Musculoskeletal Injury Risk in a Military Cadet Population Participating in an Injury-Prevention Program.

Background and Objectives: Musculoskeletal injuries are a major health hazard among military personnel. Previous research has proposed several exercise-based strategies for prevention. The purpose of this study was to investigate the effect of an exercise-based injury-prevention program on the incidence of musculoskeletal injury, motor performance and psychosocial status. Materials and Methods: Thirty-six Estonian Military Academy cadets were randomly assigned into either an intervention or control group. The intervention group followed a neuromuscular exercise-based injury-prevention warm-up program, three times per week for 6 months. The control group continued with the usual warm-up. The main outcome measure was injury incidence during the study period. Additionally, evaluation of isokinetic lower-extremity strength, postural sway, physical fitness and psychosocial status was included pre- and post-intervention. Results: During the 6-month study period, the musculoskeletal injury incidence was 43% in the intervention group and 54% in the control group (RR = 0.8; 95% CI = 0.41 to 1.99). The noted 20% risk reduction was not statistically significant (p = 0.59). Furthermore, there were no statistically significant differences between the intervention and control group in motor performance or psychosocial status measures. Conclusions: In conclusion, no effect of the exercise-based injury-prevention program on injury risk, motor performance or psychosocial status could be detected.

Resistin concentration is inversely associated with objectively measured physical activity in healthy older women.

Regular physical activity (PA) has been associated with decreased risk of many chronic diseases and increased longevity among older adults. In addition, ageing has been associated with higher levels of different inflammatory biomarkers while the association between inflammatory biomarkers and PA has remained controversial. The aim of the current investigation was to examine the association between blood biomarkers and objectively assessed PA among a sample of healthy older women with different levels of PA engagement. A total of 81 healthy women were recruited. Study participants were allocated to three groups according to accelerometer-obtained PA data. Body composition was assessed with dual-energy X-ray absorptiometry. Fasting blood samples were collected for the measurement of resistin, leptin, tumour necrosis factor alpha (TNFα) and C-reactive protein (CRP) concentrations. There were no significant differences between groups for resistin, leptin, TNFα and for CRP concentrations; however, higher moderate-to-vigorous physical activity (MVPA) groups tended to have lower level of blood biomarker concentrations. There was a significant negative relationship between resistin and steps per day. Inverse association between leptin and MVPA was significant after controlling for age. In multivariate stepwise linear regression analysis, steps per day were the strongest independent predictor for resistin, whereas for leptin, TNFα and CRP the strongest independent predictor was whole body fat mass. In conclusion, this study demonstrated negative association between resistin concentration and steps per day. Sedentary time and light PA had no relationship with resistin, leptin, TNFα or CRP concentrations.

Ergonomic Benefits of an Angle Grinder With Rotatable Main Handle in a Cutting Task.

OBJECTIVE: The aim of this study was to evaluate the ergonomic benefits of an angle grinder with a rotatable main handle in a cutting task. BACKGROUND: Angle grinder manufacturers rarely address ergonomic features in their advertisements, and if they do, the benefits are expressed in a qualitative manner. Meanwhile, quantitative information about the effects of the device on the worker is required to make informed decisions during tool selection and cumulative trauma prevention. METHOD: Eleven maintenance workers and metalworkers used an angle grinder to cut a horizontal steel rod using three wrist postures. Only one of the postures was exclusively available in the case of a rotatable main handle. The postural effect was evaluated objectively with electromyography and a force-sensing-resistor-based force glove. Subjective ratings about discomfort and control were obtained with a visual analog scale. RESULTS: The subjective ratings favor the near-neutral wrist posture. The forearm muscles' electromyographic activities were similar across the postures. Forces on the hand-handle interface were concentrated on the intermediate phalanges. If the device is operated without gloves, the forces on the intermediate phalanges may exceed the discomfort pressure threshold regardless of wrist posture. CONCLUSION: In the cutting task, the subjective measures favor the posture with a near-neutral wrist, which is a feature of the rotatable main handle. The objective measures did not allow one to prefer one posture to another. APPLICATION: The findings give insight into the impact of wrist posture on muscle activity, forces on the hand-handle interface, and discomfort. This is useful information for the person responsible for tool selection.

