Lynn Marshall - Academia.edu (original) (raw)

Papers by Lynn Marshall

Journal of Vascular Surgery

The Journal of Urology

measurement (85%) than 5ARI non-users, and a quite similar number of prostate samples (respective... more measurement (85%) than 5ARI non-users, and a quite similar number of prostate samples (respectively 28% and 26 %). Conditional adjusted odds ratio were 0.64 (95%CI, 0.44 to 0.93) and 1.76 (95%CI, 0.97 to 3.21) for low grade and high-grade prostate cancer, respectively, when comparing 5-ARI users for at least 2 years to non users (test for heterogeneity, p ¼ 0.0048). CONCLUSIONS: Our results supported a qualitative heterogeneity when considering an association between long-term exposure to 5-ARI and prostate cancer. These results are in line with previously published randomized clinical trials and, though not yet explained, should be considered when managing long-term treatment for symptomatic benign prostatic hypertrophy.

Journal of Bone and Mineral Research

Prior data in women suggest that incident clinically undiagnosed radiographic vertebral fractures... more Prior data in women suggest that incident clinically undiagnosed radiographic vertebral fractures (VFs) often are symptomatic, but misclassification of incident clinical VF may have biased these estimates. There are no comparable data in men. To evaluate the association of incident clinically undiagnosed radiographic VF with back pain symptoms and associated activity limitations, we used data from the Osteoporotic Fractures in Men (MrOS) Study, a prospective cohort study of community-dwelling men aged !65 years. A total of 4396 men completed spine X-rays and symptom questionnaires at baseline and visit 2, about 4.6 years later. Incident clinical VFs during this interval were defined by self-reported clinical diagnosis plus community imaging showing a centrally adjudicated !1 increase in semiquantitative (SQ) grade in any thoracic or lumbar vertebra versus baseline study X-rays. Incident radiographic VFs (!1 increase in SQ grade between baseline and visit 2 study X-rays) were categorized as radiographic-only (not clinically diagnosed) or radiographic plus clinical (also clinically diagnosed). Multivariable-adjusted log binomial regression was used to calculate prevalence ratios (PRs) and 95% confidence intervals (CIs). Men with incident radiographic plus clinical VF were most likely to have back pain symptoms and associated activity limitation at follow-up. However, versus men without incident VF, those with incident radiographic-only VF also were significantly more likely at follow-up to report any back pain (70% versus 59%; PR, 1.2 [95% CI, 1.1 to 1.3]), severe back pain (8% versus 4%; PR, 1.9 [95% CI, 1.1 to 3.3]), bother from back pain most/all the time (22% versus 13%; PR, 1.7 [95% CI, 1.3 to 2.2]), and limited usual activity from back pain (34% versus 18%; PR, 1.9 [95% CI, 1.5 to 2.4]). Clinically undiagnosed, incident radiographic VFs were associated with an increased likelihood of back pain symptoms and associated activity limitation. Results suggest incident radiographic-only VFs often were symptomatic, and were associated with both new and worsening back pain. Preventing these fractures may reduce back pain and related disability in older men.

Arthritis care & research, Aug 9, 2016

To investigate cross-sectional and longitudinal associations of diffuse idiopathic skeletal hyper... more To investigate cross-sectional and longitudinal associations of diffuse idiopathic skeletal hyperostosis (DISH) and thoracic kyphosis in older persons. DISH and kyphosis were assessed in 1,500 men from the Osteoporotic Fractures in Men (MrOS) study and in 1,267 women from the Study of Osteoporotic Fractures (SOF). DISH was assessed using baseline lateral spine radiographs, and Cobb angle of kyphosis was measured from baseline and followup radiographs, a mean 4.6 years later in men, and 3.7 and 15 years later in women. Linear regression was used to analyze associations of DISH with baseline Cobb angle and with percent annualized change in Cobb angle. We tested for heterogeneity among studies. DISH was identified in 222 participants in MrOS (15%) and in 156 participants in SOF (12%). Participants with DISH in both cohorts had higher baseline Cobb angles (P < 0.05), after adjustment for covariates. After approximately 4 years of followup, there was no significant difference in annua...

