Association of physical activity and bone: influence of vitamin D receptor genotype.

PURPOSE: The aim of the study was to investigate the interaction between leisure physical activity and a BsmI polymorphism at the vitamin D receptor (VDR) gene on the modulation of bone mineral density (BMD). METHODS: We studied 575 unrelated healthy postmenopausal women. Lumbar spine and femoral neck BMD were measured by dual-energy x-ray absorptiometry (DXA), and results were expressed as age-and-weight-adjusted (Z-score). VDR BsmI genotype was determined by polymerase reaction chain on peripheral blood leukocytes. RESULTS: Overall, no significant association was found between the level of leisure physical activity or VDR genotypes and adjusted BMD at both bone sites. However, in active women, there was a trend for an association between VDR genotypes and adjusted BMD at the lumbar spine. Active women, who exercised three times or more a week, carrying the "bb" genotype had a lower BMD at the lumbar spine than active women carrying "BB" genotype (ANOVA; P = 0.04). No significant difference in crude or adjusted BMD at both bone sites was found between VDR genotypes in sedentary or moderately active women. Furthermore, classification of women according to the median-age of the sample (63.1 yr) revealed a significant interaction between the level of leisure physical activity and VDR genotype on adjusted lumbar spine BMD in the older active postmenopausal women (N = 137). Older active women carrying the "bb" genotype showed a lower adjusted BMD at the lumbar spine compared with active women carrying the "BB" genotype (P = 0.007). CONCLUSION: These results suggested that gene-environment interactions such as leisure physical activity and VDR genotype may play a role in maintaining the BMD at the lumbar spine in active postmenopausal women, especially in older active women.     

Association of muscular strength with incidence of metabolic syndrome in men

PURPOSE: To examine the association between muscular strength and incidence of metabolic syndrome. METHODS: Participants were 3233 men (20-80 yr) initially free of metabolic syndrome who had two or more clinical examinations between 1980 and 2003, including baseline muscular strength and cardiorespiratory fitness assessment. Metabolic syndrome was defined according to NCEP-ATP III criteria. Muscular strength was quantified by combining body weight-adjusted one-repetition maximal measures for leg and bench presses. Cardiorespiratory fitness was assessed by maximal treadmill test. RESULTS: A total of 480 men developed metabolic syndrome during a mean follow-up period of 6.7 +/- 5.2 yr. In a Cox regression analysis adjusted for age, the hazard ratios (95% confidence intervals) of metabolic syndrome associated with the incremental categories of muscular strength were 1.00 (referent), 0.88 (0.69-1.12), 0.77 (0.60-0.98), and 0.54 (0.42-0.71), respectively (linear trend P < 0.0001). The inverse trend persisted after adjustment for smoking, alcohol intake, number of baseline metabolic syndrome risk factors, family history of diabetes, hypertension, and premature coronary disease (P = 0.004), but was attenuated (P = 0.06) when further adjusted for cardiorespiratory fitness. Compared with the lowest strength category, the highest strength category was associated with 44 and 39% lower risk (P < 0.05 each) of incident metabolic syndrome among normal weight body mass index (BMI < 25) and overweight or obese (BMI > or = 25) men, respectively. An inverse association of incident rates was also seen within stratum of age (20-39 yr, P < 0.001; 40-49 yr, P < 0.01; and 50+ yr, P < 0.05). CONCLUSIONS: Muscular strength was inversely associated with metabolic syndrome incidence, independent of age and body size. Potential benefits of greater muscular strength presumably through resistance exercise training should be considered in primary prevention of metabolic syndrome.     

中国青年女性红细胞压积参考值与地理因素的关系

目的 为制定中国青年女性红细胞压积参考值的统一标准提供科学依据。方法 收集了中国１３３个地区用Ｗｉｎｔｒｏｂｅ法测定的８４８６例健康青年女性红细胞压积参考值，并对其与地理因素的关系进行了研究。结果 发现海拔高度是影响青年女性红细胞压积参考值最主要的因素。随着海拔高度的逐渐增大，青年女性红细胞压积参考值也在逐渐地增大，相关性很显著（ｒ＝０．９０６）。用逐步回归分析的方法推导出相应回归方程Ｙ＾＝４３．     

Effects of one year of resistance training on the relation between muscular strength and bone density in elderly women

