Correlates of high-density lipoprotein cholesterol in a sample of healthy workers

Meta-analysis of the effects of smoking and smoking cessation on triglyceride levels

Smoking increases lipid levels, including triglycerides, leading to increased cardiovascular disease risk. We performed a meta-analysis to quantify the effects of smoking and smoking cessation on triglyceride levels. The PubMed and Scopus databases were searched to identify studies reporting either triglyceride levels in smokers and non-smokers or the effects of smoking cessation on triglyceride levels. Fixed- and random-effects models were used to perform the analyses when three or more studies/comparisons were available. We identified 169 and 21 studies evaluating the effects of smoking and smoking cessation, respectively, on triglyceride levels. Triglyceride levels were 0.50 mmol/L (95% confidence interval: 0.49-0.50 mmol/L) higher in smokers than non-smokers, but the effect differed widely across studies. No statistically significant effect was observed on triglyceride levels between baseline and 6 weeks (mean difference [MD] = 0.02 [-0.09, 0.12] mmol/L), 2 months (MD = 0.03 [-0.21, 0.27] mmol/L), 3 months (MD = 0.08 [-0.03, 0.21] mmol/L), or 1 year (MD = 0.04 [-0.06, 0.14] mmol/L) after quitting. However, a slightly significant decrease in triglyceride levels was observed at 1 month after cessation (MD = -0.15 [-0.15, -0.01] mmol/L). The results of this meta-analysis provide a basis for understanding the effects of smoking and smoking cessation on triglyceride levels, which could have important implications for public health.

Boiled or Filtered Coffee?

Caffeine is the most widely consumed psychostimulant drug in the world that mostly is consumed in the form of coffee. Whether caffeine and/or coffee consumption contribute to the development of cardiovascular disease (CVD), the single leading cause of death in the US, is unclear.This article examines the effects of caffeine intake, both alone and via coffee consumption, on key blood markers of CVD risk: lipoproteins (cholesterol, triglycerides), fibrinogen (a biomarker of blood clotting) and C-reactive protein (CRP; a biomarker of inflammation). These blood markers and their role in the development of CVD are reviewed first. Studies examining caffeine and coffee effects on each of these blood markers are then presented. Next, biobehavioural moderators of the relationship between caffeine and/or coffee consumption and CVD are discussed, including genetics, sex and tobacco smoking. The literature indicates a strong relationship between boiled, unfiltered coffee consumption and elevated cholesterol levels; however, there is a critical gap in the literature regarding the effects of coffee or caffeine consumption on fibrinogen or CRP, which is an independent predictor of CVD risk. Available studies are limited by small samples sizes, inclusion of only men (or few women) and unrepresented age or ethnic groups. Thiere is a critical need for controlled laboratory and epidemiological studies that include fibrinogen and CRP markers of CVD risk before conclusions can be drawn regarding the health effects of caffeine and/or coffee in a normal, healthy population of men and women.

Life-style factors associated with changes in serum lipids in a follow-up study of cardiovascular risk factors

We studied some life-style characteristics that may predict changes in total serum cholesterol and cholesterol bound to high density lipoproteins (HDL-cholesterol) in a sample of 980 healthy Spanish employees of both sexes who were followed for three years. All workers participated in a multifactorial program aimed at preventing cardiovascular disease. Linear regression models were fitted with changes in total and HDL-cholesterol as the dependent variables, after eliminating variability due to the influence of basal values. The association between lifestyle factors and lipid changes was controlled for dietary modifications. In the multivariate analysis, decreases in body mass index, and in alcohol consumption were associated with significant reductions in total serum cholesterol. Maintaining sports at post-test or starting to practice them in the interim was also significantly and independently associated with favourable changes in serum cholesterol. Leisure-time exercise (p = 0.002) and giving up smoking (p = 0.06) were each associated with increased HDL-cholesterol.

[Regular diet and cardiovascular disease risk factors]

INTRODUCTION

A survey by sampling in a county of the State of S. Paulo in 1990 sought, by means of home interviews, to analyse the habitual diet and risk factors for cardiovascular disease of people over 20 years of age.

METHODOLOGY

Of the sub-specimen of a comprehensive study population, 557 individuals, aged between 20 and 88, were interviewed. The habitual diet, characterized by the dietary history, was compared with the recommendations on energy and nutrients of the WHO and the risk factors (obesity, lipemic disorders and diabetes mellitus) diagnosed by the Body Mass Index and biochemical measurements.

RESULTS AND CONCLUSIONS

It was observed that 60% of the population consume a diet with total energy below the estimated need and that the caloric contribution of carbohydrates was of 56%, of the lipids 29% and of the proteins 15%. However, by percentile analysis, the caloric contribution of lipids and of proteins was far above the recommended levels to the detriment of the carbohydrates. Energy, caloric distribution and quantity of cholesterol were satisfactory in only 5% of diets. Among the risk factors for the cardiovascular disease studied, obesity was found to be present in 38% of individuals, lipemic disorders in 26% and diabetes mellitus in 5%. Preponderantly light physical activity together with unsatisfactory diet, both in qualitative as in quantitative terms, aggravated this scenario still further.

HDL cholesterol and mortality in Finnish men with special reference to alcohol intake

BACKGROUND

There is substantial evidence that a low serum level of HDL cholesterol (HDLC) is a risk factor for coronary deaths. However, data on older people are scarce, and previous studies have not examined this association in relation to alcohol intake.

METHODS AND RESULTS

Coronary mortality, all-cause mortality, and mortality due to alcohol and violence were related to HDLC levels among 7052 male smokers 50 to 69 years old in south and west Finland enrolled from 1984 to 1988 in the ATBC (AT, alpha-tocopherol; BC, beta-carotene) Study placebo group. During the average follow-up period of 4.7 years, 620 men died; 222 of these deaths were from coronary heart disease and 82 from causes related alcohol and violence. HDLC levels were inversely associated with coronary mortality, irrespective of age, whereas high total cholesterol was positively associated with coronary mortality among the younger men, 50 to 59 years of age, but not among the older men, 60 to 69 years old. Correction for temporal variation in HDLC measurement indicated a 43% stronger inverse association between HDLC and coronary mortality compared with that based only on a single value. The inverse association of HDLC and coronary mortality was less marked at higher levels of alcohol intake. All-cause and alcohol- and violence-related mortality were positively associated with HDLC among the younger men. All-cause mortality showed a U-shaped dose response among men > or = 60 years old.

CONCLUSIONS

Previous studies may have underestimated the beneficial effect of high HDLC because of regression-dilution bias and the confounding effect of heavy alcohol intake. This study supports the view that, particularly among older men, lipoprotein fractions may be more appropriate for screening than total cholesterol.