Journal of clinical densitometry : the official journal of the International Society for Clinical Densitometry, Jan 23, 2017

Visceral adipose tissue (VAT) measured by computed tomography (CT) is related to insulin resistan... more Visceral adipose tissue (VAT) measured by computed tomography (CT) is related to insulin resistance, lipids, and serum inflammatory markers. Our objective was to compare the strength of the associations of VAT measured using dual-energy X-ray absorptiometry (DXA-VAT) and CT (CT-VAT) with insulin resistance, serum lipids, and serum markers of inflammation. For 1117 men aged 65 and older enrolled in the Osteoporotic Fractures in Men Study, the cross-sectional associations of DXA-VAT and CT-VAT with homeostasis model assessment of insulin resistance (homa2ir), C-reactive protein, and high-density lipoprotein (HDL) cholesterol were estimated with regression models and compared using a Hausman test. Adjusted for age and body mass index, DXA-VAT was moderately associated with homa2ir (effect size 0.38, 95% confidence interval [CI]: 0.28-0.47) and modestly associated with HDL cholesterol (DXA effect size -0.29, 95% CI: -0.38 to -0.21). These associations were significantly greater than tho...

HAND, 2016

Little is known about extensor tendon failure following drill injury at the time of volar plate f... more Little is known about extensor tendon failure following drill injury at the time of volar plate fixation. Our goals were to analyze extensor tendon injury following simulated drill penetration, and change in tendon displacement during cyclic loading following simulated drill penetration injury. Extensor pollicis longus (EPL) and extensor carpi radialis brevis (ECRB) tendons were harvested from 9 fresh frozen cadaveric arms. Eighteen EPL and 18 ECRB samples were created from harvested tendons. Drill penetration injury was performed in either a continuous or an oscillating mode. Injured tendons were subjected to 1200 cycles at 1- to 15-kg cyclic load at a frequency of 1 Hz, and analyzed for failure at drill sites and change in displacement throughout the testing cycle. Ten EPL samples and 16 ECRB samples completed testing without failure. Tendon type (ECRB, EPL), mode of injury (continuous, oscillating), and location (proximal, distal) did not affect tendon displacement during loading. A single EPL tendon failed following continuous drill penetration injury. Extensor carpi radialis brevis samples had a mean change in displacement of 2.8 (standard deviation [SD]: 1.5 mm) and 5.9 mm (SD: 4.7 mm) for oscillating and continuous modes, respectively. Six EPL samples had a mean change in displacement of 4.7 (SD: 2.7 mm) and 4.3 mm (SD: 1.8 mm) for oscillating and continuous modes, respectively. Complete extensor tendon failure due to drill penetration was rare. Drill mode did not affect the degree of elongation. Increasing cyclic loading of extensor tendons after drill injury caused modest extensor tendon elongation.

Journal of aging and health, Jan 27, 2016

The aim of this study is to evaluate fall rates across body mass index (BMI) categories by age gr... more The aim of this study is to evaluate fall rates across body mass index (BMI) categories by age group, considering physical performance and comorbidities. In the Osteoporotic Fractures in Men (MrOS) study, 5,834 men aged ≥65 reported falls every 4 months over 4.8 (±0.8) years. Adjusted associations between BMI and an incident fall were tested using mixed-effects models. The fall rate (0.66/man-year overall, 95% confidence interval [CI] = [0.65, 0.67]) was lowest in the youngest, normal weight men (0.44/man-year, 95% CI = [0.41, 0.47]) and greatest in the oldest, highest BMI men (1.47 falls/man-year, 95% CI = [1.22, 1.76]). Obesity was associated with a 24% to 92% increased fall risk in men below 80 (ptrend ≤ .0001, p for interaction by age = .03). Only adjustment for dynamic balance test altered the BMI-falls association substantially. Obesity was independently associated with higher fall rates in men 65 to 80 years old. Narrow walk time, a measure of gait stability, may mediate the ...

Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research, 2016

We investigated the associations of 3D geometric measures and volumetric bone mineral density (vB... more We investigated the associations of 3D geometric measures and volumetric bone mineral density (vBMD) of the proximal femur assessed by quantitative computed tomography (QCT) with hip fracture risk among elderly men. This study was a prospective case-cohort design nested within the Osteoporotic Fractures in Men Study (MrOS) cohort. QCT scans of 230 men (65 with confirmed hip fractures) were evaluated with Mindways' QCTPRO-BIT software. Measures that are indicative of bone strength for the femoral neck (FN) and for the trochanteric region (TR) were defined. Bending strength measures were estimated by minimum section modulus, buckling strength by buckling ratio, and a local thinning index (LTI). Integral and trabecular vBMD measures were also derived. Areal BMD (aBMD) of the total proximal femur from dual-energy X-ray absorptiometry (DXA) is presented for comparison. Associations of skeletal measures with incident hip fracture were estimated with hazard ratios (HR) per standard dev...

