Search PubMed⌕ Search

Biomedical subjects

C H Bolton

Publications and source records attributed to C H Bolton.

At least 37 records · Page 2Linked to original sources
PubMed1994

Associations of the HDL2 and HDL3 cholesterol subfractions with the development of ischemic heart disease in British men. The Caerphilly and Speedwell Collaborative Heart Disease Studies.

BACKGROUND: The relative importance of HDL2 and HDL3 cholesterol as risk factors for ischemic heart disease (IHD) is still uncertain. Their associations with the incidence of IHD in the Caerphilly and Speedwell prospective studies are described. METHODS AND RESULTS: The two studies have a common core protocol and are based on a total of 4860 middle-aged men from the general population. The first follow-up was at a nearly constant interval of 5.1 years in Caerphilly and 3.2 years in Speedwell: 251 major IHD events had occurred. Lipid levels were measured on fasting samples. Different laboratories were used by the two studies. Each laboratory used ultracentrifugation to separate HDL2 and HDL3. Both subfractions were inversely associated with risk of IHD. Standardized relative odds of developing major IHD were 0.95 (95% confidence interval [CI], 0.80 to 1.14) for HDL2 cholesterol and 0.83 (95% CI, 0.68 to 1.00) for HDL3 cholesterol in Caerphilly and 0.76 (95% CI, 0.57 to 1.01) for HDL2 and 0.64 (95% CI, 0.49 to 0.83) for HDL3 in Speedwell. The association with incident IHD appeared to be stronger for HDL3 in both areas. No linear combination of the two subfractions was a better predictor of IHD than total HDL cholesterol alone. CONCLUSIONS: In British men, both HDL2 and HDL3 cholesterol are inversely associated with the incidence of IHD. However, the prediction of the risk of IHD from total HDL cholesterol alone could not be improved upon by measurement of the two HDL subfractions. The relative value of the two HDL subfractions as predictors of risk is still unresolved. The uncertainty may be due, at least in part, to problems associated with their measurement.

Cholesterol, HDL↗
PubMed1993

Plasma lipoprotein lipids in five different breeds of dogs.

Plasma and lipoprotein cholesterol and triglycerides, and apolipoproteins AI and B, were determined in five common breeds of pet dogs, labrador, beagle, West Highland terrier, cairn terrier and dachshund, kept under carefully controlled conditions approximating as closely as possible to normal domestic living. Although the total levels of both cholesterol and triglycerides in plasma did not vary significantly between the breeds, there were significant interbreed differences in the lipoprotein fractions. Thus high density lipoproteins (HDL) which are the major carriers of cholesterol in all dogs, was higher in the smallest breed, the cairn, than in the largest, the labrador. In contrast, the low density lipoprotein (LDL) was lowest in the cairn and highest in the labrador. Variation in HDL cholesterol levels arose from both subfractions, HDL2 and HDL3. Thus metabolic studies involving canine lipids should include measurement of lipoprotein lipids and take account of interbreed variation.

Animals↗
PubMed1993

Lipoprotein levels following treatment with cyproterone acetate or LHRH analogues.

Fasting serum lipoproteins were measured in patients with carcinoma of the prostate. Twelve patients were on no hormonal treatment (Group 1). Fifteen were on cyproterone acetate (Group 3), 17 were on the long-acting LHRH analogue Zoladex (Group 4) and 11 on a combination of cyproterone acetate and Zoladex (group 5). In addition, 27 patients with benign urological disease were taken as controls (Group 2). In both groups in which cyproterone acetate was part of the treatment the total high density lipoprotein cholesterol levels were significantly lower than in the other groups. Patients on cyproterone acetate alone had significantly higher levels of very low density lipoprotein (VLDL) triglyceride levels than those not on cyproterone acetate. These results confirm changes in serum lipoprotein levels in patients taking cyproterone acetate and these changes may have potential adverse effects if the treatment is prolonged.

Cholesterol↗
PubMed1992

Alcohol consumption and its relation to cardiovascular risk factors in British women.

