Dog attacks on children

extensive discussion': supporting the beneficial effects of oestrogen therapy on cardiovascular risk. Whilst he is correct in drawing attention to the fact that many studies "were concluded before the use of additional progestogens became more commonplace",' there is certainly room for some doubt whether the addition of progestogens will neutralise the beneficial effects of oestrogens on atherosclerotic vascular disease.' Experiments in primates suggest that despite an adverse effect on blood lipids, progestogens do not necessarily neutralise the protective effects of oestrogens against atherosclerosis.' There also is growing evidence for beneficial effects of oestrogens at the endothelial level, independent of any effects on blood lipids.' Furthermore, whilst he is correct in pointing out that ·few studies have evaluated hormone replacement therapy (HRn in older women with established osteoporosis, the question of bone mass screening is particularly applicable to women at and around the time of menopause when prophylaxis is the important consideration. Dr Flicker says "the worth of a bone density screening programme hinges on the assumption that the risks and benefits of HRT are almost equal".' As I have indicated the benefits appear to substantially outweigh the risks because of the prevalence of atherosclerotic cardiovascular disease in older women and the reduction of its risk by HRT. The situation regarding breast cancer risk remains unresolved but the current evidence is that if there is any increase in risk, that Increase is small, and occurs predominantly after long-term high dose therapy. Henry G Burger, FRACP, FCP Professor of Medicine, Director Prince Henry's tnstitute of Medical Research 68 Wells Street. South Melbourne. VIC 3205 1. FlickerL. The useof bone massscreeningto preventfractures. Med J Aust 1991, 154: 135-140. 2 Wilson PWF. Garrison RJ, Castelli WP. Postmenopausal estrogen use. ciqarette smoking, and cardiovascular morbidity in women over 50: The Framingham study. N EnglJ Med 1985; 313: 1038-1043. 3. Postmenopausal estrogen use and heart disease [Letters]. N Engl J Med 1986; 315 131-136. 4. Hormone-replacement therapy and heart disease [Letters]. N Engl J Med 1987; 316 1274-1275. 5. Hunt K, Vessey MP, MacPherson K, Coleman M. Longterm surveillance of mortality and cancer incidence in women receiving hormone replacement therapy Br J Obstet Gynaecol 1987; 94: 620-635 6. Adams MR, Clarkson TB, Kontnik DR, Nash HR. Contraceptive steroids -and coronary artery atherosclerosis in cynomolgus macaques. Ferttl Stertl 1987; 47: 1010-1018 Sarrel PM. Ovarian hormones and the circulation Maturitas 1990; 12: 287-298