Adiposity, lipids, alcohol consumption, smoking, and gender.

Indices of obesity, plasma lipids, and lipoprotein levels, plasma cholesteryl ester fatty acid composition, reported alcohol consumption and smoking habits were measured in 88 men and 87 women, ages over 15 years, randomly selected from the total respondents (1192) to a health survey. Most indices of obesity were related to plasma triglycerides and high-density lipoprotein levels in both sexes; to very low-density lipoprotein levels in men only; and to plasma cholesteryl ester fatty acid linoleic acid proportions in women only. The correlations with high-density lipoprotein cholesterol levels were dependent on very low-density lipoprotein triglyceride levels in men but not in women. Indices of obesity were significantly higher in nonsmoking women and reported alcohol consumption correlated with Quetelet's index (body mass index) in men. Smoking habits, but not alcohol consumption, influenced correlations between indices of obesity and plasma triglycerides and very low-density lipoprotein triglyceride levels in men. The present results showed several sex-related differences in relationships with indices of obesity. Lower very low-density lipoprotein levels, higher skinfold measurements, higher cholesteryl ester fatty acid linoleic acid proportions and lower alcohol intake in women than in men may be responsible. The data suggested that in women, altered diet composition may be linked with obesity.

Linoleic acid and susceptibility to fatal ventricular fibrillation in rats.

The effect of linoleic acid on the induction of fatal ventricular fibrillation by intravenous CaCl2 (10%), was studied in rats fed for a month from weaning on a diet with either a high or low content of linoleic acid. Studies were performed in the basal state and after pretreatment with noradrenaline, which increased the sensitivity to CaCl2 equally in animals from both diet groups. Despite considerable differences in the linoleic acid levels in the plasma and myocardium, the two groups did not differ in the incidence of fatal ventricular fibrillation. Our conclusions concerning the effect of linoleic acid on cardiac arrhythmias, and sudden death in particular, are compared with those from other studies.

Modification of nicotinic acid and prostaglandin E1 antilipolytic action in vitro.

In epididymal adipose tissue from rats, human serum antagonizes inhibition of basal lipolysis by nicotinic acid in vitro. Under similar conditions caffeine-stimulated lipolysis was unaffected by the presence of human serum. Very low density (VLDL), low density (LDL) and high density (HDL) lipoproteins were all found to antagonize the action of nicotinic acid on basal lipolysis. VLDL also antagonized prostaglandin E1 (PGE1)-inhibition of basal lipolysis in vitro. The fat cell membrane was suggested as the site at which human serum lipoproteins antagonize nicotinic acid or PGE1 antilipolytic action on basal lipolysis in vitro.

Lecithin:cholesterol acyltransferase activity, plasma and lipoprotein lipids and obesity in men and women.

Lecithin:cholesterol acyltransferase (LCAT) activity, lipid concentration, lipoprotein lipid concentrations and cholesteryl ester linoleic acid proportion were determined in the plasma of 85 subjects randomly selected from a population during a health screen survey. Mean fractional LCAT rate was significantly higher in men than in women. Molar LCAT rate correlated with low density lipoprotein (LDL) cholesterol concentration in men and with nearly all lipoprotein lipid concentrations in women. Most of these relationships were dependent on plasma unesterified cholesterol (UC) concentration. Fractional LCAT rate was correlated only with HDL cholesterol concentration in women and this relation was dependent on the influence of obesity. An inverse relationship between plasma cholesteryl ester (PCE) linoleic acid proportion and molar LCAT rate in women was also explained by influences of obesity on the data. Both fractional and molar LCAT rates were positively correlated with obesity (Quetelet's Index and subscapular skinfold thickness) in women but not in men. This study showed the influence of sex on nearly all correlations involving LCAT activity in combined groups of men and women.

Increased levels of esterified arachidonic acid in plasma by feeding gamma-linolenic acid.

The effects of diets containing 5% of methyl-gamma-linolenate (delta 6,9,12) or 5% of methyl-alpha-linolenate (delta 9,12,15) on the fatty acid composition of lipids in rat plasma were studied. After 10 days the cholesterol esters and total phospholipids in the plasma of rats fed gamma-linolenate contained higher percentages of arachidonic acid than the corresponding lipid classes in the plasma of rats fed the alpha-isomer. A fairly high percentage of gamma-linolenic acid was incorporated into the cholesterol esters of rats fed methyl-gamma-linolenate.

Changes in high density lipoprotein subfractions and other lipoproteins by exercise.

Seventeen previously sedentary men (aged 30-45) were exercised approximately twice weekly over a 10-week period during which time there was a significant fall in low density lipoprotein cholesterol, but total high density lipoprotein (HDL) did not change. The subfraction HDL2 showed an initial fall at two weeks of training with a subsequent rise above the baseline by 10 weeks. HDL3 cholesterol tended to change in an opposite direction to HDL2 thus accounting for no significant change in total HDL cholesterol. Smoking or drinking habits did not change throughout the study. As body weights did not change significantly through the study, energy intake must have increased with probable increased very low density lipoprotein (VLDL) production. Loss of apoprotein C-peptides from HDL2 associated with activation of lipoprotein lipase, and clearance of VLDL, could have caused redistribution of C-apoproteins between HDL3 leading to the changes seen, with the establishment of a new equilibrium with continued training by 10 weeks.

