Carbohydrate quantity is more closely associated with glycaemic control than weight in pregnant women with type 1 diabetes: Insights from the Diabetes and Pre-eclampsia Intervention Trial (DAPIT)

BACKGROUND

The present study aimed to explore the relationships between carbohydrate intake, body mass index (BMI) and glycaemic control (HbA1c) in pregnant women with type 1 diabetes mellitus (T1DM) METHODS: Secondary analysis of data was undertaken to assess dietary intake in a cohort of women who participated in a randomised controlled trial (RCT) of antioxidant supplementation to prevent preeclampsia (DAPIT¹⁰ ). Study-specific peripheral venous blood samples were obtained for HbA1c at 26 and 34 weeks. Diet was collected using a validated semiquantitative food frequency questionnaire at 26-28 weeks of gestation which assessed dietary intake over 2 weeks. Mean daily average nutrient intakes were analysed using Q Builder nutritional software and SPSS, version 25.

RESULTS

Dietary data were available for 547 pregnant women (72% of cohort) aged 29 years (95% confidence interval [CI] = 28.9-29.9) with average diabetes duration 11.8 years (95% confidence interval = 11.1-12.6). Average body mass index (BMI) (<16 weeks of gestation) was 26.7 kg/m² (95% CI = 26.3 -27, range 18.8-45.6 kg/m² ); 43% (n = 234) were overweight (BMI = 25.0-29.9 kg/m² ) and 20% (n = 112) were obese (BMI ≥ 30 kg/m² ). Differences in HbA1c and carbohydrate quantity and quality were found when adjusted for age and insulin dose. No differences between BMI group were observed for total carbohydrate and glycaemic control; however, differences were noted in fibre and glycaemic index.

CONCLUSIONS

Average quantity of dietary carbohydrate influenced HbA1c when adjusted for insulin dose however, BMI had less impact. More research is required on the relationship between carbohydrate consumption and glycaemic control in pregnancy.

Clinical utility of ultrasonography-measured visceral adipose tissue depth as a tool in early pregnancy screening for gestational diabetes: a proof-of-concept study

AIM

To examine, in a proof-of-concept study, the ability of visceral adipose tissue depth and subcutaneous fat depth measured in early pregnancy to predict subsequent gestational diabetes, and to assess the performance of these measures as screening tests for gestational diabetes compared with use of the current UK criteria.

METHODS

A total of 100 women in early pregnancy were recruited from a maternity hospital in Belfast, UK. Visceral adipose tissue depth and subcutaneous fat depth were measured, and each participant underwent a 75-g oral glucose tolerance test at 28 weeks' gestation for the diagnosis of gestational diabetes using WHO 2013 criteria.

RESULTS

Eighty women completed the study, of whom 15 (19%) developed gestational diabetes. Increasing visceral adipose tissue depth, but not subcutaneous fat depth, was associated with greater gestational diabetes risk after adjusting for confounding factors (odds ratio for a 1-sd rise 2.09, 95% CI 1.06-4.12; P=0.03). Visceral adipose tissue depth ≥4.27 cm had greater sensitivity compared with current National Institute of Health and Care Excellence criteria (87% vs 40%, respectively; P=0.02) and similar specificity (62% vs 74%, respectively; P=0.15) for identifying gestational diabetes.

CONCLUSIONS

Ultrasonography-measured visceral adipose tissue in early pregnancy is a potential clinical tool for improving sensitivity of selective screening for gestational diabetes, which, compared with universal oral glucose tolerance testing, is likely to reduce by half the numbers requiring this test. Further larger studies are now required for confirmation, including investigation into impact on clinical outcomes.

Maternal vitamin D and markers of glycaemia during pregnancy in the Belfast centre of the Hyperglycaemia and Adverse Pregnancy Outcome study

AIMS

To measure total 25-hydroxyvitamin D levels in women in mid-pregnancy who participated in the Belfast centre of the Hyperglycaemia and Adverse Pregnancy Outcome (HAPO) observational study, and to investigate the associations between levels of 25-hydroxyvitamin D and markers of gestational diabetes mellitus and lipid biomarkers.

METHODS

A total of 1585 pregnant women had serum samples available for measurement. Participants were recruited from the Royal Jubilee Maternity Hospital, Belfast, Northern Ireland, at 24-32 weeks' gestation, as part of the HAPO study. 25-hydroxyvitamin D concentrations were measured using liquid chromatography tandem mass spectrometry. Glucose, C-peptide and lipid levels were previously analysed in a central laboratory. Statistical analysis was performed.

RESULTS

The median (interquartile range) 25-hydroxyvitamin D concentration during pregnancy was 38.6 (24.1-60.7) nmol/l, with 65.8% of women being vitamin D-deficient (≤50 nmol/l). In regression analysis, the association between maternal 25-hydroxyvitamin D and fasting plasma glucose levels approached significance [regression coefficient -0.017 (95% CI -0.034 to 0.001); P=0.06], and a significant positive association was observed between maternal 25-hydroxyvitamin D and β-cell function [1.013 (95% CI 1.001 to 1.024); P=0.031]. Maternal 25-hydroxyvitamin D level was positively associated with HDL [0.047 (95% CI 0.021 to 0.073) P≤ 0.001] and total cholesterol [0.085 (95% CI 0.002 to 0.167); P=0.044] in regression analysis.

CONCLUSIONS

These results indicate a high prevalence of vitamin D deficiency during pregnancy, which requires identification and treatment; however, only weak associations were observed between 25-hydroxyvitamin D level and markers of glucose and insulin metabolism. This would suggest that these are of doubtful clinical significance.

Barriers to adopting a Mediterranean diet in Northern European adults at high risk of developing cardiovascular disease

BACKGROUND

Strong evidence links the consumption of a Mediterranean diet (MD) with a reduced cardiovascular disease (CVD) risk; however, there is uncertainty as to whether non-Mediterranean regions will adopt this diet. The present qualitative research aimed to investigate attitudes towards a MD in individuals at high CVD risk in a Northern European population. This information is needed to inform development of MD interventions in non-Mediterranean high-risk populations.

METHODS

Focus groups (n = 12) were held with individuals at high CVD risk from Northern Europe (≥2 CVD risk factors, aged ≥50 years, no established CVD/type 2 diabetes). Attitudes to dietary change towards a MD were explored. Data were analysed using inductive thematic analysis.

RESULTS

Sixty-seven adults participated (60% female, mean age 64 years). There was some awareness of the term MD but limited knowledge of its composition. Barriers to general dietary change were evident, including perception of expense, concern over availability, expectation of time commitment, limited knowledge, lack of cooking skills, amount and conflicting nature of media information on diets, changing established eating habits and resistance to dietary change. Barriers specific to MD adoption were also identified, including perceived difficulty living in a colder climate, perceived impact on body weight, acceptability of a MD and cultural differences.

CONCLUSIONS

Knowledge of a MD was limited in this Northern European sample at high CVD risk. In addition to general barriers to dietary change, barriers specific to a MD were identified. These findings have implications for the development of interventions aiming to promote MD adoption in non-Mediterranean populations.

Effect of pregnancy planning on maternal and neonatal outcomes in women with Type 1 diabetes

AIMS

To assess the effect of pregnancy planning on maternal and neonatal outcomes in women with Type 1 diabetes.

