Association between physical activity and scoliosis: a prospective cohort study.

BACKGROUND: Little is understood about the causes of adolescent onset idiopathic scoliosis (AIS). No prospective studies assessing the association between physical activity and idiopathic adolescent scoliosis have been carried out. We aimed to carry out the first prospective population-based study of this association. METHODS: The Avon Longitudinal Study of Parents and Children (ALSPAC) collected self-reported measures of physical ability/activity at ages 18 months and 10 years. Objective measures of physical activity were collected by accelerometry at age 11 years. scoliosis was identified using the dxa scoliosis Method at age 15 years. Participants with scoliosis at age 10 years were excluded. RESULTS: Of 4640 participants at age 15 years who had DXA scans, 267 (5.8%) had scoliosis. At age 18 months, those infants who were able to stand up without being supported were 66% less likely to have developed scoliosis by age 15 (P = 0.030) compared with infants who could not. Those children whose mothers reported they did most vigorous physical activity at age 10 years were 53% less likely to develop scoliosis (P = 0.027). Those children who did more objectively measured moderate/vigorous physical activity at age 11 were 30% less likely to have developed scoliosis (P < 0.001). Results were not affected by adjustment for age, gender, lean mass, fat mass or back pain. CONCLUSIONS: We report reduced physical ability and activity as early as age 18 months in those who go on to develop scoliosis by age 15 years. Further research is justified to examine the mechanisms underlying this association.

Association between components of body composition and scoliosis: a prospective cohort study reporting differences identifiable before the onset of scoliosis.

There is an increasing body of research suggesting that low body weight is associated with scoliosis, but this is based on case-control studies, which are prone to bias. No studies have investigated the components of body weight: fat and lean mass. We have therefore carried out the first population-based prospective study of the association between fat and lean mass at age 10 years assessed by dual-energy X-ray absorptiometry (DXA), with presence of scoliosis at age 15 years using the Avon Longitudinal Study of Parents and Children (ALSPAC). All children with scoliosis at age 10 years were excluded. Of 5299 children at age 15 years, 312 (5.9%) had scoliosis. Our results show a negative association between body mass index (BMI)/body weight at age 10 years and scoliosis at age 15 years, with a 20% reduced risk of scoliosis per SD increase in BMI (odds ratio [OR], 0.80; 95% confidence interval [CI], 0.70-0.92; p = 0.001). This association with BMI/body weight reflects associations with both fat mass and lean mass. After adjustment for age, gender, leg length, and fat mass per SD increase in lean mass, there was a 20% reduced risk of scoliosis (OR, 0.80; 95% CI, 0.65-0.97) and per SD increase in fat mass there was a 13% reduced risk of scoliosis (OR, 0.87; 95% CI, 0.74-1.03). In terms of adipocyte function, an inverse association was seen between leptin at age 10 years and scoliosis (OR for scoliosis per SD increase in leptin of 0.78; 95% CI, 0.63-0.99), and a positive association between adiponectin at age 10 years and scoliosis (OR for scoliosis per SD increase in adiponectin of 1.44; 95% CI, 0.99-2.10). This is the first study to address the association between the individual components of body weight and scoliosis in a prospective cohort study, and shows altered body composition that is present before the onset of clinically detected scoliosis.

Identifying scoliosis in population-based cohorts: development and validation of a novel method based on total-body dual-energy x-ray absorptiometric scans.

The purpose of this study was to develop and validate a novel method of identifying scoliosis on total-body dual energy X-ray absorptiometric (DXA) scans. Scoliosis was identified on total-body DXA scans by triaging to distinguish true curves from positioning errors, followed by a modified Ferguson method to measure angles. Precision was assessed on 174 children from the Avon Longitudinal Study of Parents and Children (ALSPAC), who underwent repeat DXA scans at age 15, 2-6 weeks apart. In addition, precision of angle estimation was evaluated on 20 scans measured five times. To evaluate accuracy, angle size was compared to spinal radiographs in 13 individuals with known scoliosis. Subsequently, this method was applied to estimate scoliosis prevalence rates and curve patterns from DXA scans previously obtained in 7,298 ALSPAC participants at age 9 and 5,122 at age 15. There was substantial agreement in identifying those with scoliosis on repeat DXA scans taken 2-6 weeks apart (kappa 0.74, 95 % CI 0.59-0.89). Of repeat angle measures, 95 % were within 5°. Angle size was underestimated by approximately 40 %. Prevalence of scoliosis ≥10° in the ALSPAC was 0.3 % at age 9 and 3.5 % at age 15 and was higher in girls at both time points. The mean ± SD curve size was 12 ± 4° at age 9 years and 15 ± 7° at age 15. We have developed and validated a novel method for identifying scoliosis from DXA scans. Comparison with prevalence data using more established techniques suggests our method provides valid estimates of scoliosis prevalence in population-based cohorts.

Profiling psychomotor and cognitive aging in four-way cross mice.

In part due to their genetic uniformity and stable characteristics, inbred rodents or their F1 progeny are frequently used to study brain aging. However, it is recognized that focus on a single genotype could lead to generalizations about brain aging that might not apply to the species as a whole, or to the human population. As a potential alternative to uniform genotypes, genetically heterogeneous (HET) mice, produced by a four-way cross, were tested in the current study to determine if they exhibit age-related declines in cognitive and psychomotor function similar to other rodent models of brain aging. Young (4 months) and older (23 months) CB6F1 × C3D2F1 mice were administered a variety of tests for cognitive, psychomotor, and sensory/reflexive capacities. Spontaneous locomotion, rearing, and ability to turn in an alley all decreased with age, as did behavioral measures sensitive to muscle strength, balance, and motor coordination. Although no effect of age was found for either startle response amplitude or reaction time to shock stimuli, the old mice reacted with less force to low intensity auditory stimuli. When tested on a spatial swim maze task, the old mice learned less efficiently, exhibited poorer retention after a 66-h delay, and demonstrated greater difficulty learning a new spatial location. In addition, the older mice were less able to learn the platform location when it was identified by a local visual cue. Because there was a significant correlation between spatial and cued discrimination performance in the old mice, it is possible that age-related spatial maze learning deficits could involve visual or motor impairments. Variation among individuals increased with age for most tests of psychomotor function, as well as for spatial swim performance, suggesting that four-way cross mice may be appropriate models of individualized brain aging. However, the analysis of spatial maze learning deficits in older CB6F1 × C3D2F1 mice may have limited applicability in the study of brain aging, because of a confounding with visually cued performance deficits.