes which normally has an increased islet blood perfusion. METHODS: A 50% reduction in blood glucose concentrations was achieved by intravenous administration of a rapidly acting insulin (15 IU/kg body weight). Blood flows were measured by a non-radioactive microsphere technique. RESULTS: A pronounced decrease in islet blood flow was observed in all animals, but preferentially in the Type 2 diabetic GK rats. When a similar dose of insulin was given to whole-pancreas transplanted rats only islet blood flow in the native pancreas was decreased, whereas that of the transplanted, i.e. denervated, pancreas was unchanged. Administration of 2-deoxy-D-glucose, which induces intracellular glucopenia especially in neurons, also decreased islet blood flow despite a systemic hyperglycaemia. CONCLUSION/INTERPRETATION: Hypoglycaemia leads to a preferential decrease in pancreatic-islet blood perfusion. The effect is probably mediated by the central nervous system, since 2-deoxy D-glucose-induced neuronal glucopenia caused a similar decrease in blood flow. The effects of islet blood flow are not likely to be mediated by nervous stimulation of the adrenal glands, with an associated release of catecholamines, because the transplanted pancreas was not affected by hypoglycaemia. The decreased islet blood perfusion could possibly diminish the output of insulin from the islets, thereby preventing a further decrease in blood glucose concentrations.

Animals↗

PubMed2003

Proinsulin and acute insulin response independently predict Type 2 diabetes mellitus in men--report from 27 years of follow-up study.

AIMS/HYPOTHESIS: Defects in insulin secretion and insulin action, resulting in compensatory hyperinsulinaemia, are the major abnormalities in the development of Type 2 diabetes mellitus (Type 2 diabetes). The most frequently used conventional immunoreactive assays for insulin cross-react with proinsulin. In short-term studies (<5 years), proinsulin predicts the development of Type 2 diabetes. We studied, with a 27-year follow-up, the longitudinal relationships between intact proinsulin, 32-33 split proinsulin, specific and immunoreactive insulin (IRI), acute insulin response (AIR) after an intravenous glucose load and the development of Type 2 diabetes in a population-based cohort of 50-year-old men. METHODS: Fasting peptide concentrations were measured in plasma samples, stored since 1970-73 using specific two-site immunometric assays. IRI was measured at baseline using radioimmunoassay. Associations between development of Type 2 diabetes and predictor variables, were analysed with logistic regression. Results are shown as odds ratios (ORs) with their 95% confidence intervals (CIs) for a one standard deviation increase in a predictor variable. RESULTS: Cumulative incidence of Type 2 diabetes was 33% over 27 years of follow-up. Intact proinsulin (OR, 1.57, CI, 1.16-2.14), and 32-33 split proinsulin (OR, 1.70, CI, 1.20-2.39) were associated with development of Type 2 diabetes, independent of AIR, adjusted for BMI and fasting glucose, whereas specific insulin was not (OR, 1.31, CI, 0.98-1.77), nor was IRI (OR, 1.25, CI, 0.96-1.63). Proinsulin and AIR interacted in the development of Type 2 diabetes (p<0.05). CONCLUSION/INTERPRETATION: Proinsulin predicts the development of Type 2 diabetes mellitus over a 27-year period.

Cohort Studies↗

PubMed2003

Blood flow is an important determinant of forearm glucose uptake following a mixed meal.

