Saejong Park

Accumulation of physical activity leads to a greater blood pressure reduction than a single continuous session, in prehypertension.

Background Despite limited research, the accumulation of physical activity has been recommended for the treatment of prehypertension. Objectives To compare the duration and magnitude of blood pressure reduction after accumulated physical activity with that after a single session of continuous physical activity, and to investigate sympathetic modulation as a possible mechanism for the reduction in blood pressure after each acute session. Methods Prehypertensive adults (n = 21) participated in a randomized crossover design. Ambulatory blood pressure and heart rate variability (Holter monitoring) were measured for 12 h after accumulated physical activity (4 × 10-min walks (1/h for 4 h) at 50% of VO2peak), continuous physical activity (40-min walk at 50% of VO2peak) and control treatments. Blood pressure and heart rate variability after each activity treatment were compared with the respective periods from the control treatment. Heart rate variability was correlated with reduction in blood pressure. Results Systolic blood pressure (SBP) was reduced for 11 h after accumulated physical activity (P < 0.01), and for 7 h after continuous physical activity (P < 0.05). Diastolic blood pressure (DBP) was reduced for 10 h after accumulated physical activity (P < 0.05) and for 7 h after continuous physical activity (P < 0.05). With accumulated physical activity, the differences in normalized low-frequency (r = 0.517, P < 0.01) and high-frequency (r = −0.503, P < 0.05) power were correlated with reduction in SBP and the differences in normalized low-frequency (r = 0.745, P < 0.001), high-frequency (r = −0.738, P < 0.001) powers, and low frequency: high frequency ratio (r = 0.756, P < 0.001) were correlated with reduction in DBP. With continuous physical activity, the difference in low frequency: high frequency ratio (r = 0.543, P < 0.05) was correlated with reduction in DBP. Conclusion The accumulation of physical activity appears to be more effective than a single continuous session in the management of prehypertension. Sympathetic modulation was associated with reduced blood pressure after each session.

Salivary Cortisol and Immunoglobulin A Responses During Golf Competition vs. Practice in Elite Male and Female Junior Golfers

Kim, KJ, Park, S, Kim, KH, Jun, TW, Park, DH, Kim, KB. Salivary cortisol and immunoglobulin a responses during golf competition vs. practice in elite male and female junior golfers. J Strength Cond Res 24(3): 852-858, 2010-The purpose of this study was to investigate the stress and immune responses to a competition in elite male and female junior golfers. Six male (16.2 ± 1.4 years) and 6 female junior golfers (16.4 ± 1.1 years) completed salivary collections during competition vs. practice rounds on 2 different days. Salivary samples were collected on 4 occasions (rest, before, during, and after rounds). Salivary cortisol and IgA were measured for stress and immune responses, respectively. Our results were as follows: (a) Salivary cortisol level was higher in competition than practice in male golfers (p = 0.009) but it was similar in female golfers. In male golfers, salivary cortisol level was higher before a round than at rest (p = 0.029), but it was higher after rounds than at rest (p = 0.016) in female golfers. (b) Salivary IgA was elevated during competition than during practice rounds in male golfers (p = 0.019), but not in females (p = 0.152). Salivary IgA was not significantly different among salivary collection times although it tended to be elevated during and after rounds for both male and female golfers. In conclusion, salivary cortisol and IgA were elevated during golf competition compared with practice in male junior golfers, but they were not in female golfers. Furthermore, salivary cortisol was higher before a round than rest in men, but it was higher after a round than rest in women. Both male and female junior golfers, however, showed similar salivary IgA responses during golf. Our results suggest that sex might play a role on stress and immune responses during a game of golf in elite junior golfers.

Time of day to monitor ambulatory blood pressure affects the outcome.

ObjectivesThe reproducibility of blood pressure variables from ambulatory blood pressure monitoring (AMBP) initiated at the same time of day (SAME: 1700–1900 h) was compared with the reproducibility of blood pressure variables when monitoring was initiated at opposite times of day (OPP: randomized, morning=0700–0900 h and evening=1700–1900 h). It was hypothesized that the reproducibility for SAME (n=18) would be no different than the reproducibility for OPP (n=13). MethodsThe order of AMBP sessions was randomized. The Accutracker II was used to determine average blood pressures, Crest (CrBP), Trough (TrBP), and TrBP : CrBP ratio; Averages were divided into 24-h, daytime (0600–2200 h), and night-time (2200–0600 h) for both systolic and diastolic blood pressures. A paired t-test with an intraclass correlation was used to determine the reproducibility of AMBP for both SAME and OPP. A chi-square was used to compare the distribution of reproducible AMBP variables between SAME and OPP. Significance was at P<0.05. ResultsThe reproducibility of AMBP variables for SAME and OPP was a significantly different for systolic blood pressure. All of the ambulatory systolic variables measured in the SAME group were reproducible except for the TrBP : CrBP, whereas only the systolic night-time averages of the OPP group were reproducible. Similarly all of the ambulatory diastolic variables measured in the SAME group were reproducible except for TrBP : CrBP, whereas 24-h, night-time averages, and TrBP were reproducible in the OPP group. ConclusionsAmbulatory blood pressure variables were consistently higher when the monitoring session began in the morning hours.