METHODS

Pregnancy planning was assessed retrospectively in a cohort of women who participated in the Diabetes and Pre-eclampsia Intervention Trial (DAPIT). Pregnancy planning was determined based on self-report as to whether pregnancy was planned or unplanned. The effect of pregnancy planning on maternal and neonatal outcomes was examined, controlling for confounding variables.

RESULTS

A total of 747 women were included in the study, of whom 39% considered their pregnancy unplanned. Characteristics associated with unplanned pregnancy included being younger (P<0.001), being a current smoker (P<0.001), being from a lower social class (P<0.001) and having higher HbA_1c values prior to and throughout pregnancy (P≤0.005). Significantly fewer women with unplanned vs planned pregnancies received pre-pregnancy counselling (24% vs 64%; P<0.001). Infants of women with unplanned pregnancies were more likely to be small for gestational age (<5^th centile; P=0.004), to be admitted to the neonatal care unit (P=0.001) and to have a longer stay in hospital (P=0.01). Outcomes did not differ between the groups in relation to pre-eclampsia, congenital malformations or a composite adverse outcome.

CONCLUSIONS

Risks associated with diabetes in pregnancy need to be highlighted to all women, their partners and families, and healthcare professionals. Further research is required to determine if these groups are fully aware of the risks associated with diabetes in pregnancy.

Serum 25-hydroxyvitamin D and insulin resistance in people at high risk of cardiovascular disease: a euglycaemic hyperinsulinaemic clamp study

CONTEXT

In observational studies, low serum 25-hydroxyvitamin D (25-OHD) concentration is associated with an increased risk of type 2 diabetes mellitus (DM). Increasing serum 25-OHD may have beneficial effects on insulin resistance or beta-cell function. Cross-sectional studies utilizing suboptimal methods for assessment of insulin sensitivity and serum 25-OHD concentration provide conflicting results.

OBJECTIVE

This study examined the relationship between serum 25-OHD concentration and insulin resistance in healthy overweight individuals at increased risk of cardiovascular disease, using optimal assessment techniques.

METHODS

A total of 92 subjects (mean age 56·0, SD 6·0 years), who were healthy but overweight (mean body mass index 30·9, SD 2·3 kg/m(2) ), underwent assessments of insulin sensitivity (two-step euglycaemic hyperinsulinaemic clamp, HOMA2-IR), beta-cell function (HOMA2%B), serum 25-OHD concentration and body composition (DEXA).

RESULTS

Mean total 25-OHD concentration was 32·2, range 21·8-46·6 nmol/l. No association was demonstrated between serum 25-OHD concentration and insulin resistance.

CONCLUSIONS

In this study using optimal assessment techniques to measure 25-OHD concentration, insulin sensitivity and body composition, there was no association between serum 25-OHD concentration and insulin resistance in healthy, overweight individuals at high risk of developing cardiovascular disease. This study suggests the documented inverse association between serum 25-OHD concentration and risk of type 2 DM is not mediated by a relationship between serum 25-OHD concentration and insulin resistance.

Increasing fruit and vegetable intake has no effect on retinal vessel caliber in adults at high risk of developing cardiovascular disease

BACKGROUND AND AIM

Retinal vessel abnormalities are associated with cardiovascular disease (CVD) risk. To date, there are no trials investigating the effect of dietary factors on the retinal microvasculature. This study examined the dose response effect of fruit and vegetable (FV) intake on retinal vessel caliber in overweight adults at high CVD risk.

METHODS AND RESULTS

Following a 4 week washout period, participants were randomized to consume either 2 or 4 or 7 portions of FV daily for 12 weeks. Retinal vessel caliber was measured at baseline and post-intervention. A total of 62 participants completed the study. Self-reported FV intake indicated good compliance with the intervention, with serum concentrations of zeaxanthin and lutein increasing significantly across the groups in a dose-dependent manner (P for trend < 0.05). There were no significant changes in body composition, 24-h ambulatory blood pressure or fasting blood lipid profiles in response to the FV intervention. Increasing age was a significant determinant of wider retinal venules (P = 0.004) whereas baseline systolic blood pressure was a significant determinant of narrower retinal arterioles (P = 0.03). Overall, there was no evidence of any short-term dose-response effect of FV intake on retinal vessel caliber (CRAE (P = 0.92) or CRVE (P = 0.42)).

CONCLUSIONS

This study demonstrated no effect of increasing FV intake on retinal vessel caliber in overweight adults at high risk of developing primary CVD.

CLINICAL TRIAL REGISTRATION

NCT00874341.

On the antioxidant properties of erythropoietin and its association with the oxidative-nitrosative stress response to hypoxia in humans

AIM

The aim of this study was to examine if erythropoietin (EPO) has the potential to act as a biological antioxidant and determine the underlying mechanisms.

METHODS

The rate at which its recombinant form (rHuEPO) reacts with hydroxyl (HO˙), 2,2-diphenyl-1-picrylhydrazyl (DPPH˙) and peroxyl (ROO˙) radicals was evaluated in-vitro. The relationship between the erythopoietic and oxidative-nitrosative stress response to poikilocapneic hypoxia was determined separately in-vivo by sampling arterial blood from eleven males in normoxia and following 12 h exposure to 13% oxygen. Electron paramagnetic resonance spectroscopy, ELISA and ozone-based chemiluminescence were employed for direct detection of ascorbate (A(˙-) ) and N-tert-butyl-α-phenylnitrone spin-trapped alkoxyl (PBN-OR) radicals, 3-nitrotyrosine (3-NT) and nitrite (NO2-).

RESULTS

We found rHuEPO to be a potent scavenger of HO˙ (kr = 1.03-1.66 × 10(11) m(-1) s(-1) ) with the capacity to inhibit Fenton chemistry through catalytic iron chelation. Its ability to scavenge DPPH˙ and ROO˙ was also superior compared to other more conventional antioxidants. Hypoxia was associated with a rise in arterial EPO and free radical-mediated reduction in nitric oxide, indicative of oxidative-nitrosative stress. The latter was confirmed by an increased systemic formation of A˙(-) , PBN-OR, 3-NT and corresponding loss of NO2- (P < 0.05 vs. normoxia). The erythropoietic and oxidative-nitrosative stress responses were consistently related (r = -0.52 to 0.68, P < 0.05).

CONCLUSION

These findings demonstrate that EPO has the capacity to act as a biological antioxidant and provide a mechanistic basis for its reported cytoprotective benefits within the clinical setting.

Adolescents' views about a proposed rewards intervention to promote healthy food choice in secondary school canteens

Using rewards may be an effective method to positively influence adolescent eating behaviour, but evidence regarding this approach is limited. The aim of this study was to explore young adolescent views about a proposed reward intervention associated with food choice in school canteens. Focus groups were held in 10 schools located in lower socioeconomic areas within Northern Ireland and involved 90 pupils aged 11-12 years (54 girls, 36 boys). Our findings indicated a high degree of acceptability for a reward scheme but there was major diversity in the type of rewards valued by pupils, largely defined by geographical area and socio-cultural differences. Pupils from rural areas tended to emphasize group-based and longer-term rewards, whereas pupils from urban-city schools tended to suggest individualistic and immediate rewards. The major factors influencing food choice were food price, value for money, taste and visual appearance. Pupils felt that factors outside of their control, such as being assigned to the second lunch sitting placed considerable constraints on their food choice. This research not only indicated a high degree of acceptability for a rewards-based intervention but also highlighted a number of socio-cultural and environmental factors that should be considered by researchers when developing such an intervention.

