Coffee and serum lipids: Findings from the Olivetti heart study

Coffee and serum lipids: Findings from the Olivetti heart study

Coffee and Serum Lipids: Findings from the Olivetti Heart Study FABRIZIO JOSSA, MD, VITTORIO KROGH, MD, MS, EDUARDO FARINARO, MD, SALVATORE PANICO, MD...

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Coffee and Serum Lipids: Findings from the Olivetti Heart Study FABRIZIO JOSSA, MD, VITTORIO KROGH, MD, MS, EDUARDO FARINARO, MD, SALVATORE PANICO, MD, MS, DANTE GIUMETTI, MD, ROCCO GALASSO, MD, EGIDIO CELENTANO, MD, MARIO MANCINI, MD, AND MAURIZIO TREVISAN, MD,

MS

The relationship between coffee consumption and blood lipids was analyzed in a sample of 900 male workers of southern Italy participating in the Olivetti Heart Study. In the univariate analysis, coffee drinkers (n = 856) had higher values for body mass index (P 5 0.05) and number of cigarettes smoked per day (P I O.OOl),and lower levels of serum high-density-lipoprotein cholesterol @’5 0.0.5), compared to noncoffee drinkers (n = 44). In addition, coffee consumption (cups/d) was positively related to serum triglyceride levels (r = 0.105, P I 0.01) and cigarette smoking (r = 0.491, P 5 0.01), and was inversely related to age (r = -0.122, P I 0.01). After multivariate adjustment, coffee consumption remained significantly related to age, cigarette smoking, and body mass index (data not shown). After stratification for smoking status, a significant positive linear trend between coffee consumption and serum total cholesterol was observed only in smokers. No significant trend was observed for serum triglycerides and high-density-lipoprotein cholesterol with coffee intake according to smoking status. This finding suggests that the relationship between coffee consumption and serum total cholesterol may change with the smoking status. Ann Epidemiol 1993; 3:250-255. KEY WORDS:

Coffee

consumption,

serum total cholesterol, serum triglycerides, cigarette

smoking.

This study analyzed the relationship between coffee con-

INTRODUCTION Epidemiologic

studies have suggested a relation

coffee consumption cently,

investigators

relationship

and coronary

between

heart disease (1, 2). Re-

have focused their attention

between coffee and a number

on the

of risk factors

sumption and blood lipids in a sample of healthy workers of southern Italy consuming “espresso” coffee, which differs from boiled, filtered, or percolated coffee in caffeine content and in brewing methods.

for coronary heart disease, (e.g., serum lipids (3) and blood pressure (4, 5)), in order to define a possible mechanism this association.

The relationship

tion and serum total cholesterol cross-sectional

for

between coffee consumphas been evaluated in 22

studies carried out in eight different coun-

tries (see the article by Thelle and coworkers (3) for review); the findings were somewhat

conflicting.

It has been sug-

gested that this association may be related to the clustering of atherogenic

behaviors

in coffee drinkers

noncoffee drinkers (6- 1 I), components

compared

to

of coffee other than

caffeine (since tea or cola drinks do not have the same effect) (9, 12, 13), or particular

methods

of brewing

(14-17).

MATERIALS

AND

METHODS

The Olivetti Heart Study is a longitudinal risk factors for atherosclerosis,

Factory in Naples, Italy (18). The baseline examination

on was

conducted in 1975 to 1976; the 5-year and 12-year follow-up examinations

were carried out in 1980 to 1981 and 1987 to

1988, respectively. At each examination, invited to participate, previous examinations.

all employees were

regardless of their participation

in

At the 1987 to 1988 examination

a total of 990 workers (942 males and 48 females) agreed to participate in the study, a participation

