Spine Bone Mineral Density T-score Research Articles

Quantitative computed tomography (QCT) of the forearm using general purpose spiral whole-body CT scanners: Accuracy, precision and comparison with dual-energy X-ray absorptiometry (DXA)

BackgroundDual-energy X-ray absorptiometry (DXA) allows clinically relevant measurement of bone mineral density (BMD) at central and appendicular skeletal sites, but DXA has a limited ability to assess bone geometry and cannot distinguish between the cortical and trabecular bone compartments. Quantitative computed tomography (QCT) can supplement DXA by enabling geometric and compartmental bone assessments. Whole-body spiral CT scanners are widely available and require only seconds per scan, in contrast to peripheral QCT scanners, which have restricted availability, limited spatial resolution, and require several minutes of scanning time.This study evaluated the accuracy and precision of whole-body spiral CT scanners for quantitatively assessing the distal radius, a common site of non-vertebral osteoporosis-related fractures, and compared the CT-measured densitometric values with those obtained from dual-energy-X-ray absorptiometry. Subjects and methodsA total of 161 postmenopausal women with baseline lumbar spine BMD T-scores between −1.0 and −2.5 underwent left forearm QCT using whole-body spiral CT scanners twice, 1 month apart. QCT volumes of interest were defined and analyzed at 3 specific radial regions: the ultradistal region by using slices at 8, 9, and 10 mm proximal to the ulnar styloid tip; the distal region by a slice 20 mm proximal; and the middle region by a slice 40 mm proximal. BMD, bone mineral content (BMC), volume, and average cortical thickness and circumference were measured. We evaluated QCT accuracy and precision and also report correlations between QCT and DXA for BMD and BMC. ResultsOverall accuracy and precision errors for BMD, BMC and volume were consistent with known skeletal QCT technology precision and were generally less than 3%. BMD and BMC assessed by QCT and DXA were correlated (r=0.55 to 0.80). DiscussionWhole-body spiral CT scanners allow densitometric evaluations of the distal radius with good accuracy and very good precision. This original and convenient method provides a tool to further investigate cortical and trabecular bone variables in the peripheral skeleton in osteoporotic patients. These assessments, coupled with evaluation of the effects on cortical and trabecular bone measured in response to therapies for osteoporosis, may advance our understanding of the contributors to non-vertebral fracture occurrence.

Efficacy and safety of monthly oral ibandronate in the prevention of postmenopausal bone loss

Introduction Monthly oral ibandronate has been shown to increase bone mineral density (BMD) and reduce bone turnover in postmenopausal women with osteoporosis, but its efficacy has not been investigated in women with low bone mass. The objective of this study was to examine the efficacy and safety of monthly oral ibandronate (150 mg) treatment in postmenopausal women with low bone mass. Methods This 1-year, double-blind, placebo-controlled, randomized study enrolled ambulatory postmenopausal women aged 45–60 years with baseline lumbar spine (LS) BMD T-score < − 1.0 and > − 2.5 and baseline T-score > − 2.5 at the total hip, trochanter, and femoral neck (collectively defined as the proximal femur) and no prior vertebral or low-trauma osteoporotic fractures at baseline. Subjects received either 150 mg monthly oral ibandronate or placebo. All subjects received calcium and vitamin D supplements. The primary endpoint was the relative change from baseline (%) in mean LS BMD at 1 year (intent-to-treat population). Treatment groups were compared by means of a two-way ANOVA model which adjusted for independent factors including treatment group, baseline LS BMD T-score, and time since menopause. Responder analyses examined the percentage of participants with changes from baseline in LS BMD and proximal femur BMD ≥ 0%. Adverse events and safety laboratory parameters were monitored continuously. Results A total of 77 women received monthly ibandronate and 83 women received placebo. Subjects treated with ibandronate achieved larger increases in LS BMD after 1 year compared with subjects receiving placebo (3.7% vs − 0.4% [difference of 4.1%, p < 0.0001]). After 3 months, median serum C-terminal telopeptide of type I collagen levels were reduced by > 55% in the ibandronate group compared with ∼ 4% in the placebo group. At 1 year, 88.2% of the participants treated with ibandronate achieved increases in LS BMD ≥ 0% compared with 38.6% of subjects receiving placebo. Treatment regimens were well tolerated in both the ibandronate-treated and placebo groups. Conclusion Monthly ibandronate therapy prevents bone loss in postmenopausal women with low bone mass.

