Cutaneous malignant melanoma and fluorescent lighting.

A population-based case-control study of cutaneous malignant melanoma occurring during 1980-81 was conducted in Perth, Western Australia. Three hundred and thirty-seven cases and 349 matched controls were reinterviewed in 1983 with regard to their fluorescent light exposure. The incidence rate of all melanomas was not associated with rate of exposure or cumulative exposure to all fluorescent lights or just those without diffusers. Separate analyses by histogenetic type and, where possible, body site of melanoma showed, in most instances, no consistent association between incidence rate of melanoma and exposure to fluorescent lights without diffusers. Incidence of melanomas of unclassifiable histogenetic type, however, increased with increasing duration of exposure (P-value for trend .02). This association was weaker and the P-value higher (.11) when exposure was considered only in residential rooms and offices, where light fittings are closest to the subject. Adjustment for the effects of total and intermittent sun exposure on melanoma rates did not alter the above trends appreciably.

Alcohol stimulation of renin release in man: its relation to the hemodynamic, electrolyte, and sympatho-adrenal responses to drinking.

Alcohol stimulation of the renin-angiotensin axis has been proposed as an explanation for the higher blood pressure in drinkers. This study examines the acute effects of moderate alcohol intake on PRA in relation to change in fluid and electrolyte balance, sympatho-adrenal activity, blood pressure, and heart rate in 20 normal men, aged 20-24 yr. They consumed either 750 ml nonalcoholic beer as a control or the same beverage with 1 ml/kg alcohol added, which increased the plasma alcohol concentration to 16.7 +/- 1.0 (+/- SE) mM within 70 min. PRA increased more than 2-fold 90 min after the ingestion of alcohol. This was accompanied by a decrease in diastolic blood pressure and a fall in plasma potassium, both possible stimuli to the rise in PRA. A late increase in plasma sodium, also occurring 90 min after alcohol ingestion, was attributed to plasma volume contraction after an alcohol-induced diuresis. This may have been an additional factor in stimulating renin release. Norepinephrine levels increased during both alcohol and control studies. In contrast, plasma epinephrine decreased significantly during the control study, but did not change after alcohol ingestion. Hence, alcohol stimulation of sympathetic nervous activity is unlikely to have mediated the renin release. We conclude that the acute increase in PRA associated with moderate alcohol consumption is predominantly a secondary response to changes in fluid and electrolyte balance and blood pressure. Although a direct action of alcohol on renin release was not excluded, the possibility that repeated activation of the renin-angiotensin system mediates the pressor effect of regular moderate alcohol consumption is, therefore, diminished.

Evidence for a direct effect of alcohol consumption on blood pressure in normotensive men. A randomized controlled trial.

A direct pressor effect of alcohol is proposed as the basis for the association between regular alcohol consumption and an increase in blood pressure found in population studies. To examine this further, a randomized controlled crossover trial of the effects of varying alcohol intake on blood pressure in 46 healthy male drinkers was conducted. From an average of 336 ml of ethanol per week, alcohol consumption was reduced by 80% for 6 weeks by drinking a low alcohol content beer alone. This reduction was associated with a significant reduction in systolic and diastolic blood pressure (p less than 0.001 and p less than 0.05 respectively). The mean difference in supine systolic blood pressure during the last 2 weeks of normal or low alcohol intake was 3.8 mm Hg, which correlated significantly with change in alcohol consumption (r = 0.53, p less than 0.001). Reduction of alcohol intake also caused a significant decrease in weight (p less than 0.001). After adjustment for weight change, an independent effect of alcohol on systolic but not diastolic blood pressure was still evident, with a 3.1 mm Hg fall predicted for a decrease in consumption from 350 ml of ethanol equivalent per week to 70 ml per week (p less than 0.01). Systolic blood pressure rose again when normal drinking habits were resumed. These results provide clear evidence for a direct and reversible pressor effect of regular moderate alcohol consumption in normotensive men and suggest that alcohol may play a major role in the genesis of early stages of blood pressure elevation.

Effect of dietary fats and carbohydrate on blood pressure of mildly hypertensive patients.

