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Time-course of exercise and its association with 12-month bone changes.

ABSTRACT: Exercise has been shown to have positive effects on bone density and strength. However, knowledge of the time-course of exercise and bone changes is scarce due to lack of methods to quantify and qualify daily physical activity in long-term. The aim was to evaluate the association between exercise intensity at 3, 6 and 12 month intervals and 12-month changes in upper femur areal bone mineral density (aBMD) and mid-femur geometry in healthy premenopausal women.Physical activity was continuously assessed with a waist-worn accelerometer in 35 healthy women (35-40 years) participating in progressive high-impact training. To describe exercise intensity, individual average daily numbers of impacts were calculated at five acceleration levels (range 0.3-9.2 g) during time intervals of 0-3, 0-6, and 0-12 months. Proximal femur aBMD was measured with dual x-ray absorptiometry and mid-femur geometry was evaluated with quantitative computed tomography at the baseline and after 12 months. Physical activity data were correlated with yearly changes in bone density and geometry, and adjusted for confounding factors and impacts at later months of the trial using multivariate analysis.Femoral neck aBMD changes were significantly correlated with 6 and 12 months' impact activity at high intensity levels (> 3.9 g, r being up to 0.42). Trochanteric aBMD changes were associated even with first three months of exercise exceeding 1.1 g (r = 0.39-0.59, p < 0.05). Similarly, mid-femoral cortical bone geometry changes were related to even first three months' activity (r = 0.38-0.52, p < 0.05). In multivariate analysis, 0-3 months' activity did not correlate with bone change at any site after adjusting for impacts at later months. Instead, 0-6 months' impacts were significant correlates of 12-month changes in femoral neck and trochanter aBMD, mid-femur bone circumference and cortical bone attenuation even after adjustment. No significant correlations were found at the proximal or distal tibia.The number of high acceleration impacts during 6 months of training was positively associated with 12-month bone changes at the femoral neck, trochanter and mid-femur. These results can be utilized when designing feasible training programs to prevent bone loss in premenopausal women.Clinical trials.gov NCT00697957.

SUBMITTER: Ahola R

PROVIDER: S-EPMC2784429 | biostudies-literature | 2009 Nov

REPOSITORIES: biostudies-literature

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Time-course of exercise and its association with 12-month bone changes.

Ahola Riikka R Korpelainen Raija R Vainionpää Aki A Leppäluoto Juhani J Jämsä Timo T

BMC musculoskeletal disorders 20091112

<h4>Background</h4>Exercise has been shown to have positive effects on bone density and strength. However, knowledge of the time-course of exercise and bone changes is scarce due to lack of methods to quantify and qualify daily physical activity in long-term. The aim was to evaluate the association between exercise intensity at 3, 6 and 12 month intervals and 12-month changes in upper femur areal bone mineral density (aBMD) and mid-femur geometry in healthy premenopausal women.<h4>Methods</h4>Ph ...[more]

PMID: 19909496

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Project description:Romosozumab is a therapy that stimulates bone formation and reduces bone resorption. In this study of postmenopausal women with low BMD, a second course of romosozumab following a period off treatment or on denosumab increased or maintained BMD, respectively, and was well tolerated, providing insight into treatment sequence options.IntroductionIn patients with high fracture risk, therapies that stimulate bone formation provide rapid BMD gains; currently available agents, parathyroid hormone receptor agonists, are limited to a 2-year lifetime exposure and generally used for a single treatment course. However, for long-term osteoporosis management, a second treatment course may be appropriate. Romosozumab, a therapy with the dual effect of increasing bone formation and decreasing bone resorption, reduces fracture risk within 12 months. Here, we report efficacy and safety of a second romosozumab course.MethodsIn this phase 2, dose-finding study, postmenopausal women with low bone mass (T-score ≤ - 2.0 and ≥ - 3.5) received romosozumab or placebo (month 0-24) followed by placebo or denosumab (month 24-36); participants then received a year of romosozumab (month 36-48).ResultsOf 167 participants who entered the month 36-48 period, 35 had been initially randomized to romosozumab 210 mg monthly. In participants who received romosozumab 210 mg monthly followed by placebo, a second romosozumab course (n = 19) increased BMD by amounts similar to their initial treatment (month 0-12) at the lumbar spine (12.4%; 12.0%, respectively) and total hip (6.0%; 5.5%, respectively). Following denosumab, a second romosozumab course (n = 16) increased BMD at the lumbar spine (2.3%) and maintained BMD at the total hip. Safety profiles were similar between first and second romosozumab courses.ConclusionsAfter 12 months off-treatment, a second romosozumab course again led to rapid and large BMD gains. Following denosumab, BMD gains with romosozumab were smaller than with initial treatment. No new safety findings were observed during the second course.