Sustained efficacy of risedronate in men with primary and secondary osteoporosis: results of a 2-year study

The aim of this study was to assess the effect of treatment with risedronate 5 mg daily relative to control in men with primary or secondary osteoporosis over 2 years. Osteoporosis is a common condition in men that can have serious clinical consequences. In an earlier interim report, we found that 1 year of risedronate therapy resulted in significant increases in bone mineral density (BMD) and a significant reduction in vertebral fractures compared to control in men with osteoporosis. We conducted an open-label, prospective, match-control trial on men with primary or secondary osteoporosis in a single center, outpatient setting. Men with primary or secondary osteoporosis, as defined by a baseline lumbar spine BMD T-score < or = -2.5 and a baseline femoral neck BMD T-score < or = 2.0, were eligible for this study. Patients who had been treated with bisphosphonates or fluoride within the last 12 months were excluded. A total of 316 men were randomized to risedronate (n = 158) or control (n = 158). Patients were stratified by the presence of prevalent vertebral fractures at baseline and case by case allocated to either daily treatment with risedronate 5 mg daily plus calcium (1,000 mg) and vitamin D (800 IU) or to a control group (daily alfacalcidol (1 microg) plus calcium (500 mg) for those with prevalent vertebral fractures; daily vitamin D (800 IU) plus calcium (1,200 mg) for those without previous vertebral fractures). Primary study end points were identified prior to study initiation as the incidence of new vertebral fractures and changes in BMD at the lumbar spine, femoral neck, and total hip. Other end points included incidence of nonvertebral fractures and change in body height and back pain. Compared to control, the incidence of new vertebral fractures was significantly reduced in the risedronate 5 mg daily group at 2 years [14/152 (9.2%) for risedronate vs. 35/148 (23.6%) for control (61% risk reduction; P = 0.0026)]. Treatment with risedronate 5 mg daily also resulted in significant improvements in BMD at 2 years at all three skeletal sites (lumbar spine, 6.5 vs. 2.2%; femoral neck, 3.2 vs. 0.6%; total hip, 4.4 vs. 0.4% (P < 0.001 for all treatment comparisons). Significant reductions in the incidence of nonvertebral fractures (11.8 vs. 22.3%; P = 0.032), average loss in height, and back pain were also observed in risedronate-treated patients relative to control. In this 2-year study, daily 5 mg risedronate significantly reduced the risk of vertebral and nonvertebral fractures, improved BMD, decreased height loss, and reduced back pain in men with osteoporosis. Efficacy was sustained over 2 years; a consistent 60-61% risk reduction in vertebral fractures was observed at 1 and 2 years, respectively. These data demonstrate that daily risedronate is effective long-term therapy for men with primary or secondary osteoporosis.

Effects of Denosumab on Bone Mineral Density and Bone Turnover in Postmenopausal Women

Denosumab is an investigational fully human monoclonal antibody against receptor activator of nuclear factor-kappaB ligand, a mediator of osteoclastogenesis and osteoclast survival. This study evaluated the ability of denosumab to increase bone mineral density (BMD) and decrease bone turnover markers (BTMs) in early and later postmenopausal women with low BMD. This 2-yr randomized, double-blind, placebo-controlled study was conducted in North America. Subjects included 332 postmenopausal women with lumbar spine BMD T-scores between -1.0 and -2.5. SUBJECTS were randomly assigned to receive denosumab sc, 60 mg every 6 months, or placebo. Randomization was stratified by time since onset of menopause (< or =5 yr or > 5 yr). The primary end point was the percent change in lumbar spine BMD by dual-energy x-ray absorptiometry at 24 months. Additional end points were percent change in volumetric BMD of the distal radius by quantitative computed tomography; percent change in BMD by dual-energy x-ray absorptiometry for the total hip, one-third radius, and total body; hip structural analysis; percent change in BTMs; and safety. Denosumab significantly increased lumbar spine BMD, compared with placebo at 24 months (6.5 vs. -0.6%; P<0.0001) with similar results for both strata. Denosumab also produced significant increases in BMD at the total hip, one-third radius, and total body (P < 0.0001 vs. placebo); increased distal radius volumetric BMD (P < 0.01); improved hip structural analysis parameters; and significantly suppressed serum C-telopeptide, tartrate-resistant acid phosphatase-5b, and intact N-terminal propeptide of type 1 procollagen. The overall incidence of adverse events was similar between both study groups. Twice-yearly denosumab increased BMD and decreased BTMs in early and later postmenopausal women.