Urban/rural differences in red blood cell fatty acid composition, plasma lipids and diet in Melanesian Fijians.

OBJECTIVE: The aim of the study was to compare red blood cell (RBC) fatty acid composition, plasma lipids and lipoproteins and dietary intake between urban and rural Melanesian Fijians. DESIGN: A cross-sectional study was performed in a random subsample (n = 154) from a total survey population of 589 subjects. SETTING: Melanesian Fijians living in the relatively urban settlement of Nabua, Suva and On the remote island of Qamea (rural) were studied. RESULTS: The proportions of myristic acid (1.4% versus 0.3%, P < 0.001) and arachidonic acid (10.1% versus 11.4%, P < 0.01) were significantly higher and proportions of oleic acid (14.4% versus 13.2%, P < 0.05) and linoleic acid (11.9% versus 8.1%, P < 0.001) were significantly lower in RBC from rural compared with urban men, and a similar pattern was seen in women. Plasma cholesterol levels were significantly (P < 0.05) higher in the rural subjects. Urban/rural differences in plasma cholesterol levels were not significant when the proportion of RBC myristate was taken into account. CONCLUSIONS: The results suggest that consumption of myristic acid from coconut fat is greater and the intake of linoleic acid is less in Fijians living on a remote island and may contribute to their higher plasma cholesterol levels compared with their urban counterparts.

Risk factors for coronary heart disease in New Zealand and Sweden: Dunedin and Uppsala compared.

OBJECTS: to compare men and women over the age of 35 years in Dunedin (New Zealand) and Uppsala (Sweden) in respect of anthropometric values, dietary habits and certain coronary heart disease risk factors in view of known differences in coronary mortality between the two countries. METHODS: one hundred and ninety-five Dunedin and 94 Uppsala residents were chosen randomly from the respective populations, in the former city by electoral roll, in the latter by use of unique personal number. Measurements of height, weight, waist/hip ratio, blood pressure, blood lipids were made and dietary and smoking habits assessed. RESULTS: the Swedes were taller and leaner than the New Zealanders. Blood pressure and smoking habits were not significantly different but total blood cholesterol levels were lower in Uppsala men and women. Blood triglycerides were higher in Dunedin women but high density lipoprotein cholesterol levels tended to be lower in men and women in Uppsala. CONCLUSIONS: it was found by analysis of variance that the blood lipid level differences between the two populations could be explained by body mass index. Correction of lipid values for the waist/hip ratio partly explained the higher cholesterol values in Dunedin but diet differences may also have been contributory. The differences in coronary mortality between the population of New Zealand and Sweden are compatible with the view that our blood cholesterol findings reflect the different levels of risk.

Blood pressure in a random sample of the New Zealand population.

Blood pressures were measured as part of a health check in a randomly selected sample of the New Zealand population. One thousand, four hundred and ten men and 1605 women over 15 years were studied. Measurements were made by trained observers using the Hawksley Random Zero instrument. Systolic and diastolic pressures increased with age in men and women. There were 29% of men and 24% of women over the age of 45 with pressures over 160/95 mmHg of whom 24% of men and 33% of women were on treatment for hypertension. Of all subjects 9% of men and 12% of women were on treatment for hypertension. Systolic and diastolic pressures correlated significantly with body mass index, waist/hip ratio and skinfold measurements in men and women. The most significant correlation was with the body mass index. No regional or urban/rural differences were seen in systolic or diastolic pressures. A history of hypertension in the fathers of respondents related to blood pressures in the highest tertile of diastolic blood pressures in males, and systolic pressure of females. The association was not seen between mothers of respondents in respect of diastolic pressure.

The treatment of hyperlipoproteinaemia with gemfibrozil compared with placebo and clofibrate.

In a single-blind study the lipid-lowering drug gemfibrozil was compared at fixed dosage of 1600 mg daily with placebo and other drugs (mainly clofibrate) over a nine month period in 33 patients with hyperlipidaemia. Two patients were withdrawn from the study because of gastrointestinal symptoms attributable to gemfibrozil. The drug significantly lowered plasma cholesterol and triglycerides compared to the placebo. The drug also significantly lowered plasma cholesterol and triglycerides compared to the placebo. The drug also significantly lowered very low density lipoprotein (VLDL) triglycerides and raised high density lipoprotein (HDL) cholesterol levels but a previously significant inverse relationship between VLDL triglyceride and HDL cholesterol on placebo disappeared with gemfibrozil treatment.

A double blind controlled trial of a new anorectic agent AN448.

AN448 is a new anorectic agent, which in the dose used, is without the CNS stimulant properties of the amphetamines. Patients entering the trial were a highly resistant group at least 20 percent above ideal weight chosen from an ischaemic-hyperlipidaemic clinic population. In a double blind trial of 12 patients on the active drug and nine patients on placebo, a highly significant weight loss occurred over 12 weeks in the active group only. A significant reduction in serum cholesterol occurred independently of weight loss but there was no reduction in the serum triglycerides and no change in the lipoprotein electrophoretic pattern. The drug is shown to be effective for this group of patients and may also be useful as a cholesterol lowering agent.

