Total Skeleton is a Useful Tool to Study Bone Mineral Density and Body Composition in Healthy Postmenopausal Women.

A BAGUR; S. MASTAGLIA; M ROYER; B. OLIVERI

Seatle

Congreso; 26th Anual Meeting ASBMR; 2004

Total skeleton (TS) is a useful tool to study simultaneously bone mineral density (BMD) and bodycomposition (BC) in different diseases. Endogenous estradiol (EE2) over 10 pg/ml may play a role in theprotection of BMD in healthy postmenopausal women (PMPW). The aim of this study was to evaluatethe usefulness of TS to distinguish the effect of different EE2 levels on BMD in healthy PMPW, and toanalyze its relationship with BC. Ninety-seven PMPW aged 55 to 75 years were studied. TS wasmeasured by DXA (Lunar Prodigy). Serum calcium, bone alkaline phosphatase (BAP), serum crosslaps(sCTX), E2 (a sensitive assay that detects up to 5 pg/ml), estrone and urine calcium were measured. Thegeneral characteristics of the population were (mean ± DS): weight 65 ± 11 kg, height 1.55 ± 0.05 m,BMI 27 ± 4, TS BMD 0.985 ± 0.18 g/cm2, % fat 40.4 ± 6.3, fat mass 26.5 ± 7.3 kg, lean 37.6 ± 4.5 kg,EE2 10.1 ± 4.9 pg/ml, estrone 20.7 ± 10.2 pg/ml, SHBG 42.5 ± 17 nmol/l, scalcium 9.3 ± 0.5 mg/dl,phosphate 3.6 ± 0.5 mg/dl, BAP 74.7 ± 18.1 UI/L, sCTX 542 ± 254 ng/ml and urine calcium 157 ± 78.3mg/24 hs. The population was divided according to EE2 levels: <10 and ³10 pg/ml. Women with EE2³10 pg/ml had higher BMD and BC values compared with women with EE2 <10 pg/ml: fat mass 28.2 ±7.3 vs 25.1 ± 7.1 kg (p<0.04), lean 38.6 ± 4.8 vs 36.8 ± 4.1 kg (p<0.05), weight 68.4 ± 11.3 vs 63.8 ± 9.8kg (p<0.03), TS BMD 1.028 ± 0.09 vs 0996 ± 0.08 g/cm2 (pns, 0.09) and EE2 14.3 ± 4.5 vs 6.8 ± 1.8pg/ml (p<0.0001). Obese women with BMI values over 30 (n=17) were compared with women with BMIbetween 20 and 30 (n=78). Only two women had BMI values below 20. As expected, obese women hadhigher weight, fat, lean, and BMI values as well as higher EE2 (12.2 ± 6.3 vs 9.7 ± 4.5 pg/ml, p<0.05)and TS BMD (1.030 ± 0.11 vs 1.007 ± 0.09 g/cm2, p<0.02) and lower BAP values (72.8 ± 18.8 vs 83.2 ±17.5, p<0.04) than PMPW with normal weight. No significant data were found with estrone. Thefollowing significant correlations were found: EE2 correlated with weight (r=0.2, p<0.05), fat mass(r=0.2, p<0.03 and estrone (r=0.4, p<0.0001); fat mass correlated with weight (r=0.9, p<0.0001), lean(r=0.5, p<0.001), TS BMD (r=0.4, p<0.0001), calcium (r=-0.2, p<0.03) and SHBG (r=-0.3, p<0.001). Nocorrelations were found with estrone.In conclusion, TS is a useful tool to evaluate the relation between levels of EE2 and BMD as well as tostudy differences in BC in healthy PMPW. Obese women had higher EE2 levels and TS BMD thanPMPW with normal BMI.