Factors associated with the contemplative stage of readiness to initiate osteoporosis treatment.

We investigated the factors associated with readiness for initiating osteoporosis treatment in women at high risk of fracture. We found that women in the contemplative stage were more likely to report previously being told having osteoporosis or osteopenia, acknowledge concern about osteoporosis, and disclose prior osteoporosis treatment. INTRODUCTION: Understanding factors associated with reaching the contemplative stage of readiness to initiate osteoporosis treatment may inform the design of behavioral interventions to improve osteoporosis treatment uptake in women at high risk for fracture. METHODS: We measured readiness to initiate osteoporosis treatment using a modified form of the Weinstein Precaution Adoption Process Model (PAPM) among 2684 women at high risk of fracture from the Activating Patients at Risk for OsteoPOroSis (APROPOS) clinical trial. Pre-contemplative participants were those who self-classified in the unaware and unengaged stages of PAPM (stages 1 and 2). Contemplative participants were those in the undecided, decided not to act, or decided to act stages of PAPM (stages 3, 4, and 5). Using multivariable logistic regression, we evaluated participant characteristics associated with levels of readiness to initiate osteoporosis treatment. RESULTS: Overall, 24% (N = 412) self-classified in the contemplative stage of readiness to initiate osteoporosis treatment. After adjusting for age, race, education, health literacy, and major osteoporotic fracture in the past 12 months, contemplative women were more likely to report previously being told they had osteoporosis or osteopenia (adjusted odds ratio [aOR] (95% CI) 11.8 (7.8-17.9) and 3.8 (2.5-5.6), respectively), acknowledge concern about osteoporosis (aOR 3.5 (2.5-4.9)), and disclose prior osteoporosis treatment (aOR 4.5 (3.3-6.3)) than women who self-classified as pre-contemplative. CONCLUSIONS: For women at high risk for future fractures, ensuring women's recognition of their diagnosis of osteoporosis/osteopenia and addressing their concerns about osteoporosis are critical components to consider when attempting to influence stage of behavior transitions in osteoporosis treatment.

Hip fracture trends in the United States, 2002 to 2015.

An analysis of United States (US) Medicare claims data from 2002 to 2015 for women aged ≥ 65 years found that age-adjusted hip fracture rates for 2013, 2014, and 2015 were higher than projected, resulting in an estimated increase of more than 11,000 hip fractures. INTRODUCTION: Hip fractures are a major public health concern due to high morbidity, mortality, and healthcare expenses. Previous studies have reported a decrease in the annual incidence of hip fractures in the US beginning in 1995, coincident with the introduction of modern diagnostic tools and therapeutic agents for osteoporosis. In recent years, there has been less bone density testing and fewer prescriptions for osteoporosis treatments. The large osteoporosis treatment gap raises concern of possible adverse effects on hip fracture rates. METHODS: We assessed hip fracture incidence in the US to determine if the previous decline in hip fracture incidence continued. Using 2002 to 2015 Medicare Part A and Part B claims for women ≥ 65 years old, we calculated age-adjusted hip fracture rates, weighting to the 2014 population. RESULTS: We found that hip fracture rates declined each year from 2002 to 2012 and then plateaued at levels higher than projected for years 2013, 2014, and 2015. CONCLUSIONS: The plateau in age-adjusted hip fracture incidence rate resulted in more than 11,000 additional estimated hip fractures over the time periods 2013, 2014, and 2015. We recommend further study to assess all factors contributing to this remarkable change in hip fracture rate and to develop strategies to reduce the osteoporosis treatment gap.

Correction to: Hip fracture trends in the United States, 2002 to 2015.

The name of the first author, E.M. Lewiecki, was rendered incorrectly in the original publication. The publisher regrets any inconvenience and is pleased to correct the error here.

The epidemiology of wrist fractures in older men: the Osteoporotic Fractures in Men (MrOS) study.