Clinical features of ischaemic heart disease correlated with high density lipoprotein cholesterol levels in men with hyperbetalipoproteinaemia.

Thirty males with familial hypercholesterolaemia were divided on the basis of levels of high-density lipoprotein cholesterol into tertiles of high, middle and low values. Symptoms and signs were scored on an arbitrary system by three methods which either included or excluded angiographic findings. Symptomatic severity and clinical manifestations of hyperlipidaemia were related to high-density lipoprotein cholesterol levels irrespective of the effect of age, level of the blood pressure, or levels of other lipoproteins. The association was not improved by adding weightings drawn from coronary angiographic findings.

Familial type V hyperlipoproteinaemia in identical twins homozygous for apoliprotein variant E2: report.

Hyperchylomicronaemia and elevated very low density lipoproteins were found in relatively obese 47 year old identical twin brothers. Lipoprotein apoprotein studies showed the presence of apoprotein CII, the activator of lipoprotein lipase, and both men were homozygous E2/2. Studies on the ability of the brothers to clear triglyceride rich particles showed some impairment of post heparin lipase activity, and a slower clearance of infused fat emulsion. The values improved after weight loss. There was some evidence of impaired capacity of the patients' high density lipoprotein to activate post heparin lipoprotein lipase.

Sitosterolaemia and heterozygous familial hypercholesterolaemia in a three year old girl: case report.

A case of a 3 1/2 year old female child is described in which symptomless cutaneous xanthomatosis led to the diagnosis of sitosterolaemia in the presence of a defect of low-density lipoprotein uptake by cultured fibroblasts. The condition responded to treatment by cholestyramine with normalisation of the blood lipid levels. Normal growth and development continued for three years of observation.

A register of individuals with inborn errors of lipoprotein metabolism and their families.

One hundred and fifty-five hyperlipidaemic families resident in the Christchurch and Dunedin areas were included on a computerised register with built in confidentiality safeguards. Investigation of the relatives of the 155 probands identified 519 with normal lipids and a further 381 with hyperlipidaemia. The presence of 536 hyperlipidaemic individuals in the population of the two areas indicates a frequency of at least 0.12% which extrapolates to approximately 3800 cases of familial hyperlipidaemia nationwide. Our findings suggest that less than half of these are likely to have been detected. The most common condition was the mendelian dominant disorder familial hypercholesterolaemia found in 108 families. The register has been used to facilitate detection of further cases of familial hyperlipidaemias and appropriate counseling as well as for detecting and reassuring normal relatives. It also facilitates the long term study of the treatment of the affected individuals.

Hyperbetalipoproteinaemia and hyperalphalipoproteinaemia in a single family.

Twelve members of a kindred were studied of whom six showed elevated low-density lipoprotein (LDL) cholesterol levels. Within the blood related group nine showed elevated high density lipoprotein (HDL) cholesterol levels and correspondingly elevated HDL lipoprotein apoprotein levels. The members with elevated LDL also therefore had elevated HDL. There was no family history of premature vascular disease in the kindred and the 74 year old member was clinically free of ischaemic vascular disease. It is considered that the coincidence of a familial tendency to high blood LDL and HDL was not associated with appearance of premature arterial disease in this kindred.

Age, adiposity, blood pressure and blood lipids in a rural New Zealand population.

Multiple regression analysis of data on age, blood pressure, adiposity and blood lipids from a rural New Zealand population of over 1200 adults has been undertaken. The results show that rises in blood lipids over time in the population are independent of age and correlate significantly with adiposity. Thus plasma cholesterol and triglycerides correlate with adiposity (expressed as Quetelet's index or skinfold thickness) in men whereas significant correlation in women was only between adiposity and plasma triglycerides. Systolic and diastolic blood pressure in men was strongly correlated with their plasma triglycerides, but not cholesterol, when the effect of age and adiposity was removed. In women however only a weak correlation was observed between plasma triglycerides and systolic blood pressure. The significance of the findings is discussed.

The Milton survey: Part 1, General methods, height, weight and 24-hour excretion of sodium, potassium, calcium, magnesium and creatinine.

This paper describes the methods and general aims of a survey carried out on just over 1200 subjects (about 82% of the adult population) in Milton, a small town south of Dunedin. Data were collected on personal and family history, present medication if any, 24-hour dietary recall, psychometric scores, height, weight, skin-fold thickness, anthropometry, blood pressure, heart rate, electrocardiogram, mass miniature X-ray of chest, forced expiratory volume (FEV1), fasting plasma cholesterol and triglycerides, lipoprotein pattern and fasting and post-prandial blood sugar in a selected subgroup, and 24-hour urine volume and excretion of sodium, potassium, calcium, magnesium and creatinine. Mean values are given in the paper for each 10-year age group for height, weight, Quetelet's index, 24-hour urine volume, creatinine, sodium, potassium, calcium and magnesium. These and other results will be discussed in detail in subsequent papers.