Riku Nikander

Targeted exercise against osteoporosis: A systematic review and meta-analysis for optimising bone strength throughout life

BackgroundExercise is widely recommended to reduce osteoporosis, falls and related fragility fractures, but its effect on whole bone strength has remained inconclusive. The primary purpose of this systematic review and meta-analysis was to evaluate the effects of long-term supervised exercise (≥6 months) on estimates of lower-extremity bone strength from childhood to older age.MethodsWe searched four databases (PubMed, Sport Discus, Physical Education Index, and Embase) up to October 2009 and included 10 randomised controlled trials (RCTs) that assessed the effects of exercise training on whole bone strength. We analysed the results by age groups (childhood, adolescence, and young and older adulthood) and compared the changes to habitually active or sedentary controls. To calculate standardized mean differences (SMD; effect size), we used the follow-up values of bone strength measures adjusted for baseline bone values. An inverse variance-weighted random-effects model was used to pool the results across studies.ResultsOur quality analysis revealed that exercise regimens were heterogeneous; some trials were short in duration and small in sample size, and the weekly training doses varied considerably between trials. We found a small and significant exercise effect among pre- and early pubertal boys [SMD, effect size, 0.17 (95% CI, 0.02-0.32)], but not among pubertal girls [-0.01 (-0.18 to 0.17)], adolescent boys [0.10 (-0.75 to 0.95)], adolescent girls [0.21 (-0.53 to 0.97)], premenopausal women [0.00 (-0.43 to 0.44)] or postmenopausal women [0.00 (-0.15 to 0.15)]. Evidence based on per-protocol analyses of individual trials in children and adolescents indicated that programmes incorporating regular weight-bearing exercise can result in 1% to8% improvements in bone strength at the loaded skeletal sites. In premenopausal women with high exercise compliance, improvements ranging from 0.5% to 2.5% have been reported.ConclusionsThe findings from our meta-analysis of RCTs indicate that exercise can significantly enhance bone strength at loaded sites in children but not in adults. Since few RCTs were conducted to investigate exercise effects on bone strength, there is still a need for further well-designed, long-term RCTs with adequate sample sizes to quantify the effects of exercise on whole bone strength and its structural determinants throughout life.

Femoral Neck Structure in Adult Female Athletes Subjected to Different Loading Modalities

Loading modality is a strong external determinant of structure and concomitant strength of the femoral neck. Particularly effective seem to be loadings, which arise from high impacts or impacts from atypical loading directions.

Targeted exercises against hip fragility

SummaryCompared to high-impact exercises, moderate-magnitude impacts from odd-loading directions have similar ability to thicken vulnerable cortical regions of the femoral neck. Since odd-impact exercises are mechanically less demanding to the body, this type of exercise can provide a reasonable basis for devising feasible, targeted bone training against hip fragility.IntroductionRegional cortical thinning at the femoral neck is associated with hip fragility. Here, we investigated whether exercises involving high-magnitude impacts, moderate-magnitude impacts from odd directions, high-magnitude muscle forces, low-magnitude impacts at high repetition rate, or non-impact muscle forces at high repetition rate were associated with thicker femoral neck cortex.MethodsUsing three-dimensional magnetic resonance imaging, we scanned the proximal femur of 91 female athletes, representing the above-mentioned five exercise-loadings, and 20 referents. Cortical thickness at the inferior, anterior, superior, and posterior regions of the femoral neck was evaluated. Between-group differences were analyzed with ANCOVA.ResultsFor the inferior cortical thickness, only the high-impact group differed significantly (~60%, p = 0.012) from the reference group, while for the anterior cortex, both the high-impact and odd-impact groups differed (~20%, p = 0.042 and p = 0.044, respectively). Also, the posterior cortex was ~20% thicker (p = 0.014 and p = 0.006, respectively) in these two groups.ConclusionsOdd-impact exercise-loading was associated, similar to high-impact exercise-loading, with ~20% thicker cortex around the femoral neck. Since odd-impact exercises are mechanically less demanding to the body than high-impact exercises, it is argued that this type of bone training would offer a feasible basis for targeted exercise-based prevention of hip fragility.

