Neil Binkley

University of Wisconsin–Madison, Madison, Wisconsin, United States

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Publications (162)479.01 Total impact

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    ABSTRACT: For patients undergoing screening computed tomography colonography (CTC), an opportunity exists for bone mineral density (BMD) screening without additional radiation exposure using quantitative computed tomography (QCT). This study investigated the use of dual-energy X-ray absorptiometry (DXA)-equivalent QCT Computed Tomography X-Ray Absorptiometry (CTXA) analysis at the hip obtained using CTC examinations using a retrospective asynchronous calibration of patient scans. A cohort of 33 women, age 61.3 (10.6) yr (mean [standard deviation]), had routine CTC using various GE LightSpeed CT scanner models followed after 0-9 mo by a DXA hip BMD examination using a GE Lunar Prodigy machine. Areal bone mineral density (aBMD) and T-scores of the proximal femur were measured from either prone or supine CTC examinations using Mindways QCT Pro software following standard workflow except that the CT scanners were asynchronously calibrated by phantoms scanned retrospectively of the CTC examination without the subject present. CTXA and DXA aBMD were highly correlated (R(2) = 0.907) with a linear relationship of DXA_BMD = 1.297*CTXA_BMD + 0.048. The standard error of estimate (SEE) on the linear fit was 0.053 g/cm(2). CTXA and DXA T-scores showed a linear relationship of DXA_T-score = 1.034*CTXA_T-score + 0.3 and an SEE of 0.379 T-scores. CTXA and DXA aBMD and T-score measurements showed good correlation despite asynchronous scan acquisition and retrospective QCT calibration. The SEE of 0.053 g/cm(2) is on par with the literature comparing Hologic and Lunar DXA devices. The observed relationship between CTXA and Lunar DXA aBMD matches predictions from published cross-calibrations relating CTXA to DXA aBMD measurement. Thus, opportunistic use of CTXA T-scores obtained at the time of CTC could enhance osteoporosis screening.
    Journal of clinical densitometry : the official journal of the International Society for Clinical Densitometry. 05/2014;
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    ABSTRACT: Context: Accumulated dysregulation across multiple physiological systems, or allostatic load (AL), has been proposed as the biological pathway from psychosocial adversity to poor health. Objective: To examine whether AL, constructed using biomarkers and medication data from seven systems (sympathetic, parasympathetic, hypothalamic-pituitary-adrenal axis, cardiovascular regulation, inflammation, and lipid and glucose metabolism), is associated with lower bone strength in a national sample. Design: Cross sectional study. Setting and Participants: 703 community dwelling men and women from the Study of Midlife in the United States. Outcome Measures: Bone mineral density (BMD) was measured in the femoral neck and lumbar spine. Femoral neck BMD was combined with bone size and body size to create composite indices of femoral neck strength relative to load in three failure modes: compression, bending, and impact. Results: In mixed effects linear regression controlling for clustering within families and adjusted for age, gender, race/ethnicity, body mass index, menopausal transitional stage, childhood socioeconomic status, adult finances, education level, and study center, each standard deviation (SD) increment in AL score was associated with between 0.10 and 0.11 SD decrements in lumbar spine BMD and each of the three composite strength indices (all p values < 0.05). Gender modified the association of AL only with femoral neck BMD; each SD increment in AL score was associated with 0.21 SD decrement in femoral neck BMD in men (p<0.01), but not in women. Conclusions: Accumulation of dysregulation across systems was modestly associated with lower bone strength. This study adds to the accumulating evidence that multi-system dysregulation, or AL, predicts a variety of adverse health outcomes.