Effects of Atorvastatin on Bone in Postmenopausal Women with Dyslipidemia: A Double-Blind, Placebo-Controlled, Dose-Ranging Trial

In preclinical models, inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A reductase have been shown to positively affect bone remodeling balance. Observational studies and secondary analyses from lipid-lowering trials have yielded inconsistent results regarding the effect of these agents on bone mineral density and fracture risk. Our objective was to determine whether clinically significant skeletal benefits result from hydroxymethylglutaryl-coenzyme A reductase inhibition in postmenopausal women. We conducted a prospective, randomized, double-blind, placebo-controlled, dose-ranging comparative clinical trial at 62 sites in the United States. Participants included 626 postmenopausal women with low-density lipoprotein cholesterol levels of at least 130 mg/dl (3.4 mmol/liter) and less than 190 mg/dl (4.9 mmol/liter), and lumbar (L1-L4) spine bone mineral density T-score between 0.0 and -2.5. Once-daily placebo or 10, 20, 40, or 80 mg atorvastatin was administered. We assessed percent change from baseline in lumbar (L1-L4) spine bone mineral density with each dose of atorvastatin compared with placebo. At 52 wk, there was no significant difference between each atorvastatin and placebo group or change from baseline at any tested dose of atorvastatin or placebo in lumbar (L1-L4) spine bone mineral density. Nor did atorvastatin produce a significant change in bone mineral density at any other site. Changes in biochemical markers of bone turnover did not differ significantly between each atorvastatin and placebo group. All doses of atorvastatin were generally well tolerated, with similar incidences of adverse events across all dose groups and placebo. Clinically relevant doses of atorvastatin that lower lipid levels had no effect on bone mineral density or biochemical indices of bone metabolism in this study, suggesting that such oral agents are not useful in the prevention or treatment of osteoporosis.

Intravenous zoledronic acid 5 mg in the treatment of postmenopausal women with low bone density previously treated with alendronate

This randomized, double-blind, double-dummy, multicenter trial assessed safety and efficacy of a single dose of IV zoledronic acid (ZOL) 5 mg vs. oral alendronate (ALN) 70 mg weekly in postmenopausal women with low bone mineral density (BMD) who had previously been treated with ALN. Postmenopausal women who were receiving oral ALN for at least 1 year immediately prior to randomization and with lumbar spine or femoral neck BMD T-score values ≤ − 2.0 prior to initiation of ALN were randomized to one 15-min IV infusion of ZOL 5 mg plus 52 weeks of oral placebo ( n = 113) or one IV infusion of placebo plus 52 weeks of oral ALN 70 mg ( n = 112). End points included percent change in lumbar spine BMD from baseline to month 12 and relative change from baseline in urine N-telopeptide of type I collagen (NTX), serum C-telopeptide of type I collagen (CTX), amino terminal propeptides of type I collagen (PINP), and bone-specific alkaline phosphatase (bone ALP) over 12 months. Adverse events, bone histomorphometry and microscopic appearance, and patient preference for the 2 treatment regimens were also assessed. In this study, a single infusion of ZOL 5 mg maintained BMD 12 months following the switch from oral ALN in women with osteoporosis. The mean duration of prior ALN therapy at baseline was 4 years. Mean biomarker levels in the ALN 70-mg group remained at or close to baseline levels for the duration of the study. In the ZOL 5-mg group, mean biomarker levels were reduced from baseline after 3 months, returned to baseline after 6 months, and increased thereafter but remained within the premenopausal range. The overall rates of adverse events were comparable in the 2 groups (ZOL 5 mg, 86.7%; ALN 70 mg, 80.4%). Headache occurred more commonly within the first 3 days after infusion with ZOL 5 mg (12.4%) than with ALN 70 mg (6.3%). Bone biopsies indicate that both treatments decrease excessive remodeling seen in osteoporosis. The majority (78.7%) of patients expressed preference for once yearly infusion over weekly oral therapy. We conclude that patients can be switched from oral ALN to ZOL 5 mg infusion with maintenance of therapeutic effect for at least 12 months and that patients prefer a once yearly infusion to weekly oral therapy.