Estonian hip fracture data from 2009 to 2017: high rates of non-operative management and high 1-year mortality.

Background and purpose - There are no national guidelines for treatment of hip fractures in Estonia and no studies on management. We assessed treatment methods and mortality rates for hip fracture patients in Estonia. Patients and methods - We studied a population-based retrospective cohort using validated data from the Estonian Health Insurance Fund's database. The cohort included patients aged 50 and over with an index hip fracture diagnosis between January 1, 2009 and September 30, 2017. The study generated descriptive statistics of hip fracture management methods and calculated in-hospital, 1-, 3, 6-, and 12-month unadjusted all-cause mortality rates. [CrossRef] Results - 91% (number of hips: 11,628/12,731) of the original data were included after data validation. Median patient age was 81 years, 83 years for women and 74 years for men. 28% were men. Treatment methods were: total hip arthroplasty 7%; hemiarthroplasty 25%; screws 6%; sliding hip screw 25%; intramedullary nail 27%; and nonoperative management 10%. Unadjusted all-cause mortality rates for in-hospital, 1, 3, 6, and 12 months were: 3%, 9%, 18%, 24%, and 31% respectively. The 12-month mortality rate for nonoperative management was 58%. [CrossRef] Interpretation - High rates of nonoperative management and overall high 1-year mortality rates after an index hip fracture indicate the need to review exclusion criteria for surgery and subacute care in Estonia.

Body Composition, Neuromuscular Performance, and Mobility: Comparison Between Regularly Exercising and Inactive Older Women.

The purpose of this study was to evaluate the differences in body composition, neuromuscular performance, and mobility in healthy, regularly exercising and inactive older women, and examine the relationship between skeletal muscle indices and mobility. Overall, 32 healthy older women participated. They were divided into groups according to their physical activity history as regularly exercising (n = 22) and inactive (n = 10) women. Body composition, hand grip strength, leg extensor muscle strength, rapid force development, power output, and mobility indices were assessed. Regularly exercising women had lower fat mass and higher values for leg extensor muscle strength and muscle quality, and also for mobility. Leg extensor muscle strength and power output during vertical jumping and appendicular lean mass per unit of body mass were associated with mobility in healthy older women. It was concluded that long-term regular exercising may have beneficial effects on body composition and physical function in older women.

Upper Extremity and Cue Kinematics, and Shoulder Muscle Electromyographic Activity of Novus Players of Different Skill Levels.

Our aim with the current study was to compare upper extremity and cue kinematics, and electromyographic (EMG) activation of shoulder muscles during novus (a special form of billiards) shots of different difficulty levels. Ten proficient and 10 less-skilled novus players performed 3 types of novus shots (penalties, cuts, rebounds) 10 times each. During each shot, elbow flexion and cue-forearm angles (using a movement analysis system), and surface EMG activity of the trapezius, posterior, and lateral deltoid muscles of each subject's dominant side, were measured. Data were compared between more- and less-skilled players, and successful compared with unsuccessful shots. Elbow flexion angle among the more-skilled players was 24.5% larger (P < .001) during unsuccessful cut shots than successful ones. The more-skilled players performed successful penalty and rebound shots with 26.8% and 49.8% lower (P < .01 and P < .001, respectively) EMG activity of the trapezius muscle than unsuccessful ones. Less-skilled players' shots were characterized by higher EMG activity in the trapezius muscle. The obtained findings suggest that the more-skilled novus players had acquired a different muscle recruitment pattern than less-skilled players.

Association between osteocalcin and cognitive performance in healthy older adults.

