Domain-specific physical activity, sedentary behavior, subjective health, and health-related quality of life among older adults.

PURPOSE: This study aims to investigate the association between domain-specific physical activity (PA), sedentary behavior, subjective health perception, and health-related quality of life (HR-QoL) in Korean adults aged ≥ 65 years. METHODS: This cross-sectional study analyzed 6,004 older adults from the Korean National Health and Nutrition Examination Survey 2017-2020. PA and sedentary behavior were measured using a global PA questionnaire, and HR-QoL was assessed using the EuroQol-5 Dimension (EQ-5D, three-level version). Multiple logistic regression was used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) after adjusting for confounding parameters. RESULTS: Older adults who were physically active at work showed a negative association with subjectively good health and HR-QoL, whereas those physically active in transport or leisure time showed a positive association with subjectively good health and HR-QoL. Older adults highly engaged in sedentary behavior showed a worse perception of health and HR-QoL. Compared to high sedentary behavior and physical activity during leisure time or transport, the EQ-5D index was higher than that of their counterparts. CONCLUSION: Both domain-specific PA and sedentary behavior were significantly associated with older adults' perception of health and HR-QoL. Interventions are needed to improve HR-QoL by reducing sedentary behavior and encouraging physical activity in transportation or leisure time among adults aged 65 years and above.

Association between Physical Activity and Telomere Length in Women with Breast Cancer: A Systematic Review.

The association between physical activity and telomere length (TL) has been continuously reported. However, the interplay of physical activity and TL among women with breast cancer has not been elucidated. Thus, the purpose of this systematic review was to synthesize the evidence for the association of physical activity with TL in women with breast cancer. Systematic searches were conducted to identify quantified studies using MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Web of Science, and Clinical Trials.gov. Five studies were included in this systematic review. Three of the five studies reported that physical activity has a significant relationship in delaying TL shortening, but others observed no association between physical activity and TL in breast cancer survivors. Although the heterogeneous studies acted as limitations in drawing clear conclusions, physical activity strategies show encouraging impacts in delaying TL shortening. To understand the effects of physical activity on TL shortening in breast cancer survivors, further studies are needed considering the tissue site, treatments for breast cancer, DNA extraction methods, and tools for measuring physical activity.

Satisfaction with the walking-related environment during COVID-19 in South Korea.

This study aimed to examine the satisfaction level differences between urban and rural areas with regard to their walking environment during the COVID-19 pandemic in South Korea. This online cross-sectional research was conducted using a mobile health application. Overall, 1,032 local residents who participated in the mobile healthcare program of a public health center were classified as being from either urban (n = 481, 46.6%) or rural areas (n = 551, 53.4%) for the purpose of this study. The Walkability Checklist, which includes sociodemographic information, was employed using a Chi-square test and a multivariate logistic regression to investigate whether or not the participants were satisfied with the environmental factors associated with walking. It was found that both urban and rural areas were more likely to be unsatisfied with walking comfort (adjusted OR: 24.472, 95% CI: 14.937-40.096). Regarding the walking comfort aspects of the walking environment, urban residents chose poor landscape ("needed more grass, flowers, or trees"; aOR: 13.561, 95% CI: 3.619-50.823) as their primary dissatisfaction, and rural residents chose messy streets ("dirty, lots of litter or trash"; aOR: 29.045, 95% CI: 6.202-136.015). Compared with urban residents, rural residents were more discontented with the walking environment. Thus, to promote walking activities at the community level, it is necessary to focus on walking comfort, and implement efforts related to environmental beautification.

Multidimensional Biomarker Analysis Including Mitochondrial Stress Indicators for Nonalcoholic Fatty Liver Disease.

