Diagnostic criteria for primary osteoporosis: year 2000 revision

ED-71, a new active vitamin D3, increases bone mineral density regardless of serum 25(OH)D levels in osteoporotic subjects

A previous randomized placebo-controlled double-blinded clinical trial revealed that treatment of osteoporotic subjects supplemented with 200 or 400IU/day vitamin D3 with 0.75 microg/day ED-71 for 12 months increased lumbar and hip bone mineral density (BMD) by 3.4 and 1.5%, respectively, compared to placebo group (JCE&M 90:5031,2005). These effects on BMD were stronger than any previous results using 1alpha(OH)D3 or 1,25(OH)2D3. However, there still was a concern that the effect of ED-71 could be observed because serum 25(OH)D in many of these subjects were below its optimal level. In order to address this issue, we performed post hoc analysis to compare the effect of ED-71 on lumbar and hip BMD between subjects with upper (>29 ng/mL) and lower tertiles (<25 ng/mL) of serum 25(OH)D. Lumbar BMD after 12-month treatment with 0.5, 0.75 and 1.0 microg/day ED-71 increased similarly in both lower and upper tertile groups of serum 25(OH)D. In addition, hip BMD also showed a tendency to increase when 0.75 and 1.0 microg/day ED-71 groups were combined together in both upper and lower serum 25(OH)D tertile groups, although the increase was not statistically significant. These results demonstrate that the effect of ED-71 on bone is independent of supplementary effect for nutritional vitamin D insufficiency, and suggest that ED-71 may exert its effect as a unique VDR ligand with stronger effect on bone compared to the natural ligand, 1,25(OH)2D3.

CYP17 and COMT gene polymorphisms can influence bone directly, or indirectly through their effects on endogenous sex steroids, in postmenopausal Japanese women

We aimed to assess whether circulating sex steroids would influence bone density and bone loss, whether part of this influence could be explained by genetic variation measured as polymorphisms in candidate genes affecting circulating hormone levels, or whether gene polymorphisms would have direct effects on bone in 229 postmenopausal Japanese women aged 46 years and over who had been followed for eight years (Yokohama Cohort). Bone mineral density (BMD) in the lumbar spine (L), femoral neck (FN), total hip (T) and distal radius (R) was measured every year, and endogenous sex steroid levels were determined at the start of the study. We investigated the polymorphisms of estrogen-metabolizing enzyme gene, CYP17; estrogen biosynthesis (high activity, A2/A2), CYP1A1; hydroxylation (high inducibility, vt/vt) and COMT; inactivation (low activity, L/L) with PCR-based restriction fragment length polymorphism assays. Dehydroepiandrosterone (DHEA) and androstenedione (AND) levels significantly correlated with bone density in both the axial (L) and the appendicular skeleton (FN, T and R) (r=0.194-0.229; P<0.05) whereas estradiol (E2) and AND showed significant correlations with bone change only at the axial skeleton (r=0.205 and r=-0.139, respectively; P<0.05) on the total cohort. These correlations remained significant in thin/normal-weight women [body mass index (BMI) <25 kg/m2)] even after adjustment for years since menopause (YSM) and BMI or age and BMI, suggesting an interaction of BMI and sex steroid/BMD association. On the total cohort, a difference in endogenous DHEA levels between CYP17 homozygote A2 and non-homozygote A2; an increasing trend in AND levels from COMT L/L, L/H, to H/H; and a difference in TS level between COMT homozygote L and non-homozygote L were separately observed. All observations were significant for unadjusted and adjusted analysis, except for COMT and TS. In thin/normal-weight women (BMI <25 kg/m2), the same effects of CYP17 genotypes on DHEA were observed as on the total cohort. CYP17 and COMT genes showed some direct influence on bone density. Mean percent change in T-BMD was negative for CYP17 non-homozygote A2 in contrast to a positive value for homozygote A2. Mean percent change in R-BMD showed the difference between COMT homozygote L and non-homozygote L with a larger decrease for the homozygote L. Together, CYP17 and COMT genotypes might have some effect on bone both directly and indirectly through their effects on endogenous sex steroids in postmenopausal Japanese women.

Effect of physical activity and nutrition on bone mineral density in young Japanese women

We explored factors that contributed to bone mineral density (BMD) in Japanese young women by quantifying the factors related to BMD. Between October 2003 and February 2004, we conducted a cross-sectional survey to study the status of nutritional intake and physical activity, and evaluated the various physical and serum parameters in relation to BMD. Subjects included 254 healthy female students who were 19-25 years old and were attending the Nursing School of Tokyo Women's Medical University, Japan. We measured the lumbar BMD (L2-L4) in these women. Multiple regression analysis was used to predict factors that contributed to current L2-L4 BMD. Our results showed that body mass index (BMI) (standardized regression coefficient = 0.45, P < 0.0001), past exercise habit (standardized regression coefficient = 0.15, P < 0.0059), and current total energy expenditure (standardized regression coefficient = 0.12, P < 0.03) were factors that significantly predicted the current L2-L4 BMD, with BMI as a key contributing factor. A BMI of 20.8 kg/m(2) allowed acquisition of young adult mean (YAM) irrespective of the total energy expenditure. In subjects with low BMI, L2-L4 BMD increased with higher current energy expenditure. A BMI of 20.8 kg/m(2) or greater and an energy expenditure of 32.9 METS-h/day or greater are required to acquire the YAM. We concluded that BMI and physical activity were factors that affected the BMD of Japanese young women.

Urinary gamma-glutamyltransferase (GGT) as a potential marker of bone resorption

We recently identified gamma-glutamyltransferase (GGT) as a novel bone-resorbing factor. The present study was undertaken to determine whether GGT is a marker of bone resorption in two genetic models of hyper- and hypo-function of osteoclasts, as well as in postmenopausal women with accelerated bone resorption, using type I collagen N-telopeptide (NTX) and deoxypyridinoline (DPD) as established biochemical markers. Urinary excretion of GGT, corrected for creatinine, was found to be increased in osteoprotegerin (OPG)-deficient osteoporotic mice as well as in patients with postmenopausal osteoporosis (67-83 years of age); in both cases the urinary level decreased after treatment of patients or mice with alendronate, a selective inhibitor of bone resorption, concomitantly with a reduction in DPD and NTX. Conversely, in osteopetrotic op/op mice, urinary GGT increased in parallel with DPD after induction of osteoclasts with M-CSF injection. Constant infusion of parathyroid hormone (PTH) also increased urinary GGT along with DPD. In a survey of 551 postmenopausal women (50-89 years of age) at their regular health checkup, urinary GGT excretion exhibited a high correlation with DPD (rho = 0.49, p < 0.0001). The calculated sensitivity and specificity for diagnosing elevated bone resorption, as determined by a DPD value higher than 7.6 nM/mM Cr, were 61% and 92%, respectively, when a cut-off value of 40 IU/g Cr was assigned for urinary GGT. Since GGT activity can be measured inexpensively in large numbers in a very short time, the measurement of urinary level may provide a convenient and useful method for mass screening to identify those with increased bone turnover and hence at increased risk for bone fracture.

