Acta Med Scand 203: 27-30, 1978
The Effect of Smoking on Selected Coronary Heart Disease Risk Factors in Middle-Aged Men Jan Erikssen and Sven Chr. Enger From Medical Department B , Rikshospitalet, Oslo and the Department of Clinical Chemistry, Drammen Hospital, Drammen, Norway
ABSTRACT. Associations between smoking and selected factors supposed to promote coronary heart disease ( 0 ) were studied in 1832 healthy men, 809 of whom were smokers. Triglycerides were 7% higher in smokers; the heaviest smokers had the highest levels. Unfavourable changes were not seen in the other parameters in smokers. There was no trend indicating an influence of smoking on total and HDL cholesterol in the individuals who had abstained from smoking for a few hours just before the examination. Body mass index and weight, blood pressure and resting heart rate were lower in smokers, whereas heart volume, glucose tolerance, thyroid function and ECG findings did not differ significantly in smokers and non-smokers. The present study indicates that smoking promotes the development of CHD independently of the commonly accepted CHD risk factors.
Of the commonly accepted risk factors for coronary heart disease (CHD), smoking is claimed to b e o n e of the most important in promoting premature CHD morbidity and mortality (17). We have previously shown that smoking was strongly associated with impaired lung function and poor physical performance, and possibly also with increased coronary atheromatosis as judged from coronary angiographic findings in presumably healthy middleaged men (8). The present study aims at assessing possible associations between smoking and a selected number of commonly accepted CHD risk factors by examining the CHD-free men in the same study population.
STU D Y POPULATION A N D METH O D S A total of 1832 men without any symptoms or signs of CHD were studied. They participated in a cardiovascular survey at Medical Department B, Rikshospitalet. To obtain a presumably healthy population, individuals were only accepted if the following diseases and disorders were not recorded by the factory health officer or disclosed on arrival for the survery: Known CHD, other known heart disease, hypertension under treatment with drugs, diabetes mellitus, malignancy, disorders of the locomotor system preventing a bicycle exercise test, and miscellaneous diseases (advanced lung disease, renal disease, liver disease, etc .). The survey covered 2014 men aged 40-59 years from five major companies and governmental institutions, 'i.e. 86% of the eligible men. The detailed modes of selection are presented elsewhere (6, 9, 10). Altogether 182 men were excluded from the present study because of latent CHD or chronic chest pain disclosed through the examination program. Although not a random sample, our population is a fairly representative group of healthy, middleaged men. The individuals met at 7.30 a.m. after at least 12 hours' abstinence from smoking and fasting, for an examination program (6) which in all individuals included case history, physical examination, X-ray of heart and lungs, phonocardiography, resting ECG and a near maximal bicycle exercise test with in- and postexercise ECG recordings, serum cholesterol, triglycerides and protein-bound iodine. I.v. glucose tolerance test was performed in all but 42 (7) and HDL cholesterol was assessed in a random subsample of 247 of the 1832 men (5). The individuals were divided into current non-smokers and current smokers and subdivided as never-smokers, previous smokers and individuals smoking 1-9, 10-19 and 220 cigarettes daily, regardless of inhalation habits and years of smoking. Sixty-two pipe or cigar smokers were included as cigarette smokers (1 g tobacco= 1 cigarette). Resting ECG was described paying particular attention Acta Med Scand 203
28
J . Erikssen and S . C . Enger
Table I. CHD risk factors in relation t o smoking habits among I832 presumably healthy middle-aged men i=mean value, S.E.=standard error o f i Current non-smokers ( n = l 023) Parameter
X
Body weight (kg) Body mass index" Systolic BP (mmHg) Diastolic BP (mmHg) Resting heart rate (beatslmin) Absolute heart volume (ml) Relative heart volume (ml/m2BSA) Total cholesterol (mmol/l) Trig1ycerides (mmol/l) HDL cholesterol (mmol/l) (n =247)
77.4 1.006 130.5 87.8 62.1 774 400 6.56 1.40 1.40
Current smokers (n=809) Level of significance
S.E.
X
S.E.