OBJECTIVES: There is a paucity of long term studies on exercise training in elderly women. The purpose of this study was to investigate the effects of one year of progressive resistance exercise (PRE) on dynamic muscular strength and the relations to bone mineral density (BMD) in elderly women. METHODS: Forty four healthy sedentary women (mean age 68.8 years) volunteered for this study and were randomly assigned to either an exercise group or a control group. The exercise group were involved in three one hour sessions a week for 52 weeks of supervised PRE to strengthen the large muscle groups of the body, while the control group were instructed to continue their normal lifestyle. The exercise circuit included three sets of eight repetitions at 75% of one repetition maximum focused on the large muscle groups. BMD was measured by dual energy x ray absoptiometry (Lunar DPX) at the lumbar spine and at three sites in the proximal femur. Other selected parameters of physical fitness were also measured. RESULTS: Statistical analyses (analysis of covariance) showed significant strength gains (p < 0.01) in bilateral bench press (> 29%), bilateral leg press (> 19%), and unilateral biceps curl (> 20%). No significant difference between groups was evident in body weight, grip strength, flexibility, waist to hip ratio, or the sum of eight skinfolds. Significant relations (p < 0.05) were recorded between dynamic leg strength and the BMD of the femoral neck, Ward's triangle, and the lumbar spine. CONCLUSIONS: Significant strength changes, after one year of PRE, were evident in elderly women, and the muscle increases may parallel changes in BMD; however, correlation coefficients were moderate.     

Association between isometric muscle strength and gait joint kinetics in adolescents and young adults with cerebral palsy

The purpose of this study was to determine the association between isometric muscle strength of the lower limbs and gait joint kinetics in adolescents and young adults with cerebral palsy (CP). Twenty-five participants (11 males) with bilateral spastic CP, aged 14-22 years (mean: 18.9, sd: 2.0 yr) and Gross Motor Function Classification System (GMFCS) level II (n=19) and III (n=6) were tested. Hand held dynamometry was used to measure isometric strength (expressed in Nm/kg) of the hip, knee, and ankle muscles using standardized testing positions and procedures. 3D gait analysis was performed with a VICON system to calculate joint kinetics in the hip, knee and ankle during gait. Ankle peak moments exceeded by far the levels of isometric strength of the plantar flexors, while the knee and hip peak moments were just at or below maximal isometric strength of knee and hip muscles. Isometric muscle strength showed weak to moderate correlations with peak ankle and hip extension moment and power during walking. Despite considerable muscle weakness, joint moment curves were similar to norm values. Results suggest that passive stretch of the muscle-tendon complex of the triceps surae contributes to the ankle moment during walking and that muscle strength assessment may provide additional information to gait kinetics.     

不同胎龄早产儿维生素D受体基因特点及其与骨矿化水平、25-羟维生素D-3相关性

目的探讨不同胎龄早产儿维生素D受体基因特点及其与骨矿化水平、25-羟维生素D-3[25-(OH)D3]的相关性。方法选取自2015年1月至2017年5月出生的早产儿720例为研究对象,按照胎龄划分为A组(28～32周,n=60)、B组(32～34周,n=160)与C组(34～36周,n=500)。测定并比较各组早产儿血清25-(OH)D3水平及骨定量超声波速度(SOS)值,分析维生素D受体基因特点及其与血清25-(OH)D3水平、骨定量SOS值相关性。结果血清25-(OH)D3水平及骨定量SOS值比较,B组、C组早产儿均高于A组,且C组高于B组,组间比较,差异均有统计学意义(P<0.05)。B组、C组FF、Ff基因型明显低于A组,ff基因型高于A组,且C组FF、Ff基因型明显低于B组,ff基因型高于B组,组间比较,差异有统计学意义(P<0.05)。B组、C组F等位基因频率明显低于A组,f等位基因频率明显高于A组,且C组F等位基因频率明显低于B组,f等位基因频率明显高于B组,组间比较,差异有统计学意义(P<0.05)。Pearson相关分析显示,早产儿维生素D受体基因与血清25-(OH)D3水平、骨定量SOS值呈显著负相关(P<0.05)。结论不同胎龄早产儿维生素D受体基因多态性和血清25-(OH)D3、骨矿化水平密切相关。维生素D受体基因多态性和维生素D缺乏所致的骨代谢疾病具有相关性,F等位基因高的早产儿更具骨代谢疾病的风险。     

