Serum 25-hydroxyvitamin D levels and incident falls in older women.

Three hundred eighty-seven home-dwelling older women were divided into quartiles based on mean serum 25-hydroxyvitamin D (S-25(OH)D) levels. The rates of falls and fallers were about 40% lower in the highest S-25(OH)D quartile compared to the lowest despite no differences in physical functioning, suggesting that S-25(OH)D levels may modulate individual fall risk. INTRODUCTION: Vitamin D supplementation of 800 IU did not reduce falls in our previous 2-year vitamin D and exercise RCT in 70-80 year old women. Given large individual variation in individual responses, we assessed here effects of S-25(OH)D levels on fall incidence. METHODS: Irrespective of original group allocation, data from 387 women were explored in quartiles by mean S-25(OH)D levels over 6-24 months; means (SD) were 59.3 (7.2), 74.5 (3.3), 85.7 (3.5), and 105.3 (10.9) nmol/L. Falls were recorded monthly with diaries. Physical functioning and bone density were assessed annually. Negative binomial regression was used to assess incidence rate ratios (IRRs) for falls and Cox-regression to assess hazard ratios (HR) for fallers. Generalized linear models were used to test between-quartile differences in physical functioning and bone density with the lowest quartile as reference. RESULTS: There were 37% fewer falls in the highest quartile, while the two middle quartiles did not differ from reference. The respective IRRs (95% CI) for falls were 0.63 (0.44 to 0.90), 0.78 (0.55 to 1.10), and 0.87 (0.62 to 1.22), indicating lower falls incidence with increasing mean S-25(OH)D levels. There were 42% fewer fallers (HR 0.58; 040 to 0.83) in the highest quartile compared to reference. Physical functioning did not differ between quartiles. CONCLUSIONS: Falls and faller rates were about 40% lower in the highest S-25(OH)D quartile despite similar physical functioning in all quartiles. Prevalent S-25(OH)D levels may influence individual fall risk. Individual responses to vitamin D treatment should be considered in falls prevention.

Cost-effectiveness of vitamin D supplementation and exercise in preventing injurious falls among older home-dwelling women: findings from an RCT.

UNLABELLED: This study assessed the cost-effectiveness of vitamin D supplementation and exercise, separately and combined, in preventing medically attended injurious falls among older home-dwelling Finnish women. Given a willingness to pay of €3,000 per injurious fall prevented, the exercise intervention had an 86 % probability of being cost-effective in this population. INTRODUCTION: The costs of falling in older persons are high, both to the individual and to society. Both vitamin D and exercise have been suggested to reduce the risk of falls. This study assessed the cost-effectiveness of vitamin D supplementation and exercise, separately and combined, in preventing medically attended injurious falls among older Finnish women. METHODS: Economic evaluation was based on the results of a previously published 2-year randomized controlled trial (RCT) where 409 community-dwelling women aged 70 to 80 years were recruited into four groups: (1) no exercise + placebo (D-Ex-), (2) no exercise + vitamin D 800 IU/day (D+Ex-), (3) exercise + placebo (D-Ex+), and (4) exercise + vitamin D 800 IU/day (D+Ex+). The outcomes were medically attended injurious falls and fall-related health care utilization costs over the intervention period, the latter evaluated from a societal perspective based on 2011 unit costs. Incremental cost-effectiveness ratios (ICER) were calculated for the number of injurious falls per person-year prevented and uncertainty estimated using bootstrapping. RESULTS: Incidence rate ratios (95 % CI) for medically attended injurious falls were lower in both Ex+ groups compared with D-Ex-: 0.46 (0.22 to 0.95) for D-Ex+, 0.38 (0.17 to 0.81) for D+Ex+. Step-wise calculation of ICERs resulted in exclusion of D+Ex- as more expensive and less effective. Recalculated ICERs were €221 for D-Ex-, €708 for D-Ex+, and €3,820 for D+Ex+; bootstrapping indicated 93 % probability that each injurious fall avoided by D-Ex+ per person year costs €708. At a willingness to pay €3,000 per injurious fall prevented, there was an 85.6 % chance of the exercise intervention being cost-effective in this population. CONCLUSIONS: Exercise was effective in reducing fall-related injuries among community-dwelling older women at a moderate cost. Vitamin D supplementation had marginal additional benefit. The results provide a firm basis for initiating feasible and cost-effective exercise interventions in this population.