The exercise heart rate profile in master athletes compared to healthy controls

Endurance exercise protects the heart via effects on autonomic control of heart rate (HR); however, its effects on HR indices in healthy middle‐aged men are unclear. This study compared HR profiles, including resting HR, increase in HR during exercise and HR recovery after exercise, in middle‐aged athletes and controls. Fifty endurance‐trained athletes and 50 controls (all male; mean age, 48·7 ± 5·8 years) performed an incremental symptom‐limited exercise treadmill test. The electrocardiographic findings and HR profiles were evaluated. Maximal O2 uptake (52·6 ± 7·0 versus 34·8 ± 4·5 ml kg−1 min−1; P<0·001) and the metabolic equivalent of task (15·4 ± 1·6 versus 12·2 ± 1·5; P<0·001) were significantly higher in athletes than in controls. Resting HR was significantly lower in athletes than in controls (62·8 ± 6·7 versus 74·0 ± 10·4 beats per minute (bpm), respectively; P<0·001). Athletes showed a greater increase in HR during exercise than controls (110·1 ± 11·0 versus 88·1 ± 15·4 bpm; P<0·001); however, there was no significant between‐group difference in HR recovery at 1 min after cessation of exercise (22·9 ± 5·6 versus 21·3 ± 6·7 bpm; P = 0·20). Additionally, athletes showed a lower incidence of premature ventricular contractions (PVCs) during exercise (0·0% versus 24·0%; P<0·001). Healthy middle‐aged men participating in regular endurance exercise showed more favourable exercise HR profiles and a lower incidence of PVCs during exercise than sedentary men. These results reflect the beneficial effect of endurance training on autonomic control of the heart.

The significance of frailty in the relationship between socioeconomic status and health-related quality of life in the Korean community-dwelling elderly population: mediation analysis with bootstrapping

PurposeFirstly, to investigate the prevalence of frailty and impact on health-related quality of life (HRQOL) in a Korean community-dwelling elderly population using the Fried frailty criteria; secondly, to investigate the associations among frailty, socioeconomic status (SES), and HRQOL of the Korean community-based population; and thirdly, to analyze the relationship between education, income, and frailty.MethodsNine hundred and sixty-four apparently heathy subjects from the Korean community-based population were enrolled in this prospective cross-sectional study. Using self-reported questionnaires, demographic data, SES, and HRQOL were evaluated. Frailty status was determined according to the Fried frailty criteria. After adjustment of covariates including age, sex, and BMI, multivariate linear regression analyses were conducted to assess each component of the proposed mediation models, and mediation was also verified by the bootstrapping technique.ResultsAmong the 964 participants, 530 (55.0%), 399 (41.4%), and 35 (3.6%) participants were classified into the robust, pre-frailty, and frailty group, respectively. The frail group demonstrated significantly lower HRQOL. Participants with lower income or education level had significantly higher chances of being frail. Frailty acted as a mediator in this association between low SES (education and income) and low HRQOL. Furthermore, income contributed most to the explanation of educational differences in frailty, suggesting full mediation.ConclusionFrailty has a significant negative influence on HRQOL in the community-based elderly population, and acts as a mediator between SES and HRQOL. As a mediator, income can explain educational difference related with the frailty.

Prevalence of Frailty in Patients with Osteoporotic Vertebral Compression Fracture and Its Association with Numbers of Fractures

Purpose To assess the association between frailty and osteoporotic vertebral compression fracture (OVCF) and to evaluate the relationship between numbers of OVCFs and frailty. Materials and Methods We enrolled 760 subjects, including 59 patients (with OVCF) and 701 controls (without OVCF). Successful matching provided 56 patient-control pairs. We analyzed principal clinical and demographic information, which included sex, age, height, weight, body mass index (BMI), variable frailty phenotypes, and Oswestry Disability Index (ODI) and EuroQol 5-dimension questionnaire (EQ-5D) scores. The association between frailty and OVCF was ascertained. In addition, the degrees of disability and quality of life attributable to frailty were determined. Results The prevalence of frailty was significantly higher in the OVCF group than in the control group (p<0.001). Most of the frailty phenotypes, such as exhaustion, physical inactivity, slowness, and handgrip strength, were also significantly observed in the OVCF group. Within the OVCF group, the participants with frailty had significantly higher disability and lower quality of life than those in a robust state (p<0.001 for ODI and EQ-5D). In addition, the multivariate logistic regression analysis demonstrated that the patients with low BMI [odds ratio (OR)=0.704; 95% confidence interval (CI), 0.543–0.913] and ≥3 fractures (OR=9.213; 95% CI, 1.529–55.501) within the OVCF group were associated with higher odds of frailty. Conclusion The present study showed significant relationships between frailty and OVCF, severity of symptoms, and disability induced by OVCF. Furthermore, frailty could be a causal and/or resulting factor of OVCFs.