Nonalcoholic fatty liver disease (NAFLD) is accompanied by a complex and multifactorial pathogenesis with sequential progressions from inflammation to fibrosis and then to cancer. This heterogeneity interferes with the development of precise diagnostic and prognostic strategies for NAFLD. The current approach for the diagnosis of simple steatosis, steatohepatitis, and cirrhosis mainly consists of ultrasonography, magnetic resonance imaging, elastography, and various serological analyses. However, individual dry and wet biomarkers have limitations demanding an integrative approach for the assessment of disease progression. Here, we review diagnostic strategies for simple steatosis, steatohepatitis and hepatic fibrosis, followed by potential biomarkers associated with fat accumulation and mitochondrial stress. For mitochondrial stress indicators, we focused on fibroblast growth factor 21 (FGF21), growth differentiation factor 15 (GDF15), angiopoietin-related growth factor and mitochondrial-derived peptides. Each biomarker may not strongly indicate the severity of steatosis or steatohepatitis. Instead, multidimensional analysis of different groups of biomarkers based on pathogenic mechanisms may provide decisive diagnostic/prognostic information to develop a therapeutic plan for patients with NAFLD. For this purpose, mitochondrial stress indicators, such as FGF21 or GDF15, could be an important component in the multiplexed and contextual interpretation of NAFLD. Further validation of the integrative evaluation of mitochondrial stress indicators combined with other biomarkers is needed in the diagnosis/prognosis of NAFLD.

Association Between Skeletal Muscle Mass, Physical Activity, and Metabolic Syndrome: the Korean National Health and Nutrition Examination Survey 2008-2011.

Background: Skeletal muscle mass (SM) and physical activity (PA) are major modifiable factors that can moderate and prevent the occurrence of metabolic syndrome (MetS). However, the joint association between SM and PA guidelines in MetS remains unclear. Therefore, we aimed to examine the relationship between SM and PA with MetS among Korean adults. Methods: This cross-sectional study analyzed 18,090 adults from the Korean National Health and Nutrition Examination Survey 2008-2011. We used the value of appendicular skeletal muscle mass divided by body mass index as SM. We decided on the PA guidelines using the American College of Sports Medicine guidelines. After adjusting for confounding factors, we performed logistic regression analysis to calculate the odds ratio and 95% confidence interval of MetS associated with SM and PA guidelines. Results: Participants from the highest SM quartile showed a decreased MetS risk of 58%-75%. Those who met both aerobic and resistance exercise guidelines were more likely to have lower MetS risk than those who neither. In addition, even with the same PA guideline status, participants with the highest muscle mass decreased MetS risk by 29%-81% compared with participants with the lowest muscle mass. Conclusions: Our results showed that increased SM and meeting PA guidelines are significantly associated with a decreased risk of MetS. To prevent MetS, customized strategies are needed for improving muscle mass and PA according to age and gender.

Insulin-activated store-operated Ca2+ entry via Orai1 induces podocyte actin remodeling and causes proteinuria.

Podocyte, the gatekeeper of the glomerular filtration barrier, is a primary target for growth factor and Ca2+ signaling whose perturbation leads to proteinuria. However, the effects of insulin action on store-operated Ca2+ entry (SOCE) in podocytes remain unknown. Here, we demonstrated that insulin stimulates SOCE by VAMP2-dependent Orai1 trafficking to the plasma membrane. Insulin-activated SOCE triggers actin remodeling and transepithelial albumin leakage via the Ca2+-calcineurin pathway in podocytes. Transgenic Orai1 overexpression in mice causes podocyte fusion and impaired glomerular filtration barrier. Conversely, podocyte-specific Orai1 deletion prevents insulin-stimulated SOCE, synaptopodin depletion, and proteinuria. Podocyte injury and albuminuria coincide with Orai1 upregulation at the hyperinsulinemic stage in diabetic (db/db) mice, which can be ameliorated by the suppression of Orai1-calcineurin signaling. Our results suggest that tightly balanced insulin action targeting podocyte Orai1 is critical for maintaining filter integrity, which provides novel perspectives on therapeutic strategies for proteinuric diseases, including diabetic nephropathy.

Review of physiotherapy service for athletes of 2018 Olympic Winter games: Consideration of preparation for two polyclinics.