    The Journal of clinical endocrinology and metabolism 02/2014; · 6.50 Impact Factor
  • Donald Wiebe, Neil Binkley
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    ABSTRACT: Context: We report the presence of substantial concentrations of 3-epi-25(OH)D3 in two patients and a third patient with 3-epi-25(OH)D2. Patients: The first patient, a 66-year old female receiving cholecalciferol 4000 IU daily was originally found to have 53 ng/mL of 25(OH)D3 and almost equal amount of 3-epi-25(OH)D3. Subsequently, the patient had four additional samples, each of which has similar levels of both 25(OH)D3 and 3-epi-25(OH)D3. The second patient, a seven-year-old male receiving cholecalciferol 1000 IU daily, had a 25(OH)D3 concentration of 37 ng/mL and 3-epi-25(OH)D3 of approximately 10 ng/mL. The third and most intriguing patient, a 55 year old female was receiving ergocalciferol 50,000 IU twice weekly for approximately three months at which time her serum 25(OH)D2 was 64 ng/mL and her 3-epi-25(OH)D2 was ∾32 ng/mL. This patient's physician changed her vitamin D therapy to cholecalciferol 1000 IU daily, discontinued ergocalciferol and a second specimen was collected five months later. Analysis of this last specimen found both 25(OH)D3 and 25(OH)D2 at concentrations of 12 and 24 ng/mL respectively, plus corresponding 3-epi peaks for both 25(OH)D3 and 25(OH)D2 observed chromatographically. Conclusion: The presence of a substantial concentration of 3-epi-25(OH)D in these three patients documents that one cannot assume 3-epi is a trivial metabolite of 25(OH)D for all patients. In addition, the appearance of 3-epi-25(OH)D3 when the last patient changed her vitamin D supplementation from ergocalciferol to cholecalciferol, demonstrates that the 3-epimer is probably an endogenous metabolite of 25(OH)D in humans.
    The Journal of clinical endocrinology and metabolism 01/2014; · 6.50 Impact Factor
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    ABSTRACT: The trabecular bone score (TBS) is a gray-level textural metric that can be extracted from the 2-dimensional lumbar spine dual-energy X-ray absorptiometry (DXA) image. TBS is related to bone microarchitecture and provides skeletal information that is not captured from the standard bone mineral density (BMD) measurement. Based on experimental variograms of the projected DXA image, TBS has the potential to discern differences between DXA scans that show similar BMD measurements. An elevated TBS value correlates with better skeletal microstructure; a low TBS value correlates with weaker skeletal microstructure. Lumbar spine TBS has been evaluated in cross-sectional and longitudinal studies. The following conclusions are based upon publications reviewed in this article: 1) TBS gives lower values in post-menopausal women and in men with previous fragility fractures than their non-fractured counterparts; 2) TBS is complementary to data available by lumbar spine DXA measurements; 3) TBS results are lower in women who have sustained a fragility fracture but in whom DXA does not indicate osteoporosis or even osteopenia; 4) TBS predicts fracture risk as well as lumbar spine BMD measurements in postmenopausal women; 5) Efficacious therapies for osteoporosis differ in the extent to which they influence the TBS; 6) TBS is associated with fracture risk in individuals with conditions related to reduced bone mass or bone quality. Based on these data, lumbar spine TBS holds promise as an emerging technology that could well become a valuable clinical tool in the diagnosis of osteoporosis and in fracture risk assessment. © 2014 American Society for Bone and Mineral Research.
    Journal of bone and mineral research: the official journal of the American Society for Bone and Mineral Research 01/2014; · 6.04 Impact Factor
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    ABSTRACT: The purpose of this investigation was to: (1) examine how asymmetry in lower extremity lean mass influenced force and power asymmetry during jumping, (2) determine how power and force asymmetry affected jump height, and (3) report normative values in collegiate athletes. Force and power were assessed from each limb using bilateral force plates during a countermovement jump in 167 Division 1 athletes (mass=85.7±20.3kg, age=20.0±1.2years, 103M/64F). Lean mass of the pelvis, thigh, and shank was assessed via dual-energy X-ray absorptiometry. Percent asymmetry was calculated for lean mass at each region (pelvis, thigh, and shank) as well as force and power. Forward stepwise regressions were performed to determine the influence of lean mass asymmetry on force and power asymmetry. Thigh and shank lean mass asymmetry explained 20% of the variance in force asymmetry (R=0.20, P<0.001), while lean mass asymmetry of the pelvis, thigh and shank explained 25% of the variance in power asymmetry (R=0.25, P<0.001). Jump height was compared across level of force and power asymmetry (P>0.05) and greater than 10% asymmetry in power tended to decrease performance (effect size>1.0). Ninety-five percent of this population (2.5 to 97.5 percentile) displayed force asymmetry between -11.8 to 16.8% and a power asymmetry between -9.9 to 11.5%. A small percentage (<4%) of these athletes displayed more than 15% asymmetry between limbs. These results demonstrate that lean mass asymmetry in the lower extremity is at least partially responsible for asymmetries in force and power. However, a large percentage remains unexplained by lean mass asymmetry.