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

SummaryThe 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.IntroductionBones 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.MethodsA 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.ResultsAt the distal tibia, the high-impact, odd-impact, and repetitive low-impact exercise loading groups had ~30% to 50% (p < 0.05) greater cortical area (CoA) than the referents. At the tibial shaft, these three impact groups had ~15% to 20% (p < 0.05) greater total area (ToA) and ~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.ConclusionsHigh-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.

Quality of life and physical performance and activity of breast cancer patients after adjuvant treatments

Objective: The study aimed at investigating the quality of life (QoL) and physical performance and activity, and their interrelations, in Finnish female breast cancer patients shortly after adjuvant treatments.

Effect of a vigorous aerobic regimen on physical performance in breast cancer patients — a randomized controlled pilot trial

This randomized, controlled pilot trial was carried out to assess the feasibility and efficacy of an aerobic exercise in enhancing physical performance of breast cancer patients after adjuvant treatments. The potential of the training regimen to prevent accompanying bone loss was also assessed. Thirty patients, 41–65 years of age, were randomly assigned into training or control groups shortly after adjuvant chemo- or radiotherapy. The 12-week training included a guided aerobic exercise session once a week (the effective part being either step aerobic- or circuit-training in alternate weeks) and similar home exercise sessions twice a week. Adherence to the guided sessions was 78%, while home training was performed an average 2.1 times per week. Agility assessed with figure-8 running test and peak jumping power showed significant between-group treatment-effects (∼5% and ∼10%, respectively). Judged from the accelerometer data, reaction forces up to six times body weight occurred during the training, which implies that the training could also have potential to affect bone mass. The present exercise regimen turned out to be feasible and effective among breast cancer patients in terms of physical performance. Large controlled trials are necessary to confirm these findings.

EFFECT OF NECK EXERCISES ON CERVICOGENIC HEADACHE: A RANDOMIZED CONTROLLED TRIAL

OBJECTIVE To compare the efficacy of three 12-month training programmes on headache and upper extremity pain in patients with chronic neck pain. METHODS A total of 180 female office workers, with chronic, non-specific neck pain were randomly assigned to 3 groups. The strength group performed isometric, dynamic and stretching exercises. The endurance group performed dynamic muscle and stretching exercises. The control group performed stretching exercises. Pain was assessed with a visual analogue scale. Each group was divided into 3 subgroups according to headache intensity. RESULTS At the 12-month follow-up headache had decreased by 69% in the strength group, 58% in the endurance group and 37% in the control group compared with baseline. Neck pain diminished most in the strength group with the most severe headache (p < 0.001). In the dose analysis, one metabolic equivalent per hour of training per week accounted for a 0.6-mm decrease in headache on the visual analogue scale. Upper extremity pain decreased by 58% in the strength group, 70% in the endurance group and 21% in the control group. CONCLUSION All of the training methods decreased headache. However, stretching, which is often recommended for patients, was less effective alone than when combined with muscle endurance and strength training. Care must be taken in recommending the type of training to be undertaken by patients with severe cervicogenic headache.

Differential Effects of Exercise on Tibial Shaft Marrow Density in Young Female Athletes