From the Department of Social and Preventive Medicine, State University of New York at Buffalo, Buffalo, NY (F. J., V. K., M. J.), and the Institute of Internal Medicine and Metabolic Diseases, University of Naples, Medical School, Naples, Italy (F. J., V. K., E. F., S. P., D. G., R. G., E. C., M. M., M. T.). Address reprint requests to: Fabrizio Jossa, MD, Department of Social and Preventive Medicine, State University of New York at Buffalo, 270 Farber Hall, Buffalo, NY 14214. Received January 28, 1992; revised August 26, 1992.

investigation

carried out at the Olivetti

rate of 80%. Because

of the small number, females were excluded from the present analysis. The data reported here were collected in the 1987 survey. The participants

were seen in the morning,

in the

medical facilities of the factory, after an overnight fast. The medical examination included (a) systolic and diastolic blood pressure measurements, electrocardiogram,

(b) a 12-lead standard resting

(c) anthropometric

measurements,

and

1047.2797/93/$06.00

AEP Vol. 3, No. 3 Mav 1993: 250-255

COFFEE

TABLE 1. Baseline characteristics

of 900 male workers in southern

Italy (mean f standard

Age (Y)

46.9

Body mass index serum

(kg/m2)

cholesterol

(mg/dL)

Low-density-lipoprotein Serum

cholesterol

triglycerid&

High-density-lipoprotein Alcohol

(mL/wk)

consumption

Cigarette

smoking

Prevalence

+ 7.5

(mg/dL)

46.9

? 7.4

47.7 f

9.8

26.4 2 3.1

25.3 f

2.7

148.0

+ 31.7

168.4 2 31.8

139.9 -r- 30.0

149.8 2 89.2

140.8 f

264.7

f

89.6 11.5

? 332.1

(cigarettes/d)

10.7 2 11.3

(96)

21

to gather

information

quality

balance

scale with participants

cilip) for HDL-C.

clothing.

Body mass index

shoeless (kg/m’)

and wearing

was calculated.

were performed protocol

by trained

described

Methods

indoor

by the

of the World

Manual Health

for Orga-

Coffee

consumption

was

the habitual

assessed

number

by

one

consumption

to evaluate

previous

variable

because

was ascertained

the amount

week and was also analyzed

was calculated

according

= 11% ethanol

volume, concerning

= 30% ethanol

the number

of cigarettes

described

cular ResearchSurvey Smoking

beer

was measured

tion of serum cholesterol

were both determined

2 1). High-density-lipoprotein acid

All biochemical

for Cardiovas-

Organization

variable

by enzymatic

- HDL-C

measurements

(19).

Serum

total

(TG) concen-

statistics matrix.

out to calculate cholesterol Multiple N-l

of the relationship

the adjusted

and

among

variables

standard

of covariance mean

to coffee

data were obtained

dummy

heart disease risk

(mean Analysis

according

comparisons

values

of

consumption

the different

cate-

using regression

(23). Multiple

linear

regression analysis was performed to evaluate linear between LDL-C and coffee consumption (cups/d).

trend

(20,

Table

1 summarizes

whole

sample

chloride-phosphomethods

separately. (22).

was calculated

the

and coffee

These

southern

baseline drinkers

for the drinkers

men were characterized

by a high weekly alcohol consumption and a high prevalence of both smokers (56%) and coffee drinkers (95%). The

noncoffee under

characteristics and noncoffee

Italian

coffee drinkers had significantly index and number of cigarettes

- (TG/5) performed

RESULTS

was ana-

procedures

(HDL-C)

enzymatic

were

after

(cigarettes/d).

variables.

triglycerides

and

descriptive

serum

with

was collected

and coronary

was carried

analysis

for

intake),

for determina-

Low-density-lipoprotein cholesterol (LDL-C) according to the following formula: CHOL

per day accord-

were available

for the assessment

and correlation

total

data

available

values for alcohol

on this parameter

methods

included

deviation)

this report

of missing

not being

consumption

coffee consumption

factors

analysis,

in any of

of the study.

gories for the adjusted

of magnesium

precipitation

Statistical between

for 939 of

data

The majority

(5 1 were missing

categories.