    The Journal of Strength and Conditioning Research 01/2014; · 1.80 Impact Factor
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    ABSTRACT: For patients undergoing screening computed tomography colonography (CTC), an opportunity exists for bone mineral density (BMD) screening without additional radiation exposure using quantitative computed tomography (QCT). This study investigated the use of dual-energy X-ray absorptiometry (DXA)–equivalent QCT Computed Tomography X-Ray Absorptiometry (CTXA) analysis at the hip obtained using CTC examinations using a retrospective asynchronous calibration of patient scans. A cohort of 33 women, age 61.3 (10.6) yr (mean [standard deviation]), had routine CTC using various GE LightSpeed CT scanner models followed after 0–9 mo by a DXA hip BMD examination using a GE Lunar Prodigy machine. Areal bone mineral density (aBMD) and T-scores of the proximal femur were measured from either prone or supine CTC examinations using Mindways QCT Pro software following standard workflow except that the CT scanners were asynchronously calibrated by phantoms scanned retrospectively of the CTC examination without the subject present. CTXA and DXA aBMD were highly correlated (R2 = 0.907) with a linear relationship of DXA_BMD = 1.297*CTXA_BMD + 0.048. The standard error of estimate (SEE) on the linear fit was 0.053 g/cm2. CTXA and DXA T-scores showed a linear relationship of DXA_T-score = 1.034*CTXA_T-score + 0.3 and an SEE of 0.379 T-scores. CTXA and DXA aBMD and T-score measurements showed good correlation despite asynchronous scan acquisition and retrospective QCT calibration. The SEE of 0.053 g/cm2 is on par with the literature comparing Hologic and Lunar DXA devices. The observed relationship between CTXA and Lunar DXA aBMD matches predictions from published cross-calibrations relating CTXA to DXA aBMD measurement. Thus, opportunistic use of CTXA T-scores obtained at the time of CTC could enhance osteoporosis screening.
    Journal of Clinical Densitometry 01/2014; · 1.71 Impact Factor
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    ABSTRACT: Glucocorticoids remain a cornerstone of guideline-based management of persistent asthma and allergic diseases. Glucocorticoid-induced osteoporosis (GIO) is the most common iatrogenic cause of secondary osteoporosis and an issue of concern for physicians treating patients with inhaled or oral glucocorticoids either continuously or intermittently. Patients with GIO experience fragility fractures at better dual-energy x-ray absorptiometry T-scores than those with postmenopausal or age-related osteoporosis. This might be explained, at least in part, by the effects of glucocorticoids not only on osteoclasts but also on osteoblasts and osteocytes. Effective options to detect and manage GIO exist, and a management algorithm has been published by the American College of Rheumatology to provide treatment guidance for clinicians. This review will summarize GIO epidemiology and pathophysiology and assess the role of inhaled and oral glucocorticoids in asthmatic adults and children, with particular emphasis on the effect of such therapies on bone health. Lastly, we will review the American College of Rheumatology GIO guidelines and discuss diagnostic and therapeutic strategies to mitigate the risk of GIO and fragility fractures.
    The Journal of allergy and clinical immunology 11/2013; 132(5):1019-30. · 12.05 Impact Factor
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    ABSTRACT: Given larger bone size in men, bone mineral density (BMD) precision might differ between sexes. This study compared dual-energy X-ray absorptiometry BMD precision of 3 International Society for Clinical Densitometry-certified technologists in older men and women. Each technologist scanned a cohort of 30 men and 30 women (total n = 180) by using a Lunar iDXA densitometer (GE Healthcare, Madison, WI). Each volunteer had 2 lumbar spine and bilateral hip scans with repositioning between examinations. BMD least significant change was calculated. Age and body mass index did not differ between men and women. Mean height and weight were greater in men, 174.6 cm ± 6.9 and 81.6 kg ± 11.1 respectively, (p < 0.0001) than in women, 161.5 cm ± 5.9/69.1 kg ± 14.2, respectively. Bone area was greater in men (p < 0.0001) at all sites. BMD least significant change was statistically better (p < 0.05) in women at the mean total femur (0.014 vs 0.018 g/cm(2)) and left femoral neck (0.025 vs 0.038 g/cm(2)), but not different at either total femur, the right femoral neck, or lumbar spine (all p > 0.05). In conclusion, statistically significant male/female differences in BMD precision were observed at the mean total femur and left femoral neck. Given the small magnitude of difference in g/cm(2) and inconsistent pattern, that is, no right femoral neck difference, there is virtually no clinical difference in BMD precision between sexes. These data do not support a need for sex-specific precision analyses.