Underutilization of antiosteoporotic drugs by orthopedic surgeons for prevention of a secondary osteoporotic fracture

BACKGROUND

Despite the availability of effective treatment and well-publicized treatment guidelines for preventing osteoporotic fractures, there are significant gaps in implementing the recommendations, and it is unknown how many patients are treated for prevention of secondary osteoporotic fractures. In this study, we investigate what percentage of osteoporosis patients were treated with antiosteoporotic drugs after osteoporotic fractures of the hip, wrist, and proximal humerus, and we discuss here the need for improvement in the treatment of osteoporosis following fracture.

METHODS

We studied 422 patients with osteoporotic fractures, 91 men and 331 women, with an average age of 77.1 years (range, 52-102 years). The 422 cases consisted of 299 hip fractures, 97 distal radius fractures, and 26 proximal humerus fractures. All patients underwent surgical intervention. The variables were examined to ascertain whether osteoporosis patients were medicated with antiosteoporotic drugs at postfracture.

RESULTS

Fifty-five (13%) of the 422 patients received antiosteoporotic medication at postfracture. Pharmaceutical treatment was given in 44 cases (14.7%) of hip fractures, 8 cases (8.2%) of distal radius fractures, and 3 cases (11.5%) of proximal humerus fractures. Thirty-one (7.3% of total) of the 55 patients were taking the same medication pre- and postfracture. Seven (1.7%) of the 55 were administered a different drug compared to before the fracture, and 17 (4%) started to take an antiosteoporotic drug for the first time subsequent to the fracture.

CONCLUSIONS

The present rate of treatment is insufficient given the high risk of secondary fractures and the availability of appropriate drugs that would reduce that risk.

Daily nasal spray of hPTH(1-34) for 3 months increases bone mass in osteoporotic subjects: a pilot study

INTRODUCTION

Although intermittent parathyroid hormone (PTH) injection can lead to strong anabolic effects on bone, daily subcutaneous injection is a disadvantage for patient acceptance. We have developed a nasal spray formula of parathyroid peptide [hPTH(1-34)] with peak serum hPTH(1-34) concentrations by nasal spray of 1,000 microg similar to those by subcutaneous injections of 20 microg hPTH(1-34).

METHODS

To determine the clinical efficacy and safety of nasal hPTH(1-34) spray, a randomized, open-labeled clinical trial was conducted in subjects with osteoporosis. Ninety osteoporotic subjects age 52-84 years (mean 66.5 years) were randomly assigned to receive either 250 microg (PTH250, n=31), 500 microg (PTH500, n=30), or 1,000 microg (PTH1000, n=29) of daily nasal hPTH(1-34) spray for 3 months. All received daily supplements of 300 mg calcium and 200 IU vitamin D(3).

RESULTS

Daily nasal hPTH(1-34) spray for 3 months increased lumbar bone mineral density (L-BMD) in a dose-dependent manner, and the PTH1000 group showed a 2.4% increase in L-BMD from baseline. Only the 1,000-microg dose produced consistent and statistically significant changes in markers of bone turnover; after 3 months, median serum type I procollagen N-propeptide (PINP) and osteocalcin increased 14.8% and 19.4% from baseline, while urinary type I collagen N-telopeptide (NTX) decreased 16.4%. Seven subjects developed transient hypercalcemia at 3 h after nasal hPTH(1-34) spray, but none of the subjects developed sustained hypercalcemia.

CONCLUSION

These observations demonstrate that nasal hPTH(1-34) spray is safe and well tolerated and can rapidly increase L-BMD. The results warrant further studies to examine its long-term efficacy on bone mass and fractures.

Beneficial Effect of Oral Bisphosphonate Treatment on Bone Loss Induced by Chronic Administration of Furosemide without Alteration of Its Administration and Urinary Calcium Loss

Bisphosphonate is widely used to treat patients with primary and secondary osteoporosis. The chronic administration of furosemide is considered a risk factor for osteoporosis mainly due to the increased urinary excretion of calcium, leading to a long-term negative balance of calcium. We describe two patients with mild heart failure who took furosemide for more than 5 yr and developed hyperparathyroidism and lumbago associated with low bone mineral density. Their serum levels of intact parathyroid hormone and bone mineral density (BMD) of the lumbar spine (L2-L4) were 180.8 and 144.3 pg/ml, and 71% and 80% of the mean of healthy women, respectively. The oral administration of alendronate or risedronate was effective for lumbago and improved BMD, although the urinary excretion of calcium and hyperparathyroidism were not changed. For the medical treatment of lumbago and decreased bone mass secondary to the long-term administration of furosemide, bisphosphonate is proposed when the dose of furosemide cannot be reduced. However, it may be important to give sufficient calcium and vitamin D to patients to improve secondary hyperparathyroidism.

Comparison of the effect of alendronate on lumbar bone mineral density and bone turnover in men and postmenopausal women with osteoporosis

The purpose of the present study was to compare the effect of alendronate treatment on lumbar bone mineral density (BMD) and bone turnover in men and postmenopausal women with osteoporosis. Sixty men with primary or secondary osteoporosis and 318 women with postmenopausal osteoporosis were treated with alendronate. The primary end points were lumbar BMD and urinary cross-linked N-terminal telopeptides of type I collagen (NTX) and serum alkaline phosphatase (ALP) levels. The secondary end point was the incidence of vertebral and nonvertebral fractures. Forty-seven (78.3%) men and 254 (79.9%) women who could complete the 12-month trial were analyzed. The mean ages of men and postmenopausal women were 69.1 and 70.4 years, respectively. Both men and postmenopausal women showed higher levels of urinary NTX as compared with normal range of premenopausal women. Alendronate treatment decreased urinary NTX level by 39.2% in men and 45.4% in postmenopausal women at 3 months and serum ALP level by 17.8 and 21.0%, respectively, at 12 months. Following reduction in bone turnover markers, lumbar BMD increased 5.8 and 7.6% in men and postmenopausal women, respectively, at 12 months. Reduction in urinary NTX level and increase in lumbar BMD were smaller in men than in postmenopausal women. The incidence of vertebral and nonvertebral fractures was 10.6 and 8.5%, respectively, in men and 8.3 and 7.5%, respectively, in postmenopausal women, with no significant difference in these incidences between them. These results suggested that alendronate treatment effectively increased lumbar BMD from baseline in men with primary or secondary osteoporosis following reduction in bone turnover, although its efficacy did not appear to be greater than in postmenopausal women with osteoporosis.

Visual assessment of the mandibular cortex on panoramic radiographs to identify postmenopausal women with low bone mineral densities

OBJECTIVE

The purpose of this study was to determine whether simple visual estimation of the mandibular inferior cortex width on panoramic radiographs is useful for identifying postmenopausal women with low skeletal bone mineral density (BMD).

STUDY DESIGN

Panoramic radiographs were made on 100 women aged 50-84 years who also had BMD assessment of the lumbar spine and femoral neck by dual-energy x-ray absorptiometry. The panoramic images were examined twice by 4 observers to evaluate the thickness of the mandibular inferior cortex.