Insulin-mediated vasodilation has been suggested to be of importance for glucose uptake during normoglycemic hyperinsulinemia. If this also is valid after an ordinary mixed meal remains to be evaluated. Forearm blood flow (FBF) and forearm glucose uptake change (evaluated by venous occlusion plethysmography) and glucose arteriovenous differences were evaluated over 120 minutes in 10 healthy volunteers following an ordinary mixed meal (700-900 kcal, 34% of energy from fat). Fasting arterial glucose level was 4.9+/-0.9 mmol/l, and the maximum glucose level was reached 30 minutes after the start of ingestion (6.6+/-0.8 mmol/l, p<0.0001). Plasma insulin levels were increased four-fold. FBF increased rapidly within 20 minutes after the start of ingestion and reached its maximum after 50 minutes (94% higher than baseline level, p<0.01). After 2 hours FBF was still substantially elevated (75% above baseline level, p<0.01). Forearm glucose uptake increased fivefold already after 20 minutes ( p<0.01). During the 2 hours, the increase in FBF contributed to 41% of the forearm glucose uptake ( p<0.05). The present study showed that the increase in FBF seen after an ordinary mixed meal is important for the change in forearm glucose uptake. These results support the view that modulation of limb blood flow is a determinant of glucose uptake.

Adult↗

PubMed2003

Factors affecting perinatal morbidity and mortality in pregnancies complicated by diabetes mellitus in Sudan.

To investigate the influence of obstetric factors and indices of maternal metabolic control on perinatal morbidity and mortality, 88 diabetic pregnant Sudanese women (type 1, n=38; type 2, n=31; gestational diabetes, n=19) and 50 non-diabetic pregnant control women were studied. The mean fasting blood glucose was 11.1+/-2.8 mmol/l and the mean HbA(1c) at booking interview was 8.8+/-2.1% in the diabetic women. Pregnancy complications such as Caesarean sections, urinary tract infections, pregnancy-induced hypertension and intrauterine foetal death were higher among diabetic compared with control women (P<0.0001) and varied with the type of diabetes. Infants of diabetic mothers had a higher incidence of neonatal complications than those of non-diabetic women (54.4% vs. 20.0%; P<0.0001). Infants without complications and who were born to diabetic mothers had better Apgar scores at 5 min (9.8+/-0.5 vs. 8.9+/-1.6; P<0.01) and lower cord C-peptide when compared to infants with complications (P<0.05). In conclusion, the prevalence of maternal and neonatal complications among Sudanese diabetic women and their infants is high. Maternal hyperglycaemia is an important factor affecting maternal wellbeing and neonatal morbidity and mortality.

Adult↗

PubMed2003

Basal glucometabolic status has an impact on long-term prognosis following an acute myocardial infarction in non-diabetic patients.

OBJECTIVES: Patients with diabetes are known to have a worse prognosis after an acute myocardial infarction (AMI) compared with non-diabetic patients. The primary aim of this study was to investigate the effect of glucometabolic status on long-term prognosis in non-diabetic patients with an AMI. The second aim was to evaluate the extent to which blood glucose levels at admission depended on acute stress, assessed as serum cortisol, previous glucometabolic status, measured as haemoglobin A1c (HbA1c), or both. DESIGN: In a prospective study of patients with an AMI, blood glucose, HbA1c and cortisol were measured at admission. Fasting blood glucose was determined before discharge and also afterwards, if necessary, for classification. Patients were followed-up for 5.5 years. SUBJECTS: Of the 305 consecutive patients 24% were diagnosed as diabetic and 76% as non-diabetic. MAIN OUTCOME MEASURES: Death or non-fatal myocardial re-infarction. RESULTS: In non-diabetic patients, a Cox regression model was used. With death or re-infarction as endpoint, the following prognostic factors had an impact on event-free survival: age (P<0.001), HbA1c (P=0.002), cortisol (P<0.001) and thrombolytic treatment (P=0.001). There was a correlation between cortisol and blood glucose at admission (r=0.44, P<0.001). Fasting blood glucose day 5 showed no association with event-free survival. CONCLUSIONS: In non-diabetic patients with AMI, admission HbA1c and cortisol were predictors for 5.5-year survival without recurrent non-fatal myocardial infarction. The glucometabolic status of importance for prognosis was detected by HbA1c but not by fasting blood glucose or admission blood glucose, of which the latter was influenced by cortisol.

Aged↗

PubMed2003

Body composition in adolescent girls with type 1 diabetes.