The prevalence and impact of frailty in patients with symptomatic lumbar spinal stenosis

AbstractPurposeTo investigate the prevalence of frailty in patients with symptomatic lumbar spinal stenosis (LSS) and a propensity score-matched control group, and to analyze the association between symptomatic LSS and frailty.MethodsThis study included 2 groups: 1 consisting of patients with symptomatic LSS (LSS group) and the other including healthy elderly subjects without degenerative spinal disease (control group). Baseline sociodemographic data, variables regarding frailty assessment, and clinical outcomes were collected. The frailty was assessed with Fried criteria. Between the LSS and control groups, the prevalence of frailty was compared. Among all participants, risk factors for frailty were identified using multivariate logistic regression.ResultsTotally, 843 subjects participated (142 in LSS group and 701 in control group) in this study. After the propensity score matching (142 in each group), the LSS group had significantly higher prevalence of frail than the control group (P < 0.001): 59 (41.5%) participants in the LSS group were frail, whereas 10 (7.0%) participants in the control group were frail. Within LSS group analysis showed that participants with frailty had significantly higher disability and lower quality of life compared to those in a robust state. Among all participants, LSS and age were found to be significant risk factors for frail in multivariate logistic regression model.ConclusionsThe present study highlights a strong association between symptomatic LSS and frailty. Furthermore, symptom severity and disability caused by LSS are significantly related to frailty. Therefore, early detection and appropriate treatment for frailty in patients with LSS is important.Graphical abstract These slides can be retrieved under Electronic Supplementary Material.

Physical Fitness Levels in Korean Adolescents: The National Fitness Award Project

Background Although physical fitness in adolescents has been widely studied, there is the lack of information regarding developmental patterns of various youth fitness components. The LMS (L=skewness, M=median curve, and S=coefficient of variation) statistical method has been utilized to develop growth percentiles for height and weight as well as for fitness in the US and Europe countries. The purpose of this study was to develop age- and sex-specific smoothed percentile curves for fitness using the LMS method in Korean adolescents aged 13–18 years. Methods A sample of 14,794 adolescents (7,688 boys and 7,106 girls) who participated in the National Fitness Award Project in 2013 and 2014 was analyzed. The components were cardiorespiratory fitness (20-m PACER), muscle strength (handgrip strength), muscle endurance (partial curl-up, 30-s endurance jump), and flexibility (sit and reach). Age- and sex-specific smoothed percentile curves were calculated for fitness using the LMS method. Results Age- and sex-specific smoothed percentile curves (5th, 10th, 25th, 50th, 75th, 90th, and 95th) were presented for each fitness component. Except for flexibility, fitness levels were higher in boys than in girls. In general, performance in fitness components, except for partial curl-ups, increased with age in boys. However, in girls, performance in fitness components, except for partial curl-ups, slightly increased or remained stable. Conclusion This study presented age- and sex-specific fitness percentile curves for Korean adolescents aged 13–18 years. This material might be useful in understanding and evaluating the fitness status of Korean adolescents.

Relationships among Disability, Quality of Life, and Physical Fitness in Lumbar Spinal Stenosis: An Investigation of Elderly Korean Women

Study Design A cross-sectional, case-control study. Purpose To investigate associations between physical fitness measures and disabilities related to back pain and quality of life (QOL) by the presence of symptomatic lumbar spinal stenosis (LSS) in elderly Korean women. Overview of Literature LSS leads to decreased functioning and reduced QOL. However, correlations among physical fitness, disability, and QOL have not been investigated in elderly women with LSS. Methods Participants included women aged 65 years and older (n=192), divided into a study group (n=38) and a control group (n=154) based on the presence/absence of LSS. All participants underwent physical function and fitness tests. Oswestry disability index (ODI) scores and EuroQol five-dimensional questionnaire (EQ-5D-5L) scores were used to assess disability and health-related QOL. Results The results for the handgrip strength, sit-and-reach, functional reach, and timed up and go (TUG) tests were significantly higher in the control group than the LSS group. ODI scores were significantly higher and EQ-5D-5L scores significantly lower in the LSS group. TUG and functional reach test scores were significantly correlated with ODI scores, and handgrip strength was strongly interrelated with ODI and EQ-5D-5L scores in the LSS group. No other physical fitness measures showed statistically significant relationships with ODI or EQ-5D-5L scores. Conclusions In elderly Korean women with LSS, back pain-related disability and QOL are significantly associated with some physical fitness parameters such as handgrip strength. Handgrip strength reflects general muscle strength, which is significantly interrelated with the level of disability and QOL. Our results suggest that enhancing generalized muscle strength helps to reduce disability due to back pain and improve QOL in patients with LSS.