OBJECTIVE: This study will provide to better understand the needs for physiotherapy services during the 2018 PyeongChang Olympic Winter Games (POG) from two polyclinics. It is necessary to understand the needs and what physiotherapists do during the Olympic Winter games for first time. DESIGN: An observational study. SETTING: 2018 PyeongChang Olympic Winter Games. PARTICIPANTS: Athletes who visited the physiotherapy department of polyclinics. RESULTS: During 25 the days of the POG, a total of 125 athletes (n = 125, 83 males, 42 females) visited the two polyclinics. Of all visits, 69.6% were from the mountain polyclinic and 30.4% from the city. There were three reasons for visit, most of the reason for visit was injury and injury with recovery or injury prevention. Overall, the injury rate (per 1000 athletes) was 42.8 across 13 sports visited the physiotherapy department during the POG. Total numbers of treatments sessions were 823 provided and electrophysical modalities (36.2%) was the most utilized service in POG. And also there were significant differences in the physiotherapy services provided at the two polyclinics. CONCLUSION: As each polyclinic differed in location, they addressed different populations of athletes; hence, the study provides insights into the injury trends and different physiotherapy treatments.

Exercise intervention lowers aberrant serum WISP-1 levels with insulin resistance in breast cancer survivors: a randomized controlled trial.

Insulin resistance is associated with increased risk for and recurrence of breast cancer. Recently, Wnt1-inducible signaling pathway protein-1 (WISP-1) was reported to impair glucose metabolism and insulin sensitivity. In various cancer tissues, Wnt signaling is upregulated and induces further oncogenic and metastatic activity. However, the effects of exercise on serum levels of WISP-1 and its upstream ß-catenin have not been studied in cancer patients. We investigated the effects of exercise training on Wnt signaling and insulin sensitivity in breast cancer survivors (BCS). This single-center trial randomized 46 BCS into either 12-week exercise or control groups (1:1), and included an additional 12 age-matched healthy women. Kinanthropometric parameters, serum Wnt signaling markers, and gluco-lipid profiles were evaluated before and after the intervention. Serum ß-catenin and WISP-1 concentrations were significantly higher in BCS than in healthy subjects. There was a positive correlation between ß-catenin and WISP-1 levels. Exercise training in BCS significantly reduced body fat and waist circumference and enhanced aerobic and muscular fitness. Exercise decreased ß-catenin and WISP-1 levels and improved gluco-lipid profiles. There was a notable correlation between changes in HOMA-IR indexes and serum WISP-1, but not with ß-catenin during the exercise intervention. In conclusion, a 12-week community-based exercise intervention resulted in significant reductions in serum ß-catenin and WISP-1 levels, accompanied by favorable improvements in body composition, physical fitness, and biochemical parameters in BCS. We also highlight that this is the first report concerning effects of exercise on circulating ß-catenin and WISP-1 levels and correlations between WISP-1 and insulin sensitivity, which could be important for determining prognoses for BCS.

Relationships of internet gaming reasons to biological indicators and risk of internet gaming addiction in Korean adolescent male game users.

BACKGROUND: There are no standard diagnostic criteria or interventions for internet gaming addiction (IGA) even though IGA is one of the most pervasive public health issues among youth worldwide. Internet gaming reasons or motivations have been studied as a potential predictor of IGA, but the results have been inconsistent and biological indicators of gaming reasons have rarely been studied. We sought to (1) identify categories of internet gaming reasons, (2) examine the relationship of gaming reasons to risk of IGA, and (3) describe biological indicators associated with reasons for gaming. METHODS: We used a multi-phase cross-sectional design including individual interviews; focus group discussion; and descriptive, comparative analysis. Fifteen Korean adolescent male internet gamers participated in individual interviews and eight participated in a focus group aimed at identifying reasons for internet gaming. Using the identified gaming reasons from these sources we surveyed 225 adolescent game users using a self-report questionnaire. Participants provided blood samples for assessment of norepinephrine (NE) and serum cortisol. RESULTS: We identified four major categories of internet gaming reasons: entertainment, getting along with friends, stress relief, and habitual gaming. The habitual group showed significantly greater risk of IGA than the other groups (p < .001) and the lowest plasma NE levels (p = .035), possibly indicating an alteration in autonomic function. CONCLUSION: Health care providers are encouraged to screen adolescents for excessive internet gaming and to intervene with those who report habitual gaming behaviors. When feasible, assessment of biological indicators, such as plasma NE, may help to identify youth at greatest risk of IGA.