The effect on blood pressure (BP) of replacing dietary saturated fat with either polyunsaturated fat (linoleic acid) or carbohydrate was studied in 21 untreated mildly hypertensive patients. In a randomized, double-blind, crossover protocol, all subjects received dietary supplements of cream, safflower oil, and carbohydrate in random sequence, each prepared in flavored yogurt or milk. Each supplement was administered for 6 weeks and followed by a 4-week washout period of no supplementation. Dietary linoleic acid increased from 4.6 to 13% of energy intake when the safflower oil replaced cream, while saturated fat decreased from 16 to 10%. Total fat intake was 37 to 38% during the cream and safflower oil periods but was 28% during the carbohydrate period. Compliance with the diets was demonstrated by significant changes in fasting plasma fatty acid measurements. Mean clinic BP was 135 +/- 9/93 +/- 6 mm Hg at baseline. There were no significant differences in BP measured in the clinic or at home among the three dietary periods. The protocol had more than 80% power to detect a mean effect of diet of 3 mm Hg systolic or 2 mm Hg diastolic BP. Therefore, replacing dietary saturated fat with carbohydrate or with linoleic acid does not affect BP in subjects with mild hypertension.

Cardiovascular disease risk factors in free-living men: comparison of two prudent diets, one based on lactoovovegetarianism and the other allowing lean meat.

In general, vegetarians have lower serum lipids and blood pressures than omnivores have. We tested the blood pressure and serum lipid lowering effects of two fat-modified diets differing primarily in their source of protein. Twenty-six men were randomized in an incomplete block design to two of three diets: a high-fat diet, a fat-modified lactoovovegetarian diet (LOV) and a diet in which 60% of plant protein in the LOV was replaced with lean meat (LM). Compared with the high-fat diet both prudent diets significantly lowered blood pressure, serum total cholesterol (TC), and LDL cholesterol but significantly increased serum triglycerides. The LOV diet had a significantly greater cholesterol-lowering effect than did the LM diet (10% vs 5% decrease) but blood pressure reductions were similar. The partial substitution of lean meat for plant protein in a fat-modified diet did not negate the overall cardiovascular-risk lowering of the lactoovovegetarian diet.

Effect of dietary cholesterol in normolipidemic subjects is not modified by nature and amount of dietary fat.

A double-blind, cross-over study of the effects of adding cholesterol to the diet, equal to about two egg yolks daily, was carried out in 25 men with an average plasma cholesterol of 5.3 mmol/L. There were no significant elevations in the mean plasma concentrations of cholesterol, low-density-lipoprotein cholesterol, or apolipoprotein B. The absence of an effect was seen against two background diets, one high in saturated fatty acids and the other modified in fat content and in fatty acid composition. Although the mean high-density-lipoprotein (HDL) cholesterol concentration did not change, the proportion of HDL2 particles (radius greater than 4.4 nm) increased significantly, especially in subjects who did not show a rise in plasma cholesterol; this may represent a means of clearing dietary cholesterol. The results suggest that reducing dietary cholesterol might be emphasized for hypercholesterolemic subjects rather than for the population generally.

Vegetarian diet and blood pressure levels: incidental or causal association?

Evidence that nutrients other than the major cations may influence blood pressure levels stems from studies of acculturated vegetarians and from randomized controlled dietary trials. Earlier studies of vegetarians focused on religious groups and on vegans, making it difficult to know whether their lower blood pressures were due to diet per se or to other aspects of lifestyle. Seventh-day Adventist vegetarians showed significantly less hypertension and lower blood pressures compared with Mormon omnivores, effects which were independent of differences in obesity and not due to altered sodium intake. Subsequently, controlled dietary intervention studies in healthy normotensive omnivores provided more direct evidence for a blood pressure-lowering effect of a lactoovovegetarian diet with reversible changes of 5-6 mm Hg systolic and 2-3 mm Hg diastolic occurring over 6-wk periods. Similar dietary effects in mild hypertensive subjects provides impetus for identifying the responsible nutrients.

Effects of a lacto-ovo vegetarian diet on serum concentrations of cholesterol, triglyceride, HDL-C, HDL2-C, HDL3-C, apoprotein-B, and Lp(a).