There is limited wrist fracture information on men. Our goal was to calculate frequency and identify risk factors for wrist fracture in the Osteoporotic Fractures in Men (MrOS) study. We confirmed that fracture history and certain medications are predictors, and identified novel predictors including markers of kidney function and physical performance. INTRODUCTION: To calculate the incidence of wrist fractures and their risk factors in older community-dwelling men from the US Osteoporotic Fractures in Men (MrOS) study. METHODS: Using triannual postcards, we identified incident wrist fractures (centrally confirmed by radiology) in men aged ≥ 65. Potential risk factors included the following: demographics, lifestyle, bone mineral density (BMD), selected medications, biomarkers, and physical function and performance measures. Both baseline and time-varying models were adjusted for age, race/ethnicity, MrOS geographic location, and competing mortality risks. RESULTS: We observed 97 incident wrist fractures among 5875 men followed for an average of 10.8 years. The incidence of wrist fracture was 1.6 per 1000 person-years overall and ranged from 1.0 among men aged 65-69 to 2.4 among men age ≥ 80. Significant predictors included the following: fracture history after age 50 [hazard ratio (95% CI): 2.48 (1.65, 3.73)], high serum phosphate [1.25 (1.02, 1.53)], use of selective serotonin receptor inhibitor (SSRI) [3.60 (1.96, 6.63), decreased right arm BMD [0.49 (0.37, 0.65) per SD increase], and inability to perform the grip strength test [3.38 (1.24, 9.25)]. We did not find associations with factors commonly associated with wrist and other osteoporosis fractures like falls, diabetes, calcium and vitamin D intake, and alcohol intake. CONCLUSIONS: Among these older, community-dwelling men, we confirmed that fracture history is a strong predictor of wrist fractures in men. Medications such as SSRIs and corticosteroids also play a role in wrist fracture risk. We identified novel risk factors including kidney function and the inability to perform the grip strength test.

The impact of the new National Bone Health Alliance (NBHA) diagnostic criteria on the prevalence of osteoporosis in the United States: supplementary presentation.

We evaluated the prevalence of osteoporosis using the osteoporosis diagnostic criteria developed by the National Bone Health Alliance (NBHA), which includes qualified fractures, FRAX score in addition to BMD. The expanded definition increases the prevalence compared to BMD alone definitions; however, it may better identify those at elevated fracture risk. Recently an NBHA working Group published a paper in OI with recommendations for expanding the criteria that would constitute an osteoporosis diagnosis in postmenopausal women and in men over age 50 for use in the US - Siris et al., Osteoporosis International 25(%): 1439-1443, 2014. The recommendations have now been endorsed by NOF, ASBMR and a number of professional medical groups and appear in the NOF Clinician's Guide. The new diagnostic criteria continue to include a T-score by DXA of spine or hip that is less than or equal to -2.5, but alternatively also include a hip fracture with or without BMD testing or a vertebral, pelvis, proximal humerus and in some cases a distal forearm fracture in a person with low bone mass, or a FRAX score that meets or exceeds the NOF Guide osteoporosis treatment cut point.

The impact of the new National Bone Health Alliance (NBHA) diagnostic criteria on the prevalence of osteoporosis in the USA.

We evaluated the prevalence of osteoporosis using the osteoporosis diagnostic criteria developed by the National Bone Health Alliance (NBHA), which includes qualified fractures, FRAX score in addition to bone mineral density (BMD). The expanded definition increases the prevalence compared to BMD alone definitions; however, it may better identify those at elevated fracture risk. PURPOSE: The purpose of this paper is to estimate the prevalence of osteoporosis in US adults ≥50 years using the NBHA osteoporosis diagnostic criteria. METHODS: Utilizing 2005-2008 data of the National Health and Nutrition Examination Survey (NHANES), we identified participants with osteoporosis with any one of the following: (1) femoral neck or lumbar spine T-score ≤ -2.5; (2) low trauma hip fracture irrespective of BMD or clinical vertebral, proximal humerus, pelvis, or distal forearm fracture with a T-score >-2.5 <-1.0; or (3) FRAX score at the National Osteoporosis Foundation intervention thresholds (≥3% for hip fracture or ≥20% for major osteoporotic fracture). We estimated the prevalence overall and by gender and age. RESULTS: Our sample included 1948 (54.3%) men and 1639 (45.7%) women. Approximately 12% were 80+ years and 21% were from racial/ethnic minority groups. We estimated that 16.0% (0.8) of men and 29.9% (1.0) of women 50+ years have osteoporosis. The prevalence increases with age to 46.3% in men and 77.1% in women 80+ years. The combination of FRAX score and fractures was the largest contributing factor defining osteoporosis in men (70-79, 88.1%; 80+, 80.1%), whereas T-score was the largest contributing factor in women (70-79, 49.2%; 80+, 43.5%). CONCLUSIONS: We found that 16% of men and 29.9% of women 50+ have osteoporosis based on the NBHA diagnostic criteria. Although the expanded definition increases the prevalence compared to BMD alone-based definitions, it may better identify those at elevated fracture risk in order to reduce the burden of fractures in older adults.