Irisin prevents dexamethasone-induced atrophy in C2C12 myotubes.

Irisin is a myokine secreted mainly from skeletal muscle that is known for having beneficial metabolic effects via enhancement of energy expenditure and insulin sensitivity. Studies show that irisin also acts as an autocrine/paracrine to promote myogenesis and muscle growth. However, the protective role of irisin against muscular wasting remains unclear. We confirmed that irisin secretion was upregulated by electrical pulse stimulation an in vitro exercise mimetic model. Next, we tested if irisin exerted an anti-atrophic effect on cultured C2C12 myotubes treated with dexamethasone (DEX), a representative inducer of muscular atrophy. Treatment of cultured myotubes with DEX reduced myotube size and increased proteasome activity, which were attenuated by irisin. Also, irisin effectively prevented dephosphorylation of forkhead box O (FoxO) 3α and upregulation of muscle-specific ubiquitin ligases in DEX-treated myotubes. The protective effect of irisin on DEX-mediated myotube atrophy was partially regulated by insulin-like growth factor-1-dependent signaling. These results suggested that irisin may prevent glucocorticoid-induced muscle atrophy by inhibiting FoxO-mediated ubiquitin-proteasome overactivity.

Orthostatic hypotension and health-related quality of life among community-living older people in Korea.

PURPOSE: To investigate the association of orthostatic hypotension (OH) with health-related quality of life (HRQoL) in older people living in the community. METHODS: A cross-sectional design was used. A total of 217 participants aged 65 and older were classified as having OH if their systolic or diastolic blood pressure showed a drop of ≥ 20 mmHg systolic blood pressure or ≥ 10 mmHg diastolic blood pressure, respectively, within 3 min of standing. Participants provided demographic and medical information and responded to questionnaires about their HRQoL (EuroQoL-5D-3L), as well as depression, anxiety, cognitive function, and recent physical activities. RESULTS: The number of participants with OH was 117, and those without OH numbered 100. The mean HRQoL levels were 0.56 (SD 0.29) in the OH group and 0.74 (SD 0.25) in the non-OH group (p < .001). Participants with OH were more likely to be older, women, and smokers. These participants had fewer years of education, a greater history of stroke and hypertension, and a greater number of comorbidities. The absence of OH, a higher physical activity level, a lower degree of depression, an absence of stroke history, and younger age were all significant determinants of greater HRQoL. CONCLUSIONS: The level of HRQoL of older people with OH was significantly lower than that of older people without. The presence of OH was an independent determinant of HRQoL in older adults after adjusting for covariates. This finding suggests that strategies for relieving OH could improve HRQoL in affected older adults.

Increased Serum Angiopoietin-Like 6 Ahead of Metabolic Syndrome in a Prospective Cohort Study.

BACKGROUND: Despite being an anti-obesity hepatokine, the levels of serum angiopoietin-like 6 (ANGPTL6) are elevated in various metabolic diseases. Thus, ANGPTL6 expression may reflect metabolic burden and may have compensatory roles. This study investigated the association between serum ANGPTL6 levels and new-onset metabolic syndrome. METHODS: In total, 221 participants without metabolic syndrome were randomly selected from a rural cohort in Korea. Baseline serum ANGPTL6 levels were measured using an enzyme-linked immunosorbent assay. Anthropometric and biochemical markers were analyzed before and after follow-up examinations. RESULTS: During an average follow-up period of 2.75 (interquartile range, 0.76) years, 82 participants (37.1%) presented new-onset metabolic syndrome and had higher ANGPTL6 levels before onset than those without metabolic syndrome (48.03±18.84 ng/mL vs. 64.75±43.35 ng/mL, P=0.001). In the multivariable adjusted models, the odds ratio for the development of metabolic syndrome in the highest quartile of ANGPTL6 levels was 3.61 (95% confidence interval, 1.27 to 10.26). The use of ANGPTL6 levels in addition to the conventional components improved the prediction of new-onset metabolic syndrome (area under the receiver operating characteristic curve: 0.775 vs. 0.807, P=0.036). CONCLUSION: Increased serum ANGPTL6 levels precede the development of metabolic syndrome and its components, including low high density lipoprotein, high triglyceride, and high glucose levels, which have an independent predictive value for metabolic syndrome.