Southern Medical Journal, 2016

Outpatient parenteral antimicrobial therapy (OPAT) is an effective way of treating infections, bu... more Outpatient parenteral antimicrobial therapy (OPAT) is an effective way of treating infections, but complications are common. We identified patient characteristics and OPAT treatment factors associated with increased risk of OPAT-related complications. We used a retrospective cohort design that assessed 337 adult patients treated with OPAT for orthopedic and neurosurgical infections between August 1, 2008 and May 30, 2010. Independent variables included demographics, infection characteristics, lead time factors, OPAT treatment factors, and comorbid conditions. Multivariable log-binomial regression was used to estimate the risk of OPAT complications. The mean patient age was 55 years (range 19-87), 86% had an orthopedic infection, and 44% were treated with intravenous vancomycin. OPAT complications were seen in 45% (152/337) of the cohort. Risk ratios for OPAT complications were 1.9 (95% confidence interval 1.4-2.5) in patients having no primary care provider, 1.7 (95% confidence interval 1.3-2.1) for those treated with vancomycin. Identifying specific patient characteristics and OPAT treatment factors could facilitate OPAT process improvements to reduce the risk of OPAT complications for vulnerable patients.

The Journals of Gerontology Series A: Biological Sciences and Medical Sciences, 2016

Background: Musculoskeletal pain is associated with increased fall risk among older men. However,... more Background: Musculoskeletal pain is associated with increased fall risk among older men. However, the association of back pain, the most prevalent type of pain in this population, and fall risk is unknown. Methods: We conducted a prospective investigation among 5,568 community-dwelling U.S. men at least 65 years of age from the Osteoporotic Fractures in Men Study (MrOS). Baseline questionnaires inquired about back pain and its location (such as low back), severity, and frequency in the past year. During 1 year of follow-up, falls were summed from self-reports obtained every 4 months. Outcomes were recurrent falls (≥2 falls) and any fall (≥1 fall). Associations of back pain and fall risk were estimated with risk ratios (RRs) and 95% confidence intervals (CIs) from multivariable log-binomial regression models adjusted for age, dizziness, arthritis, knee pain, urinary symptoms, self-rated health, central nervous system medication use, and instrumental activities of daily living. Results: Most (67%) reported any back pain in the past year. During follow-up, 11% had recurrent falls and 25% fell at least once. Compared with no back pain, any back pain was associated with elevated recurrent fall risk (

European Urology Focus, 2015

Antioxidants can potentially alter the progression of lower urinary tract symptoms (LUTS) through... more Antioxidants can potentially alter the progression of lower urinary tract symptoms (LUTS) through anti-inflammatory mechanisms. To determine if dietary antioxidants are associated with reduced likelihood of LUTS progression or increased likelihood of LUTS remission in untreated elderly men. A prospective cohort study of 1670 US men aged 65-100 yr. Baseline variables included the American Urological Association Symptom Index, dietary intake assessed via a 69-item Block food frequency questionnaire (FFQ), demographics, lifestyle characteristics, quality of life (SF-12), and medication use. LUTS was assessed at four time points over a mean ± standard deviation period of 6.9±0.4 yr. Group-based trajectory modeling was performed for men without prostate cancer who did not undergo LUTS treatment with medication or surgery during follow-up (n=1670). Analyses were stratified by LUTS symptoms at baseline. For men with mild baseline LUTS, we examined the likelihood of LUTS progression relative to LUTS stability. For men with moderate baseline LUTS, we analyzed the likelihood of both LUTS progression relative to LUTS stability and LUTS remission relative to progression. Odds ratios and 95% confidence intervals were estimated for quartiles of daily antioxidant intake using multivariable logistic regression. None of the dietary antioxidants (vitamin C, vitamin E, β-carotene, α-carotene, β-cryptoxanthin, lycopene, lutein/zeaxanthin) was associated with a lower probability of LUTS progression or LUTS remission. The study was limited by use of the brief Block FFQ, which contains only 69 food items and may have biased results toward the null hypothesis because of nondifferential misclassification. In this large cohort of US men, there were no significant associations between multiple dietary antioxidants and LUTS progression or remission over 7 yr. In a large cohort of elderly men, there were no significant longitudinal associations between multiple dietary antioxidants and lower urinary tract symptoms (LUTS). Our data suggest that dietary antioxidant consumption may not influence the natural history of LUTS in older men.