CONTEXT Increased mechanical loading can promote the preferential differentiation of bone marrow mesenchymal stem cells to osteoblastogenesis, but it is not known whether long-term bone strength-enhancing exercise in humans can reduce marrow adiposity. OBJECTIVE Our objective was to examine whether bone marrow density (MaD), as an estimate of marrow adiposity 1) differs between young female athletes with contrasting loading histories and bone strengths and 2) is an independent predictor of bone strength at the weight-bearing tibia. DESIGN Mid-tibial MaD, cortical area (CoA), total area, medullary area, strength strain index (SSI), and cortical volumetric bone mineral density (vBMD) (total, endocortical, midcortical, and pericortical) was assessed using peripheral quantitative computed tomography in 179 female athletes involved in both impact and nonimpact loading sports and 41 controls aged 17-40 years. RESULTS As we have previously reported CoA, total area, and SSI were 16% to 24% greater in the impact group compared with the controls (all P < .001) and 12% to 18% greater than in the nonimpact group (all P < .001). The impact group also had 0.5% higher MaD than the nonimpact and control groups (both P < .05). Regression analysis further showed that midtibial MaD was significantly associated with SSI, CoA, endocortical vBMD, and pericortical vBMD (P < .05) in all women combined, after adjusting for age, bone length, loading groups, medullary area, muscle cross-sectional area, and percent fat. CONCLUSION In young female athletes, tibial bone MaD was associated with loading history and was an independent predictor of tibial bone strength. These findings suggest that an exercise-induced increase in bone strength may be mediated via reduced bone marrow adiposity and consequently increased osteoblastogenesis.

Frequent walking, but not total physical activity, is associated with increased fracture incidence: a 5-year follow-up of an Australian population-based prospective study (AusDiab).

Current public health physical activity (PA) guidelines recommend that older adults accumulate ≥ 2.5 hours per week of moderate‐ to vigorous‐intensity PA to optimize health. The aim of this study was to examine (1) whether adults who meet the current PA guidelines are at reduced risk of fracture, (2) whether fracture risk varies by PA type/intensity and frequency, and (3) whether prolonged TV viewing, as a marker of sedentary behavior, is associated with fracture risk. This national, population‐based prospective study with a 5‐year follow‐up included 2780 postmenopausal women and 2129 men aged 50 years or older. Incident nontraumatic clinical fractures were self‐reported. Overall, 307 (6.3%) participants sustained at least one incident low‐trauma fracture (women 9.3%, men 2.3%). Multivariate logistic regression, adjusting for age, body mass index (BMI), physical function, previous fracture history, smoking, and dietary calcium and serum 25‐hydroxyvitamin D levels, showed that women who walked more than 3 hours per week or completed at least 6 weekly bouts of walking had a 51% and 56% increased fracture risk, respectively, compared with women who did no walking [odds ratio (OR) time = 1.51, 95% confidence interval (CI) 1.01–2.24; OR frequency = 1.56, 95% CI 1.07–2.27]. However, total and moderate to vigorous PA time and the accumulation of 2.5 hours per week or more of PA and TV viewing time were not associated with incident fractures. In men, there also was an increased fracture risk for those who walked more than 3 hours per week (OR = 2.30, 95% CI 1.06‐4.97) compared with those who reported no walking. In conclusion, older adults who adhered to the current PA guidelines were not protected against fragility fractures, but more frequent walking was associated with an increased fracture risk.

Recruitment of breast cancer survivors into a 12-month supervised exercise intervention is feasible

BACKGROUND The BREX study is one of the largest randomised prospective exercise interventions of breast cancer survivors which aims at investigate whether regular exercise could reduce the long-term side effects of the adjuvant treatments and improve quality of life. MATERIAL AND METHODS The study was limited to consider patients aged 35-68 years, who had recently completed adjuvant chemotherapy or started endocrine therapy. In this paper, we describe the recruitment process of the 413 randomised patients from the Helsinki University Hospital between September 2005 and September 2007. RESULTS 768 potentially eligible patients out of the 1321 screened (via medical records) were contacted by phone. After the phone call 240 patients were excluded due to health problems that contraindicated exercise training. The most common health problems were musculoskeletal disorders. A total of 528 patients were considered as eligible for the intervention. Ultimately 413 of them agreed to participate resulting in a 53.8% recruitment rate of the potentially eligible patients. The most important reasons for declining were social, not health related. Eligible patients who did not want to participate did not differ significantly from those who participated according to age, health status, breast cancer treatment and tumour type. DISCUSSION The high recruitment rate demonstrates breast cancer patients willingness to participate even in long-lasting supervised exercise programs shortly after adjuvant treatments. After taking into account the selection of the population by age and musculoskeletal health, the results of the present intervention can be generalized to represent urban breast cancer patient population in Finland.