    Journal of Clinical Densitometry 10/2013; · 1.71 Impact Factor
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    ABSTRACT: Background/Aims Densitometric lateral spine imaging (vertebral fracture assessment, or VFA) identifies prevalent vertebral fracture and improves fracture risk estimation, but is under-utilized in clinical practice. We created an algorithm to be used by bone density (DXA) technologists to identify those with moderate or higher pre-test probability of prevalent vertebral fracture who should have VFA at the time of a DXA test. Our objectives were to: a) assess changes of VFA utilization after implementation of the algorithm at a large rural multispecialty community health care organization and an academic health center; and b) assess the association of VFA results with prescription of fracture prevention medication. Methods We devised a physician DXA order option that VFA also be performed for those patients whose worst T-score (spine, femoral neck, or total hip) is between -1.5 and -2.5 PLUS age 65 years or more OR height loss 1.5 inches or more OR current glucocorticoid use. The proportion for those with an indication for VFA who had one done before and after introduction of the performance algorithm was compared with chi2 statistic. Manual medical record review was done to assess results of VFA, and logistic regression was used to estimate the multivariable-adjusted association of VFA results (positive for vertebral fracture vs. negative) with subsequent physician prescribing of fracture prevention therapy. Results After introduction of the DXA/VFA order option, 36% (331 of 969) and 87% (438 of 452) of those with a VFA indication at the two institutions had VFA performed (P-value <0.001 compared to before introduction). Those with a VFA positive for prevalent vertebral fracture had an odds ratio of 3.2 (95% C.I. 2.1 - 3.1) of starting fracture prevention medication compared to those with a VFA negative for vertebral fracture, adjusted for age, sex, prior clinical fracture, and current glucocorticoid use. Conclusions DXA technologists can successfully use an algorithm to identify those for whom VFA is indicated, provided the appropriate conditional order for VFA is part of the DXA order. Documentation of prevalent vertebral fracture appropriately increases utilization of fracture prevention therapy in a substantial subset of those who do not otherwise have an indication for therapy.
    Clinical Medicine &amp Research 09/2013; 11(3):138.
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    ABSTRACT: While several studies have noted increased fracture risk in individuals with type 2 DM (T2DM), the pathophysiologic mechanisms underlying this association are not known. We hypothesize that insulin resistance (the key pathology in T2DM) negatively influences bone remodeling and leads to reduced bone strength. Data came from 717 participants in the Biomarker Project of the Midlife in the United States Study (MIDUS II). Homeostasis model assessment of insulin resistance (HOMA-IR) was calculated from fasting morning blood glucose and insulin levels. Projected 2D (areal) bone mineral density (BMD) was measured in the lumbar spine and left hip using dual-energy X-ray absorptiometry (DXA). Femoral neck axis length and width were measured from the hip DXA scans, and combined with BMD and body weight and height to create composite indices of femoral neck strength relative to load in three different failure modes: compression, bending, and impact. We used multiple linear regressions to examine the relationship between HOMA-IR and bone strength, adjusted for age, gender, race/ethnicity, menopausal transition stage (in women), and study site. Greater HOMA-IR was associated with lower values of all three composite indices of femoral neck strength relative to load, but was not associated with BMD in the femoral neck. Every doubling of HOMA-IR was associated with 0.34 to 0.40 standard deviations (SD) decrement in the strength indices (p < 0.001). On their own, higher levels of fasting insulin (but not of glucose) were independently associated with lower bone strength. Our study confirms that greater insulin resistance is related to lower femoral neck strength relative to load. Further, we note that hyperinsulinemia, rather than hyperglycemia, underlies this relationship. Although cross-sectional associations do not prove causality, our findings do suggest that insulin resistance and in particular, hyperinsulinemia, may negatively affect bone strength relative to load.