Sarcopenia and osteopenia among 70-80-year-old home-dwelling Finnish women: prevalence and association with functional performance.

UNLABELLED: This study showed that the prevalence of sarcopenia (low muscle mass and performance) among 70-80-year-old home-dwelling Finnish women is very low, while every third woman has WHO-based osteopenia (low bone mass). Muscle mass and derived indices of sarcopenia were not significantly related to measures of functional ability. INTRODUCTION: This study aims to determine the prevalence of sarcopenia and osteopenia among four hundred nine 70-80-year-old independently living Finnish women. The study compared consensus diagnostic criteria for age-related sarcopenia recently published by the European Working Group on Sarcopenia in Older People (EWGSOP) and the International Working Group on Sarcopenia (IWG) and assessed their associations with functional ability. METHODS: Femoral bone mineral density and body composition were measured with dual-energy X-ray absorptiometry. Skeletal muscle mass index (SMI), gait speed, and handgrip strength were used for sarcopenia diagnosis. Independent samples t tests determined group differences in body composition and functional ability according to recommended diagnostic cutpoints. Scatter plots were used to illustrate the correlations between the outcome measures used for diagnosis. RESULTS: Prevalence of sarcopenia was 0.9 and 2.7 % according to the EWGSOP and IWG, respectively. Thirty-six percent of the women had WHO-based osteopenia. Women with higher gait speed had significantly lower body weight and fat mass percentage, higher lean mass percentage, and better functional ability. Women with a low SMI weighed significantly less, with no significant differences in other outcome measures. SMI, gait speed, and grip strength were significantly correlated. CONCLUSIONS: Our study suggests that when using consensus definitions, sarcopenia is infrequent among older home-dwelling women while every third woman has osteopenia. In clinical practice, attention should be paid to the decline in functional ability rather than focusing on low muscle mass alone.

Overweight in childhood and bone density and size in adulthood.

UNLABELLED: We evaluated the adult bone structural traits in relation to childhood overweight in 832 men and women. Childhood overweight was associated with larger cross-sections at long bones in both sexes. Excess weight in childhood may also lead to higher trabecular density in females and somewhat lower cortical density in men. INTRODUCTION: Excess body weight in childhood may impose more loading on growing skeleton and thus lead to more robust structure in adulthood. METHODS: This prospective cohort study evaluated the adult bone structural traits in relation to childhood overweight in a subgroup of 456 women and 376 men from the population-based cohort of Cardiovascular Risks in Young Finns Study. Between-group differences were evaluated with analysis of covariance. RESULTS: According to established body mass index (BMI) criterion at the age of 12 years, 31 women and 34 men were classified overweight in childhood. At the mean age (SD) of 36.1 (2.7) years, total cross-sectional (ToA) and cortical area (CoA) at the distal and shaft sites and cortical (shaft CoD) and trabecular (distal TrD) bone density of the nonweight-bearing radius and weight-bearing tibia were evaluated with pQCT. Despite being taller in adolescence, the adult body height of overweight children was similar. In both sexes, childhood overweight was consistently associated with 5-10% larger ToA at all bone sites measured in adulthood. CoA did not show such a consistent pattern. Women, who were overweight in childhood, had ~5% denser TrD with no difference in CoD. In contrast, TrD in men who were overweight in childhood was not different but their CoD was ~1% lower. CONCLUSIONS: Childhood overweight was consistently associated with larger long bone cross-sections in both sexes. Excess weight in childhood may also lead to higher trabecular density in women and somewhat lower cortical density in men. Specific mechanisms underlying these associations are not known.

Cross-sectional geometry of weight-bearing tibia in female athletes subjected to different exercise loadings.