Effect of increased fruit and vegetable consumption on bone turnover in older adults: a randomised controlled trial

Evidence suggests that increased fruit and vegetable (FV) intake may be associated with improved bone health, but there is limited evidence from intervention trials to support this. This 16-week study showed that increased FV consumption (five or more portions per day) does not have any effect on the markers of bone health in older adults.

INTRODUCTION

Observational evidence suggests that increased FV consumption may be associated with improved bone health. However, there is lack of evidence from intervention trials to support this. This study examined the effect of increased FV consumption on bone markers among healthy, free-living older adults.

METHODS

A randomised controlled trial was undertaken. Eighty-three participants aged 65-85 years, habitually consuming less than or equal to two portions of FV per day, were randomised to continue their normal diet or to consume five or more portions of FV per day for 16 weeks. FV were delivered to all participants each week, free of charge. Compliance was assessed at baseline and at 6, 12 and 16 weeks by diet histories and biomarkers of micronutrient status. Fasting serum bone markers (osteocalcin (OC) and C-terminal telopeptide of type 1 collagen (CTX)) were measured using enzyme-linked immunosorbent assay.

RESULTS

Eighty-two participants completed the intervention. The five portions per day group showed a significantly greater change in daily FV consumption compared to the two portions per day group (p < 0.001), and this was reflected in significant increases in micronutrient status. No significant differences were evident in change in bone markers between the two portions per day group and the five portions per day group over the 16 weeks (geometric mean of week 16 to baseline ratio (95% confidence interval): OC-0.95 (0.89-1.02) and 1.04 (0.91-1.18), respectively, p = 0.25; CTX-1.06 (0.95-1.19) and 0.98 (0.90-1.06) respectively, p = 0.20).

CONCLUSIONS

Increased FV consumption had no effect on bone markers in older adults. Larger intervention studies of longer duration are warranted to establish whether long-term FV consumption can benefit bone health.

Disordered vascular compliance in haemochromatosis

BACKGROUND

A relationship may exist between body iron stores, endothelial dysfunction and overall cardiovascular risk.

AIMS

To compare vascular compliance, biochemical endothelial function and antioxidant status between patients with homozygous hereditary haemochromatosis and healthy controls.

METHODS

Haemochromatosis patients and healthy controls were recruited. Measures of vascular compliance were assessed by applanation tonometry. Serological markers of endothelial function (plasma lipid hydroperoxides, cell adhesion molecules), antioxidant levels (ascorbate, lipid soluble antioxidants) and high-sensitivity C-reactive protein (CRP) were also measured.

RESULTS

Thirty-five hereditary haemochromatosis patients (ten females, mean age 54.6) and 36 controls (27 female, mean age 54.0) were recruited. Haemochromatosis patients had significantly higher systolic and diastolic blood pressures. Pulse wave velocity (PWV) was significantly higher in male haemochromatosis patients (9.90 vs. 8.65 m/s, p = 0.048). Following adjustment for age and blood pressure, male haemochromatosis patients continued to have a trend for higher PWVs (+1.37 m/s, p = 0.058). Haemochromatosis patients had significantly lower levels of ascorbate (46.11 vs. 72.68 μmol/L, p = 0.011), retinol (1.17 vs. 1.81 μmol/L, p = 0.001) and g-tocopherol (2.51 vs. 3.14 μmol/L, p = 0.011). However, there was no difference in lipid hydroperoxides (0.46 vs. 0.47 nmol/L, p = 0.94), cell adhesion molecule levels (ICAM: 348.12 vs. 308.03 ng/mL, p = 0.32 and VCAM: 472.78 vs. 461.31 ng/mL, p = 0.79) or high-sensitivity CRP (225.01 vs. 207.13 mg/L, p = 0.32).

CONCLUSIONS

Haemochromatosis is associated with higher PWVs in males and diminished antioxidants across the sexes but no evidence of endothelial dysfunction or increased lipid peroxidation.

Placental protein tyrosine nitration and MAPK in type 1 diabetic pre-eclampsia: Impact of antioxidant vitamin supplementation

AIM

To examine the role of placental protein tyrosine nitration and p38-Mitogen-Activated Protein Kinase α (p38-MAPKα), Extra Cellular-Signal Regulated Kinase (ERK) and c-Jun NH2-Terminal Kinase (JNK) activity, in the pathogenesis of type 1 diabetic pre-eclampsia, and the putative modulation of these indices by maternal vitamin C and E supplementation.

METHODS

Placental samples were obtained from a sub-cohort of the DAPIT trial: a randomised placebo-controlled trial of antioxidant supplementation to reduce pre-eclampsia in type 1 diabetic pregnancy. Placenta from placebo-treated: normotensive (NT) [n=17], gestational hypertension (GH) [n=7] and pre-eclampsia (PE) [n=6] and vitamin-treated: NT (n=20), GH (n=4) and PE (n=3) was analysed. Protein tyrosine nitration was assessed by immunohistochemistry in paraffin-embedded tissue. Catalytic activities of placental p38-MAPKα, ERK and JNK were measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Nitrotyrosine immunostaining was present in placebo-treated NT, GH and PE placentae, with no significant difference observed between the groups. There was a non-significant trend towards decreased p38-MAPKα activity in PE vs NT control placentae. ERK and JNK were similar among the three outcome placebo groups and vitamin supplementation did not significantly alter their activity.

CONCLUSION

Nitrotyrosine immunopositivity in normotensive diabetic placentae indicates some degree of tyrosine nitration in uncomplicated diabetic pregnancy, possibly due to inherent oxidative stress and peroxynitrite production. Our results suggest that p38-MAPKα, ERK and JNK are not directly involved in the pathogenesis of type 1 diabetic pre-eclampsia and are not modulated by vitamin-supplementation.

Haptoglobin phenotype, pre-eclampsia, and response to supplementation with vitamins C and E in pregnant women with type-1 diabetes

OBJECTIVE

The phenotype of the antioxidant and pro-angiogenic protein haptoglobin (Hp) predicts cardiovascular disease risk and treatment response to antioxidant vitamins in individuals with diabetes. Our objective was to determine whether Hp phenotype influences pre-eclampsia risk, or the efficacy of vitamins C and E in preventing pre-eclampsia, in women with type-1 diabetes.

DESIGN

This is a secondary analysis of a randomised controlled trial in which women with diabetes received daily vitamins C and E, or placebo, from 8 to 22 weeks of gestation until delivery.

SETTING

Twenty-five antenatal metabolic clinics across the UK (in north-west England, Scotland, and Northern Ireland).

POPULATION

Pregnant women with type-1 diabetes.

METHODS

Hp phenotype was determined in white women who completed the study and had plasma samples available (n = 685).

MAIN OUTCOME MEASURE

Pre-eclampsia.