    Journal of bone and mineral research: the official journal of the American Society for Bone and Mineral Research 08/2013; · 6.04 Impact Factor
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    ABSTRACT: Vitamin D supplementation is recommended for women with osteoporosis. In the FOCUS-D trial comparing the combination tablet alendronate plus vitamin D3 5,600 IU (ALN/D) with standard care (SC) prescribed by patients’ personal physicians, ALN/D was more effective in improving serum 25(OH)D and bone turnover markers by 6 months and increasing spine and hip bone mineral density (BMD) after 1 year than SC. This post hoc analysis examined the relationship between BMD gain and 25(OH)D in women in SC receiving alendronate (SC/ALN, n = 134, 52 % of the SC group) and in the ALN/D group (n = 257). At baseline, participants were of mean age 73 years and 72 % were Caucasian, with a mean 25(OH)D of 14.9 ng/mL. In the SC/ALN group, most received vitamin D, although intake of vitamin D varied extensively (51 % received <400 μg/day). In this group, end-of-study 25(OH)D correlated positively with mean percent increases from baseline in lumbar spine and femoral neck BMD [Pearson correlation coefficients (95 % CI) = 0.23 (0.02–0.41) and 0.24 (0.03–0.41), respectively]. Baseline 25(OH)D correlated with increases in only lumbar spine BMD [Pearson correlation coefficient (95 % CI) = 0.22 (0.01–0.40)]. No correlations between mean BMD change and 25(OH)D were seen with ALN/D. In conclusion, in postmenopausal women with osteoporosis and low 25(OH)D receiving alendronate and a wide range of vitamin D doses, the increase in lumbar spine and femoral neck BMD was positively correlated with serum 25(OH)D achieved by the end of the study and, to some extent, with 25(OH)D concentrations at baseline. The degree of success of alendronate therapy for osteoporosis may depend on the vitamin D status of patients.
    Calcified Tissue International 08/2013; · 2.50 Impact Factor
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    ABSTRACT: To assess the effects of timing and schedule of zoledronic acid (ZA) administration on bone mineral density (BMD) in patients beginning androgen deprivation therapy (ADT) for the treatment of recurrent prostate cancer. In this randomized, 3-arm trial, we evaluated changes in BMD after 3 different ZA administration schedules in men with recurrent prostate cancer who were beginning ADT. Forty-four patients were enrolled and randomized to receive a single dose of ZA given 1 week before beginning ADT (arm 1), a single dose of ZA given 6 months after beginning ADT (arm 2), or monthly administration of ZA starting 6 months after beginning ADT, for a total of 6 doses (arm 3). Patients who received ZA before ADT had a significant improvement in BMD at the total proximal femur and trochanter after 6 months compared with the other groups. In addition, only patients in the arm that received multiple doses improved lumbar spine BMD while on ADT, with these findings persisting to 24 months. However, this group also experienced more grade 1 adverse events. Analysis of these data suggests that ZA administration before initiation of ADT was superior to treatment 6 months after starting ADT in maintaining BMD. In addition, monthly ZA administration can increase BMD above baseline but is associated with more adverse events. Further study is needed to examine whether the timing and frequency of ZA therapy in patients on ADT can reduce fracture risk.
    Clinical Genitourinary Cancer 07/2013; · 1.43 Impact Factor
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    ABSTRACT: Bone acquisition in childhood impacts adult bone mass, and can be influenced by childhood socioeconomic conditions. Socioeconomic status is also associated with body weight which affects the load that bone is exposed to in a fall. We hypothesized that socioeconomic advantage in childhood is associated with greater bone strength relative to load in adulthood. Hip dual x-ray absorptiometry scans from 722 participants in the Midlife in the United States Study were used to measure femoral neck size and bone mineral density, and combined with body weight and height to create composite indices of femoral neck strength relative to load in different failure modes: compression, bending, and impact. A childhood socioeconomic advantage score was created for the same participants from parental education, self-rated financial status relative to others, and not being on welfare. Multiple linear regression was used to determine the association of childhood socioeconomic advantage score with femoral neck composite strength indices, stratified by gender and race (white/non-white), and adjusted for study site, age, menopause status in women, education, and current financial advantage. Childhood socioeconomic advantage was independently associated with higher indices of all three composite strength indices in white men (adjusted standardized effect sizes, 0.19 to 0.27, all p values <0.01), but not in the other three race/gender groups. Additional adjustment for adult obesity, physical activity in different life stages, smoking, and heavy drinking over the life-course significantly attenuated the associations in white men. Socioeconomic disadvantage in childhood is associated with lower hip strength relative to load in white men, and these influences are dampened by healthy lifestyle choices.