AIMS: To compare body composition in adolescent girls with Type 1 diabetes with healthy controls. RESEARCH DESIGN AND METHODS: In this population-based study, body composition was examined, using dual-energy X-ray absorptiometry (DXA) and skinfold measurements, in 18 adolescent post-menarcheal females, 16-19 years of age, with Type 1 diabetes since childhood in comparison to age-matched healthy control subjects. RESULTS: Body mass index was 2.7 kg/m2 higher in diabetic patients (26.3 +/- 2.6 vs. 23.6 +/- 3.8; P < 0.05). The overweight consisted almost entirely of increased fat mass, as evaluated by both skinfold measurements and DXA. Bone mineral density did not differ between the two groups. In diabetic females, the distribution of the fat mass was increased in the upper part of the body. The fat distribution, expressed as the abdominal-to-leg ratio, was significantly correlated to glycated haemoglobin (HbA1c) (r = 0.69; P < 0.005), daily dosage of insulin expressed per kilogram body weight (r = 0.78; P < 0.0005) and total cholesterol (r = 0.60; P < 0.001). CONCLUSIONS: The observed overweight in adolescent females with Type 1 diabetes is explained by an increased fat mass. Abdominal fat accumulation was associated with poor glycaemic control, increased need for insulin and elevated blood lipids.

Absorptiometry, Photon↗

PubMed2002

Oxidative stress and antioxidant status in type 1 diabetes mellitus.

OBJECTIVES: To test the hypothesis that type 1 diabetes is associated with increased oxidative stress and/or antioxidant status by investigating concentrations of 8-iso-prostaglandin F2alpha (8-iso-PGF2alpha) in urine and plasma and malondialdehyde (MDA) in plasma as indicators of lipid peroxidation in vivo, and antioxidant status in diabetic subjects compared with healthy control subjects. DESIGN AND SUBJECTS: Thirty-eight subjects with type 1 diabetes mellitus and 41 healthy age- and sex-matched control subjects were included in the study. Blood and urine samples were obtained and analysed for 8-iso-PGF2alpha with a newly developed radioimmunoassay, as well as for MDA, total antioxidant capacity (TAOC) and serum tocopherol levels. RESULTS: None of the variables of lipid peroxidation showed any significant difference between the two groups. Similarly, there were no significant correlations between the levels of 8-iso-PGF2alpha or MDA, and degree of glycemic control (HbA1c). Total antioxidant capacity in plasma was 16% lower amongst the subjects with type 1 diabetes than in the control group (P < 0.0005). Lipid corrected levels of alpha-tocopherol in serum were significantly increased in type 1 diabetic subjects (P < 0.05), as were gamma-tocopherol levels (P < 0.005). CONCLUSIONS: In spite of lower total antioxidant defence, our results do not support the oxidative stress hypothesis for type 1 diabetes mellitus. The higher tocopherol levels suggest that no vitamin E supplementation is necessary for subjects with type 1 diabetes mellitus.

Adult↗

PubMed2002

Reduced leptin concentrations in subjects with type 2 diabetes mellitus in Sudan.

Differences have been observed in the relationship between leptin and metabolic perturbations in glucose homeostasis. Because no information is available from indigenous African populations with diabetes, the purpose of this study was to investigate the possible associations between leptin and different clinical and biochemical characteristics of a large group of subjects with type 2 diabetes mellitus in Sudan. A total of 104 (45 men and 59 women) consecutive type 2 diabetes patients and 75 control subjects (34 men and 41 women) were studied. The body mass index (BMI), blood glucose, serum insulin, and proinsulin were measured and related to serum leptin concentrations. Leptin was higher in females than in males and correlated significantly to BMI. The main novel finding was that serum leptin was significantly lower in diabetic subjects compared with controls in both females (P =.0001) and males (P =.019), although BMI did not differ between diabetic and nondiabetic subjects. Diabetic subjects treated with sulphonylurea (n = 81) had lower BMI than those treated with diet alone or other hypoglycemic drugs (n = 23) (P =.0017), but there was no difference in leptin levels between the 2 groups after adjustment for BMI (P =.87). In diabetic subjects, serum leptin correlated positively with the homeostatic assessment (HOMA) of both beta-cell function (P =.018) and insulin resistance (P =.038), whereas in control subjects, leptin correlated with insulin resistance (P =.0016), but not with beta-cell function. Diabetic subjects had higher proinsulin levels (P =.0031) and higher proinsulin to insulin ratio (P =.0003) than nondiabetic subjects. In univariate analysis, proinsulin showed a weak correlation to leptin (P =.049). In conclusion, we show in a large cohort of Sudanese subjects with type 2 diabetes that circulating leptin levels are lower in diabetic subjects than in controls of similar age and BMI. The lower serum leptin in diabetic subjects may be a consequence of differences in fat distribution.

