静态肌力及其影响因素的探讨

目的了解不同人群的部分人体测量学参数及其静态肌力,探讨静态肌力的影响因素。方法选择193名工人、行政人员和大学生作为研究对象,其中男146例、女47例;测量其手握力、臂提举力、肩提举力和腰拉力。结果静态肌力测试结果表明,男性平均左手握力、右手握力、臂提举力、肩提举力和腰拉力分别为(42.07±7.20)、(43.92±7.14)、(26.79±4.64)、(33.79±6.88)、(88.56±17.98)kg,而女性则分别为(21.29±5.09)、(23.26±5.47)、(13.29±3.37)、(18.52±4.01)、(41.06±12.04)kg;女性各种肌力均小于男性,约为男性的50%。年龄比较可见,各种肌力以40~岁组较高。性别和体重与静态肌力存在明显相关。以体重为校正参数,可见各组握力的差异无统计学意义(P<0.05),仅男性工人腰拉力>大学生>行政人员,年龄间比较见相对肌力除腰拉力各年龄组有所不同外,其他肌力各年龄组相似。结论以体重为自变量,可建立肌力预测方程。相对肌力的计算可消除体重等肌力的干扰。     

A new predictive equation for resting energy expenditure in healthy individuals

A predictive equation for resting energy expenditure (REE) was derived from data from 498 healthy subjects, including females (n = 247) and males (n = 251), aged 19-78 y (45 +/- 14 y, mean +/- SD). Normal-weight (n = 264) and obese (n = 234) individuals were studied and REE was measured by indirect calorimetry. Multiple-regression analyses were employed to drive relationships between REE and weight, height, and age for both men and women (R2 = 0.71): REE = 9.99 x weight + 6.25 x height - 4.92 x age + 166 x sex (males, 1; females, 0) - 161. Simplification of this formula and separation by sex did not affect its predictive value: REE (males) = 10 x weight (kg) + 6.25 x height (cm) - 5 x age (y) + 5; REE (females) = 10 x weight (kg) + 6.25 x height (cm) - 5 x age (y) - 161. The inclusion of relative body weight and body-weight distribution did not significantly improve the predictive value of these equations. The Harris-Benedict Equations derived in 1919 overestimated measured REE by 5% (p less than 0.01). Fat-free mass (FFM) was the best single predictor of REE (R2 = 0.64): REE = 19.7 x FFM + 413. Weight also was closely correlated with REE (R2 = 0.56): REE = 15.1 x weight + 371.     

The Subjective Global Assessment reliably identifies malnutrition-related muscle dysfunction

BACKGROUND: Muscle dysfunction is a common finding in malnourished patients and is associated with poor outcome. We investigated whether the Subjective Global Assessment (SGA) is a valuable tool for identifying malnutrition-related muscle dysfunction. METHODS: Two hundred eighty seven consecutive patients were assessed on admission to hospital according to the SGA, anthropometric measurements, and to the results of bioelectrical impedance analysis. The SGA was used as the main criterion for the classification of malnutrition. Muscle function was assessed by handgrip strength. RESULTS: Maximal voluntary handgrip strength was significantly lower in malnourished than in well-nourished male and female patients (45.22 (13.51-67.7)kg versus 30.82(11-48) kg in men; 23.81 (5.60-56.5) kg versus 18.5 (5.90-48.8) kg in women). Handgrip strength tended to decline with age. Handgrip strength was positively correlated to body cell mass (BCM) (r=0.72, P<0.001 in men and: r=0.56, P<0.001 in women) and to body mass index (r=0.271, P=0.03 in men and r=0.183, P=0.02 in women). BCM was identified as a powerful contributor to the variation in handgrip strength (delta r2=0.645, P<0.001). CONCLUSION: The SGA appears to be a reliable bedside assessment tool for malnutrition and malnutrition-related dysfunction. Patients classified malnourished according to the SGA have an impaired functional status. Every effort should be made to provide both nutritional and physical therapy in order to improve the patients' outcome.     

