Validity of anthropometric measurements for characterizing obesity among adult survivors of childhood cancer: A report from the St. Jude Lifetime Cohort Study.

BACKGROUND: Childhood cancer survivors (CCSs) are at risk for obesity. The purpose of this project was to determine which clinical measures of body composition are most accurate among CCSs in comparison with dual-energy x-ray absorptiometry (DXA). METHODS: The agreement between the body mass index (BMI), skinfold percent body fat, and waist-to-height ratio (WHtR) and DXA was evaluated among 1361 CCSs (mean age, 32.4 ± 7.7 years) 10 or more years after the diagnosis. The sensitivity and specificity of BMI, skinfold, and WHtR obesity classifications were calculated with respect to DXA. Log-binomial regression, stratified by sex, was used to evaluate treatment-related factors for misclassification as nonobese by BMI, skinfolds, and WHtR. RESULTS: The mean body fat values were 23.3% ± 7.7% (males) and 32.3% ± 8.1% (females) for skinfolds and 26.9% ± 7.4% (males) and 38.4% ± 7.7% (females) for DXA. Pearson correlations between skinfolds and DXA were high (R = 0.83 for males, R = 0.84 for females). Skinfolds incorrectly classified 34.5% of obese males and 27.3% of obese females. BMI measures were the least sensitive with false-negative rates of 46.4% (males) and 53.1% (females). Males exposed to abdominal/pelvic radiation were at increased risk for misclassification as nonobese by BMI (relative risk, 1.57; 95% confidence interval, 1.25-1.95). The percentages classified as obese were highest with DXA (males, 63.1%; females, 84.8%) and lowest with BMI (males, 35.7%; females, 39.7%). Although skinfolds and WHtR underestimated the percentage classified as obese in comparison with DXA, the differences were not as large. CONCLUSIONS: Findings suggest that skinfolds and WHtR are better than BMI for obesity classification in CCSs. Clinicians should be aware of the high risk of misclassifying obese CCSs as nonobese.

Energy balance and fitness in adult survivors of childhood acute lymphoblastic leukemia.

There is limited information on body composition, energy balance, and fitness among survivors of childhood acute lymphoblastic leukemia (ALL), especially those treated without cranial radiation therapy (CRT). This analysis compares these metrics among 365 ALL survivors with a mean age of 28.6 ± 5.9 years (149 treated with and 216 without CRT) and 365 age-, sex-, and race-matched peers. We also report risk factors for outcomes among survivors treated without CRT. Male survivors not exposed to CRT had abnormal body composition when compared with peers (% body fat, 26.2 ± 8.2 vs 22.7 ± 7.1). Survivors without CRT had similar energy balance but had significantly impaired quadriceps strength (-21.9 ± 6.0 Newton-meters [Nm]/kg, 60°/s) and endurance (-11.4 ± 4.6 Nm/kg, 300°/s), exercise capacity (-2.0 ± 2.1 ml/kg per minute), low-back and hamstring flexibility (-4.7 ± 1.6 cm), and dorsiflexion range of motion (-3.1 ± 0.9°) and higher modified total neuropathy scores (+1.6 ± 1.1) than peers. Cumulative asparaginase dose ≥120,000 IU/m(2) was associated with impaired flexibility, vincristine dose ≥39 mg/m(2) with peripheral neuropathy, glucocorticoid (prednisone equivalent) dose ≥8000 mg/m(2) with hand weakness, and intrathecal methotrexate dose ≥225 mg with dorsiflexion weakness. Physical inactivity was associated with hand weakness and decreased exercise capacity. Smoking was associated with peripheral neuropathy. Elimination of CRT from ALL therapy has improved, but not eliminated, body-composition outcomes. Survivors remain at risk for impaired fitness.

Skeletal, neuromuscular and fitness impairments among children with newly diagnosed acute lymphoblastic leukemia.

This study describes skeletal, neuromuscular and fitness impairments among 109 children (median age 10 [range 4-18] years, 65.1% male, 63.3% white) with acute lymphoblastic leukemia (ALL). Outcomes were measured 7-10 days after diagnosis and compared to age- and sex-specific expected values. Associations between function and health-related quality of life (HRQL) were evaluated with logistic regression. Children with ALL had sub-optimal bone mineral density (BMD) Z-score/height (mean ± standard error: - 0.53 ± 0.16 vs. 0.00 ± 0.14, p < 0.01), body mass index percentile (57.6 ± 3.15 vs. 50.0 ± 3.27%, p = 0.02), quadriceps strength (201.9 ± 8.3 vs. 236.1 ± 5.4 N, p < 0.01), 6 min walk distance (385.0 ± 13.1 vs. 628.2 ± 7.1 m, p < 0.001) and Bruininks-Oseretsky Test of Motor Proficiency scores (23 ± 2.5 vs. 50 ± 3.4%, p < 0.01). Quadriceps weakness was associated with a 20.9-fold (95% confidence interval 2.5-173.3) increase in poor physical HRQL. Children with newly diagnosed ALL have weakness and poor endurance and may benefit from early rehabilitation that includes strengthening and aerobic conditioning.

Effects of moderate-volume, high-load lower-body resistance training on strength and function in persons with Parkinson's disease: a pilot study.

