Background: The independent effect of early life circumstances on adult cardiovascular risk is still unresolved. We assessed the associations of father's social class with cardiovascular risk factors and with risk of ischaemic heart disease and stroke in adult life.
Methods: We did a longitudinal study of cardiovascular disease in 5934 men aged 40-59 years at enrollment. A cross-sectional measurement survey was done between 1978 and 1980 and a follow-up questionnaire was completed in 1992. The main endpoints were non-fatal myocardial infarction and stroke based on general practitioners' reports obtained between screening and 1992 and on recall of physician-diagnosed ischaemic heart disease in the 1992 questionnaire.
Findings: Father's social class was strongly associated with social class in adulthood (fathers' occupation was manual for 41.3% of professionals [I] vs 89.1% for unskilled manual workers [V]) and was significantly related to height (non-manual vs manual 175.4 cm [SE 0.2] vs 172.9 cm [0.1], p < 0.0001) and obesity (213 [14.1%] vs 804 [20.1%], p < 0.0001) irrespective of adult social class; no association was found with blood glucose (log, 1.69 [0.005] vs 1.70 [0.003], p = 0.22) or cholesterol (6.34 [0.03] vs 6.29 mmol/L [0.02], p = 0.16. Men whose fathers' social class was manual had significantly higher rates of non-fatal myocardial infarction (342/4006 vs 92/1510) and self-reported physician-diagnosed ischaemic heart disease (686/4006 vs 192/1510) than men whose fathers' social class was non-manual, even after adjustment for adult social class and other established risk factors (relative odds 1.3 [95% Cl 1.0-1.7], p < 0.05 and 1.3 [1.1-1.6], p < 0.01, respectively). The influence of father's social class on non-fatal myocardial infarction and ischaemic heart disease was only seen in men whose adult social class was non-manual. No association was seen between father's social class and non-fatal stroke.
Interpretation: Father's social class is strongly associated with adult social class. The higher risk of non-fatal myocardial infarction and self-reported physician-diagnosed ischaemic heart disease seen in men whose father's social class was manual suggests that socioeconomic status early in life has some persisting influence on ischaemic heart disease risk in adult life.