UNLABELLED: The association of long-term sport-specific exercise loading with cross-sectional geometry of the weight-bearing tibia was evaluated among 204 female athletes representing five different exercise loadings and 50 referents. All exercises involving ground impacts (e.g., endurance running, ball games, jumping) were associated with thicker cortex at the distal and diaphyseal sites of the tibia and also with large diaphyseal cross-section, whereas the high-magnitude (powerlifting) and non-impact (swimming) exercises were not. INTRODUCTION: Bones adapt to the specific loading to which they are habitually subjected. In this cross-sectional study, the association of long-term sport-specific exercise loading with the geometry of the weight-bearing tibia was evaluated among premenopausal female athletes representing 11 different sports. METHODS: A total of 204 athletes were divided into five exercise loading groups, and the respective peripheral quantitative computed tomographic data were compared to data obtained from 50 physically active, non-athletic referents. Analysis of covariance was used to estimate the between-group differences. RESULTS: At the distal tibia, the high-impact, odd-impact, and repetitive low-impact exercise loading groups had approximately 30% to 50% (p < 0.05) greater cortical area (CoA) than the referents. At the tibial shaft, these three impact groups had approximately 15% to 20% (p < 0.05) greater total area (ToA) and approximately 15% to 30% (p < 0.05) greater CoA. By contrast, both the high-magnitude and repetitive non-impact groups had similar ToA and CoA values to the reference group at both tibial sites. CONCLUSIONS: High-impact, odd-impact, and repetitive low-impact exercise loadings were associated with thicker cortex at the distal tibia. At the tibial shaft, impact loading was not only associated with thicker cortex, but also a larger cross-sectional area. High-magnitude exercise loading did not show such associations at either site but was comparable to repetitive non-impact loading and reference data. Collectively, the relevance of high strain rate together with moderate-to-high strain magnitude as major determinants of osteogenic loading of the weight-bearing tibia is implicated.

Maintenance of exercise-induced benefits in physical functioning and bone among elderly women.

SUMMARY: This study showed that about a half of the exercise-induced gain in dynamic balance and bone strength was maintained one year after cessation of the supervised high-intensity training of home-dwelling elderly women. However, to maintain exercise-induced gains in lower limb muscle force and physical functioning, continued training seems necessary. INTRODUCTION: Maintenance of exercise-induced benefits in physical functioning and bone structure was assessed one year after cessation of 12-month randomized controlled exercise intervention. METHODS: Originally 149 healthy women 70-78 years of age participated in the 12-month exercise RCT and 120 (81%) of them completed the follow-up study. Self-rated physical functioning, dynamic balance, leg extensor force, and bone structure were assessed. RESULTS: During the intervention, exercise increased dynamic balance by 7% in the combination resistance and balance-jumping training group (COMB). At the follow-up, a 4% (95% CI: 1-8%) gain compared with the controls was still seen, while the exercise-induced isometric leg extension force and self-rated physical functioning benefits had disappeared. During the intervention, at least twice a week trained COMB subjects obtained a significant 2% benefit in tibial shaft bone strength index compared to the controls. A half of this benefit seemed to be maintained at the follow-up. CONCLUSIONS: Exercise-induced benefits in dynamic balance and rigidity in the tibial shaft may partly be maintained one year after cessation of a supervised 12-month multi-component training in initially healthy elderly women. However, to maintain the achieved gains in muscle force and physical functioning, continued training seems necessary.

Influence of weight reduction on muscle performance and bone mass, structure and metabolism in obese premenopausal women.

Muscle performance, body composition and bone mass at the lumbar spine and proximal femur with DXA, structural traits at the tibia and radius with pQCT, and biomarkers of bone metabolism were assessed at baseline and after a three-month weight reduction in obese premenopausal women. Associations between changes in weight loss and bone traits were analyzed by linear regression analysis. The mean (SD) weight loss was 4.3 (4.5) kg ranging from 14.8 kg loss to 2.1 kg gain. Muscle performance was well maintained, while no signs of bone loss or structural deterioration were observed. Changes in bone resorption were significantly associated with weight change (for CTX, r=-0.34; p=0.043, and for TRACP5b, r=-0.35; p=0.032). There were borderline (p<0.1) negative correlations between changes in biomarkers and bone traits. Reduced fat mass was associated with slight mean increase in cortical density of the radial shaft. Also total body BMC increased slightly. Changes in both fat and lean mass were associated with a change in BMC. Our findings suggest that mild-to-moderate weight reduction modulated bone turnover slightly, but they do not support the common notion that such a weight reduction would compromise bone rigidity, possibly partly due to well maintained muscle performance.