RESULTS

Intraobserver agreement varied from moderate to almost perfect. Interobserver agreements varied from fair to almost perfect. Overall mean sensitivity, specificity and positive predictive value in identifying women with low BMD were 54.7%, 82.0%, and 72.5% in the lumbar spine and 51.8%, 82.2%, and 75.7% in the femoral neck, respectively.

CONCLUSIONS

Our results suggest that simple visual estimation of the mandibular inferior cortex on panoramic radiographs may be useful for identifying postmenopausal women with low BMD.

The sample size required for intervention studies on fracture prevention can be decreased by using a bone resorption marker in the inclusion criteria: prospective study of a subset of the Nagano Cohort, on behalf of the Adequate Treatment of Osteoporosis (A-TOP) Research Group

In drug developments for osteoporosis, large-scale and longterm fracture prevention studies have been required. We investigated whether or not it was possible to reduce the sample size and observation period under new selection criteria for an osteoporotic fracture-prevention study. A Poisson regression model was used to identify independent risks for incident vertebral fracture in 515 postmenopausal women who had had no intervention for osteoporosis; this group was a subset of Nagano Cohort participants. The total observation period for this group was 2,577 person-years, and a total of 146 new vertebral fractures were observed. Risk assessment for incident vertebral fracture among numerical covariates revealed that the following items showed significant independent risks for incident fractures; namely, baseline age (hazard ratio [HR]; 1.84; 95% confidence interval (CI), 1.44-2.35; P < 0.001), number of preexisting vertebral fractures (HR, 1.28; 95% CI, 1.17-1.40; P < 0.001), baseline lumbar bone mineral density (LBMD) (HR, 0.79; 95% CI, 0.71-0.88; P < 0.001), and urinary excretion of deoxypyridinoline (DPD) (HR, 1.18; 95% CI, 1.03-1.35; P = 0.016). Because the initial urinary excretion of DPD was found to be a risk for incident vertebral fracture, in addition to the conventional risks, we assessed whether or not the sample size or observation period could be reduced by the incorporation of the urinary excretion of DPD into the selection criteria of a fracture-prevention study. The assessment of sample size was calculated, using the log rank test, at a two-tailed significance level of 5% and with a power of 80%. When osteoporotic patients with preexisting fracture were selected (conventional criteria), the 3-year probability of vertebral fracture was estimated as 14.3% in the present population. On the other hand, the new vertebral fracture rate during 3 years in the osteoporotic patients with preexisting fracture plus high urinary DPD (HR, above 1.0); (new selection criteria) was estimated as 23.2%. When the HR between test drug and placebo was changed from 0.4 to 0.8, the required sample size for any level of HR showed a 40% reduction for the new selection criteria compared to the conventional criteria. Therefore, the addition of urinary DPD level to the selection criteria is useful to reduce sample size in an osteoporosis fracture-prevention study.

Efficacy and tolerability of once-weekly administration of 17.5 mg risedronate in Japanese patients with involutional osteoporosis: a comparison with 2.5-mg once-daily dosage regimen

In this multicenter, randomized, double-blind controlled trial, the efficacy and safety of once-weekly dosing with 17.5 mg risedronate was compared with once-daily dosing with 2.5 mg risedronate in Japanese patients with involutional osteoporosis. A total of 496 patients were randomized to receive either once-weekly (n = 249) or once-daily (n = 247) treatment. All patients were supplemented with 200 mg/day calcium. Following 48 weeks of treatment, the mean (+/-SD) percent changes, from baseline, in the bone mineral density of the lumbar spine (L2-L4 BMD) in the once-weekly and once-daily treatment groups were 5.36 +/- 4.27% and 5.87 +/- 4.47%, respectively. The difference between the groups was -0.5% (95% confidence interval: -1.35% to 0.35%), demonstrating that the effect on BMD of once-weekly treatment was not inferior to that of once-daily treatment. The time-course reductions in biochemical markers of bone resorption (urinary N- and C-telopeptide of type I collagen) and bone formation (bone-specific alkaline phosphatase) were similar for the two dosing regimens. There were no differences in the incidence of new vertebral fractures or the worsening of existing fractures between the once-weekly (2.2%) and once-daily (2.7%) dosing regimens. No significant differences were observed between the two dosing regimens in the incidence or the type of adverse events. However, 10.1% of the patients in the once-daily group withdrew due to adverse events as compared to 5.2% in the once-weekly group. Moreover, drug-related adverse events, including upper gastrointestinal disorders and abnormal changes in laboratory parameters, tended to be less in the once-weekly dosing regimen than in the once-daily dosing regimen. In conclusion, once-weekly oral dosing with 17.5 mg risedronate was well tolerated in Japanese osteoporotic patients, and showed equivalent efficacy to once-daily oral dosing with 2.5 mg risedronate. This once-weekly regimen is expected to provide a more convenient therapeutic option as an alternative to daily dosing and to enhance patient compliance in long-term therapy for osteoporosis.

Computer-aided system for measuring the mandibular cortical width on dental panoramic radiographs in identifying postmenopausal women with low bone mineral density

INTRODUCTION

Mandibular inferior cortical width manually measured on dental panoramic radiographs may be useful for identifying postmenopausal women with low skeletal bone mineral density (BMD). Automatic measurement of cortical width may enable us to identify a large number of postmenopausal women with suspected low skeletal BMD. The purposes of this study were to develop a computer-aided system for measuring mandibular cortical width on dental panoramic radiographs and clarify the diagnostic efficacy of this system.

METHODS

Panoramic radiographs of 100 postmenopausal women who had had BMD assessments of the lumbar spine and the femoral neck were used in this study. Experienced oral radiologist determined the position of the mental foramen on 100 digitized dental panoramic radiographs. After determination of the mental foramen, mandibular cortical width below the mental foramen was measured automatically with a computer-aided system by identifying the area of interest, enhancing the original image, determining inner and outer margins of the cortex, and selecting an appropriate point. Cortical width measured by this system was compared with BMD of the lumbar spine and the femoral neck.

RESULTS

There were statistically significant correlation between cortical width measured by the computer-aided system and spinal BMD (r=0.50) and femoral neck BMD (r=0.54). These correlations were similar with those between cortical width by manual measurement and skeletal BMD. Sensitivity and specificity for identifying postmenopausal women with low spinal BMD by the computer-aided system were about 88.0% and about 58.7%, respectively. Those for identifying postmenopausal women with low femoral neck BMD by this system were about 87.5% and about 56.3%, respectively.

CONCLUSION

Our results suggest that our computer-aided system may be useful for identifying postmenopausal women with low skeletal BMD.