cholesterol

lyzed by a combination

by

in the present

on alcohol

and 5.9 (Pre-

available

of missing

lipid determinations

information

of variation for cholesterol,

for TG,

were

Because

considered

by a set of questions

by venipuncture

and serum

table:

1.65 (Precipat)

consumption

by volume. smoked

lipid levels and other

(CHOL)

of ethanol

conversion

of the World Health

was drawn

vari-

= 3.5% ethanol

by the Manual

was used as a continuous

Blood sample

dein the

as a continuous

to the following

smoking

ing to the protocol

consumed

consumption

by volume,

and liquor

Cigarette

by questions

of alcohol

Coefficients

1.65 (Precipat)

on 900 participants.

(n = 30). Data

The weekly absolute

tungstic

focuses

849 participants

able (mL/wk).

trations

the variables

the beginning

Alcohol

wine

on coffee

question

as a continuous

and

the 942 male workers.

of cups of coffee consumed

(cups/d).

procedure:

and

was due to serum

per day and was used in the analysis

signed

control

2.15 (Precinorm) Data

physicians

(19).

concerning

199.3 + 275.7

1.6 3.0 + 6.9d

1.84 (Precinorm)

nization

* 334.7

(SI) = mg/dL x 0.02586. (si) = mg/dL x 0.01129. vs. coffee drinkers. vs. coffee drinkers.

questionnaire

Survey

97.6

47.4 & 12.2’

58

strict

Cardiovascular

+ 36.7

11.1 + 11.4

were

to the

211.3

11.5

3.0 ?

56

(d) a self-administered

according

?

268.3

on life-style characteristics and personal and family history. In detail, weight and height were measured on a beam

All measurements

+ 41.3

43.4

3.0 + 1.6

’ Standard International Units ’ Standard International Units ’P < 0.05, noncoffee drinkers ’ P < 0.001, noncoffee drinkers

drinkers

(n = 44)

221.8

(cups/d)

of smokers

Noncoffee

+ 41.2

43.6

(n = 849)

drinkers

221.3

149.3 t

cholesterol

consumption

Coffee

(mg/dL)”

(mg/dL)

the Olivetti Heart Study

(n = 856)

26.3 ? 3.1

251

Jossa et al. SERUM LIPIDS

AND

deviation):

Coffee

All (N = 900)

Variables

Total

CONSUMPTION

drinkers,

in the coffee drinkers

while

higher levels of body mass smoked per day than did

HDL-C

compared

was significantly

to the noncoffee

lower drinkers.

252

Jossaet al. COFFEE CONSUMFTON

AEP Vol. 3, No. 3 May 1993: 250-255

AND SERUM LIF’IDS

TABLE 2. Correlation matrix: coffee consumption, lioids: the Olivetti Heart StudP

body mass index, age, cigarette smoking, alcohol intake, and serum

Body coffee Coffee consumption

Age

mass index

Smoking

0.12lb -0.050 0.043 0.12Ob 0.052 0.011 0.143b

-O.lOlb -0.021 0.142b 0.239b -0.162b 0.092‘

0.047 0.019 0.107b -0.226b 0.048

Alcohol (n = 859)

Cholesterol

High-densitylipoprotein cholesterol

Triglycerides

(cups/d)

Age (Y) Body mass index (kg/m’) Cigarette smoking (cigarettes/d) Alcohol intake (mL/wk) (n = 849) Serum total cholesterol (mg/dL) Serum triglyceridesb (mg/dL) High-density-lipoprotein cholesterol (mg/dL) Low-density-lipoprotein cholesterol (mg/dL)

-0.122b 0.031 0.491b 0.032 0.060 0.105b -0.152b 0.073

0.024 - 0.020 0.141b

0.007

0.40FJb 0.063 0.910b

-0.344b 0.158”

-0.066

”N = 900 unless otherwise indicated. b P I 0.01. r P _c 0.05.