Autosome-wide linkage analysis of hip structural phenotypes in the Old Order Amish.

INTRODUCTION: Fracture risk is associated with bone mineral density (BMD) and with other indices of bone strength, including hip geometry. While the heritability and associated fracture risk of BMD are well described, less is known about genetic influences of bone geometry. We derived hip structural phenotypes using the Hip Structural Analysis program (HSA) and performed autosome-wide linkage analysis of hip geometric structural phenotypes. MATERIALS AND METHODS: The Amish Family Osteoporosis Study was designed to identify genes affecting bone health. BMD was measured at the hip using dual X-ray absorptiometry (DXA) in 879 participants (mean age+/-SD=49.8+/-16.1 years, range 18-91 years) from large multigenerational families. From DXA scans, we computed structural measures of hip geometry at the femoral neck (NN) and shaft (S) by HSA, including cross-sectional area (CSA), endocortical or inner diameter (ID), outer diameter (OD) buckling ratio (BR) and section modulus (Z). Genotyping of 731 highly polymorphic microsatellite markers (average spacing of 5.4 cM) and autosome-wide multipoint linkage analysis was performed. RESULTS: The heritability of HSA-derived hip phenotypes ranged from 40 to 84%. In the group as a whole, autosome-wide linkage analysis suggested evidence of linkage for QTLs related to NN_Z on chromosome 1p36 (LOD=2.36). In subgroup analysis, ten additional suggestive regions of linkage were found on chromosomes 1, 2, 5, 6, 11, 12, 14, 15 and 17, all with LOD>2.3 except for our linkage at 17q11.2-13 for men and women age 50 and under for NN_CSA, which had a lower LOD of 2.16, but confirmed a previous linkage report. CONCLUSIONS: We found HSA-derived measures of hip structure to be highly heritable independent of BMD. No strong evidence of linkage was found for any phenotype. Confirmatory evidence of linkage was found on chromosome 17q11.2-12 for NN_CSA. Modest evidence was found for genes affecting hip structural phenotypes at ten other chromosomal locations.

Associations of physical activity and calcium intake with bone mass and size in healthy women at different ages.

Weight-bearing exercise and calcium intake are known to contribute to bone density. However, the relative significance of physical activity and calcium intake in the development of bone characteristics in functionally different weight-bearing and nonweight-bearing bone sites at different ages is poorly known. A total of 422 women in three age groups (25-30, 40-45, and 60-65 years) were screened from 1017 women and divided into four groups by their level of physical activity (high [PA+] and low [PA-]) and calcium intake (high [Ca+] and low [Ca-]). Total body bone mineral content (TBBMC), areal bone mineral density (BMD) of the femoral neck and distal radius, and selected dimensions and estimated strength variables (bone width, cortical wall thickness, cross-sectional moment of inertia, and section modulus of the femoral and radial shafts) were measured with dual-energy X-ray absorptiometry. Both high physical activity and high calcium intake were associated with a higher TBBMC when compared with low activity and calcium intake (1.8% and 4.6%, respectively). The BMD of the weight-bearing femoral neck was 5% higher in the PA+ groups than in the PA- groups, whereas calcium intake showed no such significant association. Neither physical activity nor calcium intake was associated with the BMD of the nonweight-bearing radius. However, both high physical activity and high calcium intake were related to larger and mechanically more competent bones in the femoral and radial shafts, the association for physical activity being stronger with increasing age. No significant interaction between physical activity and calcium intake was found with respect to any of the bone variables. These data from a cross-sectional study suggest that a moderate level of physical activity or a sufficient level of calcium intake, if maintained from childhood, can result in considerable long-term improvement in the mechanical competence of the skeleton. The clinical relevance of these findings is further emphasized by the fact that the observed patterns of physical activity and calcium intake pertain to customary lifestyle and are thus feasible targets for the primary prevention of osteoporosis.

Development of mass, density, and estimated mechanical characteristics of bones in Caucasian females.