Muscle strength in obese elderly women: effect of recreational physical activity in a cross-sectional study

BACKGROUND: Muscle strength (MS) may be impaired in obese persons, and this impairment may be a consequence of both obesity and low physical fitness. OBJECTIVE: We investigated whether MS differed between obese [body mass index (BMI; in kg/m2 > 29], normal-weight (BMI = 24-29), and lean (BMI < 24) elderly subjects and compared the MS of sedentary and active subjects according to their BMI group. DESIGN: The study included 215 obese [ (+/- SD) age: 80.0 +/- 3.5 y; BMI: 31.9 +/- 2.6], 630 normal-weight (age: 80.2 +/- 3.7 y; BMI: 26.3 +/- 1.4), and 598 lean (age: 80.7 +/- 3.5 y; BMI: 21.6 +/- 1.8) women with good functional ability. A cross-sectional design was used. Anthropometric measures (weight, height); measures of appendicular skeletal muscle mass (by dual-energy X-ray absorptiometry), isometric knee and elbow extension (by statergometer), and isometric handgrip strength (by dynamometer); and data on health status and self-reported recreational physical activity (RPA: walking, gymnastics, cycling, swimming, gardening) were collected. RESULTS: Absolute (unadjusted) MS was higher in obese than in lean women (P < 0.01), except for handgrip strength (P > 0.05). When adjusted for age, height, RPA, pain, depression, and appendicular skeletal muscle mass, MS did not differ significantly between obese, normal-weight, and lean subjects, except for knee extension (significant interaction effect with RPA; P = 0.01). With increasing BMI, lower limb strength did not change in the sedentary women but increased in active (> or = 1 h/wk in > or = 1 RPA for > or = 1 mo) women. All adjusted MS measures in active participants were significantly higher (P < 0.001) than those in their sedentary peers. CONCLUSION: The adjusted MS of elderly women is not associated with obesity but is higher in active subjects than in sedentary ones, especially in the lower limbs of obese subjects.     

Physical activity, protein intake, and appendicular skeletal muscle mass in older men.

BACKGROUND: Aging is associated with physical inactivity, low energy intake, and loss of skeletal muscle mass. It is not clear whether regular physical activity and adequate dietary protein intake can attenuate the loss of skeletal muscle mass. OBJECTIVE: We hypothesized that the maintenance of physical activity and dietary protein intake would attenuate the age-related decline in total appendicular skeletal muscle mass. DESIGN: Total appendicular skeletal muscle mass was determined by dual-energy X-ray absorptiometry in 44 healthy, older white men aged 49-85 y. Physical activity level was determined by using a uniaxial accelerometer over a 9-d period. Dietary protein intake was estimated from a 3-d food record. RESULTS: Aging was inversely associated with total appendicular skeletal muscle mass in older men (r = -0.43; slope: -0. 119 +/- 0.039 kg/y; P < 0.01). An effect of age on appendicular skeletal muscle mass persisted after standing height and physical activity were controlled for (r = -0.34; slope: -0.120 +/- 0.052 kg/y; P = 0.03). Furthermore, an effect of age on appendicular skeletal muscle mass persisted after standing height and dietary protein intake per kilogram body mass was controlled for (r = -0.41; slope: -0.127 +/- 0.045 kg/y; P < 0.01). CONCLUSIONS: Maintaining regular physical activity and adequate protein intake may not offset the age-related loss of appendicular skeletal muscle mass in older men. Prospective studies are needed to confirm these results and to determine whether anabolic physical activity (eg, strength training) can attenuate the age-related loss of muscle mass in the elderly.     

Assessment of body composition by bioelectrical impedance in a population aged greater than 60 y

Body composition was measured in a group of 35 healthy men and 37 healthy women aged 60-83 y. Body mass index (BMI) in men was 25.0 +/- 2.2 kg/m2 (means +/- SD) and in women, 25.9 +/- 3.2 kg/m2. BMI was low in relation to body fat percentage as determined by skinfold-thickness measurements or densitometry in comparison with the relation found in younger adults. Mean body fat percentage of the male subjects (aged 70.4 +/- 5.2 y) as determined by densitometry was 31.0 +/- 4.5%, whereas in women (aged 68.0 +/- 5.2 y) it was 43.9 +/- 4.3%. Body impedance correlated with fat-free mass (FFM). The best prediction formulas for the FFM from body impedance and anthropometric variables were 1) FFM (kg) = (0.671 x 10(4) x H2/R) + 3.1S + 3.9 where H is body height (m), R is resistance (omega), and S is gender (females, 0; males, 1) (r = 0.94; SEE = 3.1 kg) and 2) FFM (kg) = (0.360 x 10(4) x H2/R) + 0.359BW + 4.5S - 20T + 7.0 where BW is body weight (kg) and T is thigh circumference (m) (r = 0.96; SEE = 2.5 kg). The prediction equations from the literature, generally determined in younger populations, overestimated FFM in elderly subjects by approximately 6 kg and are not applicable to elderly subjects.     

