Low density lipoprotein composition and oxidizability in coronary disease--apparent favourable effect of beta blockers.

The oxidative modification of LDL in vivo may have an important role in atherogenesis. To determine whether LDL fatty acid, anti-oxidant composition and sensitivity to oxidation in vitro is different in subjects with established atherosclerosis we compared 20 men with angiogram proven coronary disease with 25 controls without clinical evidence of arterial disease. LDL-cholesterol, total triglycerides and LDL fatty acid composition did not differ significantly between the groups.

Changes in markers of alcohol intake in man below 'safe' drinking levels.

In a group of 343 working men, only 34 of whom regularly drank more than 60 ml of ethanol per day, logistic regression was used to determine the combination of biomarkers which best discriminated between those who regularly drank less than 30 ml or 30 ml or more of ethanol daily. The index consisted of apolipoprotein A-II, uric acid, gamma-glutamyl transpeptidase and mean corpuscular volume. Even with the relatively low level of alcohol intake reported in these subjects (assessed using a 7-day retrospective alcohol diary), the groups with higher or lower intake of alcohol were separated with a sensitivity of 68%, a specificity of 74% and a positive predictive value of 71%.

Association of lifestyle and personality characteristics with blood pressure and hypertension: a cross-sectional study in the elderly.

The association between certain lifestyle and personality characteristics and blood pressure in the elderly was assessed in a cross-sectional study of 843 independent living 60-87 year old volunteers. They comprised 338 women and 505 men of whom 35 and 30% respectively were being treated with antihypertensive drugs. Among untreated volunteers, 28% of women and 28% of men had systolic blood pressure greater than 160 or diastolic blood pressure greater than 95.

Blood pressure and body composition in children: importance of allowing for cuff size.

A cross-sectional study of blood pressure (BP) was conducted in a sample of 1312 Australian school children aged 11-12 yrs. In line with current recommendations for the measurement of BP, a cuff of appropriate size was chosen for each subject based on his or her arm circumference. Analyses revealed statistically significant independent relationships between measured BP and cuff size.

Effects of alcohol and caloric restrictions on blood pressure and serum lipids in overweight men.

We have examined the independent and combined effects on blood pressure and blood lipids of alcohol restriction and weight loss in overweight male drinkers with a view to assessing overall effects on cardiovascular risk of two widely promoted nonpharmacological approaches for hypertension. Eighty-six men with a mean age of 44.3 years, a mean regular alcohol intake of 440 ml/wk (five or six standard drinks per day), a mean blood pressure of 137.

Postural fall in blood pressure in the elderly in relation to drug treatment and other lifestyle factors.

In a study of 843 independent-living men and women aged between 60 and 87 in Perth, Western Australia, stepwise multiple regression, after correction for initial levels of systolic blood pressure, showed that postural fall in systolic blood pressure was positively related to alcohol intake of more than 20 ml/day, the use of sleeping tablets and higher levels of anxiety on the Spielberger state-trait scale, and negatively related to body mass index. Postural fall in blood pressure was not significantly related to treatment for hypertension, age, sex, patterns of usual physical activity, tea or coffee drinking, or the diagnosis of diabetes mellitus. This analysis is the first to examine the relationship between lifestyle factors and the magnitude of the fall in systolic blood pressure on standing after adjustment for the association between the change in a variable and its initial level.

Effect of chronic ethanol consumption upon cardiovascular reactivity, heart rate and blood pressure in spontaneously hypertensive and Wistar-Kyoto rats.

Objective: Clarification of the effect of chronic ethanol consumption upon cardiovascular reactivity in rats.

Design: Spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) normotensive rats were randomly allocated in groups of 10 to ethanol in tap water [20% (v:v) after the first week or tap water for 7-12 weeks].

Methods: Intra-arterial blood pressure and heart rate were measured at rest and in response to vibration and noise stress.

Dietary salt and risk factors for cardiovascular disease.

Sodium restriction by 50 to 100 mmol/day in populations with intakes averaging 150 to 180 mmol/day would likely lead to a reduction of population mean blood pressures, and less of a tendency for blood pressures to rise with age. Fewer people would require antihypertensive drug therapy, and those who did would require less drugs. The extent of any blood pressure fall would be greatest in the elderly or those with established hypertension.

Study of mechanisms of glucocorticoid hypertension in rats: endothelial related changes and their amelioration by dietary fish oils.

1. To investigate possible mechanisms of increased systolic blood pressure after 1 weeks treatment with dexamethasone and its amelioration by fish oil feeding, we have examined the reactivity of aortic rings and perfused mesenteric resistance vessels. 2.

Platelet cytosolic free calcium concentration, total plasma calcium concentration and blood pressure in human twins: a genetic analysis.

1. We used path analysis and maximum-likelihood model fitting to evaluate the relative contributions of genetic and environmental factors to the relationships observed between level of blood pressure and both total plasma calcium concentration and platelet cytosolic free calcium concentration in 109 twin pairs. 2.

Relationships between blood pressure and measures of dietary energy intake, physical fitness, and physical activity in Australian children aged 11-12 years.

Study Objective: The aim was to examine associations between blood pressure and dietary energy intake, physical activity, and physical fitness in Australian children.

Design: The study was a survey of year 7 children attending schools in metropolitan Perth.

Setting: Survey schools were located in suburbs representative of the range of socioeconomic strata in metropolitan Perth.

Fish oil feeding selectively attenuates contractile responses to noradrenaline and electrical stimulation in the perfused mesenteric resistance vessels of spontaneously hypertensive rats.