    Bone 06/2013; · 3.82 Impact Factor
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    ABSTRACT: Bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA) is used to diagnose osteoporosis and assess fracture risk. However, DXA cannot evaluate trabecular microarchitecture. This study used a novel software program (TBS iNsight; Med-Imaps, Geneva, Switzerland) to estimate bone texture (trabecular bone score [TBS]) from standard spine DXA images. We hypothesized that TBS assessment would differentiate women with low trauma fracture from those without. In this study, TBS was performed blinded to fracture status on existing research DXA lumbar spine (LS) images from 429 women. Mean participant age was 71.3 yr, and 158 had prior fractures. The correlation between LS BMD and TBS was low (r = 0.28), suggesting these parameters reflect different bone properties. Age- and body mass index-adjusted odds ratios (ORs) ranged from 1.36 to 1.63 for LS or hip BMD in discriminating women with low trauma nonvertebral and vertebral fractures. TBS demonstrated ORs from 2.46 to 2.49 for these respective fractures; these remained significant after lowest BMD T-score adjustment (OR = 2.38 and 2.44). Seventy-three percent of all fractures occurred in women without osteoporosis (BMD T-score > -2.5); 72% of these women had a TBS score below the median, thereby appropriately classified them as being at increased risk. In conclusion, TBS assessment enhances DXA by evaluating trabecular pattern and identifying individuals with vertebral or low trauma fracture. TBS identifies 66-70% of women with fracture who were not classified with osteoporosis by BMD alone.
    Journal of Clinical Densitometry 06/2013; · 1.71 Impact Factor
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    ABSTRACT: To compare the efficacy and safety of denosumab to ibandronate in postmenopausal women with low bone mineral density (BMD) previously treated with a bisphosphonate. In a randomized, open-label study, postmenopausal women received 60 mg denosumab subcutaneously every 6 months (n=417) or 150 mg ibandronate orally every month (n=416) for 12 months. End points included percentage change from baseline in total hip, femoral neck, and lumbar spine BMD at month 12 and percentage change from baseline in serum C-telopeptide at months 1 and 6 in a substudy. At month 12, significantly greater BMD gains from baseline were observed with denosumab compared with ibandronate at the total hip (2.3% compared with 1.1%), femoral neck (1.7% compared with 0.7%), and lumbar spine (4.1% compared with 2.0%; treatment difference P<.001 at all sites). At month 1, median change in serum C-telopeptide from baseline was -81.1% with denosumab and -35.0% with ibandronate (P<.001); the treatment difference remained significant at month 6 (P<.001). Adverse events occurred in 245 (59.6%) denosumab-treated women and 230 (56.1%) ibandronate-treated women (P=.635). The incidence of serious adverse events was 9.5% for denosumab-treated women and 5.4% for ibandronate-treated women (P=.046). No clustering of events in any organ system accounted for the preponderance of these reports. The incidence rates of serious adverse events involving infection and malignancy were similar between treatment groups. In postmenopausal women previously treated with a bisphosphonate and low BMD, denosumab treatment resulted in greater BMD increases than ibandronate at all measured sites. No new safety risks with denosumab treatment were identified. ClinicalTrials.gov, www.clinicaltrials.gov, NCT00936897. LEVEL OF EVIDENCE:: I.
    Obstetrics and Gynecology 06/2013; 121(6):1291-1299. · 4.80 Impact Factor
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    ABSTRACT: Dual-energy X-ray absorptiometry (DXA) is widely used to evaluate body composition in athletes. Knowledge of measurement precision is essential for monitoring body composition changes over time. This study begins characterizing DXA body composition precision in 60 (30 males and 30 females) Division 1 athletes focusing on gender, regional, and tissue type differences. Two total body scans with repositioning between were performed on the same day. Least significant change (LSC) for the root-mean-square deviation (LSCRMSD) and the percent coefficient of variation (LSC%CV) for total, lean, and fat mass was calculated for 6 regions of interest. The effect of gender, region, tissue type, and mass on the standard deviation (SD) and percent coefficient of variation (%CV) between the 2 scans was evaluated using repeated measures regression analysis. Statistically significant effects of gender, region, tissue type, and mass on SD and %CV were noted. To generalize, a nonlinear positive relationship between LSCRMSD and mass and a nonlinear negative relationship between LSC%CV and mass were observed. In conclusion, DXA body composition LSC varies among genders, regions, tissues, and mass. As such, when evaluating serial body composition in athletes, especially if assessing regional change, knowledge of precision in individuals of similar body size and gender to the population of interest is needed.
