Lana M. Widman

Metabolic syndrome in adolescents with spinal cord dysfunction.

Abstract Objective: The purpose of this study was to determine the prevalence of components of the metabolic syndrome in adolescents with spinal cord injury (SCI) and spina bifida (SB), and their associations with obesity in subjects with and without SCI and SB. Methods: Fifty-four subjects (20 SCI and 34 SB) age 11 to 20 years with mobility impairments from lower extremity paraparesis were recruited from a hospital-based clinic. Sixty able-bodied subjects who were oversampled for obesity served as controls (CTRL). Subjects were categorized as obese if their percent trunk fat measured by dual x-ray absorptiometry (DXA) was>30.0> for males and>35 .0> for females. Ten SCI, 24 SB, and 19 CTRL subjects were classified as obese. Fasting serum samples were collected to determine serum glucose, insulin, and lipid concentrations. Metabolic syndrome was defined as having #x003D;3 of the following components: (a) obesity; (b) high-density lipoprotein (HDL) <45 mg/dl for males;<50 mg/dl for females; (c) triglycerides #x003D;100 mg/dl; (d) systolic or diastolic blood pressure95th percentile for age/ height/gender, and (e) insulin resistance determined by either fasting serum glucose 100-125 mg/dl; fasting insulin #x003D;20 μU /ml; or homeostasis model assessment of insulin resistance #x003D;4.0 . Results: Metabolic syndrome was identified in 32.4>of the SB group and 55> of the SCI group. Metabolic syndrome occurred at a significantly higher frequency in obese subjects (SB = 45 .8>, SCI = 100>, CTRL = 63.2>) than nonobese subjects (SB = 0>, SCI = 10>, CTRL = 2.4>). Conclusions: The prevalence of metabolic syndrome in adolescents with SB/ SCI is quite high, particularly in obese individuals. These findings have important implications due to the known risks of cardiovascular diseases and diabetes mellitus associated with metabolic syndrome in adults, particularly those with spinal cord dysfunction.

Effectiveness of an upper extremity exercise device integrated with computer gaming for aerobic training in adolescents with spinal cord dysfunction.

Abstract Background/Objective: To determine whether a new upper extremity exercise device integrated with a video game (GameCycle) requires sufficient metabolic demand and effort to induce an aerobic training effect and to explore the feasibility of using this system as an exercise modality in an exercise intervention. Design: Pre-post intervention. Setting: University-based research facility. Subject Population: A referred sample of 8 adolescent subjects with spina bifida (4 girls, 15.5 ± 0.6 years; 4 boys, 1 7.5 ± 0.9 years) was recruited to participate in the project. All subjects had some level of mobility impairment that did not allow them to participate in mainstream sports available to their nondisabled peers. Five subjects used a wheelchair full time, one used a wheelchair occasionally, but walked with forearm crutches, and 2 were fully ambulatory, but had impaired gait. Main Outcome Measures: Peak oxygen uptake, maximum work output, aerobic endurance, peak heart rate, rating of perceived exertion, and user satisfaction. Results: Six of the 8 subjects were able to reach a Vo2 of at least 50% of their Vo2 reserve while using the GameCycle. Seven of the 8 subjects reached a heart rate of at least 50% of their heart rate reserve. One subject did not reach either 50% of Vo2 reserve or 50% of heart rate reserve. Seven of the 8 subjects increased their maximum work capability after training with the GameCycle at least 3 times per week for 16 weeks. Conclusions: The data suggest that the GameCycle seems to be adequate as an exercise device to improve oxygen uptake and maximum work capability in adolescents with lower extremity disability caused by spinal cord dysfunction. The subjects in this study reported that the video game component was enjoyable and provided a motivation to exercise.

Body composition and water compartment measurements in boys with Duchenne muscular dystrophy.