1. The mechanism of the antihypertensive effects of n-3 fatty acids were examined in spontaneously hypertensive rats (SHR) by feeding 'Max EPA' fish oil or hydrogenated coconut oil and determining the responses of perfused mesenteric resistance vessels to various contractile agents and peri-arterial nerve stimulation. 2.

A factorial study of salt restriction and a low-fat/high-fibre diet in hypertensive subjects.

Objective: To compare the independent and additive effects of sodium restriction and a low-fat, high polyunsaturated: saturated fatty acids (P:S) ratio, high-fibre diet upon blood pressure.

Design: A randomized, parallet, double-blind, placebo-controlled (for sodium) 2 x 2 factorial trial.

Setting: Clinical.

Alcohol and hypertension.

The relationship between regular alcohol consumption and blood pressure elevation is now firmly established. Outstanding issues which will be discussed relate to the nature of the dose response curve, interactions between alcohol and other dietary and behavioural factors, mechanisms involved and the question of any protective influence of alcohol on atherosclerotic and ischaemic cardiovascular disease associated with hypertension. Alcohol is an important contributory to the prevalence of hypertension, and resistance to drug therapy in drinking communities.

Strategies and difficulties in dietary intervention in myocardial infarction patients.

Randomized controlled trials along with 'within group' studies of patients with symptomatic coronary artery disease suggest that dietary and other lifestyle changes can halt progression of coronary atherosclerosis, induce regression of pre-existing severe lesions, and reduce the severity or frequency of angina. Varying combinations have been tested, including restriction of dietary total, saturated and polyunsaturated fat using lean meat or vegetarian diets, fish oil supplements, smoking cessation, stress management, and exercise training. The relative importance of each of these remains unclear.

Effects of alcohol intake on plasma fatty acids assessed independently of diet and smoking habits.

1. This study was designed to determine prospectively whether changing alcohol consumption influenced the proportion of plasma linoleic acid independently of diet or smoking habits, and to evaluate changes in the plasma linoleic acid concentration as a potential marker of changes in alcohol consumption. 2.

Reflotron cholesterol measurements in 1112 Australian children aged 10-12 years.

Objective: To study the distribution of blood cholesterol concentration in a sample of Western Australian schoolchildren.

Design: The Reflotron dry-chemistry system (Boehringer Mannheim, Germany) was used to measure cholesterol in finger-prick blood samples obtained from Year 6 children aged 10-12 years attending government schools in metropolitan Perth. Recruitment methods ensured that children from different socioeconomic strata were represented.

Urinary steroid profiles and alcohol-related blood pressure elevation.

1. From an earlier cross-sectional survey of 343 public servants, 15 pairs of non-smoking teetotallers and heavy drinkers (alcohol intake more than 350 mL/week) were matched for age and adiposity and utilized for a case-control study of the effects of alcohol on 11 beta-hydroxysteroid dehydrogenase (11 beta-OHSD) activity and blood pressure. 2.

A controlled study of the effects of aerobic exercise on antihypertensive drug requirements of essential hypertensive patients in the general practice setting.

1. To investigate the effect of an exercise training programme on antihypertensive drug requirements, 19 sedentary subjects (14 men and five women) with mild essential hypertension (systolic blood pressure greater than 140 mmHg but less than 180 mmHg), aged 29-55 years, were randomly assigned to 16 weeks of moderate intensity exercise or light intensity exercise (control), and titrated on antihypertensive drug therapy (captopril and hydrochlorothiazide) until resting systolic blood pressure (sitting) of less than 140 mmHg was achieved. 2.

Blood pressure and vascular reactivity changes in spontaneously hypertensive rats fed fish oil.

1. To examine possible mechanisms of antihypertensive effects of feeding fish oil rich in n-3 fatty acids, we have studied vascular reactivity of aortic rings and perfused mesenteric resistance vessels of spontaneously hypertensive rats (SHR) given such a diet. 2.

Effect of smoking cessation on serum apolipoprotein A-I and A-II concentrations.

This study investigated the effects of 6 weeks' smoking cessation on serum levels of total-cholesterol, triglyceride, high-density lipoprotein cholesterol (HDL-C) and apolipoproteins A-I and A-II (apo A-I and apo A-II) in 64 subjects of both sexes. Smoking cessation was associated with an increase in levels of apo A-II. Concurrent changes in weight and alcohol consumption during attempted smoking cessation, together with change in thiocyanate level, were entered as predictor variables into a multiple regression analysis.

A double-blind placebo-controlled trial of the effects of short-term potassium supplementation on blood pressure and atrial natriuretic peptide in normotensive women.

To determine the early effect of potassium loading on blood pressure regulatory mechanisms, the effect of 4 days' supplementation with 80 mmol/day KCl on blood pressure and vasodilator hormone release was examined using a double-blind crossover design in normotensive women with a baseline potassium excretion of 51.8 +/- 2.7 mmol/day.

Future directions for research into dietary and other lifestyle factors in hypertension.

1. Directions for future research into dietary and other lifestyle factors which influence blood pressure can only be signposted at this stage. It is suggested that eight parallel and interrelated paths merit attention.

The effect of lipoproteins on the release of some eicosanoids by stimulated human leukocytes. A possible role in atherogenesis.

Changes in eicosanoid generation have been examined in stimulated human peripheral leukocytes incubated with plasma lipoprotein fractions. Leukocytes (2.5 X 10(7) cells/ml, 90% neutrophils) were incubated with physiological concentrations of low density lipoprotein (LDL), high density lipoprotein (HDL) and very low density lipoprotein (VLDL).