The effects of a patient activation intervention on smoking and excessive drinking cessations: results from the PAADRN randomized controlled trial.

Patients may exhibit risky bone health behaviors. In a large pragmatic clinical trial, we tested whether a tailored patient activation DXA result letter accompanied by a bone health brochure led to smoking and excessive drinking cessations. The intervention did not, however, alter these risky bone health behaviors. INTRODUCTION: Besides dual-energy x-ray absorptiometry (DXA) screening and pharmacotherapy when indicated, beneficial bone health behaviors including proper calcium and vitamin D intake and weight-bearing and muscle-strengthening exercise should be encouraged. Similarly, risky bone health behaviors like smoking and excessive drinking should be discouraged. We examined whether a direct-to-patient activation intervention led to smoking and excessive drinking cessations. METHODS: The Patient Activation after DXA Result Notification (PAADRN) pragmatic clinical trial enrolled 7749 patients between February 2012 and August 2014. Interviews occurred at baseline and 12 and 52 weeks later. Intervention subjects were mailed an individually tailored DXA results letter accompanied by a bone health educational brochure 4 weeks post-DXA. Usual care subjects were not sent these materials. Smoking and excessive drinking were assessed by self-report at each interview. Intention-to-treat linear probability models were used. RESULTS: Mean age was 66.6 years, 83.8% were women, and 75.3% were Non-Hispanic-Whites. Smoking was reported at baseline by 7.6% of the intervention group vs. 7.7% of the usual care group (p = 0.873). Excessive drinking was reported at baseline by 6.5% of the intervention group vs. 6.5% of the usual care group (p = 0.968). Intention-to-treat analyses indicated no significant differences between the intervention vs. usual care groups at either 12 or 52 weeks post-DXA (all p values ≥ 0.346). CONCLUSION: An individually tailored DXA result letter accompanied by an educational brochure did not lead to smoking or excessive drinking cessations in patients who received DXA. TRIAL REGISTRATION: clinicaltrials.gov identifier NCT01507662.

The cost of a patient activation intervention for achieving successful outcomes: results from the PAADRN randomized controlled trial.

In a large, pragmatic clinical trial, we calculated the costs of achieving four successful patient-centered outcomes using a tailored patient activation DXA result letter accompanied by a bone health brochure. The cost to achieve one successful outcome (e.g., a 0.5 standard deviation improvement in care satisfaction) ranged from $127.41 to $222.75. INTRODUCTION: Pragmatic randomized controlled trials (RCTs) should focus on patient-centered outcomes and report the costs for achieving those outcomes. We calculated per person incremental intervention costs, the number-needed-to-treat (NNT), and incremental per patient costs (cost per NNT) for four patient-centered outcomes in a direct-to-patient bone healthcare intervention. METHODS: The Patient Activation after DXA Result Notification (PAADRN) pragmatic RCT enrolled 7749 patients presenting for DXA at three health centers between February 2012 and August 2014. Interviews occurred at baseline and 52 weeks post-DXA. Intervention subjects received an individually tailored DXA result letter accompanied by an educational bone health brochure 4 weeks post-DXA, while the usual care subjects did not. Outcomes focused on patients (a) correctly identifying their results, (b) contacting their providers, (c) discussing their results with their providers, and (d) satisfaction with their bone healthcare. NNTs were determined using intention-to-treat linear probability models, per person incremental intervention costs were calculated, and costs per NNT were computed. RESULTS: Mean age was 66.6 years old, 83.8% were women, and 75.3% were non-Hispanic whites. The incremental per patient cost (costs per NNT) to increase the ability of a patient to (a) correctly identify their DXA result was $171.07; (b) contact their provider about their DXA result was $222.75; (c) discuss their DXA result with their provider was $193.55; and (d) achieve a 0.5 SD improvement in satisfaction with their bone healthcare was $127.41. CONCLUSION: An individually tailored DXA result letter accompanied by an educational brochure can improve four patient-centered outcomes at a modest cost. TRIAL REGISTRATION: clinicaltrials.gov identifier NCT01507662.