Association between internet gaming addiction and leukocyte telomere length in Korean male adolescents.

Internet gaming addiction (IGA) has been associated with many negative health outcomes, especially for youth. In particular, the potential association between IGA and leukocyte telomere length (LTL) has yet to be examined. In this study we compared LTL in Korean male adolescents with and without IGA and examined the association between LTL and autonomic functions. Specifically, plasma catecholamine, serum cortisol, and psychological stress levels were measured as autonomic functions. Data were collected using participant blood samples analyzed for LTL, catecholamine, and cortisol levels and a set of questionnaires to assess IGA and psychological stress levels of the participants. The LTL measurements were made using a qPCR-based technique, and the relative LTL was calculated as the telomere/single copy (T/S) ratio. T/S ratio was significantly shorter in the IGA group than in the non-IGA group (150.43 ±â€¯6.20 and 187.23 ±â€¯6.42, respectively; p < .001) after adjusting for age. In a univariate regression analysis, age, daily Internet gaming time, IGA score, and catecholamine level (epinephrine and norepinephrine) were significantly associated with T/S ratio. However, duration of Internet gaming exposure, dopamine, cortisol, and psychological stress levels were not found to be associated with T/S ratio. In the final multiple linear regression model, age, daily Internet gaming time, and epinephrine level showed statistically significant relationships with T/S ratio. Our results indicate that in addition to age, involvement in excessive Internet gaming may induce LTL shortening in male adolescents, which may be partially attributable to changes in autonomic function such as catecholamine level. These findings further understanding of the health effects of IGA and highlight the need for screening and intervention strategies for male adolescents with IGA.

Genetic association of human Corticotropin-Releasing Hormone Receptor 1 (CRHR1) with Internet gaming addiction in Korean male adolescents.

BACKGROUND: The number of people with Internet gaming addiction (IGA) is increasing around the world. IGA is known to be associated with personal characteristics, psychosocial factors, and physiological factors. However, few studies have examined the genetic factors related to IGA. This study aimed to investigate the association between IGA and stress-related genetic variants. METHODS: This cross-sectional study was conducted with 230 male high school students in a South Korean city. We selected five stress-related candidate genes: DAT1, DRD4, NET8, CHRNA4, and CRHR1. The DAT1 and DRD4 genes were genotyped by polymerase chain reaction, and the NET8, CHRNA4, and CRHR1 genes were genotyped by pyrosequencing analysis. We performed a Chi-square test to examine the relationship of these five candidate genes to IGA. RESULTS: Having the AA genotype and the A allele of the CRHR1 gene (rs28364027) was associated with higher odds of belonging to the IGA participant group (p = .016 and p = .021, respectively) than to the non-IGA group. By contrast, the DAT1, DRD4, NET8, and CHRNA4 gene polymorphisms showed no significant difference between the IGA group and control group. CONCLUSIONS: These results indicate that polymorphism of the CRHR1 gene may play an important role in IGA susceptibility in the Korean adolescent male population. These findings provide a justification and foundation for further investigation of genetic factors related to IGA.

WNK1 kinase is essential for insulin-stimulated GLUT4 trafficking in skeletal muscle.