Association between vertebral fracture and increased mortality in osteoporotic patients.

Determinants of mortality were studied in a prospective study of 677 women and men with primary or secondary osteoporosis. Prevalent vertebral fractures were associated with increased mortality, but other known predictors of mortality explain a significant proportion of the excess risk. In population studies, prevalent vertebral fractures are associated with increased mortality. It is unknown whether this excess mortality is related to low bone mineral density or its determinants or whether there is an additional component associated with fracture itself. We studied 677 women and men with osteoporosis, 28-88 years old, of whom 352 had morphometrically determined vertebral fracture, to examine the risk and causes of mortality in patients with osteoporosis (defined densitometrically as a spine bone mineral density T-score < -2.5 and -3.0 for women and men, respectively, and/or one or more prevalent vertebral fractures without a history of significant trauma). The participants had enrolled in a double-blind placebo-controlled study in osteoporosis and were comprised of 483 women with postmenopausal osteoporosis, 110 women with secondary osteoporosis, and 84 men with osteoporosis of any cause. Demographics, medical history, and other measures of skeletal and nonskeletal health status were assessed at entry. During a median follow-up of 3.2 years, 37 (5.5%) participants died, with 31 of these deaths occurring in those with prevalent vertebral fractures. Compared with participants who did not have a prevalent vertebral fracture, those with one or more fractures had a 4.4-fold higher (95% CI, 1.85, 10.6) mortality rate. After adjustment for predictors for poor health--including number of medications, number of diseases, use of oral corticosteroids, alcohol intake, serum albumin and erythrocyte sedimentation rate (ESR), renal function, height, weight, gender, and age--the point estimate of risk remained elevated but was no longer statistically significant (hazard ratio, 2.4; 95% CI, 0.93, 6.23). Prevalent vertebral fractures in osteoporotic patients are associated with increased mortality. Other known predictors of mortality can explain a significant proportion of the excess risk.

Densitometric diagnosis of osteoporosis in men: effect of measurement site and normative database.

Controversy exists regarding which sites to measure, and the appropriate reference database to use, for densitometric diagnosis of osteoporosis in men. While hip and spine bone mineral density (BMD) measurement is routine, spinal osteoarthritis often elevates measured BMD in older men. Additionally, the use of male reference data is standard practice; however, recent reports suggest that a female database may be more appropriate. This study evaluated the effect of sites measured, and normative database utilized, on the densitometric diagnosis of osteoporosis in men. Spine, femur, and ultradistal radial BMD T-scores were determined in 595 male veterans using the GE Lunar male normative database. Subsequently, World Health Organization diagnostic criteria were applied, identifying 282 men with osteoporosis (T-score </= 2.5). The combination of femoral (lowest of neck or total) with the ultradistal radius site was more sensitive (p < 0.0001) for diagnosing osteoporosis than femur plus lumbar spine. When scans from 129 subjects with documented fractures were analyzed using female normative data, fewer (p < 0.0001) met an arbitrary threshold for receiving pharmacologic osteoporosis therapy. In conclusion, BMD measurement at only the spine and hip leads to underdiagnosis of osteoporosis in men. This situation will be exacerbated by utilization of a female normative database; more men with prior fracture may be categorized as not meeting a pharmaceutical intervention threshold.

