Normal value of bone mineral density of lumbar spine, proximal femur, and distal forearm of women in different age groups.

The cross sectional, descriptive study was conducted to find the reference data for bone mineral density (BMD) in normal women in the area around Thammasat University Hospital. The study population consisted of 806 women aged 15-80 years. BMD of different parts of the body were measured by dual energy photon absorptiometer. The results showed that mean (+/- SD) BMD of the lumbar spine 2, 3, 4, neck of femur, Ward's triangle of femur, greater trochanter of femur, ultradistal part of radius, and distal ulnar averaged from all age groups were 0.954 +/- 0.144, 1.027 +/- 0.151, 1.059 +/- 0.147, 0.898 +/- 0.114, 0.774 +/- 0.165, 0.777 +/- 0.103, 0.412 +/- 0.073, and 0.585 +/- 0.096 g/cm2 respectively. Overall, the peak BMD was between the age of 40-44 years old. It started decreasing from the age of 45 and decreased remarkably after the age of 50. The data is shown to be a database for our hospital's health policy, but the authors believe that it could also be used as reference data for future studies in Thailand. It is suggested that normal values in different areas should be available in the future in order to provide more specific and better health care according to demographic variation.

Prediction of bone mineral density of lumbar spine, hip, femoral neck and Ward's triangle by forearm bone mineral density.

Bone mineral density (BMD) of dual energy X-ray absorptiometry (DEXA) at both radius and ulna were measured to evaluate the correlation of those and BMD at lumbar (L) spine, hip, femoral neck and Ward's triangle. The 64 simple linear regression analysis was calculated to postulate the predicted equation by using the BMD at supradistal, distal 1/10, distal 1/6 and distal 1/3 of both forearms as independent variables, while the dependent variables were BMD at L1-L4 spine, total hip, femoral neck and Ward's triangle. 115 patients aged between 41-79 years (mean age 55.97+/-8.34 years) from the menopausal clinic, Pramongkutklao Hospital, were scanned at both forearms by Panasonic (DXA-70) DEXA and at non forearm regions by Hologic (QDR 4500) DEXA on the same day. The results showed that the BMD of each of the 4 parts of both radius and ulna had positive correlation to those of L-spine, total hip, femoral neck and Ward's triangle with r = 0.4012 to 0.7032 (P<0.001 for all). The greater distal of the forearm, the better correlation of BMD to the non forearm BMD. The 64 simple linear regression equations were constructed with regression coefficient ranging from 0.6048 to 1.9011 (P<0.001 for all). When considering the non forearm BMD, the mean BMD at Ward's triangle significantly declined more rapidly than that of L-spine, total hip and femoral neck (P<0.05 for all). It indicated that there was an early change of BMD at Ward's triangle. However, this change followed the forearm BMD. Distal forearm BMD was the earliest sign of bone loss. We can predict non forearm BMD by supradistal and distal 1/10 of forearm BMD.

Evaluation of forearm bone mineral density: comparison of dominant and non-dominant forearms.

For evaluation of forearm bone mineral density (BMD), (1) BMD of corresponding sites of dominant and non-dominant forearms were compared and (2) characteristics of each of the 4 regions of interest (ROIs) including supradistal, distal 1/10, distal 1/6 and distal 1/3 along the long bone of both forearms were analyzed. One hundred and forty one women (79 normal and 62 osteoporotic) were recruited by randomized selection from the department of Nuclear Medicine of Phramongkutklao Hospital. Both dominant and non-dominant forearms of each subject were scanned by Panasonic (DXA-70) dual energy X-ray absorptiometry (DEXA) on the same day. Lumbar spine BMD was also measured by Hologic DEXA (QDR-4500) and WHO criteria for diagnosis of osteoporosis was applied for identifying osteoporosis and normal groups. The results showed that none of the corresponding sites of BMD of both forearms were significantly different (p>0.05 for all). The BMD from distal to proximal of each long bone (radius and ulna) of both forearms was gradually increased in osteoporosis and normal groups. Further distal sites of the forearms and lower BMD were found. Comparison between mean BMD at corresponding sites in normal and osteoporotic groups, had significantly different BMD at both radii for all ROIs (p<0.05). While BMD at corresponding sites of both ulna in the 2 groups was not significantly different (p>0.05). A great percentage change of mean BMD in the osteoporotic group was seen at supradistal and distal 1/10 of both forearms when using BMD in the normal group as control. We suggest that both distal radii especially at supradistal and distal 1/10 sites should be scanned in routine practice. The distal location of the forearms had a relatively smaller amount of surrounding soft tissue than the proximal.