Background: Small case series have described successful off-label use of Daptomycin for orthopaed... more Background: Small case series have described successful off-label use of Daptomycin for orthopaedic infections when first line therapy was intolerable. We report outcomes of Daptomycin salvage therapy at 6 & 12 month follow-up in a cohort of 94 patients with orthopaedic infection. Methods: We used a retrospective design to create a cohort of patients who received Daptomycin therapy to treat orthopaedic infections over 36 months; 2007-2010. Information on patient demographics, diagnosis, antibiotic dosing and side effects was analyzed. Myopathy was defined as a rise in creatinine kinase greater than 5 times baseline, or above our normal laboratory limit. Outcomes at 6 and 12 months after initiation of Daptomycin were defined as "Infection Controlled" (off all antibiotics, on suppressive oral antibiotics, or new infection) or "Infection Not Controlled" (recurrent infection with the same organism, or death associated with initial infection). Proportions and exact 95...

Background: Previous studies demonstrate up to 35% of patients develop antibiotic and vascular ac... more Background: Previous studies demonstrate up to 35% of patients develop antibiotic and vascular access-related complications during Outpatient Parenteral Antibiotic Therapy (OPAT)1,2. This study investigated risk factors for complications during OPAT. Methods: A retrospective chart review was performed for patients indicated for 2 or more weeks of OPAT for treatment of an orthopedic or neurosurgical infection. OPAT complication was defined as an adverse antibiotic reaction (AAR), a vascular access problem (VAP), a failed OPAT plan (FOP), or all cause mortality. Only complications that resulted in an unexpected IV antibiotic change, or an early vascular line removal, or an emergency room visit, or readmission for the OPAT complication were counted. Only the first complication was analyzed for each OPAT course. Factors abstracted from medical records for evaluation in relation to OPAT complication were patient demographics, infection characteristics, lead-time inpatient factors, OPAT t...

The journals of gerontology. Series A, Biological sciences and medical sciences, Jan 11, 2015

Sleep and melatonin have been associated with healthy aging. In this study, we examine the associ... more Sleep and melatonin have been associated with healthy aging. In this study, we examine the association between melatonin levels and sleep among older men. Cross-sectional study of a community-dwelling cohort of 2,821 men aged 65 years or older recruited from six U.S. centers. First morning void urine samples were collected to measure melatonin's major urinary metabolite, 6-sulfatoxymelatonin (aMT6s). We also assessed objective and subjective sleep parameters. We used logistic regression models to calculate multivariate (MV) odds ratios (ORs), and 95% confidence intervals (CIs) adjusted for important demographic variables and comorbidities. In the overall sample, the only significant finding in fully adjusted models was that aMT6s levels were inversely associated with subjectively measured daytime sleepiness (sleepiness mean score of 5.79 in the top aMT6s quartile, and 6.26 in the bottom aMT6s quartile, MV OR, 1.32; 95% CI, 0.95-1.84; p trend ≤ .02). When restricting to men witho...

$Research paper thumbnail of Surgical menopause and nonvertebral fracture risk among older US women$

Menopause: The Journal of The North American Menopause Society, 2012

Objective-To determine whether older postmenopausal women with a history of bilateral oophorectom... more Objective-To determine whether older postmenopausal women with a history of bilateral oophorectomy prior to natural menopause (surgical menopause) have a higher risk of nonvertebral, postmenopausal fracture than women with natural menopause. Methods-We used 21 years of prospectively collected incident fracture data from the ongoing Study of Osteoporotic Fractures (SOF), a cohort study of community dwelling women without previous bilateral hip fracture who were age 65 or older at enrollment, to determine the risk of hip, wrist, and any nonvertebral fracture. Chi square and t-tests were used to compare the two groups on important characteristics. Multivariable Cox proportional hazards regression models stratified by baseline oral estrogen use status were used to estimate the risk of fracture. Results-Baseline characteristics differed significantly between the 6,616 women within SOF who underwent either surgical (1,157) or natural (5,459) menopause, including mean age at menopause (44.3 ±7.4 versus 48.9 ±4.9 years, p<.001) and current use of oral estrogen (30.2% vs 6.5%, p<.001). Fracture rates were not significantly increased for surgical versus natural menopause, even among women who had never used oral estrogen (hip fracture, hazard ratio [HR] 0.87, 95% confidence interval [CI] 0.63-1.21; wrist fracture HR 1.10, 95% CI 0.78-1.57; any nonvertebral fracture HR 1.11, 95% CI 0.93-1.32). Conclusion-These data provide some reassurance that the long-term risk of nonvertebral fracture is not substantially increased for postmenopausal women who experienced premenopausal