Increased urinary N-telopeptide cross-linked type 1 collagen predicts bone loss in patients with inflammatory bowel disease

OBJECTIVE: Reduced bone mineral density (BMD) is common in patients with inflammatory bowel disease (IBD), but the factors associated with its longitudinal rate of change have not been established. We prospectively assessed the rate of change in BMD, and its association with biochemical markers of bone turnover. METHODS: Twenty-two patients with Crohn’s disease and 14 ulcerative colitis patients age 37.1 ± 11.6 yr were followed for 2 yr. Lumbar spine (L2–L4) and femoral neck BMD were measured by dual x-ray absorptiometry at baseline and 24 months. Bone-specific alkaline phosphatase, osteocalcin, urinary N-telopeptide crosslinked type 1 collagen (NTx), parathyroid hormone, and 25-hydroxyvitamin-D were determined at baseline. RESULTS: At baseline, 59% of Crohn’s patients and 43% of ulcerative colitis patients were osteoporotic, with spine or femoral neck BMD T-score <−2.5. Spine BMD, and spine and femoral neck T-scores were lower and disease duration was longer in nine patients with ileal resection compared with nonoperated patients (0.84 ± 0.15 g/cm 2 vs 0.96 ± 0.11 g/cm 2, −3.0. ± 1.5 vs −1.7 ± 1.3, −3.2 ± 1.5 vs −2.2 ± 1.0, respectively; all p < 0.05). At 24 months, 13/36 (36%) and 14/36 (39%) patients experienced spinal and femoral neck bone loss, respectively, with mean annual percent BMD changes of −2.0% and −1.5%, respectively. NTx, a bone resorption marker, inversely correlated with spinal BMD rate of change (r = −0.4, p < 0.05). Using quartiles analysis, patients with the highest NTx (Q4) experienced the greatest decrease in spine BMD compared with patients with the lowest NTx (Q1). CONCLUSIONS: Spine and femoral neck bone loss continues over time in more than one-third of IBD patients. Increased NTx level predicts spinal bone loss in IBD patients.

Increased urinary N-telopeptide cross-linked type 1 collagen predicts bone loss in patients with inflammatory bowel disease.

Reduced bone mineral density (BMD) is common in patients with inflammatory bowel disease (IBD), but the factors associated with its longitudinal rate of change have not been established. We prospectively assessed the rate of change in BMD, and its association with biochemical markers of bone turnover. Twenty-two patients with Crohn's disease and 14 ulcerative colitis patients age 37.1 +/- 11.6 yr were followed for 2 yr. Lumbar spine (L2-L4) and femoral neck BMD were measured by dual x-ray absorptiometry at baseline and 24 months. Bone-specific alkaline phosphatase, osteocalcin, urinary N-telopeptide crosslinked type 1 collagen (NTx), parathyroid hormone, and 25-hydroxyvitamin-D were determined at baseline. At baseline, 59% of Crohn's patients and 43% of ulcerative colitis patients were osteoporotic, with spine or femoral neck BMD T-score < -2.5. Spine BMD, and spine and femoral neck T-scores were lower and disease duration was longer in nine patients with ileal resection compared with nonoperated patients (0.84 +/- 0.15 g/cm2 vs 0.96 +/- 0.11 g/cm2, -3.0 +/- 1.5 vs -1.7 +/- 1.3, -3.2 +/- 1.5 vs -2.2 +/- 1.0, respectively; all p < 0.05). At 24 months, 13/36 (36%) and 14/36 (39%) patients experienced spinal and femoral neck bone loss, respectively, with mean annual percent BMD changes of -2.0% and -1.5%, respectively. NTx, a bone resorption marker, inversely correlated with spinal BMD rate of change (r = -0.4, p < 0.05). Using quartiles analysis, patients with the highest NTx (Q4) experienced the greatest decrease in spine BMD compared with patients with the lowest NTx (Q1). Spine and femoral neck bone loss continues over time in more than one-third of IBD patients. Increased NTx level predicts spinal bone loss in IBD patients.