Assessing the feasibility of the Effectiveness of Discontinuing Bisphosphonates trial: a pilot study.

The Effectiveness of Discontinuing Bisphosphonates (EDGE) study is a planned pragmatic clinical trial to guide "drug holiday" clinical decision making. This pilot study assessed work flow and feasibility of such a study. While participant recruitment and treatment adherence were suboptimal, administrative procedures were generally feasible and minimally disrupted clinic flow. INTRODUCTION: The comparative effectiveness of continuing or discontinuing long-term alendronate (ALN) on fractures is unknown. A large pragmatic ALN discontinuation study has potential to answer this question. METHODS: We conducted a 6-month pilot study of the planned the EDGE study among current long-term ALN users (women aged ≥65 with ≥3 years of ALN use) to determine study work flow and feasibility including evaluating the administrative aspects of trial conduct (e.g., time to contract, institutional review board (IRB) approval), assessing rates of site and participant recruitment, and evaluating post-randomization outcomes, including adherence, bisphosphonate-associated adverse events, and participant and site satisfaction. We assessed outcomes 1 and 6 months after randomization. RESULTS: Nine sites participated, including seven community-based medical practices and two academic medical centers. On average (SD), contract execution took 3.4 (2.3) months and IRB approval took 13.9 (4.1) days. Sites recruited 27 participants (13 to continue ALN and 14 to discontinue ALN). Over follow-up, 22% of participants did not adhere to their randomization assignment: 30.8% in the continuation arm and 14.3% in the discontinuation arm. No fractures or adverse events were reported. Sites reported no issues regarding work flow, and participants were highly satisfied with the study. CONCLUSIONS: Administrative procedures of the EDGE study were generally feasible, with minimal disruption to clinic flow. In this convenience sample, participant recruitment was suboptimal across most practice sites. Accounting for low treatment arm adherence, a comprehensive recruitment approach will be needed to effectively achieve the scientific goals of the EDGE study.

Patient-activation and guideline-concordant pharmacological treatment after bone density testing: the PAADRN randomized controlled trial.

Patients often do not know or understand their bone density test results, and pharmacological treatment rates are low. In a clinical trial of 7749 patients, we used a tailored patient-activation result letter accompanied by a bone health brochure to improve appropriate pharmacological treatment. Treatment rates, however, did not improve. INTRODUCTION: Patients often do not know or understand their dual-energy x-ray absorptiometry (DXA) test results, which may lead to suboptimal care. We tested whether usual care augmented by a tailored patient-activation DXA result letter accompanied by an educational brochure would improve guideline-concordant pharmacological treatment compared to usual care only. METHODS: We conducted a randomized, controlled, double-blinded, pragmatic clinical trial at three health care centers in the USA. We randomized 7749 patients ≥50 years old and presenting for DXA between February 2012 and August 2014. The primary clinical endpoint at 12 and 52 weeks post-DXA was receiving guideline-concordant pharmacological treatment. We also examined four of the steps along the pathway from DXA testing to that clinical endpoint, including (1) receiving and (2) understanding their DXA results and (3) having subsequent contact with their provider and (4) discussing their results and options. RESULTS: Mean age was 66.6 years, 83.8 % were women, and 75.3 % were non-Hispanic whites. Intention-to-treat analyses revealed that guideline-concordant pharmacological treatment was not improved at either 12 weeks (65.1 vs. 64.3 %, p = 0.506) or 52 weeks (65.2 vs. 63.8 %, p = 0.250) post-DXA, even though patients in the intervention group were more likely (all p < 0.001) to recall receiving their DXA results letter at 12 weeks, correctly identify their results at 12 and 52 weeks, have contact with their provider at 52 weeks, and have discussed their results with their provider at 12 and 52 weeks. CONCLUSION: A tailored DXA result letter and educational brochure failed to improve guideline-concordant care in patients who received DXA.