Three hundred and thirty healthy Finnish girls and premenopausal women, aged 7-47 years, were examined to evaluate the natural development of bone mineral mass and density from early childhood to menopause. Bone mineral content (BMC,g) and areal density (BMD, g/cm2) were measured from the spine (L2-L4), femoral neck, trochanter region of the femur, and distal radius using dual-energy X-ray absorptiometry (DXA). In addition, the bone mineral apparent density (BMAD, g/cm3) was assessed from the above described skeletal sites, and the mechanical competence of the femoral neck was estimated. Special attention was paid to the timing of the peak values of these bone parameters as well as to the evidence of premenopausal bone loss. The BMC, BMD, and BMAD of the spine, femoral neck, and trochanter region of the femur achieved peak values around the age of 20, and the bone loss seemed to start soon thereafter. In contrast, the bone mass of the distal radius slightly increased between the ages of 20 and 47. In the femoral neck, the estimated bending strength achieved its peak value around the age of 20 and showed a slight decrease during the following decades. The highest body weight and neck-length adjusted strength values of the femoral neck were, however, found in early childhood, with the values decreasing linearly thereafter. In conclusion, this study supports previous findings of rapid bone mineral accumulation in late adolescence, and occurrence of the peak bone mass and density around the age of 20. Premenopausal bone loss seems to occur in the proximal femur and lumbar spine. Our observations of femur strength development imply that from childhood to menopause the mechanical strength of the femoral neck is well adjusted to the biomechanical loading requirements of the body.

Long-term recreational gymnastics, estrogen use, and selected risk factors for osteoporotic fractures.

The purpose of this cross-sectional study was to examine whether long-term participation in recreational gymnastics or folk dancing or estrogen replacement therapy (ERT) is associated with mechanically more competent bones and improved muscular strength and body balance. One hundred and seventeen healthy, female postmenopausal recreational gymnasts (mean age 62.1 [SD 4.7] years) and 116 sedentary controls (mean age 61.5 [4.6] years) were enrolled in the study. Bone mineral content (BMC) of the distal radius, femoral neck, and trochanter were measured with dual-energy X-ray absorptiometry. BMC of the midshaft and distal tibia and trabecular density (TrD) of the distal tibia were measured with peripheral computed quantitative tomography. Maximal isometric strength, muscular power, cardiorespiratory fitness, and body balance of the participants were also assessed. The cardiorespiratory fitness, muscular strength, and dynamic balance of the recreational gymnasts and folk dancers combined were significantly better than those of the controls, the average group difference ranging from 7.5% (95% confidence interval 5.0-9.9%) in dynamic balance to 12.8% (6.6-19. 4%) in dynamic muscular power. ERT was not associated with the fitness indicators, muscular power, or balance, but was significantly associated with the BMC at all the measured bone sites, the mean group difference between estrogen users and nonusers ranging from 6.5% (3.7-9.3%) for the tibial shaft to 11.8% (6.4-17. 0%) for the distal radius. Recreational gymnastics, in turn, was significantly associated with higher BMC at the tibia only, the mean group difference being 3.9% (0.9-6.9%) for the tibial shaft and 7.7% (3.7-11.9%) for the distal tibia. Recreational gymnastics was also associated with higher TrD at the distal tibia (5.2%; 1.2-9.2%), whereas estrogen usage did not show such association. The results indicate that ERT seems especially effective in preventing postmenopausal bone loss, whereas recreational gymnastics and folk dancing improve muscular performance and body balance in addition to increased bone mass and bone size in the tibia. All these factors are essential in prevention of fall-related fractures of the elderly.

Effect of long-term unilateral activity on bone mineral density of female junior tennis players.