Comparison of effect of treatment with etidronate and alendronate on lumbar bone mineral density in elderly women with osteoporosis

The purpose of this open-labeled prospective study was to compare the treatment effects of cyclical etidronate and alendronate on the lumbar bone mineral density (BMD), bone resorption, and back pain in elderly women with osteoporosis. Fifty postmenopausal women with osteoporosis, age ranging from 55 to 86 years (mean: 70.7 years), were randomly divided into two groups with 25 patients in each group: the cyclical etidronate group (etidronate 200 mg daily for 2 weeks every 3 months) and the alendronate group (5 mg daily). The BMD of the lumbar spine (L1-L4) measured by DXA, the urinary cross-linked N-terminal telopeptides of type I collagen (NTX) level measured by the enzyme-linked immunosorbent assay, and back pain evaluated by the face scale score were assessed at baseline, 6 months, and 12 months. There were no significant differences in baseline characteristics including age, body mass index, years since menopause, lumbar BMD, urinary NTX level, and face scale score between the two treatment groups. Etidronate treatment sustained the lumbar BMD following a reduction in the urinary NTX level and improved back pain, while alendronate treatment reduced the urinary NTX level more significantly, resulting in an increase in the lumbar BMD, and similarly improved back pain. No serious adverse events were observed in either group. This study confirmed that alendronate treatment had a greater efficacy than etidronate treatment in increasing the lumbar BMD through the reduction of bone resorption in elderly women with osteoporosis.

Factors related to spinal mobility in patients with postmenopausal osteoporosis

Quality of life in patients with spinal osteoporosis is impaired by the decline of spinal mobility. However, the factors related to the spinal mobility in these patients are still unclear. We evaluated the possible factors affecting spinal mobility in patients with postmenopausal osteoporosis. A total of 128 postmenopausal women with osteoporosis aged over 50 years (mean, 70 years) were included in this study. The thoracic and lumbar kyphosis angles and range of motion (ROM) of the total spine were measured in the upright position and at maximum flexion/extension with a computer-assisted device. The paravertebral muscle thicknesses (PVMT) of thoracic and lumbar spine in the upright position were measured using an ultrasound unit. The number of vertebral fractures was evaluated with radiographs of the spine. Isometric back extensor strength (BES) was evaluated with a strain-gauge dynamometer. Correlations between these variables were then analyzed. Age (r=-0.412), lumbar kyphosis angle (r=-0.284), BES (r=0.369), PVMT at the lumbar spine (r=0.227) and the number of vertebral fractures (r=-0.260) showed significant correlations with total spinal ROM (P<0.05). However, no significant correlations were observed between the total spinal ROM and PVMT at the thoracic spine (r=-0.069) or thoracic kyphosis angle (r=-0.138). Multiple regression analysis revealed that the BES was the most significant contributor to the total spinal ROM. The present study suggests a possible association between BES and spinal mobility in patients with postmenopausal osteoporosis.

Small bowel bacterial overgrowth may not affect bone mineral density in older people

BACKGROUND & AIMS

Small bowel bacterial overgrowth (SBBO) may be associated with malnutrition, diarrhea, and weight loss. Recently, bone mineral density (BMD) in patients with SBBO was reported to be lower, and SBBO may be an important factor in the development of metabolic bone disease. However, the subjects in these studies were relatively young patients with intestinal diseases. There is no information on the effect of SBBO on BMD in older people.

METHOD

Seventeen relatively active and 33 disabled older people participated in this study. SBBO was determined by a breath hydrogen (H2) test after ingestion of a glucose solution. BMD of the lumbar spine and femur were measured using a dual energy X-ray absorptiometry scan (DEXA).

RESULTS

One healthy control and 11 disabled subjects were SBBO-positive. The Z-scores of the lumbar spine were not statistically different between groups, and a high incidence of disorders, >70%, was seen in all groups. On the other hand, there were significant differences in the femoral BMD between the healthy controls and the SBBO-negative (P<0.001) and SBBO-positive (P<0.05) groups. No significant difference was seen in femoral BMD between SBBO-positive and SBBO-negative institutionalized people.

CONCLUSION

SBBO seems to have little effect on BMD in people approximately 80 years old.

Efficacy of periodontal disease and tooth loss to screen for low bone mineral density in Japanese women

The relationship between oral indicators and bone mineral density (BMD) has been studied by many investigators, with mixed and complex results. The purpose of the present cross-sectional study was to evaluate the associations of periodontal conditions and tooth loss with metacarpal BMD (m-BMD) in a community-based cohort and the usefulness of tooth count as a potential screening tool to detect low BMD. Subjects were 356 Japanese women (171 premenopausal, mean age 37.9+/-8.0 years; 185 postmenopausal, mean age 63.3+/-7.7 years). Periodontal status was evaluated by the Community Periodontal Index of Treatment Needs (CPITN). m-BMD was measured by computerized X-ray densitometry. The proportion of subjects with periodontitis (CPITN 3 or 4) increased as m-BMD decreased. The odds ratio (OR) of osteopenia or osteoporosis in relation to periodontitis was 3.2 (95% confidence interval [CI], 2.0--5.3). After adjustment for age and menopausal status, the OR was 2.0 (95% CI, 1.1--3.7). Among postmenopausal women, those having fewer than 20 teeth were 1.6 times more likely to have low m-BMD than those having more than 20 teeth (chi-square for trend in postmenopausal group, 4.27; P<0.05). Receiver-operating curve (ROC) analysis indicated that number of teeth remaining or CPITN score had a greater than 50/50 chance to correctly identify women with osteoporosis or osteopenia, but the areas under the curve (0.72 and 0.67, respectively) are considered less than highly accurate screening tools. These results indicate that periodontitis and tooth loss after menopause may be useful indicators of m-BMD loss in Japanese women.

Evaluation of osteoporosis in X-ray CT examination: A preliminary study for an automatic recognition algorithm for the central part of a vertebral body using abdominal X-ray CT images

We have developed an algorithm that can distinguish the central part of the vertebral body from abdominal X-ray CT images to determine whether it is possible to aid a diagnosis of osteoporosis. We classified three measures for the principal component analysis and linear discriminant function. When we judged whether patients had osteoporosis or not, the ratio usable for diagnosing osteoporosis (sensitivity) was 1.00 (15/15), and for diagnosing as normal (specificity) was 0.64 (7/11). We believe that this algorithm can be used to aid in diagnosing osteoporosis, utilizing the measures obtained from the CT images.

Effect of whole-body vibration exercise on lumbar bone mineral density, bone turnover, and chronic back pain in post-menopausal osteoporotic women treated with alendronate

BACKGROUND AND AIMS

Exercise may enhance the effect of alendronate on bone mineral density (BMD) and reduce chronic back pain in elderly women with osteoporosis. The aim of this study was to determine whether whole-body vibration exercise would enhance the effect of alendronate on lumbar BMD and bone turnover, and reduce chronic back pain in postmenopausal women with osteoporosis.

METHODS

Fifty post-menopausal women with osteoporosis, 55-88 years of age, were randomly divided into two groups of 25 patients each: one taking alendronate (5 mg daily, ALN) and one taking alendronate plus exercise (ALN+EX). Exercise consisted of whole-body vibration using a Galileo machine (Novotec, Pforzheim, Germany), at an intensity of 20 Hz, frequency once a week, and duration of exercise 4 minutes. The study lasted 12 months. Lumbar BMD was measured by dual energy X-ray absorptiometry (Hologic QDR 1500W). Urinary cross-linked N-terminal telopeptides of type I collagen (NTX) and serum alkaline phosphatase (ALP) levels were measured by enzyme-linked immunosorbent assay and standard laboratory techniques, respectively. Chronic back pain was evaluated by face scale score at baseline and every 6 months.