0.3 1 0.0035 0.54 0.32 0.30 4.5 2.0 0.037 0.024 0.030
75.7 0.989 128.6 86.0 60.4 772 402 6.67 1S O 1.37
0.34 0.004 0.60 0.36 0.34 5.0 2.2 0.041 0.027 0.032
~~~~
***
***
*
*** *** NS NS NS
**
NS
NS=not significant (p>0.05), *p
The Effect of Smoking on Selected Coronary Heart Disease Risk Factors in Middle-Aged Men Jan Erikssen and Sven Chr. Enger From Medical Department B , Rikshospitalet, Oslo and the Department of Clinical Chemistry, Drammen Hospital, Drammen, Norway
ABSTRACT. Associations between smoking and selected factors supposed to promote coronary heart disease ( 0 ) were studied in 1832 healthy men, 809 of whom were smokers. Triglycerides were 7% higher in smokers; the heaviest smokers had the highest levels. Unfavourable changes were not seen in the other parameters in smokers. There was no trend indicating an influence of smoking on total and HDL cholesterol in the individuals who had abstained from smoking for a few hours just before the examination. Body mass index and weight, blood pressure and resting heart rate were lower in smokers, whereas heart volume, glucose tolerance, thyroid function and ECG findings did not differ significantly in smokers and non-smokers. The present study indicates that smoking promotes the development of CHD independently of the commonly accepted CHD risk factors.
Of the commonly accepted risk factors for coronary heart disease (CHD), smoking is claimed to b e o n e of the most important in promoting premature CHD morbidity and mortality (17). We have previously shown that smoking was strongly associated with impaired lung function and poor physical performance, and possibly also with increased coronary atheromatosis as judged from coronary angiographic findings in presumably healthy middleaged men (8). The present study aims at assessing possible associations between smoking and a selected number of commonly accepted CHD risk factors by examining the CHD-free men in the same study population.
STU D Y POPULATION A N D METH O D S A total of 1832 men without any symptoms or signs of CHD were studied. They participated in a cardiovascular survey at Medical Department B, Rikshospitalet. To obtain a presumably healthy population, individuals were only accepted if the following diseases and disorders were not recorded by the factory health officer or disclosed on arrival for the survery: Known CHD, other known heart disease, hypertension under treatment with drugs, diabetes mellitus, malignancy, disorders of the locomotor system preventing a bicycle exercise test, and miscellaneous diseases (advanced lung disease, renal disease, liver disease, etc .). The survey covered 2014 men aged 40-59 years from five major companies and governmental institutions, 'i.e. 86% of the eligible men. The detailed modes of selection are presented elsewhere (6, 9, 10). Altogether 182 men were excluded from the present study because of latent CHD or chronic chest pain disclosed through the examination program. Although not a random sample, our population is a fairly representative group of healthy, middleaged men. The individuals met at 7.30 a.m. after at least 12 hours' abstinence from smoking and fasting, for an examination program (6) which in all individuals included case history, physical examination, X-ray of heart and lungs, phonocardiography, resting ECG and a near maximal bicycle exercise test with in- and postexercise ECG recordings, serum cholesterol, triglycerides and protein-bound iodine. I.v. glucose tolerance test was performed in all but 42 (7) and HDL cholesterol was assessed in a random subsample of 247 of the 1832 men (5). The individuals were divided into current non-smokers and current smokers and subdivided as never-smokers, previous smokers and individuals smoking 1-9, 10-19 and 220 cigarettes daily, regardless of inhalation habits and years of smoking. Sixty-two pipe or cigar smokers were included as cigarette smokers (1 g tobacco= 1 cigarette). Resting ECG was described paying particular attention Acta Med Scand 203
28
J . Erikssen and S . C . Enger
Table I. CHD risk factors in relation t o smoking habits among I832 presumably healthy middle-aged men i=mean value, S.E.=standard error o f i Current non-smokers ( n = l 023) Parameter
X
Body weight (kg) Body mass index" Systolic BP (mmHg) Diastolic BP (mmHg) Resting heart rate (beatslmin) Absolute heart volume (ml) Relative heart volume (ml/m2BSA) Total cholesterol (mmol/l) Trig1ycerides (mmol/l) HDL cholesterol (mmol/l) (n =247)
77.4 1.006 130.5 87.8 62.1 774 400 6.56 1.40 1.40
Current smokers (n=809) Level of significance
S.E.
X
S.E.
0.3 1 0.0035 0.54 0.32 0.30 4.5 2.0 0.037 0.024 0.030
75.7 0.989 128.6 86.0 60.4 772 402 6.67 1S O 1.37
0.34 0.004 0.60 0.36 0.34 5.0 2.2 0.041 0.027 0.032
~~~~
***
***
*
*** *** NS NS NS
**
NS
NS=not significant (p>0.05), *p