RESULTS

Compared with Hp 2-1, Hp 1-1 (OR 0.59, 95% CI 0.30-1.16) and Hp 2-2 (OR 0.93, 95% CI 0.60-1.45) were not associated with significantly decreased pre-eclampsia risk after adjusting for treatment group and HbA1c at randomisation. Our study was not powered to detect an interaction between Hp phenotype and treatment response; however, our preliminary analysis suggests that vitamins C and E did not prevent pre-eclampsia in women of any Hp phenotype (Hp 1-1, OR 0.77, 95% CI 0.22-2.71; Hp 2-1, OR 0.81, 95% CI 0.46-1.43; Hp 2-2, 0.67, 95% CI 0.34-1.33), after adjusting for HbA1c at randomisation.

CONCLUSIONS

The Hp phenotype did not significantly affect pre-eclampsia risk in women with type-1 diabetes.

Adiponectin multimers, body weight and markers of cardiovascular risk in adolescence: Northern Ireland Young Hearts Project

BACKGROUND

Research examining the relationship between adiponectin (AN) isoforms, body weight and cardiovascular (CV) risk factors is limited, particularly in younger populations.

OBJECTIVES

To investigate the inter-relationships between AN isoforms and CV risk factors, and their dependence on body weight status, in adolescents.

DESIGN

Blood samples from 92 obese, 92 overweight and 92 normal weight age- and sex-matched adolescents were analysed for traditional cardiovascular disease (CVD) risk biomarkers and also total, high molecular weight (HMW), medium and low molecular weight (LMW) AN.

RESULTS

A significant inverse association was observed between total and HMW AN and waist-hip ratio (P=0.015, P=0.006, respectively), triglycerides (P=0.003, P=0.003, respectively) and systolic blood pressure (P=0.012, P=0.024, respectively) and a significant positive association with high-density lipoprotein (P<0.001, P<0.001, respectively) in multi-adjusted analyses. There was no evidence of a relationship between multimeric AN and high-sensitivity C-reactive protein. There was also little evidence of a relationship between LMW AN and CVD risk factors. There was a strong, body mass index (BMI)-independent, association between AN, CVD biomarkers and the hypertriglyceridemic waist phenotype.

CONCLUSION

Prominent, BMI-independent associations between total and HMW AN, but not LMW AN, and CVD risk factors were already evident in this young population. This research in adolescents supports the contention that AN subfractions may have different biological actions. These associations in apparently healthy adolescents suggest an important role for AN and its subfractions in the pathogenesis of metabolic syndrome traits and indicate that the potential for total or HMW AN to act as early universal biomarkers of CV risk warrants further study.

Genetic susceptibility to invasive meningococcal disease: MBL2 structural polymorphisms revisited in a large case-control study and a systematic review

Invasive infection caused by Neisseria meningitidis is a worldwide public health problem. Previous reports have indicated that carriage of common 'defective' structural polymorphisms of the host mannose-binding lectin gene (MBL2) greatly increases an individual's risk of developing the disease. We report the largest case-control study so far to investigate the effect of these polymorphisms in meningococcal disease (296 PCR-positive cases and 5196 population controls, all of European ancestry) and demonstrate that no change in risk is associated with the polymorphisms overall or in any age-defined subgroup. This finding contrasts with two smaller studies that reported an increase in risk. A systematic review of all studies of MBL2 polymorphisms in people of European ancestry published since 1999, including 24,693 individuals, revealed a population frequency of the combined 'defective'MBL2 allele of 0.230 (95% confidence limits: 0.226-0.234). The past reported associations of increased risk of meningococcal disease were because of low 'defective' allele frequencies in their study control populations (0.13 and 0.04) that indicate systematic problems with the studies. The data from our study and all other available evidence indicate that MBL2 structural polymorphisms do not predispose children or adults to invasive meningococcal disease.

The effect of increased dietary fruit and vegetable consumption on endothelial activation, inflammation and oxidative stress in hypertensive volunteers

BACKGROUND AND AIMS

Public health campaigns recommend increased fruit and vegetable (FV) consumption as an effective means of cardiovascular risk reduction. During an 8 week randomised control trial among hypertensive volunteers, we noted significant improvements in endothelium-dependent vasodilatation with increasing FV consumption. Circulating indices of inflammation, endothelial activation and insulin resistance are often employed as alternative surrogates for systemic arterial health. The responses of several such biomarkers to our previously described FV intervention are reported here.

METHODS AND RESULTS

Hypertensive volunteers were recruited from medical outpatient clinics. After a common 4 week run-in period during which FV consumption was limited to 1 portion per day, participants were randomised to 1, 3 or 6 portions daily for 8 weeks. Venous blood samples for biomarker analyses were collected during the pre and post-intervention vascular assessments. A total of 117 volunteers completed the 12 week study. Intervention-related changes in circulating levels of high sensitivity C-reactive protein (hsCRP), soluble intracellular adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), von Willebrand factor (vWF) and plasminogen activator inhibitor-1 (PAI-1) did not differ significantly between FV groups. Similarly, there were no significant between group differences of change in homeostasis model assessment (HOMA) scores.

CONCLUSIONS

Despite mediating a significant improvement in acetylcholine induced vasodilatation, increased FV consumption did not affect a calculated measure of insulin resistance or concentrations of the circulating biomarkers measured during this study. Functional indices of arterial health such as endothelium-dependent vasomotion are likely to provide more informative cardiovascular end-points during short-term dietary intervention trials.

Implications of attendance patterns in Northern Ireland for abdominal aortic aneurysm screening

INTRODUCTION

Evidence supports the introduction of an abdominal aortic aneurysm (AAA) screening programme. The aims of this study were to estimate future disease patterns and to determine the effect of the proportion attending on the programme's cost-effectiveness.

PATIENTS AND METHODS

The results of the local AAA screening programme were reviewed. Ultrasonic infrarenal aortic diameter of 30 mm was considered aneurysmal. Projected population numbers from the Department of Health and current disease prevalence were used to estimate future number of potential patients. The Multi-centre Aneurysm Screening Study (MASS) Markov model was used to calculate an incremental cost-effectiveness ratio (ICER) and 95% uncertainty intervals (UI), using a 30-year time horizon and 3.5% per annum discount, to determine the effect of attendance.

RESULTS

Men were recruited from August 2004 to May 2010. 13316 were invited for a scan and 5931 (44.5%) attended. 321 AAA were diagnosed, giving a prevalence of 5.4%, while 27 large AAA (0.46%) were repaired. The annual incidence of AAA until 2021 will range from 441 to 526, with an incidence of 40-48 large AAA, with both showing a gradual increase with time. Using this attendance rate, the ICER was calculated at £2350 per life-year gained (95% UI: £1620-£4290), or £3020 per quality-adjusted life-year gained (95% UI: £2080-£5500).

CONCLUSIONS

The prevalence of disease in this local AAA screening was similar to other studies. The low attendance will result in many AAA being missed, but will not impact greatly on the long-term cost-effectiveness.

Adoption and maintenance of a Mediterranean diet in patients with coronary heart disease from a Northern European population: a pilot randomised trial of different methods of delivering Mediterranean diet advice

BACKGROUND

A Mediterranean diet has been shown to protect against coronary heart disease (CHD). Adherence to a Mediterranean diet can be assessed using a Mediterranean diet score. The primary aim of this pilot study was to examine whether CHD patients in a Northern European population would adopt and maintain a Mediterranean diet, with a secondary aim of comparing the effectiveness of different methodologies aimed at improving compliance.