RESULTS

There were no significant differences in baseline characteristics, including age, body mass index, years since menopause, lumbar BMD, urinary NTX and serum ALP levels, or face scale score between the two groups. The increase in lumbar BMD and the reduction in urinary NTX and serum ALP levels were similar in the ALN and ALN+EX groups. However, the reduction in chronic back pain was greater in the ALN+EX group than in the ALN group.

CONCLUSIONS

The results of this study suggest that whole-body vibration exercise using a Galileo machine appears to be useful in reducing chronic back pain, probably by relaxing the back muscles in post-menopausal osteoporotic women treated with alendronate.

Effect of treatment with alendronate in osteogenesis imperfecta type I: a case report

A case of osteogenesis imperfecta (OI), which was successfully treated with alendronate is reported. A 41-year-old premenopausal woman with OI type I, who had frequently been experiencing fragile fractures, consulted our clinic because of back pain associated with spinal osteoporosis. She had experienced heart surgery (aortic valve replacement) due to aortic regurgitation 5 years before her first consultation with our clinic. After the surgery, she had been taking warfarin 3 mg/day, and this treatment was continued during our follow-up period. She was treated with alendronate (5 mg/day, daily) for 18 months. The bone mineral density of the lumbar spine (L2-L4) measured by dual energy X-ray absorptiometry (Norland XR-36) increased for 18 months, and back pain markedly decreased. The urinary cross-linked N-terminal telopeptides of type I collagen and serum bone-specific alkaline phosphatase, osteocalcin, and undercarboxylated osteocalcin levels also markedly decreased. No new fragile vertebral or non-vertebral fractures were observed during the 18 months of treatment. This report provides evidence indicating that treatment with oral alendronate may have the potential to decrease bone turnover, improve the lumbar BMD, reduce back pain, and prevent new fragile fractures in premenopausal women with OI type I.

High-density linkage mapping revealed suppression of recombination at the sex determination locus in papaya

A high-density genetic map of papaya (Carica papaya L.) was constructed using 54 F(2) plants derived from cultivars Kapoho and SunUp with 1501 markers, including 1498 amplified fragment length polymorphism (AFLP) markers, the papaya ringspot virus coat protein marker, morphological sex type, and fruit flesh color. These markers were mapped into 12 linkage groups at a LOD score of 5.0 and recombination frequency of 0.25. The 12 major linkage groups covered a total length of 3294.2 cM, with an average distance of 2.2 cM between adjacent markers. This map revealed severe suppression of recombination around the sex determination locus with a total of 225 markers cosegregating with sex types. The cytosine bases were highly methylated in this region on the basis of the distribution of methylation-sensitive and -insensitive markers. This high-density genetic map is essential for cloning of specific genes of interest such as the sex determination gene and for the integration of genetic and physical maps of papaya.

Association of multiple nucleotide variations in the pituitary glutaminyl cyclase gene (QPCT) with low radial BMD in adult women

Correlation between 13 genetic variations of the glutaminyl-peptide cyclotransferase gene and adjusted aBMD was tested among 384 adult women. Among 13 variations with strong linkage disequilibrium, R54W showed a prominent association (p = 0.0003), which was more striking when examined among 309 elder subjects (> or =50 years; p = 0.0001). Contribution for postmenopausal bone loss was suggested.

INTRODUCTION

Alterations in homeostatic regulation of estrogen through the hypothalamus-pituitary-gonadal axis (HPG axis) importantly affect the pathogenesis of osteoporosis. Osteoporosis-susceptibility genes have been proposed in this hormonal axis, such as estrogen receptor genes and the gonadotropin-releasing hormone gene (GnRH). Here we report another example of genes: glutaminyl-peptide cyclotransferase gene (QPCT), an essential modifier of pituitary peptide hormones, including GnRH.

MATERIALS AND METHODS

Analyses of association of 13 single nucleotide polymorphisms (SNPs) at the QPCT locus with adjusted areal BMD (adj-aBMD) were carried out among 384 adult women. Linkage disequilibrium (LD) was analyzed by haplotype estimation and calculation of D' and r2. Multiple regression analysis was applied for evaluating the combined effects of the variations.

RESULTS AND CONCLUSIONS

LD analysis indicated strong linkage disequilibrium within the entire 30-kb region of the QPCT gene. Significant correlations were observed between the genotypes of the six SNPs and the radial adj-aBMD, among which R54W (nt + 160C>T) presented the most prominent association (p = 0.0003). Striking association was observed for these SNPs among the 309 subjects >50 years of age (R54W, p = 0.0001; -1095T>C, p = 0.0002; -1844C>T, p = 0.0002). Multiple regression analyses indicated that multiple SNPs in the gene might act in combination to determine the radial adj-aBMD. These results indicate that genetic variations in QPCT are the important factors affecting the BMD of adult women that contribute to susceptibility for osteoporosis. The data should provide new insight into the etiology of the disease and may suggest a new target to be considered during treatment.

Effects of alendronate on metacarpal and lumbar bone mineral density, bone resorption, and chronic back pain in postmenopausal women with osteoporosis

The purpose of this study was to investigate the effect of alendronate on metacarpal and lumbar bone mineral density (BMD), bone resorption, and chronic back pain in postmenopausal women with osteoporosis. Eighty postmenopausal women with osteoporosis, 59-88 years of age, were divided into two groups of 40 each according to the site of BMD measurement: the metacarpus (M) and the lumbar spine (L). All of them were treated with alendronate (5 mg/day) for 12 months. Metacarpal or lumbar BMD was measured by computed X-ray densitometry or dual-energy X-ray absorptiometry in the M or the L group, respectively, at baseline and every 6 months. Urinary cross-linked N-terminal telopeptides of type I collagen (NTX) were measured by enzyme-linked immunosorbent assay, and chronic back pain was evaluated by face scale score at baseline and every 6 months in both groups. There were no significant differences in baseline characteristics, including age, body mass index, years since menopause, urinary NTX level, face scale score, or number of prevalent vertebral fractures per patient between the two groups. Urinary NTX level was reduced and chronic back pain was improved similarly in both groups. Whereas metacarpal BMD did not significantly change in the M group (0.20% increase), lumbar BMD increased by 8.15% in the L group. These results suggest that although alendronate increases BMD of the lumbar spine, which is rich in cancellous bone, and improves chronic back pain, with suppression of bone resorption in postmenopausal women with osteoporosis, it may fail to increase cortical BMD of the metacarpus, a distal site of the upper extremity.