INTRODUCTION: cognitive deterioration and reductions of bone health coincide with increasing age. We examine the relationship between bone composition and plasma markers of bone remodelling with measures of cognitive performance in healthy adults. METHODS: this cross-sectional study included 225 old (52% women, mean age: 74.4 ± 3.3 years) and 134 young (52% women, mean age: 23.4 ± 2.7 years) adult participants from the MyoAge project. Whole body bone mineral density was measured by dual-energy X-ray absorptiometry. Blood analyses included a panel of bone-related peptides (dickkopf-1, osteoprotegerin, osteocalcin (OC), osteopontin, sclerostin, parathyroid hormone and fibroblast growth factor 23), as well as serum calcium and 25-hydroxy vitamin D assays. A selection of cognitive domains (working memory capacity, episodic memory, executive functioning and global cognition) was assessed with a standardised neuropsychological test battery. RESULTS: adjusting for covariates and multiple testing revealed that plasma OC levels were positively associated with measures of executive functioning (ß = 0.444, P < 0.001) and global cognition (ß = 0.381, P = 0.001) in the older women. DISCUSSION: these correlative results demonstrate a positive association between OC, a factor known to regulate bone remodelling, with cognitive performance in older non-demented women. Further work should address possible mechanistic interpretations in humans.

The Impact of Different Diagnostic Criteria on the Prevalence of Sarcopenia in Healthy Elderly Participants and Geriatric Outpatients.

BACKGROUND: A consensus on the diagnostic criteria for sarcopenia, a common syndrome in the elderly, has not been reached yet. Prevalence rates vary between studies due to the use of different criteria encompassing different measures, correction factors and cutoff points. OBJECTIVE: This study compared prevalence rates of sarcopenia using nine sets of diagnostic criteria applied in two different elderly populations. METHODS: The study population encompassed 308 healthy elderly participants (152 males, 156 females; mean age 74 years) and 123 geriatric outpatients (54 males, 69 females; mean age 81 years). Diagnostic criteria included relative muscle mass, absolute muscle mass, muscle strength and physical performance. RESULTS: Prevalence rates of sarcopenia varied between 0 and 15% in healthy elderly participants and between 2 and 34% in geriatric outpatients. CONCLUSION: This study clearly demonstrates the dependency of sarcopenia prevalence rates on the applied diagnostic criteria.

Changes in Indirect Markers of Muscle Damage and Tendons After Daily Drop Jumping Exercise with Rapid Load Increase.

The aim of this study was to assess changes in indirect markers of muscle damage and type I collagen degradation, as well as, patellar and Achilles tendon morphological differences during nine daily drop-jumps sessions with constant load alternated with rapid increases in load to test the hypothesis that frequent drop-jump training results in negative muscular and tendon adaptation. Young men (n = 9) performed daily drop jump workouts with progression every 3 days in terms of number of jumps, platform height and squat amplitude. Voluntary and electrically evoked knee extensor torque, muscle soreness, blood plasma creatine kinase (CK) activity and carboxyterminal cross-linked telopeptide (ICTP), patellar and Achilles tendon thickness and cross-sectional area (CSA) were assessed at different time points during the training period and again on days 1, 3, 10 and 17 after the training. The findings were as follows: (1) steady decline in maximal muscle strength with major recovery within 24 hours after the first six daily training sessions; (2) larger decline in electrically induced muscle torque and prolonged recovery during last three training sessions; (3) increase in patellar and Achilles tendons CSA without change in thickness towards the end of training period; (4) increase in jump height but not in muscle strength after whole training period. Our findings suggest that frequent drop-jump sessions with constant load alternated with rapid increases in load do not induce severe muscle damage or major changes in tendons, nonetheless, this type of loading is not advisable for muscle strength improvement. Key pointsFrequent drop jump training induces activation mode dependent muscle torque depression late in the training period.No significant changes in the thickness of patellar and Achilles tendons are observed during frequent training, while CSA increases towards the end of training period.Longitudinal effect for jump height but not for muscle strength is evident after the whole training period.

Individual and work-related risk factors for musculoskeletal pain: a cross-sectional study among Estonian computer users.