Table 2 reports the correlation matrix for coffee consumption (cups/d) and other coronary heart disease risk factors. Coffee intake (cups/d) was significantly and positively related with number of cigarettes smoked per day and TG level, while it was inversely associated with age and HDL-C level. Serum total cholesterol and TG concentrations were both positively related to body mass index, while TG correlated positively with cigarette smoking and negatively with HDL-C; HDL-C was inversely related to cigarette smoking and body mass index and positively related with alcohol intake. In addition, LDL-C was positively related with age, body mass index, cholesterol, and TG. A significant positive interaction was detected between coffee use (yes/no) and smoking (yes/no) with regard to total serum cholesterol but not TG or HDL-C (data not shown). Therefore, the association between total serum cholesterol and coffee consumption was analyzed separately in smokers and nonsmokers. Table 3 reports the outcome of the multiple regression analysis for LDL-C after stratification for smoking status: Coffee consumption was an independent positive correlate of LDL-C only in smokers. Age was positively and significantly related to LDL-C both in smokers and nonsmokers. As indicated by the regression coefficient in Table 3, one additional cup of coffee was associtaed with an increase in LDL-C levels of 2.01 mg/dL in smokers and of 1.17 mg/ dL in nonsmokers. In the sample as a whole, in a multiple regression analysis including age, body mass index, and cigarette smoking, the relationship between coffee and either serum TG or HDL-C failed to reach statistical significance (data not shown). Tables 4,5, and 6 show the adjusted (age and body mass index) mean values for cholesterol, HDLC, and TG in the different categories of coffee consumption for the whole sample and in smokers and nonsmokers separately. The analysis of covariance indicated an overall significant difference for the average LDL-C level in the various catego-

ries of coffee intake (cups/d) in only the smokers. After participants who smoke but do not drink coffee (n = 9) were excluded, the observed difference was still significant (data not shown). No significant association was detected for coffee and LDL-C in nonsmokers and in the sample as a whole. A decrease in the serum concentration of HDL-C (see Table 5) and an increase in TG (see Table 6) were detectable across coffee categories in smokers, and in the group as a whole, even though in both cases the results of analysis of covariance did not indicate statistical significance. The inclusion of alcohol consumption as a covariate in the model did not change the results (data not shown).

DISCUSSION The relationship between coffee consumption and serum lipids has been investigated in a number of cross-sectional, longitudinal, and experimental studies, with conflicting results (3, 24-32). In a review of 22 cross-sectional studies (3), ten showed a significant positive relationship between coffee and serum total cholesterol in both sexes, while in the remaining 12 TABLE 3. Multiple linear regression coefficients for LDL-C in smokers and nonsmokers: the Olivetti Heart Study Dependent

variable

LDL-C

(mg/dL) Smokers (n = 504) Independent

variables

Coffee consumption

(cups/d)

Age (~1 Body mass index (kg/m*) RI

Nonsmokers (n = 396)

B

SE

B

SE

2.012” 0.4574 0.687”

1.068 0.233 0.667

0.175 0.632” 0.679

1.115 0.190 0.498

0.02

0.04

n P I 0.05. SE = standard error of B; LDL-C = low-density-lipoprotein cholesterol.

AEP Vol. 3, No. 3 May 1993: 250-255

COFFEE CONSUMPnON

Coffee categories (cups/d) 0 l-2 3-4 5+

LDL-C (mg/dL)

n 44 296 417 143

F (overall)

140.0 146.7 148.5 153.4

Smokers (n = 504)

Nonsmokers (n = 396) LDL-C (mg/dL)

n 35 195 143 23

2.414

143.3 146.8 148.5 147.2

LDL-C n

(mg/dL)