A new total body potassium method to estimate total body skeletal muscle mass in children

A whole body skeletal muscle [(SM); kg] mass estimation model, based on total body potassium [(TBK); mmol] measured by whole body (40)K counting (WBC) was developed (SM = 0.0082.TBK) and validated in adults in a previous study. It is unknown whether the adult TBK SM prediction model is applicable for pediatric use. The aim of this study was to derive and validate a pediatric TBK SM prediction equation. SM measured by MRI was used as the criterion and TBK was measured by WBC. The protocol was completed in 116 healthy children, 66 males and 50 females, 11.7 +/- 3.5 y (mean +/- SD, range = 5-17 y). A strong linear correlation was observed between TBK and SM (r = 0.984; P < 0.001). The SM:TBK ratio was 0.0071 +/- 0.0008 kg/mmol in the children studied, much lower than the corresponding value of 0.0082 kg/mmol in adults. An empirical SM prediction equation was developed using TBK alone: SM = 0.0085.TBK - 2.83, r(2) = 0.97, SEE = 1.39 kg. Bland-Altman analysis did not disclose a significant bias in the prediction of SM. When biological factors entered along with TBK in the general linear model, another prediction equation was developed: SM = 5.52 + 0.001.TBK (mmol) + 0.081.weight (kg) - 0.049.height (cm) + 0.00004.TBK . height + race (-0.60 for Caucasian, 0.49 for African-American, and 0 for Hispanic). Because the adult TBK SM prediction model is not applicable for pediatric use, this study provides new empirical TBK SM prediction equations that should prove useful for studies on nutrition, growth, and development in children.     

Elevated plasma fatty acid concentrations prolong cardiac repolarization in healthy subjects

BACKGROUND: High fatty acid concentrations have been shown to stimulate sympathetic nervous system activity, which may modify ventricular repolarization and thus the Q-T interval on electrocardiogram recordings. OBJECTIVE: The aim of this study was to investigate whether acute elevations of plasma fatty acid concentrations influence the corrected Q-T interval (Q-Tc), Q-Tc dispersion, and sympathetic nervous system activity in healthy nonobese subjects. DESIGN: Thirty-two healthy subjects (x +/- SD: 48+/-7 y of age) received an infusion of 10% triacylglycerol emulsion plus heparin (a bolus of 200 U followed by 0.2 U min(-1) * kg body wt(-1) for 180 min); on another occasion and in random order, the same subjects received a saline infusion. RESULTS: Compared with the saline infusion, infusion of 10% triacylglycerol emulsion increased plasma fatty acids (P<0.001) and was associated with an increase in mean blood pressure (P<0.05), heart rate (P<0.05), Q-Tc (P<0.01), Q-Tc dispersion (P<0.01), and plasma epinephrine (P<0.005). Furthermore, individual changes in plasma epinephrine correlated with changes in Q-Tc (r = 0.60, P<0.001) and Q-Tc dispersion (r = 0.53, P< 0.02) even after adjustment for age, sex, and body mass index (P<0.03 for all correlations). Only changes in plasma fatty acids (P = 0.04) and plasma epinephrine (P = 0.006) concentrations were significantly and independently associated with the lengthening of the Q-T interval. CONCLUSION: Our study showed that elevated plasma fatty acid concentrations might affect cardiac repolarization, at least in part because of an increase in plasma catecholamines.     

The association between nutritional status and handgrip strength in older Rwandan refugees

OBJECTIVES: To investigate the association between nutritional status and handgrip strength in older Rwandan refugees. DESIGN: Cross-sectional study. SETTING: Rwandan refugee camp located in Karagwe district in the north-west of Tanzania. The study was carried out in the post-emergency phase. The response rate was 85%. SUBJECTS: A total of 413 men and 415 women aged 50-92 y participated in the study. METHODS: Weight, height, mid-upper-arm circumference (MUAC) and triceps skinfold were obtained using standard techniques. For people with visible kyphosis, height was estimated from armspan using regression equations developed from non-kyphotic subjects within the sample. Handgrip was measured using a mechanical handgrip dynamometer. Information regarding physical activity and health status was obtained by interview and clinical screening. RESULTS: Handgrip strength (kg) was significantly higher in men than in women (30.3+/-6.7 vs 22.3+/-5.1), and significantly lower in each older age group in both sexes. Handgrip strength was positively correlated to BMI (body mass index) and AMA (arm muscle area). The relative risk of impaired handgrip strength in individuals with poor nutritional status (BMI<18.5 kg/m(2)) compared with those of adequate nutritional status was 1.75. After controlling for potential confounders (sex, age and height), BMI remained a significant contributor to the variation in handgrip strength. CONCLUSION: Poor nutritional status is associated with poor handgrip strength independent of sex, age and height, in this refugee population. This may indicate that underweight older people are likely to have more difficulties in functioning independently in the community. Research is needed to investigate if improving nutritional status can lead to better functional ability. SPONSORSHIP: Department for International Development (UK) and HelpAge International.     

