To understand the di.erences among referencecurves for bone mineral density (BMD) for Chinese, Japanese, and American Caucasian women, we measured the BMD at the anteroposterior (AP) lumbar spine (L1-L4), lateral lumbar spine (L2-L4), hip (including the femoral neck, trochanter, intertrochanter, Ward's triangle, and total hip), and ultradistal forearm by the dual-energy X-ray absorptiometry (DXA) in a total of 2728 healthy Chinese women, aged 5-96 years. Documented BMD data for Japanese women and device manufacturer's BMD new reference databases (including the NHANES III dataset) for American Caucasian women were also used in this study. The cubic egression model was found to.t best in analyzing the age-associated variations of BMD at various sites in Chinese women, i.e., the equations had the largest coe.cient of determination (R2). At the AP/Lat spine, trochanter, intertrochanter, and Ward's triangle, BMD reference curves for Chinese women were lower than those for Japanese or Caucasian women, while at the femoral neck, total hip, and ultradistal forearm, the reference curves for Chinese women were higher than those for Japanese women, with overlaps and crossing of the curves for some age spans in comparing the Chinese and Caucasian women. There were signi.cant di.erences in the peak BMD (PBMD) at various sites among the Chinese, Japanese, and Caucasian women (P=0.000). The PBMDs for Chinese women at the lumbar spine and various sites of the hip were 5.7%

Objective. Recently our studies have shown that nylestriol in combination with levonorgestrel prevented bone loss, decreased bone turnover rate and increased the maximal loading of bone without obvious side effects in retinoic acid (RA) induced osteoporotic rats. In addition to the animal experiments, we evaluate the effect of Compound Nylestriol Tablet (CNT) on bone mineral density (BMD) in women with postmenopausal osteoporosis. Compound Nylestriol Tablet, which contains 0.5mg of nylestriol (cyclopentylethinyl estriol) and 0.15mg of levonorgestrel per tablet, was authorized as a new anti-osteoporotic agent for clinical trial in postmenopausal osteoporosis. Methods. One year's clinical observation was performed in 191 eligible patients who were randomly divided into two groups (A and B). In group A, 119 patients were treated for one year with CNT (one tablet per week) and in group B, 72 patients with placebo. Bone mineral density of lumbar antero-posterior spine (L1-L4), lateral spine, total hip and total forearm positions including radiustulna at the ultra distal areas, mid areas, and one-third areas, were measured before and after treatment. Biochemical parameters and effects of CNT on uterus, and breast were observed. Results. We found that patients treated with CNT had a significant decrease of bone loss in total forearm, including radiustulna at the ultra distal, mid, and 1=3 areas compared with control subjects (all P<0.05). An improved BMD tendency could be seen at the lumbar spine. There were no differences in the observed biochemical variables. No side-effects on uterus, or mammary glands were observed. None of the patients had uterine bleeding or vertebral fractures during one year's CNT treatment. Conclusion. These data suggested that CNT is effective, safe and convenient in treating postmenopausal osteoporosis.

optimal dosage combination of NYL/LNG. In the second set of experiments, a total of 160 female SD rats at 7 months of age were randomly divided according to their basal body weights into 16 groups (10 in each). Treatment dosages of NYL and LNG were arrayed in a 2 factor-4 level (24) factorial design, i.e., NYL level I (N1 0.015mg/kg), level II (N2 0.05mg/kg), level III (N3 0.15mg/kg) and level IV (N4 0.5mg/kg) and LNG level I (L1 0.005mg/kg), level II (L2 0.015mg/kg), level III (L3 0.05mg/kg) and level IV (L4 0.15mg/kg). For 14 d, 70mg/kg/d RA was given intragastrically to establish the osteoporotic model and NYL and LNG were then administered in different dosages on alternate days over a 3 wk period. Subsequently, body weight, uterine weight, endometrial status, Bone mineral density (BMD), bone turnover, and morphometry as well as parameters of biomechanics, serum sex hormones and lipids and estrogen receptor-a expression were determined for these rats. Results. Uterine weights at L2, L3, and L4 dosage levels were significantly lower than those at L1 (P<0.05). Serum estradiol at N4 and progesterone at N2, N3, and N4 had decreased. Bone mineral density at distal tibiae (R5) in L3 and L4, and at proximal femora (R3) in L4 had increased. The peak loading of lumbar vertebrae at N3 was higher than that at N1, N2, and N4 dosage levels and that of femora higher at N3 than that at N1 and N4. Serum alkaline phosphatase (ALP) levels at N3, N4, L2, L3, and L4 dosage levels were lower than those at N1, N2, and L1 (P<0.05). Moreover, there were lower levels of trabecular separation (Tb.Sp) at N3 and N4. The mineral apposition rates (MAR) at N2, N3, N4, L2, L3, and L4 were lower than those at N1 or L1. Bone formation rates (BFR) at L3 and L4 had significantly decreased as compared with that at L1. Levels of serum total cholesterol (TC) at N2, N3, and N4 were lower than that at N1 (P<0.05). Marked squamatization of uterine endometrium with an increased expression of estrogen receptor (ER)-a was observed at N4. Conclusion. The dosage of 0.15 mg/kg NYL prevented bone loss, decreased bone turnover rate and increased the maximal loading of bone without obvious side effects in RA-induced osteoporotic rats. The addition of 0.015–0.15 mg/kg of LNG (L2-L4) reduced uterine weights and serum ALP levels. Overall results showed that 0.15 mg/kg of NYL in combination with 0.015 mg/kg of LNG produced beneficial effects on bone metabolism in RA-induced osteoporotic rats.