Journal of Bone and Mineral Research, 2014

In men, the association between poor physical performance and likelihood of incident vertebral fr... more In men, the association between poor physical performance and likelihood of incident vertebral fractures is unknown. Using data from the MrOS study (N = 5958), we describe the association between baseline physical performance (walking speed, grip strength, leg power, repeat chair stands, narrow walk [dynamic balance]) and incidence of radiographic and clinical vertebral fractures. At baseline and follow-up an average of 4.6 years later, radiographic vertebral fractures were assessed using semiquantitative (SQ) scoring on lateral thoracic and lumbar radiographs. Logistic regression modeled the association between physical performance and incident radiographic vertebral fractures (change in SQ grade ≥1 from baseline to follow-up). Every 4 months after baseline, participants self-reported fractures; clinical vertebral fractures were confirmed by centralized radiologist review of the baseline study radiograph and community-acquired spine images. Proportional hazards regression modeled the association between physical performance with incident clinical vertebral fractures. Multivariate models were adjusted for age, bone mineral density (BMD, by dual-energy X-ray absorptiometry [DXA]), clinical center, race, smoking, height, weight, history of falls, activity level, and comorbid medical conditions; physical performance was analyzed as quartiles. Of 4332 men with baseline and repeat radiographs, 192 (4.4%) had an incident radiographic vertebral fracture. With the exception of walking speed, poorer performance on repeat chair stands, leg power, narrow walk, and grip strength were each associated in a graded manner with an increased risk of incident radiographic vertebral fracture (p for trend across quartiles &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001). In addition, men with performance in the worst quartile on three or more exams had an increased risk of radiographic fracture (odds ratio [OR] = 1.81, 95% confidence interval [CI] 1.33-2.45) compared with men with better performance on all exams. Clinical vertebral fracture (n =149 of 5813, 2.6%) was not consistently associated with physical performance. We conclude that poorer physical performance is associated with an increased risk of incident radiographic (but not clinical) vertebral fracture in older men.

Spine, 2014

Prospective cohort study. To understand whether patients actually perceive increased limitations ... more Prospective cohort study. To understand whether patients actually perceive increased limitations as compared with their preoperative state due to stiffness after lumbar arthrodesis. Lumbar arthrodesis by intention eliminates spinal motion in an attempt to decrease pain, deformity, and instability. Independent of pain, loss of mobility can impact ability to perform certain activities of daily living. The lumbar stiffness disability index (LSDI) is a validated measure of the effect of lumbar stiffness on functional activities. To date, no prospective evaluations of stiffness impacts on patient function after lumbar arthrodesis have been reported. The LSDI, 36-Item Short Form Health Survey, and Oswestry Disability Index were administered preoperatively and at 2-year minimum follow-up to 62 adult patients undergoing lumbar fusion for degenerative disease or spinal deformity. Patients also completed a satisfaction questionnaire at 2 years. Patients were separated according to the number of lumbar arthrodesis levels. Pre- and postoperative LSDI, 36-Item Short Form Health Survey physical composite score, and Oswestry Disability Index scores were compared using paired t tests. Significant improvements in Oswestry Disability Index were observed across all arthrodesis levels, and significant improvements in physical composite score were observed at level 1 and at 5 or more levels. Patients undergoing 1-level arthrodesis demonstrated statistically significant decreases in LSDI scores, indicating less impact from stiffness than at baseline. Patients with 3 or 4 levels and 5 or more levels of arthrodesis showed increases in LSDI scores, although none reached significance with the numbers available. Forty-six percent of patients reported that low back stiffness created significant limitations in activities of daily living, although 97% indicated that they would undergo the same procedure again and 91% reported that any increase in stiffness was an acceptable trade-off for their functional improvements from lumbar arthrodesis. Patients undergoing elective lumbar arthrodesis reported relatively limited functional deficit due to stiffness at 2-year follow-up. Paradoxically, patients undergoing 1-level arthrodesis actually reported significantly less limitation due to stiffness postoperatively. Although the effects of stiffness did trend toward greater impacts among patients undergoing longer fusions, 91% of patients were satisfied with trade-offs of function and pain relief in exchange for perceived increases in lumbar stiffness.