With-no-lysine 1 (WNK1) kinase is a substrate of the insulin receptor/Akt pathway. Impaired insulin signaling in skeletal muscle disturbs glucose transporter 4 (GLUT4) translocation associated with the onset of type 2 diabetes (T2D). WNK1 is highly expressed in skeletal muscle. However, it is currently unknown how insulin signaling targeting WNK1 regulates GLUT4 trafficking in skeletal muscle, and whether this regulation is perturbed in T2D. Hereby, we show that insulin phosphorylates WNK1 at its activating site via a phosphatidylinositol 3-kinase-dependent mechanism. WNK1 promotes the cell surface abundance of GLUT4 via regulating TBC1D4. Of note, we observed insulin resistance and decreased WNK1 phosphorylation in T2D db/db mice as compared to the control mice. These results provide a new perspective on WNK1 function in the pathogenesis of hyperglycemia in T2D.

Leptin regulates the expression of angiopoietin-like 6.

Angiopoietin-like 6 (ANGPTL6) is a hepatokine that antagonizes obesity and insulin resistance by increasing energy expenditure. Despite its beneficial effects on metabolism, human studies have shown a paradoxical increase in ANGPTL6 level in the serum of patients with metabolic diseases, which has been interpreted as a compensatory upregulation. However, the regulatory mechanism of ANGPTL6 remains unclear. Since upregulation of ANGPTL6 is induced on metabolic stress, we investigated the hepatic expression of ANGPTL6 by leptin, a representative adipokine of obesity. Mice on a high-fat diet showed increased serum leptin levels and hepatic Angptl6 expression, which were attenuated by exercise training. A single leptin injection also induced hepatic ANGPTL6 expression and increased serum ANGPTL6 levels. In an in vitro model using primary hepatocytes, leptin treatment significantly upregulated ANGPTL6 expression at the mRNA and protein levels, as well as the amount of secreted ANGPTL6 protein in conditioned media. Similarly, exercise training on human participants also showed diminished serum levels of leptin and ANGPTL6. Altogether, these results strongly indicated that hepatic ANGPTL6 expression was determined by leptin.

Effect of a short-term physical activity intervention on liver fat content in obese children.

Nonalcoholic fatty liver disease is the most common chronic liver disease and can present with advanced fibrosis or nonalcoholic steatohepatitis. The purpose of this study was to investigate the effect of a 7-day intense physical activity intervention on liver fat content in children with obesity. Fifty-seven obese children (mean body mass index: 26.5 ± 3.2 kg/m2; mean age: 12.0 ± 0.8 years) participated in a 7-day physical activity program. All participants were housed together, and their food intake and energy expenditure were strictly controlled. Anthropometric measurements, abdominal computerized tomography scans, and blood analyses were conducted at baseline and post-intervention. Participants lost weight by 2.53 ± 0.85 kg on average (61.0 ± 9.8 vs. 58.5 ± 9.5 kg, p < 0.05), fat mass (16.7 ± 5.1 vs. 15.7 ± 4.9 kg, p < 0.05), and serum insulin (13.7 ± 6.7 vs. 3.5 ± 2.0 µU/mL, p < 0.05). However, liver fat content was increased, presented as liver-to-spleen ratio (LSR) where lower LSR represents higher liver fat content. The intervention increased aspartate transaminase level (29.42 ± 6.78 IU/L vs. 33.50 ± 9.60 IU/L, p < 0.001). The change in liver fat content was not associated with the change in fasting insulin and liver enzymes. Short-term intense physical activity increased liver fat content independent of change in fasting insulin level and liver enzymes. This is the first human study to report increased liver fat content after physical activity-induced rapid weight loss.

Effects of Exercise Training on Physical Fitness and Biomarker Levels in Breast Cancer Survivors.

