Incidence of myocardial infarction in women. A cohort study of risk factors and modifiers of effect.
OBJECTIVE
To assess whether the increased incidence of myocardial infarction and death associated with smoking, hypertension, hyperlipidaemia and diabetes varies significantly between groups defined in terms of occupation, education and marital status.


METHODS
Malmö, Sweden.


METHODS
9351 women, aged 28-55, with a mean follow up of 10.7 years.


RESULTS
Smoking, hypertension (> or = 160/95 mm Hg or treatment), hyperlipidaemia (cholesterol > or = 6.5 mmol/l or triglycerides > or = 2.3 mmol/l), diabetes, low occupation and education levels were significantly more common among women who experienced a fatal or nonfatal myocardial infarction during the follow up (n = 104) than in other women (n = 9247). Exposure to smoking, hypertension and hyperlipidaemia showed substantial differences between groups defined in terms of education, occupation and marital status. The association between low occupation and myocardial infarction remained statistically significant after adjustments for several potential confounders (RR = 2.6, 95% CI 1.1, 6.0). Single women had similarly higher adjusted mortality rates than married women (RR = 1.4, 95% CI 1.1, 1.8). When other major risk factors were taken into account, the relative risk for mortality and myocardial infarction associated with smoking was 2.6 (95% CI 2.0, 3.4) and 7.8 (95% CI 4.4, 13.9), respectively.


CONCLUSIONS
In this urban female population, short education and low occupation level were both associated with an increased prevalence of smoking, hypertension, hyperlipidaemia and diabetes. Low occupation level increases the rate of cardiac events caused by exposure to these four risk factors.
Engström
G
G
Department of Community Medicine, Malmö University Hospital, Sweden.
Tydén
P
P
Berglund
G
G
Hansen
O
O
Hedblad
B
B
Janzon
L
L
D000328:Adult; D015331:Cohort Studies; D003920:Diabetes Mellitus / Q000453:epidemiology; D015987:Effect Modifier, Epidemiologic; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006949:Hyperlipidemias / Q000453:epidemiology; D006973:Hypertension / Q000453:epidemiology; D015994:Incidence; D008875:Middle Aged; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000453:epidemiology*; D012044:Regression Analysis; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology; D012923:Social Class; D013548:Sweden / Q000453:epidemiology; D014505:Urban Population