BACKGROUND: Occupational use of computers has increased rapidly over recent decades, and has been linked with various musculoskeletal disorders, which are now the most commonly diagnosed occupational diseases in Estonia. The aim of this study was to assess the prevalence of musculoskeletal pain (MSP) by anatomical region during the past 12 months and to investigate its association with personal characteristics and work-related risk factors among Estonian office workers using computers. METHODS: In a cross-sectional survey, the questionnaires were sent to the 415 computer users. Data were collected by self-administered questionnaire from 202 computer users at two universities in Estonia. The questionnaire asked about MSP at different anatomical sites, and potential individual and work related risk factors. Associations with risk factors were assessed by logistic regression. RESULTS: Most respondents (77%) reported MSP in at least one anatomical region during the past 12 months. Most prevalent was pain in the neck (51%), followed by low back pain (42%), wrist/hand pain (35%) and shoulder pain (30%). Older age, right-handedness, not currently smoking, emotional exhaustion, belief that musculoskeletal problems are commonly caused by work, and low job security were the statistically significant risk factors for MSP in different anatomical sites. CONCLUSIONS: A high prevalence of MSP in the neck, low back, wrist/arm and shoulder was observed among Estonian computer users. Psychosocial risk factors were broadly consistent with those reported from elsewhere. While computer users should be aware of ergonomic techniques that can make their work easier and more comfortable, presenting computer use as a serious health hazard may modify health beliefs in a way that is unhelpful.

Postural stability in relation to anthropometric and functional characteristics in women with knee osteoarthritis following total knee arthroplasty.

INTRODUCTION: Due to the controversial information about postural stability in patients with lower limb joints osteoarthritis (OA), the following main questions are raised: how serious is the postural stability disturbance and which factors have an impact on postural stability before and after total knee arthroplasty (TKA). MATERIALS AND METHODS: Force plate was used to assess postural stability and custom-made dynamometer was used to assess isometric maximal voluntary contraction (MVC) force of leg extensor muscles; besides, knee pain and knee range of motion (ROM) was evaluated in 14 female patients (aged 46-68 years) with knee OA 1 day before, and 3 and 6 months following TKA and once in healthy controls (aged 48-70). Relationship between postural stability during standing and selected anthropometric and functional characteristics were investigated with Spearman's correlation coefficients. RESULTS: Remarkable reduction of knee pain and improvement in active ROM for the operated leg were shown after unilateral TKA. MVC force of leg extensor muscles achieved the preoperative level half a year after TKA. The centre of pressure (COP) of sway displacement in anterioposterior (AP) and mediolateral direction and the equivalent area of COP sway for the operated leg did not differ before, 3 and 6 months after TKA and compared to the non-operated leg. The trace speed was 6 months after TKA equal to the preoperative level. Only the COP of sway displacement in AP direction is significantly greater in knee OA patients both before and after TKA compared with healthy controls. CONCLUSIONS: Knee OA patients' postural stability characteristics did not differ significantly both before and after TKA. Compared to healthy controls, the COP of sway displacement in AP direction is mostly disturbed. Correlation analysis confirms that increased postural sway is associated with an increased equivalent area of COP. In knee OA patients higher body mass index ensures reduced trace speed and lower knee ROM. LEVEL OF EVIDENCE: Prospective comparative study, Level II.

Physiological and functional evaluation of healthy young and older men and women: design of the European MyoAge study.

Within the European multi-centre MyoAge project, one workpackage was designed to investigate the contribution of age-related changes to muscle mass, contractile characteristics and neural control in relation to reductions in mobility in older age. The methodology has been described here. Test centres were located in Manchester, UK; Paris, France; Leiden, The Netherlands; Tartu, Estonia and Jyväskylä, Finland. In total, 182 young (18-30 years old, 52.2 % female) and 322 older adults (69-81 years old, 50 % female) have been examined. The participants were independent living, socially active and free from disease that impaired mobility levels. The older participants were selected based on physical activity levels, such that half exceeded current recommended physical activity levels and the other half had lower physical activity levels than is recommended to maintain health. Measurements consisted of blood pressure; anthropometry and body composition (dual-energy X-ray absorptiometry and magnetic resonance imaging); lung function; standing balance and cognitive function (CANTAB). Mobility was assessed using the Timed Up and Go, a 6 min walk, activity questionnaires and accelerometers to monitor habitual daily activities. Muscle strength, power, fatigue and neural activation were assessed using a combination of voluntary and electrically stimulated contractions. Fasting blood samples and skeletal muscle biopsies were collected for detailed examination of cell and molecular differences between young and older individuals. The results from this study will provide a detailed insight into "normal, healthy" ageing, linking whole-body function to the structure and function of the neuromuscular system and the molecular characteristics of skeletal muscle.