Defining physiologically "normal" vitamin D in African Americans.

UNLABELLED: The relationship between serum 25(OH)D and intact parathyroid hormone (iPTH) was evaluated in the Multicenter Osteoarthritis Study (MOST). No further change in iPTH was observed for African Americans with 25(OH)D levels above 20 ng/ml, suggesting that compared to Caucasians, lower vitamin D targets for sufficiency may be appropriate for African Americans. INTRODUCTION: Vitamin D levels ≥30 ng/ml are commonly considered "normal" based upon maximal suppression of iPTH; however, this has recently been challenged and the optimal 25(OH)D level among non-Caucasians is unclear. We evaluated the cross-sectional relationship between serum 25(OH)D and iPTH in a sample of Caucasian and African American adults. METHODS: We used baseline serum samples of participants from the Multicenter Osteoarthritis Study (MOST) for this analysis and used three methods to model the relationship between 25(OH)D and iPTH: ordinary least squares regression (OLS), segmented regression and Helmert contrasts. RESULTS: Among Caucasians (n = 1,258), 25(OH)D and iPTH ranged from 4 to 51 ng/ml and 2 to 120 pg/ml and from 3 to 32 ng/ml and 3 to 119 pg/ml in African Americans (n = 423). We observed different thresholds between African Americans and Caucasians using each analytic technique. Using 25(OH)D as a categorical variable in OLS, iPTH was statistically higher at lower 25(OH)D categories than the 24-32 ng/ml referent group among Caucasians. However, in African Americans, the mean iPTH was only significantly higher at 25(OH)D levels below 15 ng/ml. Using segmented regression, iPTH appeared to stabilize at a lower 25(OH)D level in African Americans (19-23 ng/ml) compared to in Caucasians (>32 ng/ml). Helmert contrasts also revealed a lower threshold in African Americans than Caucasians. CONCLUSION: Among MOST participants, the 25(OH)D thresholds at which no further change in iPTH was observed was approximately 20 ng/ml in African Americans versus approximately 30 ng/ml in Caucasians, suggesting optimal vitamin D levels in Caucasians may not be applicable to African Americans.

A pragmatic randomized trial comparing tablet computer informed consent to traditional paper-based methods for an osteoporosis study.

OBJECTIVE: Methods to improve informed consent efficiency and effectiveness are needed for pragmatic clinical trials. We compared informed consent using a tablet computer to a paper approach to assess comprehension and satisfaction of patients and clinic staff for a future osteoporosis clinical trial. METHODS: Nine community-based practices identified and recruited patients to compare the informed consent processes (tablet vs. paper) in a mock osteoporosis clinical trial. The tablet informed consent included an animation summarizing the trial, complete informed consent document, and questions to assess and reinforce comprehension of the study. Participants were women age ≥55 years with ≥1 year of alendronate use. We surveyed participants to assess comprehension and satisfaction and office staff for satisfaction and perceived time demands. RESULTS: The nine practices enrolled 33 participants. There was not a significant difference in comprehension between the tablet vs. paper informed consent [mean (SD) tablet: 12.2 (1.0) vs. paper: 11.4 (1.7)]. Office staff preferred the tablet to the paper informed consent for identifying potential study participants (two-sided t-test p = 0.02) despite an increased perceived time spent to complete the tablet process [tablet: 28.3 min (SD 16.3) vs. paper: 19.0 min (SD 6.9); p = 0.08]. CONCLUSIONS: Although, there were no significant differences in participant satisfaction and comprehension with the tablet informed consent compared to a paper informed consent, patients and office staff trended towards greater satisfaction with the tablet informed consent. Larger studies are needed to further evaluate the utility of electronic informed consent in pragmatic clinical trials.