The effect of intervention with a lacto-ovo vegetarian diet on serum concentrations of cholesterol, triglyceride, total high-density lipoprotein cholesterol (HDL-C), HDL2-C, HDL3-C, low-density lipoprotein cholesterol, apoprotein-B, apoprotein-HDL, and Lp(a) was studied in 19 men and 17 women. Most weekday meals were obtained from a single source and dietary records were completed to assess the changes in nutrient intakes. Blood was collected in the 6th wk of each dietary period. Because of strong correlations between many of the changes in nutrient intakes, principal component (factor) analysis was used followed by stepwise multiple regression analysis to identify associations between changes in diet and changes in lipid, lipoprotein or apoprotein levels. Three principal components accounted for 92.0% of the variation in lipid levels: factor 1 represented an increase in saturated fat, total fat, monounsaturated fat, cholesterol, and energy intake: factor 2 represented an increase in fiber and polyunsaturated fat, and decrease in protein intake; factor 3 an increase in total carbohydrate, complex carbohydrate, and energy intake. Where a change in a variable was significantly associated with change in diet, one factor appeared primarily responsible for the change; total cholesterol (factor 2, p = 0.034); triglyceride (factor 3, p = 0.005); apo-HDL (factor 1, p = 0.014); HDL2-C (factor 2, p = 0.023), HDL3-C (factor 3, p = 0.015). A borderline significant association was seen for total HDL-C (factor 2, p = 0.055).

Effects of alcohol consumption on serum lipoprotein-lipid and apolipoprotein concentrations. Results from an intervention study in healthy subjects.

Serum levels of cholesterol, triglyceride, cholesterol in low density lipoprotein (LDL) and in high density lipoprotein (HDL) and its major subfractions, and of apolipoproteins A-I, A-II and B were measured in 48 healthy men at the end of two 6-week periods in which they consumed normal alcohol (5.0%, v/v) or low alcohol (0.9%, v/v) beer, respectively. Other dietary and behavioural variables were kept constant. Mean levels of triglyceride, HDL cholesterol, HDL2- and HDL3 cholesterol, and apolipoproteins A-I and A-II were higher at the end of the normal compared with the low alcohol periods, and levels of LDL cholesterol were lower. Body weight was greater at the end of the normal alcohol period than at the end of the period of low alcohol but multiple regression analysis suggested that the changes in lipoprotein-lipid and apolipoprotein levels were due primarily to the change in alcohol consumption rather than concomitant changes in body weight. This study confirms an effect of alcohol on both major subfractions of HDL and on its major apolipoproteins.

The relationship of blood pressure to diet and lifestyle in two religious populations.

The association between blood pressure and a vegetarian diet was studied in relation to obesity, sex, age and lifestyle in 98 Seventh-day Adventist (SDA) lacto-ovo vegetarians, 82 SDA omnivores and 113 Mormon omnivores aged 25 to 44 years. Mean blood pressures adjusted for age, height and weight were significantly lower in SDA vegetarians than in Mormon omnivores (115.6/68.7 and 121.2/72.2, respectively, in males and 109.1/66.7 and 114.9/72.6, respectively, in females) and were not related to past or current use of alcohol, tobacco, tea and coffee, physical activity, personality or religious observance. Mean blood pressures in SDA omnivore males (121.7/71.7) were similar to those in Mormon males, while those in SDA omnivore females (109.9/67.4) were similar to SDA vegetarian females. Quetelet's Index in these subgroups demonstrated the same pattern as blood pressure and may reflect, in part, the high level of physical activity in female SDA omnivores. The prevalence of mild hypertension (greater than or equal to 140 mmHg systolic or greater than or equal to 90 mmHg diastolic) was 10 and 8.5% in Mormon and SDA omnivores, respectively, compared with 1 to 2% in SDA vegetarians. Analysis of diet records showed that vegetarians ate significantly more dietary fibre, polyunsaturated fat, magnesium and potassium and significantly less total fat, saturated fat and cholesterol than did Mormon omnivores. SDA omnivores had a dietary pattern which was less homogeneous, and which lay between those of the other groups. Which, if any, of these dietary differences were responsible for the blood pressure differences could not be determined in this study.

Alcohol, personality and predisposition to essential hypertension.

