Hormones and Calcium Metabolism 



229 



Albright subsequently extended his concept to embrace both the male and female 

 sex hormones. He pointed out, that osteoporosis was a feature of ovarian agenesis, 

 which may be true (Turner, 1938), but claimed that it was also a feature of 

 eunuchoidism, which is open to some doubt (Labhart and Courvoisier, 1950). Since 

 that time, the concept that the gonadal hormones play a part in the pathogenesis of 

 osteoporosis has been questioned by many people and the present position is confusing 

 to say the least. 



There is no doubt that the oestrogenic hormones affect calcium metabolism. Dis- 

 regarding their highly specific effects in birds and mice, which have no counterpart in 

 other species, there is convincing evidence that they inhibit the resorption of meta- 

 physeal bone in rats (Lindquist et al., 1960). In humans, there can be no doubt that 

 a fall in bone volume occurs soon after the menopause in women and that a similar 

 though less marked change occurs after the age of 50 in males. We (Nordin et al., 

 in press) have found a fall in spinal density and metacarpal cortical thickness in 

 women 5 to 10 years after the menopause and (like other workers in the field) we 

 have seen several cases of osteoporosis following an artificial menopause. Moreover, 

 the development of osteoporosis in the iliac crest starts at the age of about 50 (Beck 

 and Nordin, 1960) particularly in women (Saville, 1962). On a recent visit to 

 Africa, India, Japan, Cen- 

 tral America and other coun- 

 tries, I observed that spinal 

 osteoporosis did not appear 

 in any part of the world 

 before middle age in either 

 males or females after which 

 there was a sharp rise in in- 

 cidence in women and a less 

 marked rise in men (Fig. 3). 

 It is true that Donaldson 

 and Nassim (1954) found 

 no relation between osteo- 

 porosis and artificial meno- 

 pause but if one takes all the 



facts mto account it appears probable that reduced sex hormone activity play some part, 

 directly or indirectly, in the development of osteoporosis in women and possibly in men. 



When it comes to considering the mechanism of action of sex hormones on calcium 

 metabolism in man, one finds that the effect of the oestrogens is better established 

 than that of the androgens. Thus the balance data of Albright and Reifenstein 

 (1948) repeatedly demonstrate a fall in urinary calcium on the administration of 

 oestrogenic hormones to cases of osteoporosis, although the changes in feacal calcium 

 are less convincing. Ackerman et al. (1954) observed a slight fall in urinary cal- 

 cium in elderly women given oestrogens when in negative calcium balance. Henne- 

 MAN and Wallach (1957) found that oestrogen therapy had improved the calcium 

 balance in 13 out of 15 published cases. However, the only large changes in balance 

 were those reported by Anderson (1950). The most convincing data are those of 

 Shorr (1945) who showed that oestradiol benzoate lowered urinary calcium and 

 raised urinary citrate, an observation which we have recently confirmed (Fig. 4). 



percentages ot osteoporotic films among 373 male and 

 mbar spine X-rays examined in United Kingdom, India, 

 Japan, United States and Finland 