Efficacy of training program for ambulatory competence in elderly women

The optimal prevention of osteoporotic fractures in the elderly consists of increasing the bone density and preventing falls. We report on the efficacy of training program to promote ambulatory competence in elderly women. Twenty-five elderly women were enrolled in our training program, which is a three-month program consisting of dynamic balance training with Galileo 900 (Novotec, Pforzheim, Germany) once a week, combined with daily static balance (standing on one leg like a flamingo) and resistance (half-squat) training. The mean age of the participants was 72.8 years (range, 61-86 years). After 3 months of training, the step length, knee extensor muscle strength, and maximum standing time on one leg were significantly increased, while the walking speed and hip flexor muscle strength were not significantly altered. During the study period, no serious adverse events such as new vertebral fractures or adverse cardiovascular symptoms were observed in any participant. The present preliminary study shows that our training program may have the potential to promote ambulatory competence in elderly women.

Quantitative ultrasound of the calcaneus as a screening tool to detect osteoporosis: different reference ranges for caucasian women, african american women, and caucasian men

The interpretation of results measured by quantitative ultrasound (QUS) of the heel depends on the population studied. We measured estimated bone mineral density (BMD) of the heel using the Hologic Sahara sonometer. People were studied at county fairs, health fairs, and churches. Subjects were not on treatments that would affect bone density, other than calcium supplementation. This included 823 Caucasian women, 131 African American women, and 301 Caucasian men. In contrast to women, for Caucasian men the squared term for age was not significant, and a straight line of decline was the best fit for estimated BMD. African American women had a standard deviation larger than that reported by Hologic for Caucasian women. We compared a history of self-reported fractures with a subject's estimated BMD. An estimated BMD of 0.57 gm/cm2 included 75% of all fractures. This cutoff point was associated with increased fracture prevalence in subjects over age 50, relative risk of 1.4. This result corresponds to the Hologic data T-score of -0.2. When used as a screening tool for osteoporosis fracture risk, an estimated BMD of 0.57 gm/cm2 seems reasonable in those subjects over age 50.

Effects of cyclical etidronate with alfacalcidol on lumbar bone mineral density, bone resorption, and back pain in postmenopausal women with osteoporosis

The purpose of the present open-labeled, randomized, prospective study was to compare the effects of cyclical etidronate combined with alfacalcidol with those of cyclical etidronate alone on lumbar bone mineral density (BMD), bone resorption, and back pain in postmenopausal women with osteoporosis. Forty postmenopausal women with osteoporosis, 60-86 years of age, without any vertebral fractures in the lumbar spine, were randomly divided into two groups with 20 patients in each group. One group was treated with cyclical etidronate (oral etidronate 200 mg daily for 2 weeks every 3 months) and the other was given cyclical etidronate combined with alfacalcidol (cyclical etidronate plus alfacalcidol 1 Ig daily continuously). The BMD of the lumbar spine (L1-L4) measured by dual-energy X-ray absorptiometry, urinary crosslinked N-terminal telopeptides of type I collagen (NTX) measured by an enzyme-linked immunosorbent assay, and back pain evaluated by the face scale score were assessed at baseline, 6 months, and 12 months. There were no significant differences in baseline characteristics including age, body mass index, years since menopause, lumbar BMD, urinary NTX level, and face scale score between the two treatment groups. Both treatments significantly reduced the urinary NTX level and back pain. Cyclical etidronate combined with alfacalcidol significantly increased the lumbar BMD with a more significant reduction in the urinary NTX level than cyclical etidronate alone, but cyclical etidronate alone did not significantly increase the lumbar BMD. Alleviation of back pain was similar in the two groups. These results suggest that cyclical etidronate combined with alfacalcidol appears to be more useful than cyclical etidronate alone for increasing the lumbar BMD by more markedly suppressing bone resorption in postmenopausal women with osteoporosis.

Impact of postural deformities and spinal mobility on quality of life in postmenopausal osteoporosis

The objective of the study was to evaluate the impact of postural deformities and spinal mobility on quality of life (QOL) in patients with spinal osteoporosis. A total of 157 postmenopausal women aged over 60 years with osteoporosis were divided into five groups according to their postural deformities: round back (RB, n=41), hollow round back (HRB, n=33), whole kyphosis (WK, n=40), lower acute kyphosis (LAK, n=18), and normal posture (NP, n=25). QOL was evaluated using the Japanese Osteoporosis QOL Questionnaire (JOQOL) proposed by the Japanese Society for Bone and Mineral Research. This questionnaire contains six domains, with higher scores indicating higher levels of QOL. The number of vertebral fractures, thoracic kyphosis and lumbar lordosis angles, and spinal range of motion (ROM) during maximum flexion and extension were also measured with radiographs. Total QOL scores in RB, HRB, WK, and LAK groups were significantly lower than those in the NP group, and those in WK group were even lower compared with the other groups ( P<0.05). All the groups with postural deformities, but not the NP group, showed significant positive correlations between total QOL score and spinal ROM (0.521</= r</=0.747, P<0.05). Total QOL score showed a significant correlation with age, number of vertebral fractures, lumbar lordosis angle, and spinal ROM in a total of 157 patients. However, multiple regression analysis revealed that spinal ROM best correlated with total QOL score. We concluded that QOL in patients with osteoporosis was impaired by postural deformities, especially by whole kyphosis, and that spinal mobility has a strong effect on QOL in these patients.

Association of genetic variation of the RIL gene, encoding a PDZ-LIM domain protein and localized in 5q31.1, with low bone mineral density in adult Japanese women

Twin and family studies had shown that genetic factors are important determinants of bone mass. Multiple genes might be involved. One candidate gene, the reversion-induced LIM gene ( RIL), is a PDZ and LIM-domain-containing protein and has been localized within the cytokine cluster of chromosome 5 (5q31.1). In a genetic study of 370 adult Japanese women, we investigated the correlation between radial bone mineral density (BMD) and a genetic variation (-3333T-->C) of the 5'-flanking region of RIL gene. A significant association was identified between the RIL variation -3333T-->C and radial BMD ( r=0.15, P=0.003). The variation of the RIL locus may be an important determinant of osteoporosis.

Association of molecular variants, haplotypes, and linkage disequilibrium within the human vitamin D-binding protein (DBP) gene with postmenopausal bone mineral density

Possible contribution of vitamin D-binding protein (DBP) gene for determination of BMD was tested by characterizing 13 SNPs in 384 adult Japanese women. When the effect of a specific single SNP was tested, five SNPs (-39C>T, IVS1+827C>T, IVS1+1916C>T, IVS1-1154A>G, and IVS11+1097G>C) correlated with BMD significantly at various levels. The chromosomal dosage of one haplotype (T-C-C-G-T-C in -39C>T, IVS1+827C>T, IVS1+1916C>T, IVS1-1154A>G, D432E, and IVS11+1097G>C) displayed significant correlation with adjusted radial BMD (r = 0.15, p = 0.008; n = 331). Multiple regression analyses revealed a most significant correlation with the combination of IVS1+827C>T and D432E (r2 = 0.029, p = 0.005). These results indicate a complex combined effect of several SNPs within the DBP gene that might underlie susceptibility to low radial BMD and osteoporosis.

INTRODUCTION

Osteoporosis results from the interplay of multiple environmental and genetic determinants. The gene encoding vitamin D-binding protein (DBP), a key factor for regulating calcium homeostasis through the vitamin D endocrine system, is a probable candidate for conferring susceptibility to osteoporosis.

