Background: Although dual-energy x-ray absorptiometry (DXA) assessed areal bone density (aBMD) is the clinical standard for determining fracture risk, the majority of older adults who sustain a fracture do not have osteoporosis (T-score < −2.5). Importantly, bone fragility results not only from low BMD, but also from deterioration in bone structure. We used high-resolution peripheral quantitative computed tomography (HR-pQCT) data from eight cohorts to evaluate whether HR-pQCT indices were associated with fracture risk independently of femoral neck (FN) aBMD and FRAX (Fracture Risk Assessment Tool) score. Methods: Participants included 7,254 individuals (66% women) from cohorts in the USA (Framingham, Mayo Clinic), France (QUALYOR, STRAMBO, OFELY), Switzerland (GERICO), Canada (CaMos), and Sweden (MrOS). We used Cox proportional hazards models to estimate hazards ratios (HRs) for the association between bone parameters (per standard deviation, SD, deficit) and incident fracture, adjusting for age, sex, height, weight and cohort. Findings: Mean baseline age was 69 (±9) years (range, 40 to 96). Cumulative incidence of fracture was 11% (n=765) over a mean follow-up time of 4.6 (± 2.4) years. The majority of participants (92%) had a femoral neck T-score >−2.5, and thus did not meet diagnostic criteria for osteoporosis. Failure load was the bone measure most strongly associated with risk of fracture: tibia HR=2.40 (1.98-2.91), radius HR=2.13 (1.77-2.56), per SD decrease in failure load. HRs for other bone indices ranged from HR=1.12 (1.03-1.23) per SD increase in tibia cortical porosity to HR=1.58 (1.45-1.72) per SD decrease in radius trabecular volumetric bone density (vBMD). After further adjustment for FN aBMD or FRAX, HRs were attenuated, but most bone parameters remained significantly associated with fracture. Cortical density, trabecular number, and trabecular thickness at the distal radius were the best set of predictors of fracture; while the same indices plus cortical area were identified for the tibia. These HR-pQCT indices and failure load improved prediction of fracture, beyond FN aBMD alone or FRAX. Interpretation: Results from this large international cohort of women and men confirm prior studies showing that deficits in trabecular and cortical bone density and structure contribute to fracture risk independently of aBMD and FRAX. Measurements of cortical and trabecular bone density and morphology at the peripheral skeleton may improve identification of those at highest risk for fracture. Funding: National Institutes of Health, National Institute of Arthritis Musculoskeletal and Skin Diseases, R01AR061445

http://hyper.ahajournals.org/ Downloaded from Dong et al Effects of Air Pollution on Blood Pressure 579pollution on BP in different parts of the world are unclear but may result from spatial and temporal variability in pollution sources and composition. 17,18 Compared with short-term effects of air pollution, there is little information on the relation between chronic exposure to air pollution and prevalent hypertension. Inconsistent results have also been reported on the association between incident hypertension and air pollution. For instance, Coogan et al 19 showed in a 10-year follow-up for incident hypertension and diabetes mellitus of black women from Los Angeles that NO X (but less PM 2.5 ) borderline increased the risk of becoming hypertensive. However, Sørensen et al 20 reported that longterm exposure (1 and 5 years) to NO X was not associated with incident self-reported hypertension in a Danish cohort. We hypothesized that at the population level, long-term exposure to ambient air pollution is associated with higher BP and higher prevalence of hypertension among humans. In this study, we tested this hypothesis in the 11 Districts Chinese Study, a cross-sectional study of air pollution and adult health in a large, well-characterized population-based sample, residing in northeast China, where there are wide differences in inter-and intracity gradients and ambient pollutant levels, offering a valuable opportunity to assess the associations between exposure and response. Methods Study Cities Selection and Subject RecruitmentMore than 20 million people reside in 14 cities in Liaoning province in northeast China. To maximize the inter-and intracity gradients of the pollutants of interest and minimize the correlation between district-specific ambient pollutants, in April 2009, we selected 3 cities (Shenyang, Anshan, and Jinzhou) based on the results of air pollution measurements between 2006 and 2008. There are 5, well-identified geographic districts in Shenyang, and 3 districts in Anshan and Jinzhou, respectively. Three communities within 1 km of air-monitoring sites were randomly chosen from these districts resulting in 33 locales, and from each of these, 700 to 1000 households were randomly identified. One participant, aged 18 to 74 years, was selected from each household without replacement. Our entry criterion was that the subject should have lived at that place for at least 5 years. The design and conduct of this investigation was reviewed and approved by Human Studies Committee of China Medical University. Before data collection, a written informed consent form was obtained from each participant. Ambient Air PollutionIn each of the selected study districts, there was only 1 municipal air pollution monitoring station, which was located 1 mile from the participants' homes. Measurements of PM 10 , SO 2 , NO 2 , and O 3 concentrations from 2006 to 2008 were obtained at the stations. The measurements were subject to uniform criteria for monitoring, siting, instrumentation, and quality assurance. Thes...