METHODS

Sixty-one patients with a diagnosis of CHD were randomised to one of three groups: either to receive conventional dietetic advice for CHD or advice to implement a Mediterranean-style diet using either behavioural counselling or nutritional counselling. Patients received a follow-up assessment at 6 months (adoption) and a subset of patients was followed up at 12 months (maintenance). The primary outcome measure was the between-group difference in the mean change in Mediterranean diet score (MDS).

RESULTS

The change in MDS was not significantly different between groups. However, all three groups reported a significant within-group increase in MDS (P < 0.01) at 6 and 12 months follow-up.

CONCLUSIONS

All three groups made dietary changes towards a Mediterranean diet, but behavioural counselling did not have significant additional benefit over nutritional counselling in initiating and maintaining dietary change, and neither method offering specific Mediterranean diet advice had any significant benefit in terms of improvement in MDS over conventional dietetic practice.

Association of diabetes with age-related macular degeneration in the EUREYE study

OBJECTIVE

To examine the association between self-reported diabetes history and early or late age-related macular degeneration (AMD) in the European population.

METHODS

Participants aged 65 years and over in the cross-sectional population-based EUREYE study underwent an eye examination including digital retinal photography. The images were graded at a single centre. A structured questionnaire was administered by trained field workers for putative risk factors for AMD including history of diabetes mellitus. Logistic regression models were used to examine the association between diabetes and stages of AMD, taking account of potential demographic, behavioural, dietary and medical (history of cardiovascular disease) confounders.

MAIN OUTCOME MEASURES

Photographic images were graded according to the modified International Classification System for AMD and stratified into five exclusive stages from no signs of AMD (AMD stage 0), early AMD (Stages 1-3) and late AMD (Stage 4). Late AMD was subdivided in neovascular AMD (NV-AMD) or geographic atrophy (GA).

RESULTS

Data on diabetes history and potential confounders were available in 2117 control subjects without AMD, 2182 with early AMD, 49 with GA and 101 with NV-AMD. Of all participants, 13.1% reported a history of diabetes. After adjusting for potential confounders, subjects with neovascular AMD compared with controls had increased odds for diabetes (odds ratio 1.81; 95% confidence interval, 1.10 to 2.98, p = 0.02). Subjects with AMD grades 1 to 3 or GA had no increased odds for diabetes compared with those without AMD.

CONCLUSIONS

In the EUREYE study, after multiple adjustments, positive association of diabetes mellitus with neovascular AMD was found. The hypothesis that diabetes is associated with neovascular AMD but not with geographic atrophy may suggest a different pathogenesis of the two advanced forms of the disease and needs to be further evaluated.

The effects of cilostazol on exercise-induced ischaemia-reperfusion injury in patients with peripheral arterial disease

OBJECTIVES

Cilostazol improves walking distance in peripheral arterial disease (PAD) patients. The study objectives were to assess the effects of cilostazol on walking distance, followed by the additional assessment of cilostazol on exercise-induced ischaemia-reperfusion injury in such patients.

METHODS

PAD patients were prospectively recruited to a double-blinded, placebo-controlled trial. Patients were randomised to receive either cilostazol 100mg or placebo twice a day. The primary end-point was an improvement in walking distance. Secondary end-points included the assessment of oxygen-derived free-radical generation, antioxidant consumption and other markers of the inflammatory cascade. Initial and absolute claudication distances (ICDs and ACDs, respectively) were measured on a treadmill. Inflammatory response was assessed before and 30 min post-exercise by measuring lipid hydroperoxide, ascorbate, alpha-tocopherol, beta-carotene, P-selectin, intracellular and vascular cell-adhesion molecules (I-CAM and V-CAM), thromboxane B(2) (TXB(2)), interleukin-6, interleukin-10, high-sensitive C-reactive protein (hsCRP), albumin-creatinine ratio (ACR) and urinary levels of p75TNF receptor. All tests were performed at baseline and 6 and 24 weeks.

RESULTS

One hundred and six PAD patients (of whom 73 were males) were recruited and successfully randomised from December 2004 to January 2006. Patients who received cilostazol demonstrated a more significant improvement in the mean percentage change from baseline in ACD (77.2% vs. 26.6% at 6 weeks, p=0.026 and 161.7% vs. 79.0% at 24 weeks, p=0.048) as compared to the placebo. Cilostazol reduced lipid hydroperoxide levels compared to a placebo-related increase before and after exercise (6 weeks: pre-exercise: -11.8% vs. +5.8%, p=0.003 and post-exercise: -12.3% vs. +13.9%, p=0.007 and 24 weeks: pre-exercise -15.5% vs. +12.0%, p=0.025 and post-exercise: -9.2% vs. +1.9%, p=0.028). beta-Carotene levels were significantly increased in the cilostazol group, compared to placebo, before exercise at 6 and 24 weeks (6 weeks: 34.5% vs. -7.4%, p=0.028; 24 weeks: 34.3% vs. 17.7%, p=0.048). Cilostazol also significantly reduced P-selectin, I-CAM and V-CAM levels at 24 weeks as compared to baseline (p<0.05). There was no difference between treatment groups for ascorbate, alpha-tocopherol, interleukin-6 and -10, hsCRP and p75TNF receptor levels.

CONCLUSIONS

Cilostazol significantly improves ACD, in addition to attenuating exercise-induced ischaemia-reperfusion injury, in PAD patients.

Alcohol increases homocysteine and reduces B vitamin concentration in healthy male volunteers--a randomized, crossover intervention study

BACKGROUND

Few studies have examined the effect of alcohol consumption on total homocysteine (tHcy) concentrations.

AIM

To assess the effect of an 8-week intervention with vodka or red wine on plasma tHcy and B vitamin concentrations in healthy male volunteers. To assess the effect on tHcy according to methylenetetrahydrofolate reductase (MTHFR) 677C>T genotype.

DESIGN AND METHODS

A randomized controlled crossover intervention study measuring tHcy and serum folate and vitamin B(12) concentrations was conducted in 78 male subjects (21-70 years). Following a 2-week washout period during which no alcohol was consumed, all subjects consumed 24 g alcohol (either 240 ml red wine or 80 ml vodka)/day for a 2-week period. Following a further 2-week washout, participants consumed the alternate intervention for 2 weeks.

RESULTS

A significant increase in plasma tHcy was observed after the 2-week red wine intervention (5%, P = 0.03), and a non-significant increase in tHcy with vodka intervention (3%, P = 0.09). When the two interventions were compared, the change in tHcy did not differ between the vodka and red wine interventions (P = 0.57). There were significant decreases in serum vitamin B(12) and folate concentrations, and this decrease did not differ between interventions. The increase in tHcy observed in both interventions did not vary by MTHFR 677C>T genotype.

CONCLUSION

A 2-week alcohol intervention resulted in a decrease in folate and vitamin B(12) status and an increase in plasma tHcy. The effect of alcohol intervention on tHcy, folate and vitamin B(12) concentrations did not differ between the red wine and vodka intervention groups.