Circulating levels of adipokines and IGF-1 are associated with skeletal muscle strength of young and old healthy subjects.

It is known that adipose tissue mass increases with age, and that a number of hormones, collectively called adipokines, are produced by adipose tissue. For most of them it is not known whether their plasmatic levels change with age. Moreover, it is known that adipose tissue infiltration in skeletal muscle is related to sarcopenia and loss of muscle strength. In this study we investigated the age-related changes of representative adipokines and insulin-like growth factor (IGF)-1 and their effect on muscle strength. We studied the association between circulating levels of adiponectin, leptin, resistin and IGF-1 and muscle strength. This cross-sectional study included 412 subjects of different age (152 subjects aged 18-30 years and 260 subjects aged 69-81 years) recruited within the framework of the European research network project "Myoage". The levels of adiponectin (both in male and female subjects) and leptin (only in males) were significantly higher in old subjects compared to young, while those of IGF-1 were lower in old subjects. In old subjects adiponectin, resistin and the resistin/IGF-1 ratio (but not IGF-1 alone) were inversely associated with quadriceps torque, while only adiponectin was inversely associated with handgrip strength independently from percentage of fat mass, height, age, gender and geographical origin. The ratio of leptin to adiponectin was directly associated with handgrip strength in both young and old subjects. These results suggest that in humans the age-associated loss of strength is associated with the levels of representative adipokines and IGF-1.

Risk factors for musculoskeletal pain amongst nurses in Estonia: a cross-sectional study.

BACKGROUND: Routine statistics indicate a high frequency of work-related musculoskeletal disorders in Estonia. We aimed to describe the prevalence of musculoskeletal pain (MSP) amongst Estonian nurses, and to explore associations with personal characteristics and occupational risk factors. METHODS: As a part of an international investigation (the Cultural and Psychosocial Influences on Disability (CUPID) study), a cross-sectional survey was carried out amongst registered nurses at Tartu University Hospital, focusing on pain at six anatomical sites (low back, neck, shoulder, elbow, wrist/hand and knee) lasting for more than a day during the past year and past month. Associations with regional and multi-site (≥2 anatomical sites) pain were analysed by logistic regression. RESULTS: Analysis was based on 221 female nurses (response rate 57%). The overall prevalence of MSP was 84% in the past year and 69% in the past month. The prevalence of multi-site pain was 60% in the past year and 40% in the past month. Low back, neck and knee were the sites most commonly painful. Pain in the past year tended to be more frequent at older ages, and with higher emotional exhaustion, and at most sites, with poor self-rated health, and reported distress from somatic symptoms. Multi-site pain was also significantly associated with older age and tendency to somatise. CONCLUSIONS: The prevalence of MSP among Estonian nurses is high. Psychological risk factors such as somatising tendency have an important impact. However, none of the risk factors examined seems likely to explain the high frequency of work-related musculoskeletal disorders in Estonia.

Leg extensor muscle strength, postural stability, and fear of falling after a 2-month home exercise program in women with severe knee joint osteoarthritis.

BACKGROUND AND OBJECTIVE. The aim of this study was to compare the leg extensor muscle strength, the postural stability, and the fear of falling in the women with severe knee joint osteoarthritis (OA) before and after a 2-month home exercise program (HEP). MATERIAL AND METHODS. In total, 17 women aged 46-72 years with late-stage knee joint OA scheduled for total knee arthroplasty participated in this study before and after the 2-month HEP with strengthening, stretching, balance, and step exercises. The isometric peak torque (PT) of the leg extensors and postural stability characteristics when standing on a firm or a foam surface for 30 seconds were recorded. The fear of falling and the pain intensity (VAS) were estimated. RESULTS. A significant increase in the PT and the PT-to-body weight (PT-to-BW) ratio of the involved leg as well as the bilateral PT and the PT-to-BW ratio was found after the 2-month HEP compared with the data before the HEP (P<0.05). The PT and the PT-to-BW ratio of the involved leg were significantly lower compared with the uninvolved leg before the HEP (P<0.05). The center of the pressure sway length (foam surface) decreased significantly after the HEP (P<0.05). Significant correlations were found between the PT of the involved leg and the bilateral PT and the fear of falling and between the PT of the involved leg and the postural sway (foam surface) before the HEP. CONCLUSIONS. After the 2-month HEP, the leg extensor muscle strength increased and the postural sway length on a foam surface decreased. The results indicate that the increased leg extensor muscle strength improves postural stability and diminishes the fear of falling in women with late-stage knee joint OA.

