In acromegaly, increased bone mineral density (BMD) is determined by GH-excess, gonadal function and gender.
OBJECTIVE
The aim of our study was to evaluate bone metabolism and bone mineral density (BMD), and to indicate the main determinants of these parameters in a large group of patients with active acromegaly.


METHODS
A group of 121 active acromegalics, aged 23-80 years, from a single endocrinological center was studied. Serum GH, IGF-I, LH, FSH, PRL, estradiol/testosterone, osteocalcin (OC), type I collagen carboxyterminal telopeptide (ICTP) as well as BMD by DXA at spine L2-L4, femoral neck, Ward's triangle and trochanter were measured.


RESULTS
Serum OC and ICTP concentrations were elevated (mean+/-SEM: 31.7+/-2.2 microg/L, p<0.001; 7.3+/-0.5 microg/L, p<0.001, respectively), and positively correlated with each other, as well as with IGF-I. BMD (Z-scores) was increased at L2-L4, femoral neck and trochanter (0.35+/-0.15, p=0.016; 0.60+/-0.11, p<0.001 and 0.59+/-0.13, p<0.001; respectively). The main determinants of Z-scores and ICTP were gonadal status and gender, while of OC was IGF-I. Eugonadal acromegalics had higher than normal serum OC and ICTP, as well as Z-scores at all measured sites. Hypogonadal patients (2/3 of the population) had significantly higher serum ICTP concentrations and lower BMD at all sites, when compared to eugonadal acromegalics. Thirty five percent of hypogonadal subjects had T-score<-1. Men had significantly higher serum ICTP and lower Z-scores than women.


CONCLUSIONS
(i) In active acromegaly, enhanced IGF-I-dependent bone turnover and increased BMD is observed. (ii) In hypogonadal acromegalics, high bone resorption decreases BMD and may lead to osteoporosis. (iii) There is a smaller increase in bone resorption and greater increase in BMD in women with acromegaly than in men.
Zgliczynski
Wojciech
W
Department of Endocrinology, Centre for Postgraduate Medical Education, Warsaw, Poland.
Kochman
Magdalena
M
Misiorowski
Waldemar
W
Zdunowski
Piotr
P
D000172:Acromegaly / Q000097:blood* / Q000150:complications; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015519:Bone Density / Q000502:physiology*; D001862:Bone Resorption / Q000097:blood / Q000209:etiology* / Q000503:physiopathology; D004958:Estradiol / Q000097:blood; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D019382:Human Growth Hormone / Q000097:blood*; D006801:Humans; D007006:Hypogonadism / Q000097:blood* / Q000150:complications; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D008875:Middle Aged; D015675:Osteocalcin / Q000097:blood; D017698:Postmenopause / Q000378:metabolism; D011388:Prolactin / Q000097:blood; D012737:Sex Factors; D018709:Statistics, Nonparametric; D013739:Testosterone / Q000097:blood
D015675:Osteocalcin; D019382:Human Growth Hormone; D013739:Testosterone; D004958:Estradiol; D007334:Insulin-Like Growth Factor I; D011388:Prolactin; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone