medical and biological sciences - Collegium Medicum - Uniwersytet ...

46Hanna Styczyńska et al.similar, what suggests that OPG levels gradually increasedas gestational age progressed [18,23]. Thismay be related with the increasing level of estradiolfound during pregnancy. In postmenopausal womena significant, positive relationship between OPG andestradiol was found [24,25], but such a correlation wasnot confirmed in pregnant women [19]. Contrary to theothers [18,19] we found a weak positive correlationbetween OPG and OC but only at the 1 st trimester.We noticed a significant increase in OPG duringpregnancy. It is consistent with previous observationsin women [18,19]. Similarly to earlier findings [18],we observed much higher rise in OPG at the end of 3 rdtrimester with concomitant decline of serum calcium.Data on bone turnover markers during pregnancyare inconsistent. Among bone formation markers bonealkaline phosphatase was shown to rise with gestationalage [10,18,19] whereas osteocalcin did notchange or similarly to N-terminal propeptide of collagentype I showed a biphasic pattern with decreasefrom 1 st to second trimester, followed by increase inthe 3 rd [10,16,18]. We have measured biochemicalmarkers in fasting morning samples only twice, at 1 stand 3 rd trimester and observed the elevation in OCduring pregnancy, especially at 36-37 wks.Bone resorption, reflected by serum CTx, increasedsignificantly during pregnancy with peak levels at theend of 3 rd trimester that confirms data by other authors[5, 10, 11, 19]. This was accompanied by a decreasein serum calcium, especially before the delivery(36-37wks).Serum CTx and OPG seemed to be the only parametersto indicate elevated bone turnover. The nomogramproposed for the Polish premenopausalwomen indicated that serum CTx value over 0,490ng/ml and OC > 34 ng/ml (>95 th percentile) reflect theelevated bone turnover [26]. From our data it may beconcluded that, at least, increrased CTx during 1 sttrimester may be a good predictor for faster bone lossduring pregnancy.Our results confirm that serum OPG and bone turnovermarkers levels increase during pregnancy andclearly show that bone resorption precedes bone formation.In pregnancy many factors known to influence onthe bone mass undergo changes: increased calciumdemand, change in nutritional habits, changes in bodyweight and fat content, changed levels of physicalactivity and hormones with potential to affect bonemetabolism [27]. This may be the main reason fordifficulties in finding the exact role of OPG in relationto bone turnover during pregnancy. While the determinationof osteocalcin at the beginning of pregnancy,seems to be of limited clinical use, measuring OPG asa factor related to bone turnover or a bone resorptionmarker, such as CTx, may have a good predictive valuefor later pregnancy-associated bone loss or osteoporosis.This work was supported by grant BW 17/2002from The Nicolaus Copernicus University in Torun.CopernicusUniversity NICOLAUSCOPERNICUS UNIVERSITY NICOLAUSREFERENCES1. Tudor-Locke C, McColl RS. Factors related to variation inpremenopausal bone mineral status: a health promotionapproach. Osteoporos Int 2000; 11: 1-24.2. Stumpf UC, Kurth AA, Windolf J, Fassbender WJ. Pregnancy-associatedosteoporosis : an underestimated andunderdiagnosed severe disease. A review of two cases inshort- and long-term follow-up. Adv Med Sci 2007; 52:94-97.3. Laktasic-Zerjavic N., Curkovic B., Babic-Naglic D., PotockiK., Prutki M., Soldo-Juresa D.: Transient osteoporosisof the hip in pregnancy. Successful treatment withcalcitonin. Z.Rheumatol 2007, 66, 510-34. Sowers M. Pregnancy and lactation as risk factors forsubsequent bone loss and osteoporosis. J Bone MinerRes1996; 11: 1052-1060.5. Yoon BK, Lee JW, Choi D, Roh CR, Lee JH. Changes inbone markers during pregnancy and puerperium. J KoreanMed Sci 2001; 15: 189-193.6. Kovacs C,Kronenberg M. Maternal-fetal calcium and bonemetabolism during pregnancy, puerperium, and lactation.Endocrine Rev 1997; 18(6): 832-837.7. Kent G, Price R, Gutteridge D, et al. Effect of pregnancyand lactation matrnal bone mass and calcium metabolism.Osteoporos Int 1993; Suppl. 1: 44-47.8. Ensom M, Liu P, Stephenson M. Effect of pregnancy onbone mineral density in healthy women. Obstet Gynecol2002;57(12): 99-111.9. Holmberg-Marttila D, Sievanen H, Tuimala R. Changes inbone mineral density during pregnancy and postpartum:prospective data on five women. Osteoporos Int 1999;10:41-46.10. Hellmeyer L, Ziller V, Anderer G, Ossendorf A, SchmidtS, Hadji P. Biochemical markers of bone turnover duringpregnancy : a longitudinal study. Exp Clin EndocrinolDiabetes 2006, 114:506-510.11. Black AJ, Topping J, Durham B, Farquharson RG, FraserWD. A detailed assessment of alterations in bone turnover,calcium homeostasis, and bone density in normalpregnancy. J Bone Miner Res 2000; 15(3): 557-563.12. Krieger I. Odrowąż-Sypniewska G. Osteoprotegeryna.Ortop Traumatol Rehab 2004; 6(1): 123-129.13.Philips TA, Ni J, Hunt JS. Death-inducing TNF superfamilyligands and receptors are transcribed in human