Musculoskeletal disorders and functional characteristics of the neck and shoulder: Comparison between office workers using a laptop or desktop computer.

BACKGROUND: Using a laptop for work is gaining rapid popularity, but there is little evidence of how it influences musculoskeletal disorders (MSDs) and functional characteristics of the neck and shoulder area. OBJECTIVE: This study aimed to compare the prevalence of upper body MSDs and functional characteristics of the neck between office workers using a laptop or desktop computer. METHODS: A total of 110 office workers with a mean age of 41±10 years participated. 45 office workers (73% female) used a laptop and 65 office workers (86% female) used desktop computers. The prevalence of MSDs was recorded using the Nordic Musculoskeletal Questionnaire. Active range of motion (AROM), maximal voluntary isometric contraction (MVC) force, joint position error (JPE), and pain-pressure threshold (PPT) of the neck and shoulder area were measured. RESULTS: Laptop users experienced significantly more MSDs in the right shoulder area on the day of participation (p < 0.001, OR = 4.47), during the previous 7 days (p < 0.01, OR = 3.74), and at 6 months (p < 0.01, OR = 3.57). Laptop users also experienced significantly more MSDs in the left shoulder during the previous 7 days (p < 0.05, OR = 2.44). There were no statistically significant differences in any of the functional characteristics of the neck and shoulder area between the groups. CONCLUSION: Using the laptop computer for office work may pose a higher risk of developing MSDs in the right shoulder area, but might not have long-term effects on the functional characteristics of the neck and shoulder area.

The relationship between bone parameters, body composition, and lower extremity strength in road cyclists.

BACKGROUND: This study aimed to compare the relationships between bone and body composition parameters, and isometric maximal voluntary contraction (MVC) force of knee extensor (KE) muscles in road cyclists and untrained controls. METHODS: Twelve male road cyclists and 12 controls aged 20-34 years participated. The isometric MVC force of the KE muscles was assessed by a custom-made dynamometer. Bone mineral content (BMC), bone mineral density (BMD), and body composition were assessed using Dual-Energy X-ray Absorptiometry. RESULTS: No differences were found in body mass, lean body mass, leg lean mass, MVC, whole body, and leg BMD and BMC between cyclists and controls. Controls had a significantly greater (P<0.001) body mass index (BMI), whole body (P<0.01), and leg fat (P<0.001) mass than athletes. In road cyclists, BMC correlated positively with body mass (r=0.73; P<0.01) and BMI (r=0.65; P<0.05), body (r=0.85; P<0.001) and leg lean mass (r=0.81; P<0.001); BMD correlated positively with lean body mass (r=0.60; P<0.05), leg lean mass (r=0.65 and r=0.60; P<0.05). MVC of KE muscles correlated positively with bone parameters (P<0.01) and lean mass (P<0.05) only in controls. CONCLUSIONS: Regular cycling training was associated with lower BMI, and body and leg fat mass. There were no significant differences in bone parameters, body and leg lean mass, and isometric MVC force of KE muscle variables between road cyclists and controls. In road cyclists, bone parameters are associated with body mass, and body and leg lean mass, but not with the isometric strength of KE muscles.

Changes in irisin, inflammatory cytokines and aerobic capacity in response to three weeks of supervised sprint interval training in older men.