High peak bone mass in early adulthood is an important protective factor against osteoporotic fractures in later life, but little is known about the effects of exercise on growing bone. The purpose of this cross-sectional study was to determine at which state of maturity (Tanner stage), the areal bone mineral density (BMD) differences between the playing and nonplaying arms of junior tennis players become obvious, and to clarify in each developmental stage which training and background variables, if any, could explain the interindividual differences in bones' response to mechanical loading. Ninety-one 7- to 17-year-old female tennis players and 58 healthy female controls were measured. In each Tanner stage, differences in BMD in playing and nonplaying (dominant and nondominant) arms (proximal humerus, humeral shaft, and distal radius) and BMD of the lumbar spine and nondominant distal radius were compared between the controls and players. Within each Tanner stage of players, the associations between training and background variables and BMD differences were analyzed with Spearman rank correlation coefficients. In players, BMD differences between the playing and nonplaying arms were significant (P < 0.05- < 0.001) in all Tanner stages, with the mean difference ranging from 1.6 to 15.7%. In controls, these dominant-to-nondominant arm differences were clearly smaller (ranging from -0.2 to 4.6%), but significant at some measured sites. In comparison with the relative side-to-side arm differences between the players and controls (i.e., examination of the training effect), the mean difference was not obvious and significant until the adolescent growth spurt (i.e., the girls in Tanner stage III with a mean age of 12.6 years). In the lumbar spine, significant BMD differences between players and controls were not found until Tanner stage IV (mean age 13.5 years; 8.7%, P < 0.05) and V (mean age 15.5 years; 12.4%, P < 0.05). In a nonloaded site of the skeleton (nondominant distal radius), no significant BMD differences were found between the players and controls in any Tanner stage. In the correlation analysis, the Tanner I and II players (mean ages 9.4 and 10.8 years) showed no significant associations between any of the predictive variables and the side-to-side BMD differences, while in Tanner stages III, IV, and V, such associations could be found; the total amount of training hours during the playing career and the number of training sessions per week showed a significant and systematic correlation (rs ranging from 0.43 to 0.80) with the side-to-side BMD differences in several measured bone sites. In conclusion, this study suggests that in a majority of female junior tennis players, the benefit of unilateral activity on bone density does not become clearly evident until the adolescent growth spurt or Tanner stage III. The total amount of training during the player's career and the current training frequency (sessions per week) seem to best explain the training effect on bone tissue, leaving, however, room for speculation on the still unknown factors that modulate the loading response of a growing bone.

Associations of hormone replacement therapy with bone structure and physical performance among postmenopausal women.

The purpose of this cohort study was to focus on factors associated with bone mass and structure of lower limbs and physical performance after menopause. Eighty nonsmoking women with a mean age of 62.1 (SD 0.8) years participated in the study. They were classified into two groups by their use of hormone replacement therapy (HRT), either the current users (n = 43) or the never or discontinued users (n = 37). The tibial shaft and distal tibia were scanned with peripheral computed tomography. For the shaft region, the bone mineral content (BMC, g), cortical density (CoD, g/cm(3)), cortical area (CoA, mm(2)), and section modulus (BSI, mm(3)) were determined. For the distal part, the evaluated variables were BMC, total area (ToA), ratio of cortical to total area (CoA/ToA), trabecular density (TrD, g/mm(3)), cortical thickness, BSI, and buckling ratio. Isometric and dynamic muscle strength of the leg extensors, agility and postural sway, and cardiorespiratory capacity (VO(2max)) were measured. Unadjusted values for all bone variables were slightly higher among the HRT users compared to nonusers, with the exception of TrD with no difference. After controlling for body weight, the mean differences (95% confidence interval) remained significant for CoD of the tibial shaft and BSI of the distal tibia, the mean between-group differences being 1.5% (0.4 to 2.5%) and 23.0% (7.1 to 41.3%), respectively. Underlying the greater bending strength, HRT users had thicker cortices and a greater ratio of CoA/ToA. No differences existed between the two study groups for lower limb isometric or dynamic power, cardiorespiratory capacity, or postural balance or sway. HRT may offer protection against bone loss and maintain bone strength, although its ability to improve physical performance is not evident.

Effect of alendronate and exercise on bone and physical performance of postmenopausal women: a randomized controlled trial.