Adult↗

PubMed2001

An ordinary mixed meal transiently impairs endothelium-dependent vasodilation in healthy subjects.

This study was designed to evaluate the effects of an ordinary mixed meal on endothelium-dependent vasodilation. Ten young healthy volunteers were given a mixed meal (minced meat sauce with rice, 900 kcal, 34% of the energy content was fat). In the fasting state, at 60 and 120 min after the start of the meal, endothelium-dependent vasodilation and endothelium-independent vasodilation were evaluated by local infusion of metacholine (4 microg min (-1)) and sodium nitroprusside (10 microg min (-1)) in the brachial artery. Blood flow in the forearm was measured using venous occlusion plethysmography. Endothelium-dependent vasodilation decreased from 15.4 +/- 3.3 (mean +/- SD) at fasting to 13.7 +/- 3.5 mL min (-1) (100 mL tissue)-1 (P < 0.01) 60 min after feeding, but had returned to the fasting level at 120 min. At 60 min, but not in the fasting state, the serum level of free fatty acids was inversely related to endothelium-dependent vasodilation (r=-0.74, P < 0.05), although no significant net changes in FFA levels were seen. Endothelium-independent vasodilation was not affected by the mixed meal. No similar attenuations in endothelium-dependent vasodilation were seen during control meals. In conclusion, an ordinary mixed meal transiently attenuated endothelium-dependent vasodilation. Free fatty acids may be involved in this effect on endothelial function.

Adult↗

PubMed2001

Ageing impairs insulin-mediated vasodilatation but not forearm glucose uptake.

BACKGROUND: It is unclear if insulin-mediated vasodilatation is altered by ageing and if this affects insulin-mediated glucose uptake. MATERIAL AND METHODS: A 2-h euglycaemic hyperinsulinaemic clamp (56 mU m(-2) min(-1)) was performed in 10 healthy, nonobese elderly men (70-75 years) and 13 young men (23-28 years). Forearm blood flow (FBF) was measured by venous occlusion plethysmography and forearm glucose uptake was calculated by arterial and venous serum glucose determinations in the forearm. RESULTS: Insulin induced an increase in FBF in the younger men (from 3.9 +/- 1.1 SD to 5.9 +/- 2.2 mL min(-1) 100(-1)mL tissue, P < 0.001), but this insulin-mediated vasodilatation was completely blunted in the elderly subjects. Glucose extraction during the clamp was significantly higher in the elderly subjects (1.2 +/- 0.76 vs. 0.82 +/- 0.37 mmol L(-1) at 120 min, P < 0.01), resulting in a similar forearm glucose uptake in the two groups. On the other hand, whole-body glucose uptake was significantly decreased in the elderly subjects (5.3 +/- 1.8 vs. 8.0 +/- 1.1 mg kg(-1) min(-1), P < 0.001). CONCLUSION: The present study showed that the ability of insulin to induce vasodilatation is blunted in the forearm in healthy, nonobese elderly subjects. However, the elderly compensate for this impairment with an increased glucose extraction from arterial blood to maintain an unaltered forearm glucose uptake.

Adult↗