BACKGROUND: This study investigated the effects of supervised short-term sprint interval training (SIT) on circulating irisin, interleukin (IL)-6 and tumour necrosis factor (TNF)-α concentrations, and aerobic capacity and body composition values in healthy older men. METHODS: Eleven older men (63±8 years; 178.0±5.5 cm; 82.7±8.6 kg; 22.7±3.7% body fat) underwent SIT (6 repetitions of 30 s all-out cycling bouts with 4 min active recovery after each bout) three days a week for three consecutive weeks. Body composition measured by dual-energy X-ray absorptiometry, aerobic capacity assessed by direct peak oxygen consumption (VO2peak) test and morning fasting blood samples were obtained before and after a 3-week SIT intervention. RESULTS: Nine supervised SIT sessions moderately (effect size [ES] =0.65; P<0.05) increased irisin concentrations (from 135.40±28.73 to 154.20±47.09 ng.mL-1) together with moderate decreases (P<0.05) in IL-6 (ES=0.89; from 1.26±0.44 to 0.87±0.44 pg.mL-1) and TNF-α (ES=0.64; from 5.10±1.23 to 4.31±1.20 pg.mL-1) levels in older men. In addition, increase in VO2peak was significant but small (ES=0.25; P<0.05; from 36.0±7.1 to 37.8±6.7 mL.min.-1kg-1), while no changes (P>0.05) in body composition variables were observed after a short-term SIT period. CONCLUSIONS: A 3-week SIT intervention with only nine training sessions increased circulating irisin concentrations, improved inflammatory profile and aerobic capacity without changes in body composition in healthy older men. Accordingly, a short-term SIT programme is a time efficient alternative for traditional aerobic training to improve metabolic health and aerobic capacity in older adults.

Neurometabolic correlates of posturography in normal aging and older adults with mild cognitive impairment: Evidence from a 1H-MRS study.

Proton magnetic resonance spectroscopy (1H-MRS) holds promise for revealing and understanding neurodegenerative processes associated with cognitive and functional impairments in aging. In the present study, we examined the neurometabolic correlates of balance performance in 42 cognitively intact older adults (healthy controls - HC) and 26 older individuals that were diagnosed with mild cognitive impairment (MCI). Neurometabolite ratios of total N-acetyl aspartate (tNAA), glutamate-glutamine complex (Glx), total choline (tCho) and myo-inositol (mIns) relative to total creatine (tCr) were assessed using single voxel 1H-MRS in four different brain regions. Regions of interest were the left hippocampus (HPC), dorsal posterior cingulate cortex (dPCC), left sensorimotor cortex (SM1), and right dorsolateral prefrontal cortex (dlPFC). Center-of-pressure velocity (Vcop) and dual task effect (DTE) were used as measures of balance performance. Results indicated no significant group differences in neurometabolite ratios and balance performance measures. However, our observations revealed that higher tCho/tCr and mIns/tCr in hippocampus and dPCC were generic predictors of worse balance performance, suggesting that neuroinflammatory processes in these regions might be a driving factor for impaired balance performance in aging. Further, we found that higher tNAA/tCr and mIns/tCr and lower Glx/tCr in left SM1 were predictors of better balance performance in MCI but not in HC. The latter observation hints at the possibility that individuals with MCI may upregulate balance control through recruitment of sensorimotor pathways.

Body fat and components of sarcopenia relate to inflammation, brain volume, and neurometabolism in older adults.

Obesity and sarcopenia are associated with cognitive impairments at older age. Current research suggests that blood biomarkers may mediate this body-brain crosstalk, altering neurometabolism and brain structure eventually resulting in cognitive performance changes. Seventy-four older adults (60-85 years old) underwent bio-impedance body composition analysis, handgrip strength measurements, 8-Foot Up-and-Go (8UG) test, Montreal Cognitive Assessment (MoCA), blood analysis of interleukin-6 (IL-6), kynurenine, and insulin-like growth factor-1 (IGF-1), as well as brain magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy (1H-MRS), estimating neurodegeneration and neuroinflammation. Normal fat% or overweight was associated with larger total gray matter volume compared to underweight or obesity in older adults and obesity was associated with higher N-acetylaspartate/Creatine levels in the sensorimotor and dorsolateral prefrontal cortex. Muscle strength, not muscle mass/physical performance, corresponded to lower kynurenine and higher N-acetylaspartate/Creatine levels in the dorsal posterior cingulate and dorsolateral prefrontal cortex. The inflammatory and neurotrophic blood biomarkers did not significantly mediate these body-brain associations. This study used a multimodal approach to comprehensively assess the proposed mechanism of body-brain crosstalk.