The nature of the relationship between alcohol, personality and blood pressure levels was examined in 491 working men who completed detailed questionnaires which included Eysenck's personality inventory. Alcohol had an effect on systolic blood pressure levels independent of all other factors studied. However, in 152 non-smoking moderate to heavy drinkers (greater than 18 g ethanol per day) the extroversion/introversion trait was the most significant predictor of systolic blood pressure levels, and in introverted drinkers the prevalence of hypertension (greater than or equal to 140 mmHg systolic or greater than or equal to 90 mmHg diastolic) was three times that of extroverted drinkers and nine times that of teetotallers. This association between introversion and 'hypertension' was not seen in drinkers who also smoked cigarettes. The interactions between environmental stimuli (alcohol, smoking) and presumably genetically determined personality characteristics may have an important bearing on concepts of essential hypertension and point to new approaches for investigation.

Biochemical and neurohormonal responses to the introduction of a lacto-ovovegetarian diet.

OBJECTIVE: To assess the mechanisms of the blood pressure-lowering effect of a vegetarian diet in the early and later stages of dietary intervention. DESIGN: After 2 weeks without intervention (baseline), 20 normotensive men were matched for age and body mass index and randomly allocated to an omnivorous (control) or a lacto-ovovegetarian diet for 6 weeks in a parallel trial. METHODS: Ambulatory blood pressures were recorded between 0800 and 1700 h on alternate days during the first week of intervention, twice in the second week and weekly thereafter. Blood samples collected after a standard breakfast were analysed for plasma noradrenaline, adrenaline, atrial natriuretic peptide (ANP), renin, aldosterone, glucose and insulin. Factor and multiple regression analyses were used to assess the association among neurohormonal factors, blood pressures and diet. Results were analysed for the first week of the diet and for the entire 6 weeks. RESULTS: Ambulatory blood pressures at work were lower on the vegetarian diet than in the controls. This blood pressure decrease was associated with a factor representing lower plasma catecholamine and renin activity levels throughout the study, and a factor representing reduced plasma glucose and insulin levels in week 1 of intervention only. Plasma ANP levels were significantly higher during week 1 of the vegetarian diet. CONCLUSIONS: A blood pressure lowering effect of a vegetarian diet during normal working activity was shown. Using factors derived from the biochemical variables, results were in keeping with the hypothesis that these effects may be mediated by reduced sympatho-adrenal activity consequent to altered glucose and insulin handling. An early increase in plasma ANP may contribute to the blood pressure reduction.

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. PARTICIPANTS: Ninety-five hypertensive subjects (mean blood pressure, 137/83 mmHg), mean age 53.5 years, consuming less than 30 ml ethanol/day were selected from community volunteers. Seventy-nine treated and twelve untreated hypertensives completed the trial. INTERVENTION: Subjects followed either a low-sodium, low-fat/high-fibre diet (less than 60 mmol sodium/day; 30% fat energy; P:S ratio = 1; 30-50 g fibre/day) or a low-sodium, normal-fat/normal-fibre diet (less than 60 mmol sodium/day; 40% fat energy; P:S ratio = 0.3; 15 g fibre/day) for 8 weeks. Half of each group received 100 mmol/day NaCl and the remainder received placebo. MAIN OUTCOME MEASURES: Blood pressure and blood lipids. RESULTS: Sodium restriction significantly reduced standing and supine systolic blood pressure, with no effect upon diastolic blood pressure. The low-fat/high-fibre diet had no effect upon blood pressure, but significantly reduced total cholesterol, low-density lipoprotein cholesterol and high-density lipoprotein cholesterol. CONCLUSIONS: Sodium restriction reduced blood pressure and did not raise low-density lipoprotein cholesterol. A low-fat/high-fibre diet did not reduce blood pressure but lowered cholesterol levels. A combination of the two regimes has the greater potential for reducing cardiovascular risk in hypertensives.

Plasma calcium and cortisol as predisposing factors to alcohol related blood pressure elevation.