METHODS

To test a possible contribution of the DBP gene for determination of bone mineral density (BMD) of adult women, we have characterized 13 single nucleotide polymorphisms (SNPs) within the DBP gene in DNA from 384 adult Japanese women and attempted to correlate specific SNPs with BMD.

RESULTS AND CONCLUSIONS

Sixteen major haplotypes accounted for 80% of the variations, indicating allelic complexity in this genomic region. Pairwise linkage disequilibrium (LD), measured by the D' and r2 statistics, demonstrated a general pattern of decline with increasing distance, but individual LD values within small genomic segments were diverse. Regression analysis for adjusted BMD revealed significant correlation with respect to five of them (-39C>T, IVS1+827C>T, IVS1+1916C>T, IVS1-1154A>G, and IVS11+1097G>C) at various levels. An intronic SNP (IVS11+1097G>C) with the highest significance of association (p = 0.006) showed significant LD with four SNPs located around the first exon (r2 values > 0.18, D' > 0.5). A non-synonymous coding SNP, D432E, showed a comparable level of correlation, but it was in a moderate LD only with IVS11+1097G>C. The chromosomal dosage of one haplotype (T-C-C-G-T-C in -39C>T, IVS1+827C>T, IVS1+1916C>T, IVS1-1154A>G, D432E and IVS11+1097G>C) estimated in each subject displayed significant correlation with adjusted radial BMD (r = 0.15, p = 0.008; n = 331). Furthermore, multiple regression analyses revealed that the most significant correlation was achieved for the combination of IVS1+827C>T and D432E (r2 = 0.029, p = 0.005). These results indicate a complex combined effect of several SNPs within the DBP gene that might underlie susceptibility to low radial BMD and osteoporosis.

Effects of treatment with etidronate and alfacalcidol for osteogenesis imperfecta type I: a case report

A case of osteogenesis imperfecta (OI) that was successfully treated with oral etidronate and alfacalcidol is reported. A 36-year-old man with OI type I who had frequently been experiencing fragile fractures in the long bones of the upper and lower extremities presented to our hospital with back pain caused by fragile thoracic vertebral fractures. He was treated with intermittent cyclical etidronate (200 mg/day for 2 weeks per 3 months) and alfacalcidol (1 microgram/day, daily) over 18 months. The bone mineral density of the lumbar spine (L1-L4) measured by dual-energy X-ray absorptiometry (Hologic QDR 1500 W) increased over 18 months, and back pain due to thoracic vertebral fractures markedly decreased. No new fragile vertebral or nonvertebral fractures were observed during the 18 months of treatment. This report provides evidence indicating that treatment with intermittent cyclical oral etidronate and alfacalcidol has potential use in adult patients with OI type I.

Association of a promoter haplotype (-1542G/-525C) in the tumor necrosis factor receptor associated factor-interacting protein gene with low bone mineral density in Japanese women

Osteoporosis, a multifactorial common disease, is believed to result from the interplay of multiple environmental and genetic factors that regulate bone mineral density (BMD). Tumor necrosis factor receptor associated factor-interacting protein (I-TRAF) is an essential effecter of the tumor necrosis factor receptor-signaling cascade, one of the most potent bone-resorbing systems. In genetic studies of 382 Japanese adult women, we found that genotypes of two promoter variations of I-TRAF gene, -1542T/G and -525G/C, were similarly associated with radial BMD levels. Two variations were in almost complete linkage disequilibrium (D' = 0.978, r(2) = 0.917, chi(2) = 695, 2, P = 3.4 x 10(-153)), and there were two exclusive haplotypes (-1542T/-525C, frequency 0.74, and -1542G/-525G, frequency 0.24) among our test subjects. When BMD values were compared among the three haplotypic categories (-1542G/-525G homozygotes, heterozygotes, and -1542T/-525C homozygotes), BMD was lowest among -1542G/-525C homozygotes (mean +/- SD = 0.382 +/- 0.060 g/cm(2)), highest among -1542T/-525G homozygotes (0.405 +/- 0.051 g/cm(2)), and intermediate among heterozygotes (0.395 +/- 0.056 g/cm(2)) (r = 0.11, P = 0.030). The observed trend supported a codominant effect of the relevant haplotype of I-TRAF gene in determination of radial BMD. These results suggested that variation of I-TRAF might be an important determinant for postmenopausal osteoporosis.

Dental panoramic radiograph as a tool to detect postmenopausal women with low bone mineral density: untrained general dental practitioners' diagnostic performance

The detection of postmenopausal women with low bone mineral density (BMD) is an important strategy to reduce the incidence of osteoporotic fracture. Recent studies suggested that incidental findings on dental panoramic radiographs may be used as a tool to detect women with low BMD. However, little is known whether this finding is sufficiently assessed by untrained general dental practitioners (GDPs). The purpose of this study was to investigate: (1) the observer agreement and (2) the diagnostic efficacy in detecting women with low BMD, when untrained GDPs assess the appearance (normal or eroded) of the mandibular inferior cortex on dental panoramic radiographs of postmenopausal women. Twenty-seven GDPs were asked to classify the appearance of the mandibular inferior cortex on dental panoramic radiographs of 100 postmenopausal women who had completed BMD assessments of the lumbar spine and of the femoral neck. Intra-and inter-observer agreements were analyzed with kappa statistics. The diagnostic efficacy (sensitivity, specificity and predictive values) was analyzed by comparing two groups classified by the mandibular inferior cortex (women with normal and women with eroded mandibular inferior cortex) with those classified by BMD (women with normal BMD and women with osteopenia or osteoporosis). The mean sensitivity and specificity were 77% and 40%, respectively, when BMD of the lumbar spine was used as standard and 75% and 39%, respectively, when BMD of the femoral neck comprised the standard. Nineteen untrained GDPs (70%) presented a moderate to almost perfect intra-observer agreement. We conclude that dental panoramic radiograph may be used in clinical dental practice to identify postmenopausal women who have undetected low BMD and should undergo further testing with bone densitometry.

Kyphoplasty for vertebral compression fractures: 1-year clinical outcomes from a prospective study

OBJECT

Over the past 15 years, vertebroplasty has emerged as a treatment for vertebral compression fractures. This technique, however, does not restore vertebral height and is associated with a high rate of cement leakage. Recently, kyphoplasty was developed in an effort to circumvent this problem. Although its immediate results have been reported, it is unclear whether the benefits endure.

METHODS

Seventy-eight consecutive patients underwent 188 kyphoplasty procedures. The patients responded to Short Form-36 (SF-36) questionnaires, a visual analog scale (VAS) for pain rating, and the Oswestry disability index (ODI) instrument; additionally they underwent detailed neurological and radiographic examinations pre- and postoperatively. The preoperative SF-36, VAS, and ODI scores, the neurological examination results, and the radiographic data were compared with the postoperative findings. Thirteen patients died of disease progression or unrelated illness. Of the surviving patients, complete data were available in 62% (minimum follow-up period 12 months, mean 18 months). Complications included one myocardial infarction and five cases of asymptomatic cement extravasation. No case of neurological deterioration occurred during the follow-up period. Significant improvements in seven measures of the SF-36 inventory as well as on the ODI and VAS were noted early postoperatively, and these persisted throughout the follow-up period, despite a statistically insignificant decline in the measure of general health at last follow-up examination.