Molecular detection of exercise-induced free radicals following ascorbate prophylaxis in type 1 diabetes mellitus: a randomised controlled trial

AIMS/HYPOTHESIS

Patients with type 1 diabetes mellitus are more susceptible than healthy individuals to exercise-induced oxidative stress and vascular endothelial dysfunction, which has important implications for the progression of disease. Thus, in the present study, we designed a randomised double-blind, placebo-controlled trial to test the original hypothesis that oral prophylaxis with vitamin C attenuates rest and exercise-induced free radical-mediated lipid peroxidation in type 1 diabetes mellitus.

METHODS

All data were collected from hospitalised diabetic patients. The electron paramagnetic resonance spectroscopic detection of spin-trapped alpha-phenyl-tert-butylnitrone (PBN) adducts was combined with the use of supporting markers of lipid peroxidation and non-enzymatic antioxidants to assess exercise-induced oxidative stress in male patients with type 1 diabetes (HbA(1c) 7.9 +/- 1%, n = 12) and healthy controls (HbA(1c) 4.6 +/- 0.5%, n = 14). Following participant randomisation using numbers in a sealed envelope, venous blood samples were obtained at rest, after a maximal exercise challenge and before and 2 h after oral ingestion of 1 g ascorbate or placebo. Participants and lead investigators were blinded to the administration of either placebo or ascorbate treatments. Primary outcome was the difference in changes in free radicals following ascorbate ingestion.

RESULTS

Six diabetic patients and seven healthy control participants were randomised to each of the placebo and ascorbate groups. Diabetic patients (n = 12) exhibited an elevated concentration of PBN adducts (p < 0.05 vs healthy, n = 14), which were confirmed as secondary, lipid-derived oxygen-centred alkoxyl (RO.) radicals (a(nitrogen) = 1.37 mT and abeta(hydrogen) = 0.18 mT). Lipid hydroperoxides were also selectively elevated and associated with a depression of retinol and lycopene (p < 0.05 vs healthy). Vitamin C supplementation increased plasma vitamin C concentration to a similar degree in both groups (p < 0.05 vs pre-supplementation) and attenuated the exercise-induced oxidative stress response (p < 0.05 vs healthy). There were no selective treatment differences between groups in the primary outcome variable.

CONCLUSIONS/INTERPRETATION

These findings are the first to suggest that oral vitamin C supplementation provides an effective prophylaxis against exercise-induced free radical-mediated lipid peroxidation in human diabetic blood.

CLINICAL TRIALS REGISTRATION NUMBER

ISRCTN96164937.

Altered free radical metabolism in acute mountain sickness: implications for dynamic cerebral autoregulation and blood-brain barrier function

We tested the hypothesis that dynamic cerebral autoregulation (CA) and blood-brain barrier (BBB) function would be compromised in acute mountain sickness (AMS) subsequent to a hypoxia-mediated alteration in systemic free radical metabolism. Eighteen male lowlanders were examined in normoxia (21% O(2)) and following 6 h passive exposure to hypoxia (12% O(2)). Blood flow velocity in the middle cerebral artery (MCAv) and mean arterial blood pressure (MAP) were measured for determination of CA following calculation of transfer function analysis and rate of regulation (RoR). Nine subjects developed clinical AMS (AMS+) and were more hypoxaemic relative to subjects without AMS (AMS-). A more marked increase in the venous concentration of the ascorbate radical (A(*-)), lipid hydroperoxides (LOOH) and increased susceptibility of low-density lipoprotein (LDL) to oxidation was observed during hypoxia in AMS+ (P < 0.05 versus AMS-). Despite a general decline in total nitric oxide (NO) in hypoxia (P < 0.05 versus normoxia), the normoxic baseline plasma and red blood cell (RBC) NO metabolite pool was lower in AMS+ with normalization observed during hypoxia (P < 0.05 versus AMS-). CA was selectively impaired in AMS+ as indicated both by an increase in the low-frequency (0.07-0.20 Hz) transfer function gain and decrease in RoR (P < 0.05 versus AMS-). However, there was no evidence for cerebral hyper-perfusion, BBB disruption or neuronal-parenchymal damage as indicated by a lack of change in MCAv, S100beta and neuron-specific enolase. In conclusion, these findings suggest that AMS is associated with altered redox homeostasis and disordered CA independent of barrier disruption.

Smoking impairs endothelial function in human saphenous vein in an ex vivo model

The aim of this ex vivo experimental study was to assess the effect of smoking, diabetes mellitus, and hypertension on endothelial function in human saphenous vein, a commonly used conduit for coronary and peripheral arterial bypass surgery. A segment of long saphenous vein harvested during infrainguinal bypass surgery was mounted in an organ bath for isometric tension studies. Vein rings were precontracted to submaximal contraction with phenylephrine, followed by endothelium-dependent relaxation with acetylcholine. Long saphenous vein segments were collected from 26 patients, including five females, with a mean age of 66.4 years (range 48-92). Current smokers had impaired endothelium-dependent relaxation compared to ex- and nonsmokers (10.2%, n=13, vs. 32.9%, n=13; p<0.010). However, ex-smokers and nonsmokers did not have a significant difference in relaxant responses to acetylcholine (29.1%, n=8, vs. 24.6%, n=5; p=nonsignificant [ns]). Similarly, diabetic and nondiabetic patients did not show a significant difference in endothelium-dependent relaxation (23.1%, n=10, vs. 15.6%, n=16; p=ns). The relaxant responses in hypertensive and normotensive patients were not different (20.4%, n=12, vs. 22.5%, n=14; p=ns). Smoking has a deleterious effect on the endothelial function of saphenous vein, and smoking cessation may improve the long-term durability of saphenous vein used as a bypass graft in patients undergoing arterial reconstruction.

Obesity and the lung: 1. Epidemiology

Obesity is the most common metabolic disease in the world and its prevalence has been increasing over several decades. The World Health Organization (WHO) predicts that, by 2015, around 700 million adults will be obese (at least 10% of the projected global population). This will be a huge health and economic burden with associated increases in diabetes, cardiovascular and musculoskeletal disease, and malignancy. While there has been little focus on the impact of obesity on respiratory disease, there are clear effects on pulmonary function and inflammation which will increase the prevalence and morbidity of lung disease. There is an inverse relationship between body mass index and forced expiratory volume in 1 s. Increases in body weight lead to worsening of pulmonary function. The reasons for this include the mechanical effects of truncal obesity and the metabolic effects of adipose tissue. Obesity is linked to a wide range of respiratory conditions including chronic obstructive pulmonary disease, asthma, obstructive sleep apnoea, pulmonary embolic disease and aspiration pneumonia. It is important for those providing care for people with respiratory disease to appreciate the impact of obesity and to provide appropriate advice for weight reduction. Healthcare planners should consider the impact of obesity for future resources in respiratory care.

Portable mass spectrometry for measurement of anaesthetic agents and methane in respiratory gases

Monitoring the composition of gases breathed by anaesthetised patients requires measurement methods with fast responses, high accuracy and good reliability. There is also an increasing demand for systems to be able to monitor more than one target analyte simultaneously, but some gas analysers can be sensitive to the presence of methane gas in exhaled breath, consequently leading to inaccurate measurements of the anaesthetic agent. This study investigated the feasibility of employing portable quadrupole mass spectrometry to monitor volatile anaesthetic agents (halothane, isoflurane and sevoflurane), methane accumulation in anaesthetic rebreathing systems, and inspired and exhaled carbon dioxide and oxygen concentrations during equine anaesthesia in a clinical setting. The volatile anaesthetic agents were easily measurable and methane was detectable. The instrument had an advantage over short wavelength infrared absorption spectrometry analysers because it could monitor anaesthetic agents and other respiratory gases simultaneously and at extremely low concentrations, although further optimisation is required.