Background. Resistance training research has demonstrated positive effects for persons with Parkinson's disease (PD), but the number of acute training variables that can be manipulated makes it difficult to determine the optimal resistance training program. Objective. The purpose of this investigation was to examine the effects of an 8-week resistance training intervention on strength and function in persons with PD. Methods. Eighteen men and women were randomized to training or standard care for the 8-week intervention. The training group performed 3 sets of 5-8 repetitions of the leg press, leg curl, and calf press twice weekly. Tests included leg press strength relative to body mass, timed up-and-go, six-minute walk, and Activities-specific Balance Confidence questionnaire. Results. There was a significant group-by-time effect for maximum leg press strength relative to body mass, with the training group significantly increasing their maximum relative strength (P < .05). No other significant interactions were noted (P > .05). Conclusions. Moderate volume, high-load weight training is effective for increasing lower-body strength in persons with PD.

Effects of unstable surface training on measures of balance in older adults.

The purpose of this investigation was to examine the effects of a 5-week, low-cost unstable surface balance training program in sexagenarians. Nineteen men and women (60-68 years; 83.7 +/- SD kg) were randomly assigned to a control or training group. The training group performed various balance activities on air-filled rubber disks for 5 weeks. Each thrice-weekly session was supervised, and progression was based on proficiency. While in an upright position, static balance (length of path [LOP] of the center of pressure) was assessed in both eyes-open and eyes-closed states for each leg separately as well as for both legs. Participants also performed the timed up-and-go (TUG) test and completed the Activity-specific Balance Confidence (ABC) questionnaire. A significant group x time effect for the ABC questionnaire was found (p = 0.04). Tukey post hoc analysis indicates that the balance training program increased self-perceived balance confidence (p < 0.01). No significant group x time interactions were noted for TUG or LOP. Because no objective measure of balance or function was changed, the increase in ABC may be spurious. Unstable surface training may not be effective in improving balance among persons for whom balance is not problematic. However, the large number of acute training variables in such a program leaves opportunity for further research in this paradigm.

Impaired leg extensor strength in individuals with Parkinson disease and relatedness to functional mobility.

Previous investigations have demonstrated leg strength deficits in persons with Parkinson's disease (PD) as compared to neurologically-normal adults. However, the exact mode of contraction by which strength is assessed may determine how closely such deficits are related to functional performance. The purpose of this study was to better understand the relationship of strength and functional mobility in persons with PD (n = 17, mean H&Y stage = 2.0) via comparison to a group of similar age healthy controls (n = 10) using a multi-joint isometric test of strength and various measures of functional mobility. Tests included isometric leg press maximum force relative to body mass, the Activities-specific Balance Confidence scale (ABC), postural sway under various unilateral stance and visual conditions, and the timed up and go (TUG). Relative force (p = 0.044) and ABC questionnaire mean scores (p < 0.001), showed controls performing better than PD subjects. The control group performed better than the PD group for length of path of the center of pressure except in the eyes closed positions (p < 0.05 for all). TUG time (p = 0.052) was not significantly different between the PD group and healthy controls. Leg press maximum force relative to body mass was however significantly correlated with TUG time (r = -0.68, p = 0.003) in persons with PD. There were no gender differences for any variables. These results suggest that some balance and functional mobility task performances are more worse for persons with mild-to-moderate PD than for neurologically-normal age-matched controls, which may be influenced by lessened lower extremity multi-joint strength. Strength training of the lower extremity utilizing such multi-joint actions may be beneficial for this population.

Effect of resistance training on blood oxidative stress in Parkinson disease.

UNLABELLED: Oxidative stress seems to be involved in the pathogenesis of Parkinson disease (PD). Exercise training can increase endogenous antioxidant protection and decrease the production of reactive oxygen and nitrogen species. PURPOSE: To investigate the effect of exercise training on oxidative status in persons with PD. METHODS: Sixteen subjects with PD were match-randomly assigned to resistance exercise (n = 8) or a no-exercise control group (n = 8) on the basis of disease stage (Hoehn and Yahr stages I and II) and sex. Supervised exercise was performed twice weekly for 8 wk, consisting of three sets each of the leg press, leg curl, and calf press. Resting blood samples were taken from subjects before and after the intervention and assayed for markers of oxidative stress [malondialdehyde (MDA) and hydrogen peroxide (H2O2)] and antioxidant capacity (superoxide dismutase, catalase, glutathione peroxidase, and trolox-equivalent antioxidant capacity). RESULTS: The exercise program was well-tolerated and associated with modest trends toward decreased oxidative stress and increased antioxidant capacity. The two biomarkers of oxidative stress were decreased after exercise training [MDA (15%) and H2O2 (16%)]. With these changes, a postintervention difference was apparent between the resistance exercise training and control groups for H2O2 (P = 0.007), with a trend for difference noted for MDA (P = 0.06). The mean increases in superoxide dismutase (9%) and glutathione peroxidase (15%) noted in the exercise training group were not statistically significant (P > 0.05). CONCLUSIONS: Short-term resistance training may be associated with reduced oxidative stress in subjects with PD. Future studies with larger samples, inclusive of a higher volume of resistance exercise, are needed to extend these findings.