9 101 274 120

0.311

124.6 145.3b 148.21‘ 153.0 2.983’

studies the evidence for a link was less consistent. For example, in the Tromso Heart Study (24) coffee consumption was positively associated with cholesterol and TG levels in both sexes and was inversely associated with HDL-C in females, while in the Tecumseh Study (25) an association was reported only in women. In a cross-sectional study of nearly 5000 Australians, Shirlow and Mathers (26) reported that caffeine consumption was significantly associated with cholesterol levels only in females, while use of caffeinated coffee, but not total caffeine consumption, was positively related to cholesterol levels in males. Kark and colleagues (27) reported a positive association of coffee drinking (but not tea) with cholesterol in both sexes in Jerusalem. A recent report from the Health Professional Follow-up Study detected an increase in cholesterol levels with increasing consumption of decaffeinated coffee but not regular coffee (28). Finally, no significant relationship between coffee consumption and cholesterol has been found in the Framingham Study (29), the National Health and Nutrition Examination Survey (30), and the Western Electric Study (31). Lack of association in the present study, after multivariate adjustment, between coffee and TG and HDL-C is consistent with most of the findings of previous reports (see the article by Thelle and coauthors (3) for review). The TABLE 5. Adjuste& mean values of HDL-C by coffee consumption categories: the Olivetti Heart Study

Coffee categories (cups/d) 0 l-2 3-4 5+ F (overall)

n 44 296 417 143

HDL-C (mg/dL) 47.3 46.0 46.4 45.6 1.527

Nonsmokers (n = 396)

n 35 195 143 23

’Adjusted for age and body mass index. HDLC = high-density-lipoprotein cholesterol.

All (N = 900) Coffee categories (cups/d) 0 l-2 3-4 5+ F (overall)

n 44 296 417 143

TG (mg/dL) 140.8 139.1 151.2 156.0 1.677

Nonsmokers (n = 396)

n 35 195 143 23

TG (mg/dL) 138.5 134.3 142.2 131.3 1.591

Smokers (n = 504) TG n 9 101 274 120

(mg/dL) 124.8 139.2 158.0 158.6 2.456

’Adjusted for age and body mass index TG = triglycerides.

’Adjusted for age and body mass index. b P < 0.01. c P < 0.05. LDL-C = low-density-lipoprotein cholesterol.

All (N = 900)

253

TABLE 6. Adjusted” mean values of serum TG by coffee consumption categories: the Olivetti Heart Study

TABLE 4. Adjusteh mean values of LDL-C by coffee consumption categories: the Olivetti Heart Study All (N = 900)

Jossaet al. AND SERUM LIPIDS

HDL-C (mg/dL) 48.3 47.5 45.9 50.0 1.277

Smokers (n = 504) HDL-C n 9 101 274 120

(mg/dL) 43.7 44.0 41.0 40.9 2.254

results of the studies on the relationship of coffee consumption with coronary heart disease are contradictory as well. Several studies suggested that excessive coffee drinking is associated with an increased risk of coronary heart disease, but many others failed to show such an association (see earlier publications (1, 2) for reviews). Case-control and cross-sectional studies more often showed a positive association, while longitudinal studies generally did not support this finding (1, 2). The discrepancies on the association between coffee and cholesterol among studies have been postulated to be due to (a) the inaccurate measurement of coffee and caffeine intake (32), (b) differences in brewing methods (14-17), and/or (c) the possible role of confounding variables (33). With regard to the brewing methods, some investigators speculated that boiled or percolated coffee contains a lipid-raising factor which is removed by filtering (14-17). Therefore consumption of filtered coffee should not be associated with an increase in cholesterol. However, in contrast with this hypothesis, Pietinen and coworkers (34) reported in a Belgian study with approximately 18,000 participants, that consumption of filtered coffee was associated with increased cholesterol levels. The present study has a number of differences compared to previous studies that need to be emphasized. First, Italians drink “espresso” coffee, the grinding procedure and brewing method for which differs from those for boiled, filtered, or percolated coffee. Espresso is brewed in machines in which hot water under forced steam passes in a short time through darkly roasted, finely ground coffee beans. Compared to boiled and percolated coffee, brewed by a prolonged contact between coffee beans and hot water, espresso is characterized by a very short period of contact between water and the coffee grounds. Second, a demitasse of espresso (approximately 30 to 50 mL) contains on average 50 to 70 mg of caffeine (35), while the amount of caffeine@ a cup of boiled, filtered, or percolated coffee (approximately 150 to 200 mL) is much higher (100 to 150 mg) (36). Third, Italians drink their coffee black so that cream or milk consumption with coffee, hypothesized to be responsi-