Diagnosis of heterozygous familial hypercholesterolaemia in children

BACKGROUND

Most children with familial hypercholesterolaemia (FH) are diagnosed by raised blood cholesterol levels, but the test lacks sensitivity and specificity. As such children have evidence of vascular dysfunction at an early age, correct identification of affected individuals is important so that treatment can be started.

AIM

To determine levels of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) in children with genetically proven FH and their unaffected siblings, in order to identify a diagnostic cut-off point if possible.

DESIGN

Retrospective case-note survey.

METHODS

We studied the notes of 115 children aged 3-16 years, 69 proven FH and 46 unaffected sibs, 65 boys and 50 girls, from 31 families and 21 different mutations. Data recorded were age, sex, TC, and (when available) LDL-C.

RESULTS

The lowest TC level in an affected individual was 4.7 mmol/l and the highest in normal individual was 6.05 mmol/l. This overlap range included 21 children (18% of the total). The corresponding figures for LDL-C were 3.0 and 3.7 mmol/l, which included eight children (8%).

CONCLUSION

TC is not an effective test for differentiating affected and unaffected children with FH. LDL-C is better, but genetic testing remains the method of choice, especially if treatment decisions are to be taken.

Hypokalaemic paralysis precipitated by distal renal tubular acidosis secondary to Sjögren's syndrome

A 43-year-old woman presented with a sudden onset of hypokalaemic paralysis requiring intubation and ventilatory support. Subsequent biochemical and clinical assessments established a diagnosis of distal renal tubular acidosis (RTA) in association with underlying Sjögren's syndrome as the aetiology of her profound hypokalaemia. Distal RTA is rare, but Sjögren's syndrome is one of the more common causes in adults and should be considered in the differential diagnosis of patients who present with hypokalaemic muscular paralysis.

Cigarette smoking and age-related macular degeneration in the EUREYE Study

OBJECTIVE

To examine the association between cigarette smoking and age-related maculopathy (ARM) including age-related macular degeneration (AMD) in the European population.

DESIGN

Cross-sectional study.

PARTICIPANTS

Four thousand seven hundred fifty randomly sampled > or =65-year-olds from 7 study centers across Europe (Norway, Estonia, United Kingdom, France, Italy, Greece, and Spain).

METHODS

Participants underwent an eye examination and digital retinal photography. The images were graded at a single center. Smoking history was ascertained by a structured questionnaire administered by trained fieldworkers. Multinomial and binary logistic regressions were used to examine the association between smoking history and ARM grade and type of AMD, taking account of potential confounders and the multicenter study design.

MAIN OUTCOME MEASURES

Photographic images were graded according to the International Classification System for ARM and stratified using the Rotterdam staging system into 5 exclusive stages (ARM 0-3 and ARM 4, also known as AMD). Age-related macular degeneration also was classified as neovascular AMD or geographic atrophy (GA).

RESULTS

One hundred fifty-eight cases were categorized as AMD (109 neovascular AMD and 49 GA); 2260 had no signs of ARM (ARM 0). Current smokers had increased odds of neovascular AMD (odds ratio [OR], 2.6; 95% confidence interval [CI], 1.4-4.8) or GA (OR, 4.8; 95% CI, 2.1-11.1), whereas for ex-smokers the odds were around 1.7. Compared with people with unilateral AMD, those with bilateral AMD were more likely to have a history of heavy smoking in the previous 25 years (OR, 5.1; 95% CI, 1.3-20.0). The attributable fraction for AMD due to smoking was 27% (95% CI, 19%-33%). There was no consistent association with ARM grades 1 to 3 and smoking.

CONCLUSIONS

These findings highlight the need for increasing public awareness of the risks associated with smoking and the benefit of quitting smoking. Patients with unilateral disease who are current smokers should be advised of the risk of second-eye disease.

Effect of lycopene supplementation on insulin-like growth factor-1 and insulin-like growth factor binding protein-3: a double-blind, placebo-controlled trial

OBJECTIVE

Studies have suggested a link between lycopene and insulin-like growth factor-1 (IGF-1). The aim of this study was to test the effect of lycopene supplementation on IGF-1 and binding protein-3 (IGFBP-3) status in healthy male volunteers. DESIGN, SETTING, SUBJECTS AND INTERVENTION: This was a 4 week randomized, double-blind, placebo-controlled study of lycopene supplementation (15 mg/day) in healthy male volunteers (n=20). Fasting blood samples were collected at baseline and after 4 weeks. Samples were analysed for lycopene by high-performance liquid chromatography (HPLC) and IGF-1 and IGFBP-3 by enzyme-linked immunosorbent assay (ELISA). Changes in end points from baseline were compared in those who received placebo versus those who received the lycopene supplement.

RESULTS

Median change in lycopene from baseline (post-supplement - baseline) was higher in subjects in the intervention than those on placebo (lycopene group 0.29 (0.09, 0.46); placebo group 0.03 (-0.11, 0.08) micromol/l; median (25th, 75th percentiles), P<0.01). There was no difference in median change in IGF-1 concentrations (lycopene group -0.6 (-2.6, 1.9); placebo group -1.15 (-2.88, 0.95) nmol/l, P=0.52), or median change in IGFBP-3 concentrations (lycopene group 245 (-109, 484); placebo group 101 (-34, 234) nmol/l, P=0.55) between intervention and control groups. Change in lycopene concentration was associated with the change in IGFBP-3 in the intervention group (r=0.78; P=0.008; n=10).

CONCLUSIONS

Lycopene supplementation in healthy male subjects has no effect on IGF-1 or IGFBP-3 concentrations in a healthy male population. However, the association between change in lycopene concentration and change in IGFBP-3 in the intervention group suggests a potential effect of lycopene supplementation on IGFBP-3.

Homocysteine and coronary heart disease risk in the PRIME study

INTRODUCTION

Despite recent meta-analyses suggesting that homocysteine is an independent predictor of coronary heart disease (CHD), there is debate regarding whether elevated homocysteine may be deleterious only in the presence of other risk factors, with which it acts synergistically to exert a multiplicative effect on CHD risk, emerging only as a CHD predictor in patients with pre-existing risk factors. The Prospective Epidemiological Study of Myocardial Infarction (PRIME) Study is a multicentre prospective study of 10593 men from France and Northern Ireland, investigating cardiovascular risk factors. We investigated: (1) whether higher homocysteine is associated with increased CHD risk in the PRIME case-control cohort; (2) whether homocysteine interacts synergistically with pre-existing CHD risk factors.

METHODS

Homocysteine was measured in 323 participants who had developed CHD at 5-year follow-up and in 638 matched controls.

RESULTS

There was no significant difference in homocysteine between cases and controls (p=0.18). Homocysteine was significantly higher in current smokers (geometric mean mumol/l (interquartile range mumol/l) 9.45 (7.43, 11.75)) compared with non-smokers (8.90 (7.32, 10.70); p=0.007). There was a significant interaction between homocysteine, smoking and CHD risk (chi2=10.29, d.f.=2, p=0.006).