Mechanisms by which alcohol consumption might cause hypertension were examined in 30 pairs of healthy drinking (greater than 275 g ethanol per week) and teetotal men closely matched for age and obesity. Both systolic and diastolic blood pressures were significantly higher in the drinkers. Plasma calcium levels correlated with diastolic blood pressures (r = 0.51, P = 0.004) in drinkers only. After adjusting for plasma albumin, diastolic pressures increased by 6.9 mmHg for each 0.1 mM increment of plasma calcium. It is proposed that regular alcohol consumption predisposes to hypertension by facilitating calcium accumulation in cells involved in blood pressure regulation. In the combined population of drinkers and teetotallers plasma cortisol correlated positively with diastolic pressure (r = 0.35, P = 0.012) and negatively with plasma potassium (r = -0.38, P = 0.006); this suggests a role for the pituitary/adrenal axis as a significant determinant of blood pressure differences between healthy subjects.

Nutrient intake, blood pressure, serum and urinary prostaglandins and serum thromboxane B2 in a controlled trial with a lacto-ovo-vegetarian diet.

Fifty-nine healthy omnivores volunteered for a randomized crossover trial with a lacto-ovo-vegetarian (L-O-V) diet. Twenty-one 1-day diet records were kept throughout the project as a means of assessing food and nutrient intakes, and samples of serum and urine were assayed to evaluate change in prostanoid metabolism. While on the L-O-V diet subjects ate more vegetable protein, wholegrain cereals, polyunsaturated oils, fruits and vegetables, and avoided eating meat, fish or poultry. The L-O-V diet contained significantly more polyunsaturated fatty acids, fibre, vitamin C, vitamin E, magnesium, calcium and potassium, and less total protein, saturated fat, monounsaturated fat and vitamin B12 than the control omnivore diet. Changes in nutrient intakes were subjected to principal components analysis to identify dimensions of change in nutrient intakes. Three Factors accounted for 83% of the total variation in dietary intake. Blood pressure changes were significantly and negatively (F = 17.4, P less than 0.001 for systolic; F = 6.09, P = 0.02 for diastolic pressure) related to individual scores for only one Factor--that representing an increase in intake of polyunsaturated fat, fibre, vitamin C, vitamin E, calcium and magnesium, and a fall in intake of protein and vitamin B12. Blood pressure changes were unrelated to change in body weight or sodium intake. Serum and urinary prostanoids were not affected by eating the L-O-V diet.

Comparison of diets supplemented with fish oil or olive oil on plasma lipoproteins in insulin-dependent diabetics.

This study was designed to compare changes in high-density lipoprotein (HDL)- and low-density lipoprotein (LDL)-cholesterol in normolipidaemic male insulin-dependent diabetics (IDD) following dietary supplementation with either the fish oil concentrate Max EPA or olive oil. The contribution of the small quantity of cholesterol in Max EPA to these changes was also examined. Twenty-seven subjects were matched in groups of three and randomly allocated to one of three treatment groups of nine subjects each. Subjects were given 15 1-g capsules of oil daily for 3 weeks, consisting of either Max EPA, olive oil, or olive oil to which was added the same amount of cholesterol as contained in Max EPA, respectively. There was a significant increase in eicosapentaenoic acid, and a decrease in arachidonic acid, in the platelet membrane phospholipids of subjects taking Max EPA. In this group, there was an approximately 30% increase in serum HDL2-cholesterol (0.59 +/- 0.07 to 0.77 +/- 0.11 mmol/L, mean +/- SEM; P less than .01) and a corresponding decrease in HDL3-cholesterol (0.79 +/- 0.03 to 0.71 +/- 0.03 mmol/L; P less than .05). Although total and LDL-cholesterol concentrations were also higher after Max EPA, the changes were not significant. Triglycerides were significantly decreased by Max EPA. There were no significant changes in lipids in the groups given olive oil. These results show that compared with olive oil, dietary supplementation with Max EPA substantially increases HDL2-cholesterol in insulin-dependent diabetics. This is most likely due to a selective effect of omega 3 fatty acids.(ABSTRACT TRUNCATED AT 250 WORDS)

Methicillin-resistant Staphylococcus aureus in Western Australia, 1983-1992.