254

Jossaet al. COFFEE

CONSUMPTION

AEP Vol. 3, No. 3 May 1993: 250-255

AND SERUM LIPIDS

ble for the increased cholesterol levels among coffee drinkers in other countries (37), does not apply to our population. Finally, diet and health behaviors

are different in our

sample compared to those observed in studies from northern European

and North

clude differences sumption,

American

countries

(38). These in-

in diet, cigarette smoking,

alcohol con-

and their intercorrelations.

Since both cigarette smoking and coffee consumption are life habits strongly related in the general population, their possible interactive effect on cholesterol may have important public health implications in the prevention of coronary heart disease. Further

studies are needed to confirm

this finding and to detect the responsible

components

in-

volved.

Despite these differences, we detected a positive relationship between coffee consumption terol and LDL-C

and serum total choles-

but only in smokers.

Dr. Trevisan

Our results support the previous findings of Heyden and associates (39), who found that LDL-C cantly higher and HDL-C significantly) County

levels were signifi-

levels were lower (although

in 361 smoking

participants

Study who consumed

not

of the Evans

five or more cups of coffee

per day compared to nonsmokers

tween smoking and coffee among 2033 Australian

found a significant positive

between coffee and cholesterol

not in nonsmokers,

after controlling

in smokers but

for a number of con-

founders (age, body mass index, alcohol consumption,

and

dietary fats). The observed interactive tween coffee consumption

effect suggests a synergism be-

and cigarette smoking on choles-

terol levels, although neither the pharmacologically agents in cigarette mechanisms

have been elucidated. As experimental

have shown (41, 42), the only established

metabolic

of cigarette smoking and coffee consumption in free fatty acid and TG concentrations

studies effect

is an increase through

release. (In addition,

gested that coffee contains the excretion

active

smoke or coffee nor their physiologic

crease in catecholamine

an in-

Bjelke sug-

components

that may reduce

of bile acids and neutral

sterols, therefore

increasing serum total cholesterol

levels and reducing the

risk factor for colon cancer (43).) It has also been questioned the components

responsible

whether caffeine is one of

for the observed

association

between coffee and cholesterol (12-14, 27, 28,41,44). Two trials found that decaffeinated coffee increased cholesterol levels (28,45)

and a number of studies reported no associa-

tion of cholesterol with caffeinated beverages different from coffee (12, 13, 27). A number of studies reported that the positive association between coffee and cholesterol could be related to the clustering of atherogenic behaviors in coffee drinkers compared to noncoffee drinkers (9, 11, 13): for instance, drinkers may have a more atherogenic

coffee

diet compared

to

noncoffee drinkers. Dietary data are not available in the present study, but a cross-sectional observation carried out in Italy (40) detected a significant association between coffee and cholesterol

after controlling

of a Research

was funded

Heart,

Career

Lung,

in part by a grant from NATO

Development

and Blood

Award

Institute.

for International

(K04

The study

Collaboration

in Research. We would Company,

like to acknowledge

with special thanks

and Ms. Ida Bartolomei

(head

the support

to Dr. Antonio nurse)

received

from the Olivetti

Scottoni

(medical

of the Olivetti

Factory

director)

in Naples.

be-

females

but not in 2724 males. Panic0 and coworkers (40), in the Italian Nine Community Study, a multicenter investigation association

is a recipient

from the National

who did not drink coffee.

Shirlow and Mathers (26) detected a similar interaction

of risk factors for atherosclerosis,

HL02189)

for dietary fats.

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