CONCLUSIONS

Kyphoplasty is an effective treatment for vertebral compression fractures. The benefits presented in the early postoperative period and persisted at 1 year posttreatment.

Effects of projective bone area size of the spine on bone density and the diagnosis of osteoporosis in healthy pre-menopausal women in China

The aim of this study was to understand the effects of projective bone area (BA) size of the spine on bone density and the diagnosis of osteoporosis. Measurements of BA, bone mineral content (BMC), areal bone density (aBMD) and volumetric bone density (vBMD) at the posteroanterior (PA) lumbar spine (vertebrae L2-L4) followed by a paired PA/lateral spine (L2-L4) were made using a dual-energy X-ray absorptiometry (DXA) fan-beam bone densitometer (Hologic QDR 4500A) in 1436 healthy pre-menopausal women aged from 20 to 56-years-old. At the PA and lateral lumbar spine, there was a significant positive correlation between BA and BMC (r=0.762 and 0.762, p=0.000) and aBMD (r=0.370 and 0.352, p=0.000), but not vBMD (r=0.000 and 0.102, p=0.813 and 0.063). When BA at the PA spine changed by one standard deviation (SD), BMC and aBMD correspondingly changed by 12.6% and 4.3% on the basis of their respective means while vBMD indicated no change. When a variation of 1 SD was observed in BA at the lateral spine, BMC, aBMD and vBMD correspondingly changed by 13.8%, 4.4% and 1.73% on the basis of their respective means. Through an intercomparison among large, intermediate and small BA groups, significant differences were found in the means of subject's height, weight, BMC and aBMD at the PA and lateral spine as well as the detection rate of osteoporosis by aBMD (p=0.000). Detection rates of osteoporosis by aBMD at the PA, lateral spine and vBMD in healthy pre-menopausal women aged from 40 years to 56 years were 4.5%, 16.4% and 9.7%, respectively, in the small BA group; 1.3%, 6.4% and 7.3%, respectively, in the intermediate BA group; and 0, 0 and 5.5%, respectively, in the large BA group. No significant differences were found in the detection rates of osteoporosis by vBMD among the groups. The results of multiple linear regression revealed that the major factors influencing BA of the lumbar spine was height. In healthy pre-menopausal women of the same race and age, the BA size of the lumbar spine would have significant influence upon aBMD and the diagnosis of osteoporosis, i.e. the larger the BA, the greater the aBMD and the lower the osteoporosis detection rate while conversely, the smaller the BA, the smaller the aBMD and the higher the osteoporosis detection rate. Though vBMD does not change with BA sizes of the lumbar spine, it is a sensitive marker for diagnosing osteoporosis.

Extraordinarily low bone mineral density in an old female chimpanzee (Pan troglodytes schweinfurthii) from the Mahale Mountains National Park

We examined bone mineral density (BMD) of the femoral neck and lumbar vertebrae of four chimpanzee skeletons from Mahale Mountains National Park, Tanzania, and four captive ones, with a dual energy X-ray absorptiometer. The BMD of Wansombo, an old female chimpanzee from Mahale, was remarkably lower than the mean of the other six younger adult female chimpanzees and categorized as osteoporosis. Posture, locomotion, and trunk-sacral anatomy of chimpanzees may have prevented fractures in Wansombo, whose BMD was below human osteoporosis criteria.

Association of a haplotype (196Phe/532Ser) in the interleukin-1-receptor-associated kinase (IRAK1) gene with low radial bone mineral density in two independent populations

Osteoporosis, a multifactorial common disease, is believed to result from the interplay of multiple environmental and genetic determinants, including factors that regulate bone mineral density. Interleukin-1 (IL-1) is one of the most potent bone-resorbing factors, and interleukin-1-associated kinase 1 (IRAK1) is an essential effector of the IL-1 receptor signaling cascade. In genetic studies of two independent populations of postmenopausal women (cohort A: 220 individuals and cohort T: 126 individuals) from separated geographical regions of Japan, we found that radial bone mineral density levels had similar associations with IRAK1 genotypes in both populations. Two amino acid-substituting variations in the gene, encoding Phe196Ser and Ser532Leu, were in complete linkage disequilibrium (D' = 1.0000, r2 = 1.0000, chi2 = 192.000, p = 1.2 x 10(-43)), and we found two exclusive haplotypes (196F/532S, frequency 0.74; 196S/532L, frequency 0.26) of the IRAK1 gene among our test subjects. In both populations, a significant association with decreased radial bone mineral density was identified with haplotype 196F/532S (in cohort A: r = 0.21, p = 0.0017; in cohort T: r = 0.23, p = 0.011). Radial bone mineral density was lowest among 196F/532S homozygotes, highest among 196S/532L homozygotes, and intermediate among heterozygotes. Accelerated bone loss also correlated with the 196F/532S haplotype in a 5-year follow-up. These results suggest that variation of IRAK1 may be an important determinant of postmenopausal osteoporosis, in part through the mechanism of accelerated postmenopausal bone loss.

Association of a Trp16Ser variation in the gonadotropin releasing hormone signal peptide with bone mineral density, revealed by SNP-dependent PCR typing

Osteoporosis is believed to result from interplay among multiple environmental and genetic determinants, including factors that regulate bone mineral density (BMD). Among those factors, adequate estrogen is essential for achievement of peak bone mass as well as for postmenopausal maintenance of skeletal homeostasis. Gonadotropin-releasing hormone (GnRH) from the hypothalamus is the primary determinant in the hypothalamic-pituitary-gonadal feedback system. In genetic studies of 384 postmenopausal Japanese women, we found a significant association between BMD and an amino acid variation (Trp16Ser) located within the signal peptide of GnRH (r = 0.143, P = 0.005). These results were achieved by genotyping all subjects using a newly developed SNP-dependent PCR method. This automated, high-throughput, and inexpensive procedure is suitable for typing large numbers of samples. BMD was lowest among 16Ser/Ser homozygotes, highest among 16Trp/Trp homozygotes, and intermediate among heterozygotes. A case-control study involving 125 osteoporosis patients and 92 healthy controls revealed a significant association between the presence of a 16Ser GnRH allele and affected status (chi(2) = 4.74, P = 0.041). The results suggested that variation of the GnRH signal peptide may be an important risk factor for postmenopausal osteoporosis.

[Pharmacotherapy of osteoporosis]

Osteoporosis with increased risk of bone fracture is a disabling syndrome that naturally occurs as long as one ages and moves on two legs. Recent progress in bone cell biology has shed light on the mechanisms underlying the anti-osteoporotic properties of drugs that have been in use for a long time, providing a fresh stage for novel pharmacotherapies. In addition, large scale clinical trials developed in the past decade appear not only to rationalize the clinical utilities of these drugs but also to provide new concepts for the development of new therapeutic modalities. Progress in the fields of basic and clinical research field is briefly reviewed herein.