    Journal of Clinical Densitometry 05/2013; · 1.71 Impact Factor
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    ABSTRACT: BACKGROUND: Decreased 25-hydroxyvitamin D [25(OH)D] concentrations have been associated with an increased prevalence and severity of asthma and a lower response to inhaled corticosteroids. OBJECTIVE: The objective was to determine the association between serum 25(OH)D concentrations and asthma prevalence, severity, and response to asthma treatment. DESIGN: Secondary analyses were conducted in 2 samples of adolescents 12-20 y of age: 1) NHANES 2001-2006 (n = 6487), a cross-sectional nationally representative sample of the US population, and 2) a cohort of inner-city adolescents with asthma managed prospectively for 46 wk with guidelines-based therapy in the Asthma Control Evaluation (ACE; n = 226) trial. RESULTS: Mean (±SD) serum 25(OH)D concentrations in the NHANES and ACE samples were lower in African Americans than in non-African Americans (NHANES: 14.9 ± 6.5 compared with 23.0 ± 8.4 ng/mL, P < 0.0001; ACE: 11.2 ± 6.9 compared with 15.8 ± 7.1 ng/mL, P < 0.0001). In the NHANES sample, mean concentrations did not differ between participants without and with asthma (African Americans: 14.9 ± 6.4 compared with 15.0 ± 6.6 ng/mL, respectively, P = 0.87; non-African Americans: 23.0 ± 8.5 compared with 23.6 ± 8.2 ng/mL, respectively, P = 0.16). In the ACE models that used either a predefined cutoff (<20 ng/mL) or linear regression, 25(OH)D concentrations showed either no relation or minor contradictory correlations with indicators of asthma severity, treatment requirements, spirometry, or atopy/inflammation. CONCLUSION: In 2 samples of adolescents, overall serum 25(OH)D concentrations were low and were not consistently associated with the presence of asthma, multiple asthma characteristics, asthma morbidity, or response to treatment. The ACE trial was registered at clinicaltrials.gov as NCT0011441.
    American Journal of Clinical Nutrition 04/2013; · 6.50 Impact Factor
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    ABSTRACT: Chinese translation Osteoporosis is a prevalent but underdiagnosed condition. To evaluate computed tomography (CT)-derived bone mineral density (BMD) assessment compared with dual-energy x-ray absorptiometry (DXA) measures for identifying osteoporosis by using CT scans performed for other clinical indications. Cross-sectional study. Single academic health center. 1867 adults undergoing CT and DXA (n = 2067 pairs) within a 6-month period over 10 years. CT-attenuation values (in Hounsfield units [HU]) of trabecular bone between the T12 and L5 vertebral levels, with an emphasis on L1 measures (study test); DXA BMD measures (reference standard). Sagittal CT images assessed for moderate-to-severe vertebral fractures. CT-attenuation values were significantly lower at all vertebral levels for patients with DXA-defined osteoporosis (P < 0.001). An L1 CT-attenuation threshold of 160 HU or less was 90% sensitive and a threshold of 110 HU was more than 90% specific for distinguishing osteoporosis from osteopenia and normal BMD. Positive predictive values for osteoporosis were 68% or greater at L1 CT-attenuation thresholds less than 100 HU; negative predictive values were 99% at thresholds greater than 200 HU. Among 119 patients with at least 1 moderate-to-severe vertebral fracture, 62 (52.1%) had nonosteoporotic T-scores (DXA false-negative results), and most (97%) had L1 or mean T12 to L5 vertebral attenuation of 145 HU or less. Similar performance was seen at all vertebral levels. Intravenous contrast did not affect CT performance. The potential benefits and costs of using the various CT-attenuation thresholds identified were not formally assessed. Abdominal CT images obtained for other reasons that include the lumbar spine can be used to identify patients with osteoporosis or normal BMD without additional radiation exposure or cost. National Institutes of Health.
    Annals of internal medicine 04/2013; 158(8):588-95. · 13.98 Impact Factor
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    ABSTRACT: Context:Vitamin D is increasingly recognized as an important immunomodulator. Lower levels of 25-hydroxyvitamin D (25[OH]D) and 1,25-dihydroxyvitamin D (1,25[OH]2D) are observed in persons living with HIV.Objective:The purpose of this study was to evaluate the relationship of 25(OH)D, and 1,25(OH)2D to HIV viral load, and CD4+ T cells in HIV-infected adults.Design:This was a cross-sectional study completed between January 2010 and April 2011.Setting:This study was conducted with volunteers who received HIV care in Wisconsin at either a University-based HIV clinic or an urban community HIV clinic.Patients:One hundred twelve adults with HIV infection participated in this study.Main Outcome Measures:The primary outcome for this study was the relationship between 1,25(OH)2D and HIV viral load. Secondary outcomes included relationships between 25(OH)D and HIV viral load, 25(OH)D and 1,25(OH)2D to CD4+ T cells, and predictors of vitamin D deficiency.Results:The 112 volunteers included 24 women and 3 transgender individuals; 68% were from the university clinic, and 32% were from the urban clinic. Mean age was 44.2 years. The mean 25(OH)D level was 22.5 ng/mL; mean 1,25(OH)2D level was 23.5 pg/mL. Twenty-two percent had 25(OH)D ≤10 ng/mL; 53% had values <20 ng/mL, and 73% were ≤30 ng/mL. There was no association between vitamin D and CD4. A nonlinear relationship between viral load and 1,25(OH)2D was found. For 1,25(OH)2D below 32 pg/mL, for each 10 pg/mL decrease in 1,25(OH)2D, (log10) viral load increased by 0.84 (95% CI: 0.16-1.51, P = .015). For 1,25(OH)2D above 32 pg/mL, for each 10 pg/mL increase in 1,25(OH)2D, (log10) viral load increased by 0.36 (95% CI: 0.15-0.57, P = .0009).Conclusion:Vitamin D deficiency was common in this HIV population, as seen in other HIV cohorts. A novel, U-shaped relationship between 1,25(OH)2D and viral load, with the lowest and highest 1,25(OH)2D levels seen with high viral loads, was found and deserves further study.
