[Cardiovascular risk factors and prevention in women: similarities and differences].
Epidemiological evidence shows that among women, the incidence of all, including less severe, coronary events is still increasing. However, owing both to diminished lethality as well as the reduction in the rate of acute myocardial infarction, mortality has globally decreased. The strong association observed between mortality and major cardiovascular risk factors as well as between their temporal changes and the occurrence of coronary disease makes the undertaking of multifactorial prevention strategies, including the formulation of risk charts for asymptomatic women and men, necessary. The different "penetrance" of risk factors in women, together with their interaction with female hormones, plays an important role in the development of cardiovascular disease. The excess risk of cigarette smoking is 2-4 times higher in women than in men and the correlation with the number of cigarettes smoked daily is distinct. However, the risk starts to decrease immediately after stopping and after 3-5 years is similar to that of non-smokers. In women, the association between hypertension, coronary artery disease and early mortality is stronger than in men: there is no threshold below which the risk disappears. Diet and lifestyle strongly influence the development of hypertension. For this reason, the American Heart Association/American College of Cardiology guidelines recommend adherence to a set of dietary and lifestyle habits including body weight control and physical activity. In particular, diet may modify the "penetrance" of risk factors in women: hence excess intake of saturated fatty acids associated with decreased cereals, fruit and vegetables does not only alter the lipid profile but also increases the risk of coronary disease. An elevated total/HDL cholesterol ratio and the presence of lipoprotein(a) constitute significant risk factors for coronary events. On the other hand, high HDL cholesterol levels (> 45 mg/dl) are considered to be protective in women. However, data on the efficacy of strategies aimed at reducing blood LDL levels in hypercholesterolemic women are limited and controversial. Pharmacological therapy is recommended in women with primary familial hypercholesterolemia and during menopause when the patient presents with two or more risk factors. Besides, pharmacological therapy is also indicated for women with a history of coronary artery disease in whom benefits exceed those observed in male patients with a similar clinical picture. In diabetic women, the risk of coronary mortality is increased 3 to 7-fold compared to the 2 to 3-fold increase observed in diabetic men. Diabetes definitely increases the effects of the other risk factors and modifies the protective effect by estrogens. However, to date, there is no evidence that keeping glucose levels within normal limits reduces the risk of coronary artery disease nor has a glycemic threshold capable of predicting mortality risk in diabetic women been established. For this reason, guidelines for such patients are aimed at keeping the other risk factors under strict control in order to significantly reduce their effect. Obesity results in a series of metabolic alterations that increase the risk of cardiovascular disease in both sexes. Although most, if not all, data confirm that obesity alone is not of predictive value, central obesity constitutes a risk factor for cardiovascular disease. A body mass index < 24.9 kg/m2 and a waist circumference < 80 cm are recommended so as to decrease the likelihood of developing a menopausal insulin-resistance syndrome. It has been demonstrated that in men, a sedentary lifestyle is correlated with a higher cardiovascular and all-cause mortality; some recent observational studies suggest a 25-30% decrease in the mortality risk for women who perform physical exercise. Current guidelines recommend at least 30 min daily of dynamic moderately vigorous activity, including brisk walking. Rather than to the reduction in the serum levels of endogenous estrogens, the increase in the incidence of disease and of mortality following menopause should be attributed to the age-related modifications in risk factors which result in an increased risk of coronary artery disease. In spite of the proved detrimental effect of estrogen deficiency on LDL- and HDL-cholesterol, on arterial smooth muscle cell proliferation and on insulin secretion and in spite of the data of numerous observational studies and of the HERS trial (all, however, with methodological limitations), clinical evidence does not justify widespread estrogen prescription, not even for purposes of secondary prevention. Besides, the dosages and the route of administration are still subject of debate. (ABSTRACT TRUNCATED)
Unità Operativa di Cardiologia, USL Regione Valle d'Aosta, Ospedale Mauriziano, IRCC, Torino.
M
M
Sclavo
D002318:Cardiovascular Diseases / Q000453:epidemiology* / Q000517:prevention & control*; D005260:Female; D006801:Humans; D008297:Male; D012307:Risk Factors; D012737:Sex Factors