OBJECTIVE: To examine the relation between alcohol consumption and risk factors for coronary heart disease in women. DESIGN: Cross sectional study of a stratified random sample of the population grouped into five categories of habitual alcohol consumption. SETTING: People registered with general practitioners at two large health centres in east Bristol, England. SUBJECTS: 1048 women aged 25-69 years. MAIN OUTCOME MEASURES: Fasting plasma concentrations of insulin, total cholesterol, total triglycerides, and high density lipoprotein cholesterol, including its subfractions HDL2 and HDL3, and body mass index. RESULTS: Compared with non-drinkers women consuming a moderate amount of alcohol (1-20 g/day) had lower plasma concentrations of triglycerides, by 0.19 mmol/l (95% confidence interval 0.07 to 0.35); cholesterol, by 0.4 mmol/l (0.19 to 0.61); and insulin, by 1.4 mU/l (0.43 to 1.97) and a lower body mass index, by 1.2 kg/m2 (0.43 to 1.97). They also had higher concentrations of high density lipoprotein cholesterol, by 0.09 mmol/l (0.03 to 0.15); HDL2 cholesterol by 0.05 mmol/l (-0.02 to 0.10) and HDL3 cholesterol, by 0.06 mmol/l (0.06 to 0.11). All these were independent of body mass index, smoking habits, and taking oral contraceptives. CONCLUSIONS: Moderate alcohol consumption is associated with lower levels of cardiovascular risk factors in women. Insulin may have a central role.

Adult↗
PubMed1992

Plasma triglyceride and high density lipoprotein cholesterol as predictors of ischaemic heart disease in British men. The Caerphilly and Speedwell Collaborative Heart Disease Studies.

OBJECTIVE: To assess the roles of plasma triglyceride and high density lipoprotein (HDL) cholesterol concentrations in predicting ischaemic heart disease. DESIGN: Two prospective cohort studies with common core protocols. SETTING AND PARTICIPANTS: Both cohorts are 100% samples of middle aged men. In Caerphilly the 2512 men were living within a defined area. In Speedwell the 2348 men were registered with local general practitioners. MAIN OUTCOME MEASURES: Fasting blood samples were taken at initial examination and plasma lipid concentrations were measured. Major ischaemic heart disease events were assessed from hospital notes, death certificates, and electrocardiograms. RESULTS: At first follow up, after an average of 5.1 years in Caerphilly and 3.2 years in Speedwell, 251 major ischaemic heart disease events had occurred. Men with triglyceride concentrations in the top 20% of the distribution had a relative odds value for ischaemic heart disease of 2.3 (95% confidence interval (95% CI) 1.3 to 4.1) compared with men in the bottom 20%, after adjusting for both plasma total and HDL cholesterol, and non-lipid risk factors. Men in the lowest 20% of the distribution of HDL cholesterol concentration had a relative odds value of 1.7 (95% CI 1.0 to 2.8) compared with the top 20%, after adjustment was made for total cholesterol and triglyceride concentrations, and non-lipid risk factors. These relations were not caused by beta blockers, which were being taken by 5% of the men. CONCLUSIONS: Plasma triglyceride concentration predicts major ischaemic events after allowance is made for total and HDL cholesterol concentrations and other risk factors. In these populations, triglyceride is a more important predictor than total cholesterol concentration.

Adrenergic beta-Antagonists↗
PubMed1989

Plasma and lipoprotein lipids and apolipoproteins AI, AII and B in patients with chronic airflow limitation.

Plasma and lipoprotein cholesterol and triglycerides, and plasma apolipoproteins AI, AII and B were compared in patients with chronic airflow limitation, and normal controls matched for body mass index. The controls were non-smokers, and free from respiratory disease. High-density lipoprotein (HDL) cholesterol concentration was significantly elevated in the patients, due mainly to a raised HDL2 cholesterol level. HDL triglyceride was significantly lower in the patients. All other lipids were not different from normal. Apolipoprotein AI levels were significantly raised in the patients but other apolipoproteins were unchanged. The changes found may account in part for the fact that patients with chronic airflow limitation have a lower incidence of atherosclerotic heart disease.