In this randomized, double-blind, placebo-controlled 12-month trial we evaluated effects of weight- bearing jumping exercise and oral alendronate, alone or in combination, on the mass and structure of bone, risk factors for falling (muscle strength and power, postural sway, and dynamic balance), and cardiorespiratory fitness in postmenopausal women. A total of 164 healthy, sedentary, early postmenopausal women were randomly assigned to one of four experimental groups: (1) 5 mg of alendronate daily plus progressive jumping exercise, (2) 5 mg alendronate, (3) placebo plus progressive jumping exercise, or (4) placebo. The primary endpoint was 12-month change in bone mass and geometry (measured with dual-energy X-ray absorptiometry and peripheral computed tomography at several axial and limb sites) and physical performance; the secondary endpoint was change in biochemical markers of bone turnover. The jumping exercise was conducted an average 1.6 +/- 0.9 (mean +/- SD) times a week. Alendronate daily was effective in increasing bone mass at the lumbar spine (alendronate vs placebo 3.5%; 95% CI, 2.2-4.9%) and femoral neck (1.3%; 95% CI, 0.2-2.4%) but did not affect other bone sites. Exercise alone had no effect on bone mass at the lumbar spine or femoral neck; it had neither an additive nor an interactive effect with alendronate at these bone sites. However, at the distal tibia the mean increase of 3.6% (0.3-7.1%) in the section modulus (that is, bone strength) and 3.7% (0.1-7.3%) increase in the ratio of cortical bone to total bone area were statistically significant in the exercise group compared to the nonexercise group, indicating exercise-induced thickening of the bone cortex. Bone turnover was reduced in alendronate groups only. Alendronate had no effect on physical performance while the jumping exercise improved leg extensor power, dynamic balance, and cardiorespiratory fitness. As conclusion Alendronate is effective in increasing bone mass at the lumbar spine and femoral neck, while exercise is effective in increasing the mechanical properties of bone at some of the most loaded bone sites, as well as improving the participants' muscular performance and dynamic balance. Together alendronate and exercise may effectively decrease the risk of osteoporotic fractures.

Determinants of bone mineralization in 8 to 20 year old Finnish females.

OBJECTIVES: To study the determinants of bone mass and density in Finnish girls and young women. DESIGN: A cross-sectional study. SUBJECTS: One hundred and seventy six 8 to 20 year old female volunteers living in the city of Tampere, Finland. METHODS: Calcium intake was estimated from a 7 d calcium intake diary (CaD). Bone mineral content (BMC) and areal density (BMD) were measured by dual-energy X-ray absorptiometry (DXA) at the lumbar spine, femoral neck and distal radius. Volumetric bone mineral apparent density (BMAD) was estimated from these DXA data. In addition, anthropometric characteristics, isometric muscle strength, and the Tanner stage were determined. Menstrual status and physical activity level were assessed by a questionnaire and personal interview. RESULTS: Body weight and Tanner stage were the most important determinants of BMC and BMD. Physical activity was the only not growth-related factor associated with BMC, BMD and BMAD. Therefore, it was examined in detail between the PA and NA groups. Site-specific benefits varied from 5-7% for the BMC (lumbar spine and radius) and BMD (lumbar spine and femoral neck) and was about 5% for the BMAD (femoral neck). CONCLUSIONS: Body weight seems to be the most important determinant of the BMC and BMD of growing Finnish girls, but during puberty exercise may beneficially affect BMD at the loaded skeletal sites. Exercise may increase femoral BMAD during peripubertal years. There was no association between calcium intake and the bone variables, but the high level so calcium intake in all age groups of the study was likely to explain the lack of association.

A multi-component exercise regimen to prevent functional decline and bone fragility in home-dwelling elderly women: randomized, controlled trial.

SUMMARY: This study showed that combination of strength, balance, agility and jumping training prevented functional decline and bone fragility in home-dwelling elderly women. The finding supports the idea that it is possible to maintain good physical functioning by multi-component exercise program and thus postpone the age-related functional problems. INTRODUCTION: This 1-year randomized, controlled exercise intervention trial assessed the effects of two different training programs and their combination on physical functioning and bone in home-dwelling elderly women. METHODS: One hundred and forty-nine healthy women aged 70-78 years were randomly assigned into: group 1-resistance training (RES), group 2-balance-jumping training (BAL), group 3-combination of resistance and balance-jumping training (COMB), and group 4-controls (CON). Self-rated physical functioning, leg extensor force, dynamic balance, and bone mass and structure were measured. RESULTS: Self-rated physical functioning improved in the COMB group, but was reduced in the CON group; the mean inter-group difference was 10% (95% CI: 0-22%). Mean increase in the leg extensor force was higher in the RES (14%; 4-25%) and COMB (13%; 3-25%) compared with the CON groups. Dynamic balance improved in the BAL (6%; 1-11%) and in the COMB (8%; 3-12%) groups. There were no inter-group differences in BMC at the proximal femur. In those COMB women who trained at least twice a week, the tibial shaft structure weakened 2% (0-4%) less than those in the CON group. CONCLUSIONS: Strength, balance, agility, and jumping training (especially in combination) prevented functional decline in home-dwelling elderly women. In addition, positive effects seen in the structure of the loaded tibia indicated that exercise may also play a role in preventing bone fragility.