NOS3 gene polymorphisms and exercise hemodynamics in postmenopausal women

We tested whether the G894T and T-786C NOS3 polymorphisms were associated with exercise cardiovascular (CV) hemodynamics in sedentary, physically active, and endurance-trained postmenopausal women. CV hemodynamic parameters including heart rate (HR), systolic (SBP) and diastolic (DBP) blood pressures and cardiac output (Q), as determined by acetylene rebreathing, stroke volume (SV), arteriovenous oxygen difference (a-vO2 diff), and total peripheral resistance (TPR) were measured during submaximal (40, 60, 80 %) and maximal (approximately 100 % VO2max) exercise. NOS3 G894T genotype was not significantly associated, either independently or interactively with habitual physical activity (PA) level, with SBP, Q, TPR, or a-vO2 diff during submaximal or maximal exercise. However, NOS3 894T non-carriers had a higher submaximal exercise HR than NOS3 894T allele carriers (120 +/- 2 vs. 112 +/- 2 beats/min, p = 0.007). NOS3 894T allele carriers had a higher SV than 894T non-carriers (78 +/- 2 vs. 72 +/- 2 ml/beat, p = 0.03) during submaximal exercise. NOS3 894T non-carriers also had a higher maximal exercise HR averaged across habitual PA groups than T allele carrier women (165 +/- 2 vs. 158 +/- 2 beats/min, p = 0.04). NOS3 894T allele carriers also tended to have a higher SV during maximal exercise than 894T non-carriers (70 +/- 2 vs. 64 +/- 2 ml/beat, p = 0.08). NOS3 T-786C genotype was not significantly associated, either independently or interactively, with any of the CV hemodynamic measures during submaximal or maximal exercise. These results suggest an association of NOS3 G894T genotype with submaximal and maximal exercise CV hemodynamic responses, especially HR, in postmenopausal women.     

白细胞介素6基因多态性与河南地区汉族人群脓毒症的关系

目的 探讨白细胞介素6(IL-6)基因-572G/C和-174C/G多态性与中国河南地区汉族人群脓毒症的关系.方法 以人群为基础进行脓毒症病例对照研究,应用PCR-RFLP技术对99例脓毒症患者和260例正常对照的IL-6基因-572C/G和-174G/C多态性进行分析.结果 所有病例和对照基因型分布符合Hardy-W...     

No association between ACE I/D polymorphism and cardiovascular hemodynamics during exercise in young women

The ACE I/D polymorphism has been shown to interact with habitual physical activity levels in postmenopausal women to associate with submaximal and with maximal exercise hemodynamics. This investigation was designed to assess the potential relationships between ACE genotype and oxygen consumption (VO2), cardiac output (Q), stroke volume (SV), heart rate (HR), blood pressure (BP), total peripheral resistance (TPR), and arteriovenous oxygen difference ([a-v]O2 diff) during submaximal and maximal exercise in young sedentary and endurance-trained women. Seventy-seven 18-35-yr-old women underwent a maximal exercise test and a number of cardiac output tests on a treadmill using the acetylene rebreathing technique. ACE genotype was not significantly associated with VO2max (II 41.4+/-1.2, ID 39.8+/-0.9, DD 39.8+/-1.1 ml/kg/min, p=ns) or maximal HR (II 191+/-2, ID 191+/-1, DD 193+/-2 bpm, p=ns). In addition, systolic and diastolic BP, (a-v)O2 diff, TPR, SV, and Q during maximal exercise were not significantly associated with ACE genotype. During submaximal exercise, SBP, Q, SV, HR, TPR, and (a-v)O2 diff were not significantly associated with ACE genotype. However, the association between diastolic BP during submaximal exercise and ACE genotype approached significance (p=0.08). In addition, there were no statistically significant interactions between ACE genotype and habitual physical activity (PA) levels for any of the submaximal or the maximal exercise hemodynamic variables. We conclude that the ACE I/D polymorphism was not associated, independently or interacting with habitual PA levels, submaximal, or maximal cardiovascular hemodynamics in young women.     

A correlation between muscular strength and hydroxyproline concentration in human patellar tendon

The connective tissue of the knee is frequently injured by athletes, especially those involved in contact sports. It would be important in the prevention of injury as well as the strategy of physical fitness training to know whether the connective tissue is modified in response to athletic stress or training. The potential modification investigated was variability in the concentration of hydroxyproline, a post-translationally modified imino acid found principally in collagen protein. A correlation was sought between this variability and the leg strength parameters torque (expressed as ft-lbs), torque/body weight and work (expressed as ft-lbs). In a preliminary study of five subjects, no correlation was found between hydroxyproline concentration of the patellar tendon and any of the leg strength parameters. These results suggest that this modification of the collagen in connective tissue does not occur in response to athletic stress or training, but rather, for the small number of subjects investigated, appeared to be relatively constant across a range of leg strengths.     

