Prediction of fracture risk by radiographic absorptiometry and quantitative ultrasound: a prospective study.

Recent developments in computer-assisted radiographic absorptiometry (RA) and quantitative ultrasound techniques (QUS) provide readily accessible and relatively inexpensive methods for assessing bone mineral status. However, few population-based studies have investigated the ability of RA and ultrasound to predict fracture risk prospectively. We explored the ability of RA and QUS to predict fracture risk among 560 postmenopausal women from the Hawaii Osteoporosis Study; average follow-up was 2.7 years. An incident vertebral fracture was defined as a decrease of more than 15% in vertebral heights on subsequent films. Self-reported nonspine fractures were verified by medical records. The prospective associations of vertebral fractures, nonspine fractures, and any (spine or nonspine) fractures with bone measurements were examined using logistic regression, adjusting for age. Both phalangeal bone mineral density (BMD) and metacarpal BMD, measured using RA, predicted future fracture risk. The age-adjusted odds ratios (corresponding to 1 SD decrease in BMD) for vertebral fractures, nonspine fractures, and any fractures were 3.41, 1.50, and 1.91, respectively, for phalangeal BMD, and 1.71, 1.49, 1.55, respectively for metacarpal BMD. Calcaneal broadband ultrasound attenuation (BUA) also showed significant association with fracture risk, with age-adjusted odds ratios of 1.50, 1.89, and 1.72 for vertebral fractures, nonspine fractures, and any fractures, respectively. We conclude that hand RA and calcaneal BUA are significant predictors of nonspine fracture, vertebral fracture, and overall fracture risk. The attractive features of these techniques, such as portability, relatively low cost, and ease of use, make them promising alternatives to conventional bone measurement techniques used for the assessment of fracture risk.

[Mass-screenings for osteoporosis using computed X-ray densitometry (CXD): in a mobile unit].

The early diagnosis and treatment of osteoporosis is considered to be important for the prevention of fractures which often cause elderly to become bed-ridden. Computed X-ray densitometry (CXD), a method to measure bone mineral content in the metacarpus II utilizing a simple X-ray image, has been used for mass-screening of osteoporosis, because of its utility and reliability. However, due to its requiring adequate X-ray equipment, this method is often unsuitable for use in small facilities in a remote mountain areas. The use of CXD for osteoporosis screening, was attempted in a mobile unit for tuberculosis screening, by our public health center. The results showed that it is possible to use CXD in combination with a mobile unit, correcting the obtained values according to the radiographic conditions. With this set-up, CXD was used for mass-screening of osteoporosis in a total of 1150 subjects living in mountainous areas of Yoshino-gun, Nara prefecture, and CXD was found to be convenient and effective for mass-screening. The use of CXD in a mobile chest X-ray unit can be expected to be useful for mass-screening of osteoporosis especially in remote mountainous areas having inadequate X-ray equipment.

Predicting vertebral deformity using bone densitometry at various skeletal sites and calcaneus ultrasound.

We investigated the usefulness of bone density measurements from multiple skeletal sites and calcaneus ultrasound for evaluating the probability of vertebral deformation. Bone mineral density (BMD) was measured at the second metacarpal and middle phalanges using radiographic absorptiometry of hand radiographs, and at the lumbar spine using dual-energy x-ray absorptiometry. Distal radius and proximal radius were measured using single-energy x-ray absorptiometry (SXA), expressed as bone mineral content (BMC, grams per centimeter), and as BMD (grams per square centimeter). The calcaneus was measured using both SXA (BMD) and broadband ultrasound attenuation (BUA). Among the women in this study (mean age 74, SD = 5), 84 women developed new vertebral deformations (57 cases with one and 27 cases with two or more deformations), which were identified on serial radiographs during an average of 9 years prior to the measurements of bone density. Logistic regression analysis was used to calculate odds ratios for risk of deformation corresponding to a 1-SD difference in density or ultrasound, adjusted for age. All bone measurements were significantly associated with vertebral deformation, with odds ratios (95% confidence intervals) ranging from 1.40 (1.10, 1.78) for proximal radius BMD to 1.88 (1.45, 2.44) for calcaneus BMD measurements. Measurements of calcaneal BUA, calcaneal BMD, and hand BMD generally remained significant when included simultaneously with another measurement in the same model, suggesting that spine or radius BMD may not provide much additional information about risk of deformation. It appears that all of the measurements of bone density and ultrasound provide useful information regarding the probability of deformation. These findings await confirmation in a prospective study.