A statewide screening programme has prevented imported strains of methicillin-resistant Staphylococcus aureus (MRSA) from becoming established in any hospital in Western Australia (WA). Recently, notifications of MRSA in WA have increased, prompting a review of surveillance data for the period 1983-1992. Our aims were to determine: (i) the distribution by age and sex of persons with MRSA; (ii) changes in notification rates over time and by location in WA; and (iii) temporal changes in antimicrobial resistance patterns. There were 631 notifications of MRSA for the 10 year period 1983-1992, ranging from a low of 36 in 1988 to a high of 117 in 1992. When the distribution by age and sex was examined, three age group peaks were apparent: 0-9 years, 20-39 years and 60-79 years. There was a predominance of females in the 20-39 years age group, reflecting a greater proportion of hospital nursing staff carrying MRSA. In those aged 50 years or more, there was a marked predominance of males. The highest notification rates overall occurred in the remote Kimberley region of WA, however, rates increased significantly in all regions of the state in 1992. Based on antimicrobial resistance patterns, MRSA was classified into two groups: multiresistant imported strains which often caused outbreaks in hospitals; and a less resistant MRSA (WA MRSA). WA MRSA appears to have originated in the Kimberley region and then spread widely in the community to other regions of the state, and the proportion of WA MRSA has increased significantly since 1989.

Hospitalisation of the elderly during the last year of life: an application of record linkage in Western Australia 1985-1994.

STUDY OBJECTIVE: To measure the trend, pattern, and cost of time spent in hospital during the last year of life in Western Australia and to identify trends in the place of death. The results were compared with those reported from the Oxford Record Linkage Study. DESIGN: Mortality records for those aged 65 years and over were linked to inpatient hospital morbidity records with a date of separation within one year before death. Comparative inpatient resource utilisation was estimated using ANDRG 3.0 cost weights for Australian public hospitals. SETTING: Western Australia. PARTICIPANTS: All 68,875 persons aged 65 years and over who died between 1 January 1985 and 31 December 1994. MAIN RESULTS: Increasing proportions of all age groups (65-74, 75-84, and 85+ years) were admitted to hospital at least once in the year before death during 1985-94, but the chance of admission decreased with age. There was a trend towards a greater number of shorter admissions per person. Total bed days per person showed no significant increase, except at ages 65-74 years. Total inpatient resource utilisation during the last year of life was lowest and remained constant in those aged 85 years and over, while increasing gradually (3.7% per annum) in the younger elderly. The Western Australian population spent more time in hospital in the last year of life at ages 65-74 years, but the advanced elderly spent less time in hospital, when compared with the Oxford Region. CONCLUSIONS: Recent gains in life expectancy and higher per capita health expenditure have not been accompanied by more time spent in hospital during the last year of life at ages 75+ years. International differences between Western Australia and Oxford can be explained by differences in aged care provision.

Relationships between age, body weight, physical fitness and sex-hormone-binding globulin capacity.

The associations between sex-hormone-binding globulin capacity (SHBG), age, body mass index (BMI), and physical fitness have been studied in 34 men and 36 women. Multivariate analysis was used to look for independent associations with SHBG. The data indicate that when controlled for a number of other factors SHBG levels are related, in men but not in women, to age (positively, p less than 0.001) and BMI (negatively, p less than 0.001).

Population-based linkage of health records in Western Australia: development of a health services research linked database.

OBJECTIVES: To introduce the Western Australian Health Services Research Linked Database as infrastructure to support aetiologic, utilisation and outcomes research. To compare the study population, data resources, technical systems and organisational supports with international best practice in record linkage and health research. METHOD AND RESULTS: The WA Linked Database systematically links the available administrative health data within an Australian State of 1.7 million people. It brings together, initially, six core data elements (birth records, midwives' notifications, cancer registrations, in-patient hospital morbidity, in-patient and public out-patient mental health services data and death records). It will be updated regularly and is designed, in future extensions, to include data on primary, residential and domiciliary care and health surveys. Linkage uses probabilistic matching of patient names and other identifiers. Geocodes for spatial analysis are assigned using address linkage and mapping software. By June 1997, the project had taken 2 1/2 years to develop the system and link seven million core data records from 1980 to 1995. CONCLUSIONS: The system is consistent with international benchmarks, from four centres of excellence, for the study population, core datasets, matching and geocoding, and collaborative networks. There are prospects to redress deficiencies in primary medical contact and other data resources, validation studies, tracing systems and a more supportive legal framework. IMPLICATIONS: The WA Linked Database will be used in combination with medical record audits to provide a comprehensive evaluation of health system performance.