Long-term recreational gymnastics provides a clear benefit in age-related functional decline and bone loss. A prospective 6-year study.

INTRODUCTION: Bone fragility and decreased functional performance are risk factors for osteoporotic fractures. The influence of long-term recreational gymnastics on the maintenance of bone rigidity and physical performance was evaluated. METHODS: One hundred and seven gymnasts and 110 referents (93% of the original sample) participated in this 6-year prospective study. Analysis of covariance (ANCOVA) was used to estimate the between-group differences and changes by time, and regression analyses to find predictors for changes. RESULTS: In both groups agility and leg extensor power decreased by over 3% and 10%, respectively, but the original between-group differences, favoring the gymnasts, persisted. Proximal femur bone mineral content (BMC) decreased approximately 0.5% per year in both groups, and femoral neck section modulus decreased. Trabecular density of the distal tibia declined only marginally, and cortical area of the tibial midshaft remained unchanged, while cortical density decreased about 2% in both groups. After adjustment by age, height, weight, change in weight, and follow-up time, antiresorptive medication and high calcium intake accounted most for the maintenance of bone rigidity. CONCLUSIONS: In spite of similar rates of decline in bone characteristics and physical performance, the recreational gymnasts' overall physical condition was comparable to the level that their less active referents had shown approximately 5 years earlier.

Structural effects of raloxifene on the proximal femur: results from the multiple outcomes of raloxifene evaluation trial.

INTRODUCTION: Raloxifene improves spine bone mineral density (BMD), and its ability to reduce vertebral fractures by 40-50% suggests that it increases vertebral strength. Positive effects on hip BMD suggest a similar strengthening of the hip, but dimensional ambiguities in BMD by dual energy x-ray absorptiometry (DXA) make it difficult to infer strength effects directly. Hip fractures may be too infrequent to evaluate in practical clinical trials; even the Multiple Outcomes of Raloxifene Evaluation (MORE) study with 7,705 subjects was insufficiently powered to show a comparable reduction in hip fractures. METHODS: An alternative evaluation of hip DXA data in structural terms should provide more direct evidence of treatment effects on hip strength. Hip scans from a subset of the MORE study, including 4,806 postmenopausal women with osteoporosis randomized to daily oral doses of placebo, 60 mg, or 120 mg of raloxifene were reanalyzed by the hip structure analysis (HSA) method. Scans acquired at baseline, 1, 2, and 3 years were evaluated to extract BMD and cross-sectional geometry across the narrowest point on the neck (NN), the intertrochanteric region (IT), and the proximal shaft 1.5 times the minimum neck width distal to the intersection of the neck and shaft axes. RESULTS: While femur outer diameter expanded during follow-up at all three regions, there were no differences in expansion between groups; treatment influenced mainly the amount and distribution of bone within cross-sections. Effects were similar at the two dose levels at the NN region although the 120 mg dose produced a greater effect on section modulus (SM) at the IT region and on BMD, bone cross-sectional area (CSA), SM, average cortical thickness (CT), and buckling ratio (BR) at the shaft region. Compared with placebo after 3 years, treatment groups showed 0.4-2% higher BMD, CSA, SM, and CT and 1-2% lower BR. The smallest treatment effects were evident at the shaft at 60 mg. CONCLUSIONS: We conclude that raloxifene does not influence periosteal apposition in the proximal femur but it nevertheless produces small but significant improvement in resistance to axial and bending stresses (CSA and SM, respectively) at all analyzed regions. The significant reductions in buckling ratio suggest that additional strength loss due to cortical instability is also ameliorated by treatment.