Assessment of bone density in the distal radius with computer assisted X-ray densitometry (CXD).

A modified and improved radiographic absorptiometry of the distal radius which enables on-site analysis, called computer assisted X-ray densitometry (CXD), was evaluated from the viewpoint of quality assessment. Its precision and the correlation with dual energy X-ray absorptiometry (DXA) was evaluated in 12 volunteers (mean age 44.7 years). The profile of CXD-measured radial bone mineral density (RBMD) from 142 subjects (75 premenopausal and 67 postmenopausal women, mean ages 44.9 and 50.6 years, respectively) were compared with previous data by other methodologies of bone mineral analysis. The intra-assay coefficient of variation (CV) was 0.617%, the inter-assay CV was 2.064%, and the inter-observer CV was 0.673%. The correlation between CXD-measured RBMD and DXA-measured RBMD was of statistical significance (r2 = 0.733, P < 0.01). The correlation of CXD-measured RBMD with age, height or weight corresponded well with previous reports. CXD-measured RBMD and DXA-measured vertebral bone mineral density (VBMD) also had a significant positive correlation, but their correlation was not so close (r2 = 0.149, P < 0.01). The discriminative ability of osteoporosis by CXD was of acceptable level (odd's ratio = 5.72, P < 0.05), when assessed by comparison with bone dystrophy score (BDS) on the plain vertebral radiogram. Although some problems remain in technical standardization, CXD could be an easy, inexpensive, and widely applicable alternative of non-weight bearing cancellous bone densitometry.

Metacarpal bone mass in normal and osteoporotic Japanese women using computed X-ray densitometry.

The metacarpal bone mineral density (BMD) and metacarpal index (MCI) of the second metacarpal bone were measured by computed X-ray densitometry (CXD) (Teijin Ltd., Tokyo), which we have established with the development of microdensitometry of radiographs. In this study, we evaluated the basic attributes of this CXD method and determined the age-related changes in both metacarpal measurements in normal Japanese women. The precision in vivo was measured in eight subjects. The precision errors [coefficient of variation (CV)] were 0.2-1.2% CV for metacarpal BMD and 0.4-2.0% CV for MCI, respectively. We have obtained low precision error and more rapid analysis, within 3 minutes respectively, compared with the previous methods. Age-related changes in the metacarpal measurements were evaluated in 1438 normal women. Both measurements showed the most significant decrease in the sixth decade of life. The rate of decrease in the sixth decade was 1.6%/year for metacarpal BMD and 1.5%/year for MCI. On comparison between metacarpal BMD by CXD and spine BMD using dual energy X-ray absorptiometry (DXA) in 248 normal women with and without menstruation, the two measurements were found to be similarly decreased in the subjects within 5 years after menopause. There was also no significant difference in the Z-score between metacarpal BMD and spine BMD within 5 years after menopause. These results indicate that early postmenopausal bone loss occurs not only in the spine but also in the metacarpal bone.(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in fatty acid composition in sardines (Sardinops melanosticta) with cooking and refrigerated storage.

The influence of cooking and later storage in a refrigerator for 7 days on the fatty acid composition of lipids in sardines (Sardinops melanosticta) was studied. The total lipid and triacylglycerol (TG) levels did not change and the phospholipid (PL) level decreased somewhat with cooking or during storage. The fatty acid composition of the total lipids and TG fractions was little changed and that in the PL fractions was somewhat changed by the cooking. The composition of the polyunsaturated fatty acids (PUFA) in lipids of sardine precooked at 100 or 170 degrees C for 30 min changed from 42.7 to 38.3 or 33.5%, respectively, for total lipids and from 51.5 to 38.4 or 37.6%, respectively, for PL fractions during storage. The fatty acids in lipids from the ordinary meat of sardine was stable and those in the dark meat were extremely unstable during storage after cooking. We concluded that the PUFA in the lipids of sardines were stable to cooking, but unstable to oxidation during storage in a refrigerator. The PUFA of lipids in the dark meat of sardine were extremely unstable to oxidation.