McDonald CM, Carter GT, Abresch RT, Widman L, Styne DM, Warden N, Kilmer DD: Body composition and water compartment measurements in boys with Duchenne muscular dystrophy. Am J Phys Med Rehabil 2005; 84:483–491. Objective:Duchenne muscular dystrophy (DMD) patients have a lower percentage of total body water and higher extracellular water to intracellular water (ECW/ICW) ratio compared with normal subjects. However, it is not known whether this is due to increased fat mass or a decreased amount of ICW in muscle cells in DMD patients. The purpose of this study was to (1) determine the effect of increased fat mass and decreased lean mass on the ECW to ICW ratio in DMD patients and to (2) determine the validity of multifrequency bioelectrical impedance analysis (MFBIA) in assessing body composition in DMD patients. Design:This study has a quasi-experimental, comparative design using nonequivalent groups. A total of 46 boys ranging from 6 to 13 yrs of age participated in this study. There were 12 nonobese able-bodied controls, 19 obese able-bodied children (obese), and 15 boys with DMD. Body composition was measured by dual-energy x-ray absorptiometry (DEXA). Body composition and body water compartment analysis were assessed by MFBIA. All measurements obtained using MFBIA were compared with those obtained using DEXA for validation. Results:Both MFBIA and DEXA measures were strongly correlated in control (r = 0.99), obese (r = 0.92), and DMD subjects (r = 0.95). However, lean tissue mass measured by DEXA in the DMD subjects was only slightly higher (19.2 ± 1.1 vs. 18.2 ± 1.2, P < 0.02) than as measured by MFBIA. Mean percentage of body fat measured by DEXA in the DMD subjects (30.4 ± 3.1%) was significantly lower than as measured by MFBIA (38.7 ± 2.2%). The mean percentage of body fat measured by DEXA in the control group (23.2 ± 1.8%) was significantly (P < 0.001) lower than as measured by MFBIA (28.6 ± 1.6%). The mean percentage of body fat measured by DEXA in obese able-bodied controls (40.8 ± 0.9%) was not significantly different from that measured by MFBIA (40.4 ± 1.5%). Compared with the obese and control subjects, DMD subjects showed reduced ICW and ECW, with an increased ECW/ICW ratio, as expected. However, the percentage of fat for the DMD group was not different from the obese group. Conclusions:DMD patients have elevated ECW/ICW ratios compared with obese subjects and nonobese controls. However, obese subjects and nonobese controls had similar ECW/ICW ratios, despite the increased fat tissue mass in obese subjects. This suggests that the elevated ECW/ICW ratios in DMD subjects are not due to increased fat mass but rather some other mechanism, likely impaired cellular homeostasis due to muscle membrane instability. Although MFBIA slightly underestimates lean tissue mass in boys with DMD, it has a potential role as an inexpensive and easy to use measurement tool to measure changes in muscle mass in the clinical setting.

Body composition and resting energy expenditure in patients aged 11 to 21 years with spinal cord dysfunction compared to controls: comparisons and relationships among the groups.

Abstract Objectives: To compare body composition in patients aged 11 to 21 years with spinal dysfunction due to spinal cord injury (SCI) and spina bifida (SB) vs able–bodied control (CTRL) and able–bodied overweight (OW) groups and to examine the relationships between resting energy expenditure (REE) and total lean mass (TLM) in the SCI, SB, CTRL, and OW groups. Methods: Two hundred fifteen subjects, including 85 CTRL, 31 OW, 33 SCI, and 66 SB, were evaluated. Body composition was estimated by dual energy x-ray absorptiometry (DXA). Measurements included height, weight, total lean mass (TLM), fat tissue mass (FTM), body mass index (BMI), BMI percentile (BMI%tile), and %fat. Resting energy measurements were obtained in fasting subjects with an open-circuit indirect calorimeter. Results: There were gender differences in height, weight, BMI, TLM, fat mass,%fat, and REE. The REE in the SCI and SB groups was significantly different from that in the CTRL and OW groups, but no significant difference was found between the SCI and SB groups. The SB group had significantly higher REE/TLM ratios than did the other groups. The %fat was significantly higher in the SB and OW groups as compared to the CTRL and SCI groups. TLM was significantly higher in CTRL and OW groups as compared to SCI and SB groups, with the lowest TLM found in the SB group. Conclusion: Patients aged 11 to 21 years with SB or SCI have significant lean tissue mass deficits by DXA as compared to able–bodied CTRL and OW groups, with the greatest deficits in total lean mass measured in SB. The absolute REE values were significantly reduced in both SCI and SB groups in association with their lean tissue deficits. Interestingly, REE/TLM ratios were remarkably constant in the CTRL, OW, and SCI groups but significantly elevated in the SB group. One would expect an even greater degree of adiposity in the SB group if their REE/TLM ratios were not elevated relative to those without congenital paralysis.

Aerobic Fitness and Upper Extremity Strength in Patients Aged 11 to 21 Years With Spinal Cord Dysfunction as Compared to Ideal Weight and Overweight Controls

