Social class and ischaemic heart disease: use of the male:female ratio to identify possible occupational hazards.

In England and Wales there has been an increasing excess of ischaemic heart disease death rates among men and women of social classes IV and V compared with those in classes I and II and this excess is greater in young than in old adults. The male excess over women in IHD death rates is much greater in social classes I and II than in classes IV and V. Although men in professional occupations are at low risk for IHD compared with men in other occupations, women married to professional men are at an even lower risk compared with other women. Also, women married to men in unskilled occupations have relatively higher IHD rates than their husbands. These patterns are not seen for "all causes," cerebrovascular disease, chronic bronchitis, or stomach cancer, where the social class mortality gradients are similar in men and women. There may thus be factors associated with professional occupations that increase the risk of IHD despite the relatively low death rates of men engaged in them. In addition there may be factors operating in women in social classes IV and V that put them at a particularly high risk for the development of IHD.