No abstract

OBJECTIVE To evaluate the association between thoracic kyphosis and physical function. DESIGN Prospective cohort. SETTING Framingham, Massachusetts. PARTICIPANTS Framingham Heart Study Offspring and Third Generation cohort members who had computed tomography (CT) performed between 2002 and 2005 and physical function assessed a mean 3.4 years later (N = 1,100; mean age 61 ± 8, range 50–85). MEASUREMENTS Thoracic kyphosis (Cobb angle, T4–T12) was measured in degrees using supine CT scout images. Participants were categorized according to Cobb angle to compare those in the highest quartile (Q4, most-severe kyphosis) with those in the lowest quartiles (Q1–Q3). Quick walking speed (m/s), chair-stand time (seconds), grip strength (kg), and self-reported impairments were assessed using standardized procedures. Analyses were adjusted for age, height, weight, smoking, follow-up time, vertebral fractures, and prevalent spinal degeneration. RESULTS Thoracic kyphosis was not associated with physical function in women or men, and these results were consistent in those younger than 65 and those aged 65 and older. For example, walking speed was similar in adults younger than 65 with and without severe kyphosis (women, Q4: 1.38 m/s, Q1–Q3: 1.40 m/s, P = .69; men, Q4: 1.65 m/s, Q1–Q3: 1.60 m/s; P = .39). CONCLUSION In healthy relatively high-functioning women and men, kyphosis severity was not associated with subsequent physical function. Individuals at risk of functional decline cannot be targeted based on supine CT thoracic curvature measures alone.

Hyperkyphosis is a common spinal disorder in older adults, characterized by excessive forward curvature of the thoracic spine and adverse health outcomes. The etiology of hyperkyphosis has not been firmly established, but may be related to changes that occur with aging in the vertebrae, discs, joints, and muscles, which function as a unit to support the spine. Determining the contribution of genetics to thoracic spine curvature and the degree of genetic sharing among co-occurring measures of spine health may provide insight into the etiology of hyperkyphosis. The purpose of our study was to estimate heritability of thoracic spine curvature using T4–T12 kyphosis (Cobb) angle and genetic correlations between thoracic spine curvature and vertebral fracture, intervertebral disc height narrowing, facet joint osteoarthritis (OA), lumbar spine volumetric bone mineral density (vBMD), and paraspinal muscle area and density, which were all assessed from computed tomography (CT) images. Participants included 2063 women and men in the second and third generation offspring of the original cohort of the Framingham Study. Heritability of kyphosis angle, adjusted for age, sex, and weight, was 54% (95% confidence interval [CI], 43% to 64%). We found moderate genetic correlations between kyphosis angle and paraspinal muscle area ( ρ^G, −0.46; 95% CI, −0.67 to −0.26), vertebral fracture ( ρ^G, 0.39; 95% CI, 0.18 to 0.61), vBMD ( ρ^G,−0.23; 95% CI, −0.41 to −0.04), and paraspinal muscle density ( ρ^G,−0.22; 95% CI, −0.48 to 0.03). Genetic correlations between kyphosis angle and disc height narrowing ( ρ^G, 0.17; 95% CI, −0.05 to 0.38) and facet joint OA ( normalρ^G, 0.05; 95% CI, −0.15 to 0.24) were low. Thoracic spine curvature may be heritable and share genetic factors with other age-related spine traits including trunk muscle size, vertebral fracture, and bone mineral density.