Abstract Objective: To determine whether the aerobic fitness, upper extremity strength, and body composition in groups of adolescents with mobility impairment due to thoracic and upper lumbar spinal cord injury (SCI) or spina bifida (SB) are significantly different from those in groups of adolescents without mobility impairment who are of normal weight (CTRL) or overweight (OW). Subjects: One hundred fifteen total subjects were evaluated including 59 female (19 SB, 9 SCI, 17 OW, and 14 CTRL) and 56 male (18 SB, 1 0 SCI, 8 OW, and 20 CTRL) participants aged 11 to 21 years. Methods: Aerobic fitness was assessed using a ramp protocol with a magnetically braked arm ergometer. Heart rate and oxygen uptake (V02) were recorded. Peak isokinetic upper arm and shoulder strength values were determined with a dynamometer. Body composition was estimated using dual energy x–ray absorptiometry (DEXA). Male and female subjects were categorized as overweight if their percent body fat by DEXA exceeded 25% and 30%, respectively. Results were analyzed with an ANOVA using the Bonferroni correction. Significance was accepted at P<0.05. Results: The percent body fat of both the male and female SB and SCI subjects was significantly higher than CTRL but was not different than OW. In general, the shoulder extension and flexion strength in both the SB and SCI males and females was significantly lower than that of the CTRL and OW. The SCI and SB subjects had significantly reduced aerobic capacity (VO2 /kg) compared to the CTRL subjects but were not different than the OW subjects. During the maximal exercise test, the SB and SCI subjects reached exhaustion at significantly lower workloads than the CTRL and OW subjects. Conclusions: Patients age 11 to 21 years with SB and SCI had reduced aerobic capacity that was associated with being overweight and having reduced upper extremity strength. These data suggest that interventions to increase strength and fitness and to manage weight should be recommended in this population.

Behavioral Intervention, Exercise, and Nutrition Education to Improve Health and Fitness (BENEfit) in Adolescents With Mobility Impairment Due to Spinal Cord Dysfunction

Abstract Background/Objective: Determine the effects of a nutrition education and exercise intervention on the health and fitness of adolescents with mobility impairment due to spinal cord dysfunction from myelomeningocele and spinal cord injury. Subjects participated in a 16-week intervention consisting of a behavioral approach to lifestyle change, exercise, and nutrition education to improve fitness (BENEfit) program. Participants were given a schedule of aerobic and strengthening exercises and attended nutrition education and behavior modification sessions every other week along with their parent(s). Subjects: Twenty adolescents (aged 11–18 years, mean 15.4 ± 2.2 years) with spinal cord dysfunction. Methods: Subjects were tested immediately prior to starting and upon completion of the program. Aerobic fitness was measured using a ramp protocol with an arm ergometer. Heart rate and oxygen uptake were measured. Values at anaerobic threshold and maximum oxygen uptake were recorded. Peak isokinetic arm and shoulder strength were determined with a dynamometer. Body composition was estimated with dual–energy x–ray absorptiometry. Serum chemistry included measures of cholesterol, high–density lipoprotein, low-density lipoprotein, and triglycerides. Results: Fourteen individuals completed all testing sessions. There was no significant overall change in weight, body mass index, body mass index z–scores, or serum chemistry. Overall, there was a significant increase in whole body lean tissue without a concomitant increase in whole body fat. Fitness measures revealed a significant increase in maximum power output, work efficiency as measured by the amount of power output produced aerobically, and resting oxygen uptake. Strength measurements revealed a significant increase in shoulder extension strength and a trend towards increased shoulder flexion strength. There were no significant changes in high–density lipoprotein, low–density lipoprotein, total cholesterol, or triglycerides. Conclusions: The BENEfit program shows promise as a method for improving the health and fitness of adolescents with mobility impairments who are at high risk for obesity and obesity-related health conditions.

Altered body composition affects resting energy expenditure and interpretation of body mass index in children with spinal cord injury.

Abstract Background: lndividuals with spinal cord injury (SCI) typically undergo changes in their body composition (reduction in lean body mass and an increase in fat mass) that can Iead to secondary complications associated with diminished physical activity and obesity. Methods: This study used dual energy X-ray absorptiometry (DXA) to estimate the totallean tissue mass (L TM), total body fat, and total bone mineral content (BMC) to assess the relationship between body mass index (BMI), body composition, and resting metabolic rate (RMR) in a group of children with SCI who were matched with able-bodied controls for age and sex. Body composition and RMR were measured in 18 boys and 9 girls (1 0-21 years of age) who had a SCI in the previous 1 to 3 years andin 27 age-and sex-matched controls. Results: Children with SCI had significantly lower mean LTM than control subjects (3 7.6 ± 9.6 kg and 46.7 ± 9.2 kg, respectively; P < 0.001) and higher percent body fat (26.4 ± 7.9% and 20.2 ± 8.5%, respectively; P < 0.02) as measured by DXA, despite their reduced BMI (1 8.9 ± 3.8 kg/m2 and 21.2 ± 2.9 kg/m2 , respectively; P < 0.01 ). Children with SCI had lower RMR than the controls subjects (1213 ± 334 kj/d and 1511 ± 257 kj/d, respectively), but there was no difference in RMR when adjusted for LTM. Conclusion: Children with SCI have lower RMRs that are associated with their reduced LTM. The reduction in LTM and RMR may predispose children with SCI to relative gains in body fat. BMI significantly underestimates body fat in children with SCI.