BACKGROUND: Exercise has been identified as a beneficial intervention to enhance quality of life in breast cancer survivors. In addition, there has been a noteworthy increase in studies emphasizing the benefits of exercise in cancer. We sought to summarize the empirical literature concerning the effects of exercise on physical fitness and biomarker levels in breast cancer survivors according to the type of exercise. METHODS: We searched PubMed and PubMed Central for studies on the association of exercise with the levels of various biomarkers and physical fitness in breast cancer survivors. We investigated the effects of different types of exercise (aerobic, resistance, or combined) on breast cancer survivors, with changes in physical fitness and biomarker levels as the primary outcomes. RESULTS: In total, 118 research papers published from 2012 to July 2016 were retrieved from PubMed and PubMed Central. Of these, 24 papers met our inclusion criteria. All types of exercise were found to improve physical fitness in breast cancer survivors. However, the results with regard to biomarkers were controversial. CONCLUSION: The findings of this review suggest that combined exercise is associated with better outcomes than aerobic or resistance exercise alone in breast cancer survivors.

Circulating irisin levels as a predictive biomarker for sarcopenia: A cross-sectional community-based study.

AIM: Myokines are peptides released by the skeletal muscle, and have gained popularity as potential biomarkers for sarcopenia. Irisin is a recently identified myokine, but its role in pathological sarcopenia remains unclear. We investigated the validity and accuracy of circulating irisin levels as a potential biomarker for sarcopenia. METHODS: We evaluated the anthropometrics, body composition, sarcopenia-related parameters and serum irisin levels of 715 community-dwelling Koreans. Sarcopenia was determined on the basis of the clinical diagnostic criteria of muscle atrophy and weakness, which were proposed by the Asian Working Group for Sarcopenia. RESULTS: Circulating irisin levels were correlated with appendicular lean mass/height2 (rmen = 0.275; rwomen = 0.321) and handgrip strength (rmen = 0.219; rwomen = 0.312) in both sexes (all P < 0.01). Furthermore, the mean circulating irisin levels were lower in the sarcopenia group than in the normal group (all P < 0.05). In the logistic regression models, the association between serum irisin concentration and incident sarcopenia persisted even after adjusting for potential confounders, such as sex, age and fat indices (odds ratio 0.20, 95% CI 0.07-0.60; P for trend <0.01). The predictive values of serum irisin for sarcopenia were <1.0 µg/mL in men and <1.16 µg/mL in women, with the area under the receiver operating characteristic curves of 0.87 (95% CI 0.77-0.99) and 0.68 (95% CI 0.55-0.81), respectively (all P < 0.01). CONCLUSIONS: A low level of circulating irisin is a sensitive marker for muscle weakness and atrophy. Irisin is a potential biomarker for muscle dysfunction that could help predict the onset of sarcopenia and provide new avenues for monitoring age-related muscle changes. Geriatr Gerontol Int 2017; 17: 2266-2273.

Hemodynamic Adaptations to Regular Exercise in People With Spinal Cord Injury.

OBJECTIVE: To investigate the real-time cardiovascular response to the progressive overload exercise in different levels of spinal cord injury (SCI), and to find out whether regular exercise has effect on these cardiovascular responses. METHODS: The study enrolled 8 able-bodied individuals in the control group plus 15 SCI subjects who were divided into two groups by their neurological level of injury: high-level SCI group (T6 or above) and low-level SCI group (T7 or below). Also, subjects were divided into exercise group and non-exercise group by usual exercise habits. We instructed the subjects to perform exercises using arm ergometer according to the protocol and checked plethysmograph for the real time assessment of blood pressure, heart rate, and cardiac output. RESULTS: Six subjects were included in high-level SCI group (3 cervical, 3 thoracic injuries), 9 subjects in low-level SCI group (9 thoracic injuries), and 8 able-bodied individuals in control group. During arm ergometer-graded exercise, mean arterial pressure (MAP) was significantly lower in high-level SCI subjects of non-exercise group, compared with high-level SCI subjects of exercise group. In addition, HR was significantly higher in low-level SCI group compared with control group. CONCLUSION: There are significant differences in mean arterial pressure of high-level SCI group according to usual exercise habits. We discovered that even in non-athlete high-level SCI, regular exercise can bring cardiac modulation through blood pressure control.