    The Journal of clinical endocrinology and metabolism 03/2013; · 6.50 Impact Factor
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    ABSTRACT: Purpose:To retrospectively assess the prevalence and clinical outcomes of unreported vertebral compression fractures at abdominal computed tomography (CT).Materials and Methods:This HIPAA-compliant study had institutional review board approval; the need for informed consent was waived for this retrospective analysis. A total of 2041 consecutive adult patients (1640 women, 401 men; age range, 19-94 years) underwent both abdominal multidetector CT and dual-energy x-ray absorptiometry (DXA) within 6 months of each other between 2000 and 2007, before sagittal CT reconstructions were obtained routinely. Transverse (axial) and retrospective sagittal multidetector CT reconstructions were reviewed for the presence of moderate or severe vertebral body compression fractures of the lower thoracic and lumbar spine by using the Genant visual semiquantitative method. Twenty-six patients were excluded for evidence of pathologic fracture or for technical factors limiting compression fracture detection. Electronic medical records were reviewed for patients with moderate or severe compression fractures to determine whether the fracture was reported at prospective CT interpretation, was known previously, or was diagnosed subsequently. Correlation was made with central DXA T scores. Statistical analysis was performed with the Student t test and Fisher exact test.Results:At least one moderate or severe vertebral body compression fracture was identified retrospectively at CT in 97 patients (mean age, 70.8 years). Fractures involved one level in 67 and multiple levels in 30 patients, for a total of 141 fractures. In 81 (84%) patients, prospective CT diagnosis was not made. Patients in whom fractures were reported prospectively were significantly older and were more likely to have a severe compression fracture (P < .05). In 52 (64%) patients with an unreported fracture, the vertebral compression fracture was not known clinically. In 18 patients, subsequent diagnosis of a compression fracture was determined by means of another imaging study (median interval, 7 months). At DXA, 39 (48%) of 81 patients with unreported vertebral body compression fractures had a nonosteoporotic T score (greater than -2.5).Conclusion:Most clinically important vertebral body compression fractures in nontrauma patients at risk for low bone mineral density may go unreported at abdominal multidetector CT if sagittal reconstructions are not routinely evaluated.© RSNA, 2013.
    Radiology 02/2013; · 6.34 Impact Factor

Publication Stats

4k Citations
479.01 Total Impact Points

Institutions

  • 1994–2014
    • University of Wisconsin–Madison
      • • Department of Radiology
      • • Department of Medicine
      • • Institute on Aging
      Madison, Wisconsin, United States
  • 2006–2012
    • New Mexico Clinical Research and Osteoporosis Center
      Albuquerque, New Mexico, United States
    • Overton Brooks VA Medical Center
      Shreveport, Louisiana, United States
    • University of Vermont
      Burlington, Vermont, United States
  • 2011
    • The University of Sheffield
      • Medical School
      Sheffield, England, United Kingdom
  • 2009
    • University of Cincinnati
      Cincinnati, Ohio, United States
  • 2008
    • Park Nicollet Health Services
      Minneapolis, Minnesota, United States
  • 2007
    • Medical University of South Carolina
      • Department of Pediatrics
      Charleston, SC, United States
  • 2005
    • Medical College of Wisconsin
      Milwaukee, Wisconsin, United States
  • 2003
    • Wake Forest School of Medicine
      • Division of Radiologic Sciences
      Winston-Salem, NC, United States