Adult↗
PubMed1989

Coffee, blood pressure and plasma lipids: a randomized controlled trial.

A randomized controlled trial was conducted to examine the effects of coffee (as commonly drunk in Britain) on blood pressure and plasma lipids in healthy subjects. Fifty-four subjects followed three regimens successively, the order being randomized according to a Latin square design: five or more cups of coffee daily for 4 weeks; five or more cups of decaffeinated coffee daily for 4 weeks but no ordinary coffee; no coffee for 4 weeks. Coffee appeared to cause a small rise (of 3 mm Hg) in recumbent systolic blood pressure; this effect was less than, and obscured by, changes induced by posture and mild stress. No consistent changes attributable to coffee were found in diastolic blood pressure or pulse rate. Small changes in the expected directions occurred in plasma high density lipoprotein (HDL) cholesterol and apolipoprotein AI (decrease), and in total cholesterol, non-HDL cholesterol and apolipoprotein B (increase), but none of these were statistically significant. The effect of coffee on risk of heart disease in Britain is probably small.

Adolescent↗
PubMed1988

Particle size of wheat, maize, and oat test meals: effects on plasma glucose and insulin responses and on the rate of starch digestion in vitro.

When normal volunteers ate isocaloric wheat-based meals, their plasma insulin responses (peak concentration and area under curve) increased stepwise: whole grains less than cracked grains less than coarse flour less than fine flour. Insulin responses were also greater with fine maizemeal than with whole or cracked maize grains but were similar with whole groats, rolled oats, and fine oatmeal. The peak-to-nadir swing of plasma glucose was greater with wheat flour than with cracked or whole grains. In vitro starch hydrolysis by pancreatic amylase was faster with decreasing particle size with all three cereals. Correlation with the in vivo data was imperfect. Oat-based meals evoked smaller glucose and insulin responses than wheat- or maize-based meals. Particle size influences the digestion rate and consequent metabolic effects of wheat and maize but not oats. The increased insulin response to finely ground flour may be relevant to the etiology of diseases associated with hyperinsulinemia and to the management of diabetes.

Amylases↗
PubMed1988

Associations of alcohol consumption with plasma high density lipoprotein cholesterol and its major subfractions: the Caerphilly and Speedwell Collaborative Heart Disease Studies.

In surveys of 4860 middle-aged men in Caerphilly (South Wales) and Speedwell (Bristol) alcohol consumption has been related to high density lipoprotein (HDL) cholesterol and its major subfractions, HDL2 and HDL3, measured in a single fasting blood sample. The results confirm that high density lipoprotein cholesterol concentration increases as the amount of alcohol regularly consumed increases. The relationship appears to be linear and is independent of age, smoking habit, body mass index, low density lipoprotein cholesterol and plasma total triglyceride. This rise in HDL cholesterol is not mediated through either HDL2 cholesterol or HDL3 cholesterol alone. Both subclasses increase significantly and by similar amounts with increasing alcohol intake.

Alcohol Drinking↗
PubMed1988

Dietary determinants of plasma lipids and lipoproteins: the Caerphilly Study.

Associations between nutrient intakes and plasma lipids were examined in a representative sample of 653 middle-aged men in Caerphilly, South Wales. Nutrient intakes were calculated from 7-d weighed intake records and were expressed both as g/d and as a percentage of total energy intake. In multivariate analyses, after taking the effects of potential confounding factors (age, body mass index and smoking habit) into account, the percentage of variance in the plasma lipid concentrations which could be explained solely by the dietary variables was very small, ranging from 1 to 7 per cent. Associations which were statistically significant included a positive association between saturated fat intake and both total cholesterol and low density lipoprotein cholesterol; a negative association between carbohydrate intake and both total cholesterol and high density lipoprotein cholesterol (HDL-C); a positive association between magnesium intake and an HDL-C subfraction (HDL2-C); a positive association between alcohol intake and each of the following: HDL-C, its subfractions and triglyceride.