Energy expenditure, physical activity, and body composition of ambulatory adults with hereditary neuromuscular disease.

Persons with neuromuscular disease (NMD) have progressive weakness and wasting of skeletal muscle, reduced fat-free mass, and increased fat mass relative to healthy control subjects. To test the hypothesis that resting energy expenditure (REE), estimated total daily energy expenditure (TEE), and physical activity patterns are altered in ambulatory adults with NMD, 26 adult men and women with slowly progressive NMD and 19 able-bodied control subjects similar in age and weight were evaluated. REE was measured after an overnight fast by indirect calorimetry, TEE by heart rate monitoring, and body composition by air-displacement plethysmography. REE was not significantly different between NMD and control subjects; however, TEE was significantly reduced in NMD subjects compared with control subjects, respectively (women: 7.8 +/- 1.5 compared with 10.5 +/- 2.8; men: 10.2 +/- 3.6 compared with 12.7 +/- 2.6 MJ/d; P < or = 0.01), indicating that NMD subjects expended less energy in physical activity than did control subjects. NMD subjects also tended toward an increased energy cost of physical activity, particularly at higher activity levels (P = 0.06). Multiple regression analysis indicated that for all subjects combined, adiposity was positively associated with age and TEE and negatively associated with time spent in the active heart rate range and fat-free mass (P < or = 0.0001). This relation did not differ between NMD and control subjects, nor did it differ between men and women. We hypothesize that because of their reduced physical activity and increased adiposity, persons with NMD may be at risk for developing secondary conditions such as cardiovascular disease, hypertension, and diabetes.

24-hour lung preservation: simplified versus conventional University of Wisconsin solution in a porcine model.

BACKGROUND: Experimentally, the University of Wisconsin solution (UW) has been shown to be superior to the EuroCollins solution (EC) for lung graft preservation. We showed previously that the inclusion of the trisaccharide raffinose as an impermeant in the UW is largely responsible for this superiority. In this study, we used a new porcine model of isolated lung reperfusion to evaluate the use of a simple solution of phosphate-buffered raffinose (PBr) for lung preservation. METHODS: Lungs were stored for 24 hr at 4 degrees C after a single pulmonary artery flush with either UW (n = 5) or PBr (n = 5) solution. Left lungs were ventilated with room air and reperfused for 4 hr by venovenous extracorporeal circulation from a support animal. Controls (n = 5) were flushed with UW and reperfused without storage. RESULTS: Control lungs performed better than those stored in either solution in terms of oxygenation (P = 0.034) and airway pressure (P = 0.032). There were no significant differences between the two stored groups for any parameters. Data for stored lungs after 4 hr of reperfusion (means with 95% confidence intervals) include oxygenation (mm Hg): control 101.6 (14.5), UW 85.2 (14.5), PBr 75.0 (14.5); blood flow (ml/ min): control 572 (90), UW 466 (90), PBr 468 (90); peak airway pressure (mm Hg): control 15.9 (3.0), UW 21.0 (3.0), PBr 22.6 (3.0); pulmonary artery pressure (mm Hg): control 17.5 (3.2), UW 22.3 (2.9), PBr 24.5 (2.9). Graft edema (percentage tissue water): control 86.4 (0.8), UW 89.9 (1.8), PBr 89.3 (1.0). CONCLUSION: PBr is a far simpler and less expensive alternative to UW, and appears to provide a similar level of lung graft protection.

High-pressure suction drainage via a polyurethane foam in the management of poststernotomy mediastinitis.

