Cardiovascular risk factors in women.

Rates of CHD have been shown to be considerably higher in men than women in all countries where reliable prevalence data are available, including those countries with low rates of the disease, such as Japan (World Health Organization, 1989). In the UK, for women at any given age, the death rate for CHD is approximately equivalent to that seen in men 10 years earlier (Fig. 1). This earlier presentation in men means that CHD often occurs during a man’s active middle years, with consequently greater social and economic impact on individuals and their families. These differences in age at occurrence have almost certainly contributed to the perception that CHD is a disease of men and one to which women are relatively resistant. Whilst it is certainly true that being female confers some protection against CHD, it is also true that CHD is a major cause of death in women, responsible for 23% of all female mortality and the major cause of premature death in women less than 60 years old (Office of Population Censuses and Surveys, 1993). It is also well established that women who suffer a myocardial infarct (MI) have a poorer prognosis than men. In the Framingham study, the 12-month mortality after MI was 45% for women and 20% for men (Kannel et al. 1979). This could be related to their greater age at occurrence or to the greater prevalence of factors such as diabetes or hypertension in women compared with men. It has also been shown that following an MI, women are less likely to be offered intensive drug and surgical therapy. Others have suggested that the later occurrence and greater severity at first MI in women are due to differences in the biological processes involved (Walsh & Grady, 1995) and, for this reason, the assumption that cardiovascular risk factors are the same in men and women may be incorrect (Hulley et al. 1992). This question is difficult to address because much of the research into the causes, prevention and treatment of the disease has been conducted only in men and provides an inadequate basis for discriminating gender-specific risk factors in CHD.