Comparative muscular strength of men and women: a review of the literature.

The results from nine separate studies reporting comparable static and dynamic muscle strength measurements between men and women have been reviewed. The statistical data from these studies are presented in graphical and tabular form illustrating, when appropriate, the mean +/- 1 S.D., and the mean percentage difference between men and women for the given measurement.     

瘦素受体基因Gln223Arg多态性与多囊卵巢综合征的相关性研究

目的探讨瘦素受体(LEPR)基因的多态性(SNPs)与多囊卵巢综合征(PCOS)疾病易感性和临床内分泌代谢特征的关系。方法检测PCOS患者(PCOS组100例)和排卵正常女性(对照组154例)的生殖激素、人体测量学、糖代谢等指标。采用聚合酶链式反应(PCR)和DNA测序方法,检测PCOS妇女和正常排卵妇女Gln223Arg基因(rs1137100)的基因型分布,分析其与PCOS临床和内分泌代谢特征的关联。结果 PCOS组与对照组的LEPR Gln223Arg的基因型和等位基因分布差异均无统计学意义(P>0.05)。在PCOS患者中,AG和AA基因型患者胰岛素抵抗指数(HOMA-IR)较GG基因型有升高趋势,差异有统计学意义(P<0.05),所以推测LEPR Gln223Arg基因可能导致PCOS患者胰岛素抵抗,从而间接导致PCOS的发生。其他内分泌及糖代谢指标在不同基因型之间的比较差异无统计学意义(P>0.05)。结论 LEPR Gln223Arg基因多态性可能通过调节胰岛素敏感性来影响PCOS患者内分泌代谢,从而诱发PCOS的发生。     

Association between vitamin E and enhanced athletic performance in sled dogs

PURPOSE: To determine the association between prerace plasma vitamin E concentration and performance in sled dogs competing in the 1998 Iditarod Race. METHODS: Prerace blood samples were collected from 670 dogs. Samples were analyzed for plasma vitamin E concentration while controlling for selected hematological and biochemical variables and signalment. Starting in teams of 16, exercise consisted of running up to 1159 miles pulling a laden sled and musher via checkpoints. The records of dogs that were withdrawn from the race for health reasons, fatigue, or strategic or technical reasons, and those of dogs that finished the race were analyzed. Multiple logistic regression and Cox proportional hazards analysis were used to determine factors associated with endurance. Multiple linear regression analysis was used to determine factors associated with team speed. RESULTS: A total of 323 dogs (48%) were withdrawn from racing at various distances from the start. Median time to finish for 39 teams was 11.5 d and the winning time was 9.2 d. Dogs with prerace plasma vitamin E concentrations > 40.7 microg.mL-1 were 1.9 times more likely to finish (P = 0.0006) and had 1.8 times less of a risk of being withdrawn for every mile ran (P = 0.03) than were dogs with plasma vitamin E concentrations between 16.3 and 40.7 microg.mL-1. Neither a team's mean prerace vitamin E concentration, nor the proportion of dogs within a team with high (> 40.7 microg.mL-1) vitamin E concentration was associated with team speed. CONCLUSIONS: Dogs with higher plasma vitamin E concentrations have enhanced endurance compared with dogs with lower plasma vitamin E concentrations, but the plasma vitamin E status of a team is not associated with team speed.     

The effects of water-based strength exercise on quality of life in young women

Background

Exercise improves quality of life (QoL). However, little is known concerning the effects of different volumes of strength exercise on QoL. The aims of this study are to: (1) evaluate the effects of water-based strength exercise on QoL of healthy young women and (2) compare the effects of different volumes of water-based strength exercises on QoL of healthy young women.

Methods

Sixty-six participants were randomly allocated into four groups with different volumes of exercise. The participants performed water-based strength exercises for 20 weeks, two times a week, supervised by trained physiologists.

Results

A significant improvement was found in overall QoL (F = 5.96; p = 0.018) and in physical (F = 22.01; p < 0.001), psychological (F = 8.408; p = 0.006) and environment domains (F = 8.34; p = 0.006). In addition, a significant decrease of depressive symptoms was found (F = 22.32; p < 0.001). No difference was found between groups in any domain of QoL or depressive symptoms.

Conclusion

Water-based strength exercise improves specific domains of QoL and decreases depressive symptoms of young healthy women. Different volumes of exercise promote similar effects on QoL and depressive symptoms.