BACKGROUND: This study was performed to evaluate the effectiveness of suction drainage in the management of early poststernotomy mediastinitis. METHODS: From September 1998 to August 1999, we encountered nine cases of poststernotomy mediastinitis out of 1,209 adult median sternotomies performed in this time period. All these cases were treated with suction drainage, which was recently introduced to our management protocol. From September 1997 to August 1998, we encountered 11 cases of poststernotomy mediastinitis of 1,343 adult median sternotomies. All these cases were initially treated by closed drainage and irrigation, which was our previous first-line management. We used the latter group as historical controls for the evaluation of suction drainage. Lengths of hospitalization were compared using the Mann-Whitney U test, and success versus failure of the primary treatment was compared using the chi2 test. RESULTS: Treatment with the suction dressing resulted in a decreased length of hospitalization after treatment starts (p = 0.02) and a lower rate of treatment failure (p = 0.03). CONCLUSIONS: The use of high-pressure suction drainage is a valuable adjunct in the early management of poststernotomy mediastinitis.

Nutritional aspects of neuromuscular diseases.

Evidence suggests that individuals with DMD have reduced skeletal development, including decreased linear growth and bone mineral density, compared to normal subjects. Despite their reduced muscle mass, a high percentage of DMD patients are overweight. Body composition measurements can assist with monitoring changes in fat mass and skeletal muscle mass as the disease progresses. Weight management in overweight DMD patients is indicated because excess adiposity burdens mobility and breathing, but only one study in two DMD patients has documented that weight reduction can be done safely. In the latter stages of the disease most DMD subjects become underweight because of an acceleration in skeletal muscle protein degradation relative to its synthesis. Studies of energy, protein and branched chain amino acid supplementation in DMD have yielded promising but inconclusive results, and more well-designed studies are needed in this area. Although there is currently no cure for DMD, studies on the role of nutritional therapy in increasing the quality of life in these patients are urgently needed. Studies in adults with various SP-NMDs indicate a reduction in fat-free mass and an increase in fat mass relative to controls. The newly developed method of air displacement plethysmography for measuring body composition is ideally suited for SP-NMD subjects because it requires very little effort and the measurement procedure is relatively fast. Dual energy x-ray absorptiometry technology has been proposed for distinguishing myogenic from neurogenic SP-NMDs from calculation of the fat-to-lean soft tissue ratio, which is higher in patients with myogenic muscular atrophy. Studies on the energy metabolism of ambulatory SP-NMD subjects indicate that their basal metabolic rate is either similar to or slightly lower than controls, but 24-hour energy expenditure is about 25% lower than controls. This reduction in 24-hour energy expenditure is due to a reduction in physical activity in SP-NMD. Studies examining the roles of energy expenditure, physical activity, and diet in the development of adiposity and risk for secondary chronic diseases in SP-NMD subjects are currently underway.

A porcine ex vivo paracorporeal model of lung transplantation.

A technique is described which allows perfusion of an isolated, ventilated pig lung with an extracorporeal veno-venous circuit from a support animal. This model is stable for up to 4 h, and avoids some of the disadvantages of alternative small animal and large animal models of lung transplantation. It may be useful in the investigation of factors affecting lung preservation and reperfusion injury.

Simulated work performance tasks in persons with neuropathic and myopathic weakness.

OBJECTIVES: To determine the test-retest reliability of selected simulated work performance tasks in persons with neuropathic and myopathic weakness and control subjects, and the association between muscular performance during these work tasks and conventional isolated muscle group testing. DESIGN: Measurement of three tasks performed on a work simulation device on two different days separated by 1 week. Associations between work task performance and previously reported strength measures in six muscle groups by hand-held dynamometry (HHD) were examined. SETTING: Human performance laboratory of a university. PARTICIPANTS: Convenience sample of ambulatory outpatients with hereditary motor and sensory neuropathy, type I (n = 9), myotonic muscular dystrophy (n = 10), and able-bodied controls (n = 11). MAIN OUTCOME MEASURES: For work simulation, isokinetic peak torque and total work; and for HHD, maximal isometric torque. RESULTS: Mean between-session differences for work simulation tasks ranged from -11% to +4% for peak torque and from -12% to +12% for total work; test sessions did not differ significantly for either patient or control groups. All groups had between-session intraclass correlation coefficients usually >.80, indicating good consistency. In general, correlations between peak torque during work simulation and HHD were strongest in the control group. CONCLUSION: Persons with neuromuscular weakness reliably performed the simulated work tasks examined in this investigation. Work simulation tasks may be a useful tool to assess muscular performance in persons with neuromuscular weakness.