Cholesterol↗
PubMed1986

Alcohol and high-density-lipoprotein cholesterol: a randomized controlled trial.

1. A randomized controlled trial of cross-over design was set up to examine the effect of alcohol on blood lipids and certain haematological variates relevant to ischaemic heart disease. 2. One hundred subjects drank some alcohol for 4 weeks (mean intake 18.4 g/d) and abstained totally for 4 weeks, the order of these periods being randomized. 3. Alcohol appeared to produce a rise of 7% in serum high-density-lipoprotein (HDL) cholesterol, probably due to a rise in the HDL2 subfraction. 4. No significant change was detected in plasma fibrinogen or the other haematological indices. 5. These results are consistent with the hypothesis that a moderate intake of alcohol confers some protection against heart disease.

Adult↗
PubMed1985

Demonstration of an abnormality of C apoprotein of very low density lipoprotein in patients with gout.

The very low density (VLDL) apolipoproteins of 12 male patients with gout have been studied by analytical isoelectric focusing. The relative percentage distribution of the C apolipoproteins was calculated and compared with that from 12 normolipidaemic and 12 'lipid-matched' controls. In the gout patients apolipoprotein CII (apo CII) represented 19.6% of the VLDL C proteins and the CII/CIII2 ratio was 0.57. In the normolipidaemic controls apo CII represented 28.8% and in the lipid-matched controls 33.1% of VLDL apo C, and the CII/CIII2 ratio approached one in each control group. These differences were significant. This suggests that a reduction in VLDL apo CII may predispose to the hypertriglyceridaemia that is commonly found in patients with gout.

Adult↗
PubMed1982

Changes in certain blood constituents during Ramadan.

Fasting serum cholesterol, triglycerides, thyroxine, triiodothyronine, uric acid, gastrin, and insulin were measured in a group of 24 Muslims at the beginning and end of Ramadan--the Muslim month of fasting. There was a significant increase in the levels of total serum cholesterol, thyroxine, and uric acid and a significant fall in body weight. There was no significant change in the levels of total serum triglycerides, triiodothyronine, gastrin, insulin (fasting), or in the rise in gastrin or insulin 1/2 h after food. These changes, although unlikely to affect normal people, may be significant in patients. Physicians working in Muslim countries should be aware that Ramadan may affect some laboratory findings.

Adult↗
PubMed1980

Estimation of cholesterol in bile: assessment of an enzymatic method.

Cholesterol in bile has been estimated using two variants of the cholesterol oxidase method and compared with gas-liquid chromatographic (GLC) assay. As published, the enzymatic method seriously underestimated biliary cholesterol. This was due to interference by other constituents of bile, particularly bilirubin and lecithin. However, by dilution of reagents and samples in water and isopropanol respectively a close correlation with the GLC method is achieved. It is concluded that the cholesterol oxidase method as published is unsuitable for the estimation of cholesterol in bile, but in modified form it is simple, accurate and economical.

1-Propanol↗
PubMed1980

Enzyme induction and serum and lipoprotein lipids: a study of glutethimide in normal subjects.

1. Serum and lipoprotein cholesterol and triglycerides were measured before, during and after the administration of glutethimide (500 mg daily) for 21 days to six healthy volunteer subjects. 2. Evidence of enzyme induction was provided by significant rises in D-glucaric acid excretion and antipyrine clearance. 3. Concentrations of total serum cholesterol, very-low-density-lipoprotein-, low-density-lipoprotein and high-density-lipoprotein-cholesterol rose significantly during treatment. 4. The time course of these changes was delayed in comparison with the rise and fall in D-glucaric acid excretion. 5. There was no change in the triglyceride content of either whole serum or lipoprotein fractions at any time during the trial. 6. The study provides further evidence that enzyme-inducing agents cause a rise in certain lipid concentrations.

Adult↗