Internal migration, coffee drinking, and nonfatal myocardial infarction in Italy

Coffee consumption and risk of myocardial infarction: a dose-response meta-analysis of observational studies

Background

Previous epidemiological studies have provided inconsistent conclusions on the effect of coffee consumption in the development of myocardial infarction (MI). The aim of the study was to evaluate the influence of coffee consumption and its potential dose-response patterns on the risk of developing MI.

Materials and Methods

Three databases were searched for evidence of eligible studies. A random-effects model was used to pool the fully adjusted odds ratios (ORs) and the corresponding 95% confidence intervals (CIs). Dose-response analysis was performed to show the effect of each cup increased in daily coffee drinking on the risk of MI.

Results

Seventeen studies involving 233,617 participants were included in our study. The association between coffee consumption and risk of MI did not show statistical significance when pooling the outcome data for the coffee consumption categories of 1~2 vs. < 1 cup per day (OR = 1.06, 95% CI: 0.94–1.19) and 2~3 vs. < 1 cup per day (OR = 1.07, 95% CI: 0.94–1.23). Compared with < 1 cup, daily drinking of 3~4 cups and > 4 cups of coffee were significantly associated with the risk of MI, and the pooled ORs (95% CIs) were 1.40 (1.11–1.77) and 1.48 (1.22–1.79), respectively. The dose–response analysis showed a “J–shaped” curve relationship of the risk of MI with coffee consumption.

Conclusions

Daily drinking of more than three cups of coffee was associated with a significantly increased risk of MI. This positive association was only found in men but not in women. The impact of gender on this association should be further evaluated.

Coffee consumption and risk of coronary heart disease: a meta-analysis

BACKGROUND AND AIMS

During the past three decades the relationship between habitual coffee drinking and coronary heart disease (CHD) has been assessed in numerous studies, with conflicting results. The aim of this study was to systematically examine the data published on the association between habitual coffee consumption and risk of CHD.

METHODS AND RESULTS

Thirteen case-control and 10 cohort studies were included. Case-control studies incorporated 9487 cases of CHD and 27,747 controls, and cohort studies included a total of 403,631 participants that were followed for between 3 and 44 years. The summary of odds ratios (OR) for the case-control studies showed statistically significant associations between coffee consumption and CHD for the highest intake group (>4 cups/day), OR 1.83 (95% CI 1.49-2.24; P<0.0001), and for the second highest category (3-4 cups/day), OR 1.33 (95% CI 1.04-1.71; P<0.0001), while no significant association emerged for low daily coffee intake (< or =2 cups/day), OR 1.03 (95% CI 0.87-1.21; P=0.45). The analysis of long-term follow-up cohort studies did not show any association between the consumption of coffee and CHD, with a relative risk (RR) of 1.16 (95% CI 0.95-1.41; P=0.14) for the highest category, and 1.05 (95% CI 0.90-1.22; P=0.57) and 1.04 (95% CI 0.90-1.19; P=0.60) for the second and third highest categories, respectively. These results did not differ substantially when controlling for region of origin, fatal and non-fatal events, year of publication, and number of years of follow-up.

CONCLUSIONS

Despite a significant association between high consumption of coffee and CHD reported among case-control studies, no significant association between daily coffee consumption and CHD emerged from long-term follow-up prospective cohort studies.

Alcohol, smoking, coffee and risk of non-fatal acute myocardial infarction in Italy

OBJECTIVES

To assess the relation between cigarette smoking, alcohol, coffee, decaffeinated coffee and tea consumption, and the risk of non-fatal acute myocardial infarction (AMI).

DESIGN AND SETTING

Hospital-based case-control study conducted in 1995-1999 in Milan, Italy.

PATIENTS

507 cases with a first episode of non-fatal AMI, and 478 controls admitted to hospital for acute diseases.

METHODS

Information was collected by interviewer-administered questionnaires. Odds ratios (OR) and 95% confidence intervals (CI) were calculated by multiple logistic regression.

RESULTS

Compared to alcohol non-drinkers the OR was 0.6 (95% CI: 0.4-0.9) in drinkers, and 0.5 in drinkers of > 3 drinks/day. The OR for > 1 drink/day of wine was 0.5, and those for beer, amari, grappa and spirits ranged between 0.4 and 0.6. Compared to never smokers, the OR was 2.2 (95% CI: 1.5-3.1) among current smokers, and 4.6 among current smokers of > or = 25 cigarettes/day. The risk was similar to that of never smokers > or = 5 years after cessation (OR: 1.1 after 5-9 years, 0.7 after > or = 10 years). The OR was 2.3 for low tar cigarettes and 2.0 for high tar ones. The OR for coffee intake (expresso and mocha) was around unity up to 3 cups/ day, but rose to 1.9 (95% CI: 1.1-3.3) for > or = 6 cups/ day. Moderate decaffeinated coffee and tea intake was not associated with AMI risk. Compared to non-smokers drinking < or = 3 cups of coffee/day, the OR was 1.6 among non-smokers drinking > 3 cups of coffee/ day and 3.3 (95% CI: 2.1-5.0) among current smokers drinking < or = 3 cups of coffee/day. Compared to alcohol drinkers with a coffee intake of < or = 3 cups/ day, alcohol non-drinkers with higher coffee intake had an OR of 2.2, and compared to non-smokers alcohol drinkers, the OR was 3.3 in current smokers alcohol non-drinkers.

CONCLUSIONS

In this Italian population alcohol intake was inversely associated to AMI risk, while smoking and heavy (but not moderate) coffee drinking increased the risk.