Project description:Abstract Objectives Obesity imposes risk to cardiometabolic health; however, intentional weight loss in obese older adults remains controversial. Using data from the CROSSROADS Study (clinicaltrials.gov #NCT00955903), this ancillary study investigated effects of exercise with and without intentional weight loss on changes in cardiometabolic risk assessed by four risk-scoring tools. Methods Participants (n = 134, 39% male, 23% African American, 70.2 ± 4.7 y) were randomized to exercise (n = 48), exercise + nutrient-dense weight maintenance diet (n = 44), or exercise + nutrient-dense caloric restriction of 500 kcals/day (n = 42). The following risk scores were calculated using baseline and 12-month data: Framingham risk assessment, Cardiometabolic Disease Staging (CMDS), metabolic syndrome classification by the International Diabetes Federation (IDF), and metabolic syndrome classification by the National Cholesterol Education Program's Adult Treatment Panel (ATP III). Generalized Estimating Equations were employed to determine differences between groups with ethnicity, sex, and age as covariates. Results Group-time interaction was not significant in application of IDF or ATPIII. Group-time interaction was significant for Framingham and CMDS (P = 0.005 and 0.041, respectively). Upon post-hoc analysis, significant within-group improvements in Framingham scores were observed for exercise + weight maintenance (P < 0.001, r = −1.682) and exercise + weight loss (P = 0.020, r = −0.881). In analysis of between-group differences in Framingham scores, a significant decrease was observed in the exercise + weight maintenance group (P = 0.001, r = −1.723) compared to the exercise group. For CMDS, the exercise + weight loss group had significant within-group improvements (P = 0.023, r = - 0.102). For between-group differences in CMDS, the exercise + weight loss group showed significant risk score reduction (P = 0.012, r = −0.142) compared to the exercise group. Conclusions Risk assessment by Framingham and CMDS showed greater sensitivity to change in cardiometabolic risk factors. Results suggest obese older adults can lower cardiometabolic risk by engaging in exercise + weight maintenance or exercise + weight loss by moderate caloric restriction. Funding Sources R01AG033094 NIA, K07AG043588 NIA, P30DK056336 NIDDK.

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Project description:Abstract Objectives The Visceral Adiposity Index (VAI) was developed to estimate adipose tissue dysfunction as well as visceral fat distribution. In an ancillary analysis of the CROSSROADS Study (clinicaltrials.gov #NCT00955903), this study investigated the effects of exercise with and without intentional energy restriction on VAI changes among older adults with obesity. Methods Participants (n = 163, 37.4% male, 70.3 ± 4.7 years) were randomized to the following groups: exercise only, exercise + nutrient-dense weight maintenance diet, and exercise + nutrient-dense energy restriction of 500 kcal/d. Visceral adiposity determined by magnetic resonance imaging (MRI) and dual-energy X-ray absorptiometry (DXA), anthropometrics, and cardiometabolic biomarkers were assessed at baseline and 12 months. Waist circumference, body mass index, triglycerides, and high-density lipoprotein (HDL) cholesterol were used to compute VAI at both time points. Data were analyzed utilizing Spearman's correlations and general linear models to determine differences among groups following adjustment for covariates. Results Among all participants, significant correlations were observed between VAI and glucose, insulin, tumor necrosis factor-alpha (TNF-α), and the adiponectin: leptin ratio at baseline (r = 0.343, P < 0.001; r = 0.363, P < 0.001; r = 0.200, P = 0.011; r = −0.246, P = 0.002, respectively). DXA and MRI measures of visceral adiposity were not significantly correlated with VAI. Upon completion of the 12-month study period, there were significant differences in VAI among groups [F (2,137) = 5.957, P = 0.003)]. Post hoc analysis revealed that VAI was significantly lower in the exercise + nutrient-dense energy restriction group compared to the exercise only group (P = 0.002). Conclusions Results suggest that VAI may be an adequate measure of adipose tissue dysfunction, yet its ability to estimate levels of visceral adiposity warrants further investigation to determine clinical utility. Nonetheless, results suggest that an exercise + nutrient-dense energy restriction intervention may reduce VAI among older adults with obesity. Funding Sources NIH.

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Time-course of exercise and its association with 12-month bone changes.

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Time-course of exercise and its association with 12-month bone changes.

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