CONCLUSIONS

These findings suggest that elevated homocysteine is significantly associated with CHD risk in current smokers.

The Effect of Pravastatin on Intima Media Thickness of the Carotid Artery in Patients with Normal Cholesterol

OBJECTIVE

Carotid intima media thickness (IMT) is a good indicator of the severity of atherosclerotic disease. Statins have been found to reduce carotid IMT in patients with hypercholesterolaemia. The aim of this study was to investigate if pravastatin is effective in reducing IMT in normocholesterolaemic patients with carotid artery disease.

METHODS

Patients with carotid artery stenosis and normal cholesterol levels who were not on a statin, were recruited. Patients were randomised to receive pravastatin or placebo daily. Serum concentration of cholesterol and IMT of common carotid arteries were measured before randomisation and at 3 monthly intervals thereafter, for 9 months. IMT was analysed to give the mean of a standardised 2 cm of the common carotid artery (CCA). Results are expressed as median (IQR) and comparison made using the Wilcoxon signed ranks test.

RESULTS

Fifty-four patients were examined. Twenty-eight patients were randomised to active treatment. There was no difference in demographic details and co-morbid states between the two groups. A significant reduction in cholesterol concentration was observed from 3 months in patients randomised to the pravastatin group [5.14(4.72-5.88) vs. 4.11(3.44-5.33), p < 0.05], while there was also a significant decrease in combined IMT form 6 months [1.53(1.36-1.87) vs. 1.41 (1.33-1.78), p < 0.05].

CONCLUSIONS

The results demonstrate that pravastatin reduces intima media thickness of the common carotid artery in normocholesterolaemic patients with moderate carotid stenosis.

Brisk walking, fitness, and cardiovascular risk: a randomized controlled trial in primary care

STUDY OBJECTIVE

To examine the effects of 30 min of self-paced, non-supervised, brisk walking, 5 days per week on the health and fitness of people aged 50-65 years.

DESIGN

Randomized controlled trial. Members of the intervention group (n = 21) were directed to walk briskly for 30 min, 5 days per week, for 12 weeks. Individuals were given the choice to complete the 30 min of walking in one session or in shorter bouts of no less than 10 min. They were asked to record in a diary the time spent walking and the number of steps taken during a single walk using a pedometer. Participants in the control group (n = 10) were asked to maintain their habitual lifestyle and not change their activity or dietary habits. Measurements of body mass index (BMI), waist/hip ratio (WHR), blood pressure, functional capacity, total cholesterol, triglyceride, and lipoprotein subfractions were taken before and after the program. Changes in 10-year risk estimate for coronary heart disease and stroke were calculated using Framingham risk equations.

SETTING

Three urban general practices patients: 31 healthy, sedentary 50- to 65-year-old participants recruited following contact by their general practitioner.

MAIN RESULTS

The mean time spent walking by the intervention group was 27.72 (+/-9.79) min/day: their adherence to the protocol was 90.3%. Significant decreases in systolic and diastolic blood pressure, reduction in stroke risk, and increased functional capacity were found within the walking group between baseline and 12-week measurements. No changes were found in these parameters within the control group. Significant reductions in 10-year risk of CHD were observed in both groups. No significant changes were found in lipid levels or anthropometric measurements in either group.

CONCLUSIONS

The study provides evidence for the benefit to fitness and cardiovascular risk of the "30-min brisk walking, 5 days a week" message to people aged 50-65 years who participated in an unsupervised home-based walking program. Further study to overcome the problem of poor recruitment and determine the minimum effective dose of exercise to improve cardiovascular risk prediction scores is required.

Endothelial function, insulin action and cardiovascular risk factors in young healthy adult offspring of parents with Type 2 diabetes: effect of vitamin E in a randomized double-blind, controlled clinical trial

BACKGROUND AND AIMS

Endothelial dysfunction, insulin resistance and oxidative stress are believed to be central and associated mechanisms in atherogenesis. We aimed to determine the effect of the antioxidant vitamin E on endothelial function, insulin action and cardiovascular risk markers in young healthy adult offspring of parents with Type 2 diabetes.

METHODS

Healthy, glucose-tolerant adults (18-38 years), 14 (12 male/2 female) with at least one parent with Type 2 diabetes, and 14 (12 male/2 female) subjects with no family history of diabetes (controls) were studied. Insulin action was assessed by euglycaemic hyperinsulinaemic clamp (1 mU/kg/min). Endothelial function was assessed by forearm blood flow (FBF) responses to intra-brachial artery infusions of acetylcholine (ACh) (endothelium-dependent vasodilation), sodium nitroprusside (SNP) (endothelium-independent vasodilation) and N(G)-monomethyl L-arginine (LNMMA) (nitric oxide synthase inhibition). Thirteen offspring (18-38 years, 11 male/2 female, BMI < 30 kg/m2) completed a randomized, double-blind, crossover trial (12 weeks vitamin E 800 IU/day or placebo, 6-week washout).

RESULTS

Exogenous glucose infusion rates to maintain euglycaemia were positively associated with response to acetylcholine in offspring (r = 0.61, P < 0.05), and were linked with triglycerides. Vitamin E had no effect on endothelial function, insulin action or cardiovascular risk markers in healthy adult offspring of parents with Type 2 diabetes.

CONCLUSIONS

Our results support a positive association between insulin action and endothelial-dependent vasodilation in young healthy adult offspring of parents with Type 2 diabetes, but indicate no effect of vitamin E on these parameters.

Ten-year trends for fatness in Northern Irish adolescents: the Young Hearts Projects—repeat cross-sectional study

OBJECTIVE

To examine secular trends in measures of fatness over a 10-y period (the 1990s) in Northern Irish schoolchildren.

DESIGN

Repeat cross-sectional surveys.

SUBJECTS

In total, 12- and 15-y-old children randomly selected from post-primary schools. A total of 1015 children studied between 1989 and 1990, and 2017 studied between 1999 and 2001.

MEASUREMENTS

The same study methods were applied in both surveys. Body mass index (BMI) was calculated from height and weight, and percentage body fat (%BF) was derived from skinfold measurements at four sites. Dietary intake was assessed using a diet history method and habitual physical activity (PA) was estimated from a self-report questionnaire.

RESULTS

Increases were seen in both height and weight in all age-sex groups. The overall prevalence of overweight/obesity increased from 15.0 to 19.6%, but 12-y-old girls contributed most to this increase (15.9-26.3%), with a modest increase observed also in 15-y-old boys. Increases in mean BMI (19.2-20.3 kg/m2) and mean %BF (25.8-27.1%) were seen in 12-y-old girls, with no significant changes in any of the other subgroups. Mean energy intake increased in girls but not in boys, while mean PA score decreased in 12-y-old girls, but was unchanged in the other three groups. All age-sex groups showed substantial increases in the sugar intake while fat intake increased in girls and decreased in boys.

CONCLUSION

Increases in indices of fatness were seen among school-age children in Northern Ireland during the 1990s. Trends differed between age-sex groups with the largest changes seen in 12-y-old girls. It remains to be seen whether the large increase in overweight/obesity in this group tracks into adulthood, with consequences for chronic disease incidence in women.