Childhood fitness reduces the long-term cardiometabolic risks associated with childhood obesity.

OBJECTIVE: The objective of this study was to examine whether childhood cardiorespiratory fitness attenuates or modifies the long-term cardiometabolic risks associated with childhood obesity. DESIGN AND METHODS: The study consisted of a 20-year follow-up of 1792 adults who participated in the 1985 Australian Schools Health and Fitness Survey when they were 7-15 years of age. Baseline measures included a 1.6-km run to assess cardiorespiratory fitness and waist circumference to assess abdominal adiposity. At follow-up, participants attended study clinics where indicators of Metabolic Syndrome (MetS) (waist circumference, blood pressure, fasting blood glucose and lipids) were measured and cardiorespiratory fitness was reassessed using a submaximal graded exercise test. RESULTS: Both high waist circumference and low cardiorespiratory fitness in childhood were significant independent predictors of MetS in early adulthood. The mutually adjusted relative risk of adult MetS was 3.00 (95% confidence interval: 1.85-4.89) for children in the highest (vs lowest) third of waist circumference and 0.64 (95% confidence interval: 0.43-0.96) for children with high (vs low) cardiorespiratory fitness. No significant interaction between waist circumference and fitness was observed, with higher levels of childhood fitness associated with lower risks of adult MetS among those with either low or high childhood waist circumference values. Participants who had both high waist circumference and low cardiorespiratory fitness in childhood were 8.5 times more likely to have MetS in adulthood than those who had low waist circumference and high cardiorespiratory fitness in childhood. Regardless of childhood obesity status, participants with low childhood fitness who increased their relative fitness by adulthood had a substantially lower prevalence of MetS than those who remained low fit. CONCLUSIONS: Childhood waist circumference and cardiorespiratory fitness are both strongly associated with cardiometabolic health in later life. Higher levels of cardiorespiratory fitness substantially reduce the risk of adult MetS, even among those with abdominal obesity in childhood.

Impact of body mass index on the relationship between muscle quality and physical function in older women.

OBJECTIVES: To investigate the impact of body mass index (BMI) (normal weight, overweight, obese) on the relationship between muscle quality (MQ) and physical function in community-dwelling older women. DESIGN: Cross-sectional study. SETTING: University research laboratory. PARTICIPANTS: Community-dwelling older women (n = 94, 73.6 ± 5.4 y) stratified by BMI (normal weight: 20.0-24.9 kg/m2; overweight: 25.0-29.9 kg/m2; obese: ≥ 30.0 kg/m2). MEASUREMENTS: Body mass index using height and weight, leg extension power via the Nottingham power rig, body composition using dual-energy X-ray absorptiometry, and physical function (6-minute walk, 8-foot up-and-go, 30-second chair stand). Muscle quality was defined as leg power (watts) normalized for lower-body mineral-free lean mass (kg). RESULTS: Following adjustments for covariates, muscle quality was significantly higher in women of normal BMI compared to overweight (10.0 ± 0.4 vs. 8.7 ± 0.4 watts/kg, p = 0.03). Muscle quality was a significant predictor of performance on the 6-minute walk and 8-foot up-and-go in normal and overweight women (all p < 0.05) and performance on the 30-second chair stand in normal and obese women (both p < 0.05). Body mass index did not significantly impact the association between MQ and physical function (all p > 0.05). CONCLUSIONS: Muscle quality varies by BMI, yet the relationship to physical function is not significantly different across BMI groups. The results imply that interventions that increase MQ in older women may improve physical function, regardless of BMI.

Predictive associations between alternative measures of childhood adiposity and adult cardio-metabolic health.

OBJECTIVE: To estimate associations between alternative measures of childhood adiposity and indicators of cardio-metabolic health in adulthood, both unadjusted and adjusted for changes in adiposity from childhood to adulthood. DESIGN AND METHODS: The study consisted of a 20-year follow-up of 2188 adults who had participated in the 1985 Australian Schools Health and Fitness Survey when they were between 7 and 15 years of age. Baseline and follow-up measures of body composition included height and weight, waist and hip circumferences and skinfold thicknesses at four sites. At follow-up, participants attended study clinics where component indicators of the metabolic syndrome (MetS) (waist circumference, blood pressure, fasting blood glucose and lipids) were measured. RESULTS: Waist circumference and skinfold measures were the strongest predictors of subsequent MetS (2009 Joint Scientific Statement definition) in early adulthood. For example, relative risks (RRs) for children in the highest (vs lowest) quarter of waist circumference were 4.8 (95% confidence interval (CI): 2.5-9.2) for males and 5.8 (95% CI: 2.4-14.2) for females. After adjusting for change in waist circumference from childhood to adulthood, each 10 cm increase in childhood waist circumference was associated with an approximate twofold increase in risk for adult MetS (RR = 2.1 (95% CI: 1.7-2.7) among males and RR = 2.3 (95% CI: 1.6-3.4) among females). CONCLUSION: Elevated waist circumference and skinfold thickness measures in childhood appear to be the strongest predictors of subsequent MetS in early adulthood. The increased risk associated with higher waist circumference in childhood appears to be independent of changes in waist circumference from childhood to adulthood.

Effectiveness of an outside-the-boot ankle brace in reducing parachuting related ankle injuries.

OBJECTIVES: To examine the efficacy of an outside-the-boot parachute ankle brace (PAB) in reducing risk of ankle injury to army paratrooper trainees and to identify inadvertent risks associated with PAB use. DESIGN: The authors compared hospitalization rates for ankle, musculoskeletal, and other traumatic injury among 223,172 soldiers trained 1985-2002 in time periods defined by presence/absence of PAB use protocols. Multiple logistic regression analysis estimated adjusted odds ratios (OR) and 95% confidence intervals for injury outcomes, comparing pre and post brace periods to the brace protocol period. SETTING: A research database consisting of training rosters from the US Army Airborne training facility (Fort Benning, GA) occupational, demographic, and hospitalization information. MAIN OUTCOME MEASURES: Injuries were considered training related if they occurred during a five week period starting with first scheduled static line parachute jump and a parachuting cause of injury code appeared in the hospital record. RESULTS: Of 939 parachuting related hospitalizations during the defined risk period, 597 (63.6%) included an ankle injury diagnosis, 198 (21.1%) listed a musculoskeletal (non-ankle) injury, and 69 (7.3%) cited injuries to multiple body parts. Risk of ankle injury hospitalization was higher during both pre-brace (adjusted OR 2.38, 95% CI 1.92 to 2.95) and post-brace (adjusted OR 1.72, 95% CI 1.27 to 2.32) periods compared with the brace protocol period. Odds of musculoskeletal (non-ankle) injury or injury to multiple body parts did not change between the brace and post-brace periods. CONCLUSION: Use of a PAB during airborne training appears to reduce risk of ankle injury without increasing risk of other types of traumatic injury.