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- Cöster, Marcus E., et al.
(författare)
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Effects of an 8-year childhood physical activity intervention on musculoskeletal gains and fracture risk
- 2016
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Ingår i: Bone. - : Elsevier BV. - 8756-3282. ; 93, s. 139-145
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Tidskriftsartikel (refereegranskat)abstract
- Background Physical activity (PA) in childhood is associated with musculoskeletal benefits while the effect on fracture risk is yet to be determined. The aim of this study was to evaluate whether extension of a PA intervention leads to improvement in musculoskeletal traits with an accompanied reduced fracture risk. We hypothesized that the PA program would have beneficial effects in both sexes, but more so in girls since they tend to be less physically active than boys during this time frame. Methods In one elementary school we increased physical education (PE) from 60 to 200 min per school week and followed 65 girls and 93 boys from a mean age of 7 years until a mean age of 15 years. Thirty-nine girls and 37 boys in three other schools continued with 60 min of PE per week during the same years and served as controls. We measured bone mineral content (BMC), areal bone mineral density (aBMD), and bone area annually with dual energy X-ray absorptiometry, and leg muscle strength with a computerized dynamometer. In 3534 children within the same PE program (1339 in the intervention and 2195 in the control group) we registered incident fractures during the 8-year study period and estimated annual sex-specific fracture incidence rate ratios (IRRs). Results Girls in the intervention group annually gained more total body less head aBMD, spine aBMD (p < 0.01), femoral neck BMC (p < 0.05), lumbar vertebrae size (p < 0.05), and knee flexion strength (p < 0.05) than girls in the control cohort. In boys we found no group differences. There was an inverse correlation between number of years with extra PE and the annual IRR of sustaining fractures in both girls (r = − 0.90 (95% CI − 0.98 to − 0.51); p < 0.001) and boys (r = − 0.74 (95% CI − 0.94 to − 0.02); p < 0.05). Conclusion In this 8-year pediatric school-based moderate exercise intervention program there is an inverse correlation in both sexes between annual IRR and each additional year of extra PA. A sub-cohort of girls in the intervention group had greater gains in bone mass, bone size, and muscle strength, which could possibly explain the inverse correlation between years within the PA program and fracture risk, while in boys the reason for the inverse correlation remains unknown. It should be noted that differences in unreported factors such as skeletal maturity status, diet, and spare time PA could confound our inferences. That is, true causality cannot be stated.
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| 2. |
- Lewerin, Catharina, 1961, et al.
(författare)
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Low serum iron is associated with high serum intact FGF23 in elderly men: The Swedish MrOS study
- 2017
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Ingår i: Bone. - : Elsevier BV. - 8756-3282 .- 1873-2763. ; 98, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- Background: Fibroblast growth factor (FGF23) is a protein that is produced by osteoblasts and osteocytes. Increased serum levels of FGF23 have been associated with increased risks of osteoporotic fractures and cardiovascular disease, particularly in participants with poor renal function. Serum iron (Fe) has been suggested as a regulator of FGF23 homeostasis. Objective: To determine whether Fe and iron status are determinants of the levels of intact FGF23 (iFGF23) in elderly men. Methods: The MrOS study is a population-based study of elderly men (N = 1010; mean age, 75.3 years; range, 69-81 years). The levels of Fe, transferrin saturation (TS), and ferritin were evaluated in relation to the serum concentrations of iFGF23 before and after adjustments for confounders. Results: TS<15% was found in 3.5% (34/977) of the participants, who had a higher median level iFGF23 compared with the remaining subjects (47.4 mu rnol/L vs. 41.9 mu mol/L, p = 0.008). The levels of iFGF23 correlated negatively (un-adjusted) with the levels of Fe (r = -0.17, p < 0.001), TS (r = -0.16, p < 0.001) and serum ferritin (r = -0.07, p = 0.022). In addition, in participants with estimated glomerular filtration rate eGFRCystatin C > 60 mL/min, the levels of iFGF23 correlated (age-adjusted) negatively with the levels of Fe (r = -0.15, p < 0.001) and TS (r = -0.17, p < 0.001). The level of iFGF23 correlated positively (un-adjusted) with lumbar spine bone mineral density (BMD) (r = 0.14, p < 0.001), total body BMD (r = 0.11, p = 0.001), and total hip BMD (r = 0.09, p = 0.004). The corresponding correlations, when adjusted for age, weight, and height were: r = 0.08, p = 0.018; r = 0.05, p = 0.120; and r = 0.02, p = 0.624, respectively. No associations were found between BMD and the levels of Fe or TS. Multiple step-wise linear regression analyses [adjusting for age, body mass index (BMI), comorbidity index, cystatin C, C-reactive protein (hs-CRP), serum vitamin D 25-OH (25OHD), phosphate, calcium, parathyroid hormone (PTH), erythropoietin, hemoglobin, lumbar spine BMD, apolipoprotein B/A1 ratio] were performed in three separate models with Fe, TS or ferritin as potential explanatory variables. Fe and TS, but not ferritin, were independent predictors of iFGF23 level (standardized beta-values: -0.10, p <0.001; 0.10, p <0.001; and -0.05, p = 0.062, respectively). Conclusion: Low levels of Fe in elderly men are associated with high levels of iFGF23, independently of markers of inflammation and renal function, suggesting an iron-related pathway for FGF23 regulation. (C) 2017 Elsevier Inc. All rights reserved.
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