Plasma cortisol levels increase with age in obese subjects

In order to assess the influence of age, sex, and body mass on plasma cortisol concentrations, we measured the 24-hour Integrated Concentration (IC) of cortisol (F) in 36 obese subjects (16 males, 20 females) aged 5.3-56.4 years, BMI = 35.5 +/- 7.3 kg/m2 and compared with 119 nonobese subjects, body mass indices (BMI) 21.2 +/- 2.7 kg/m2, aged 8.8-66.2 years (55 males, 64 females). Subjects were nondiabetic, normotensive, without history of psychiatric illness, and otherwise in good health. IC studies were performed using a continuous blood withdrawal methodology, and IC-F was assayed from the 24 hour pooled sample by a protein binding method. The effect of age and gender on IC-F was analyzed by multivariate regression. In the nonobese group there was no effect of age or sex on IC-cortisol levels, the mean IC-F = 173.8 +/- 44.1 nmol/L. A statistically significant but weak negative effect of BMI on IC-cortisol (r=-.18, p<0.05) was present. In the obese subjects there was a significant increase in IC-cortisol levels with age IC-F(nmol/L) = 2.76 x age(years) + 85.0 (r2=.36, p<0.0001). IC-cortisol levels tended to be lower in obese males than females when controlled for age (p<0.05). We conclude that in nonobese subjects IC-F levels are independent of age and gender. However, there is a significant increase of IC-cortisol levels with age in obese individuals. The observed increase of IC-cortisol with age may contribute to metabolic complications of obesity.     

A practical posture for hand grip dynamometry in the clinical setting

BACKGROUND & AIMS: The optimal testing position for hand grip strength, which is a useful functional measure of nutritional status, is open to debate. We therefore examined the systematic difference between different postures in order to establish a methodology that is clinically relevant, easy to perform and reproducible. METHODS: Grip strength was measured in the dominant and non-dominant hands with a strain gauge dynamometer in three positions: lying at 30 degrees in bed with elbows supported, seated in an armchair with elbows supported and in a chair with elbows unsupported. The average of three readings made in each position, each 1 min apart, was recorded. RESULTS: 55 normally nourished subjects (26 male) were studied. Mean (95% CI) grip strengths measured in the dominant hand with the subject in bed, sitting in an armchair and sitting in a chair were 45.7 (42.3-49.2), 46.3 (42.9-49.8) and 48.5 (45.4-51.7) kg, respectively for males. Corresponding values for females were 29.4 (27.0-31.8), 29.3 (26.8-31.9) and 31.6 (28.8-34.3) kg. There was no significant difference (Student t-paired test) between measurements made in bed and on an armchair (P = 0.49), but the measurements made in a chair were significantly higher than those made in bed (P = 0.001) and in an armchair (P = 0.004). No statistical difference was present, comparing the three separate measurements in each position (Student t-paired test). CONCLUSIONS: Measurement of grip strength using hand dynamometry is reproducible and consistent. As all patients are not able to sit in a chair with elbows unsupported, in clinical practice it is more practicable to perform hand dynamometry with the elbows supported in a bed or armchair.     

Validation of a bioelectrical impedance analysis equation to predict appendicular skeletal muscle mass (ASMM)

RATIONALE: Appendicular skeletal muscle mass (ASMM) is useful in the evaluation of nutritional status because it reflects the body muscle protein mass. The purpose of this study was to validate, against dual-energy X-ray absorptiometry (DEXA), a BIA equation to predict ASMM to be used in volunteers and patients. METHOD: Healthy men (n = 246 men, BMI 25.3+/-2.9 kg/m(2)) and women (n =198, 24.1+/-3.6 kg/m(2)), and heart, lung and liver transplant patients (213 men, BMI of 24.6+/-4.4 kg/m(2); 113 women, BMI 23.0+/-5.2 kg/m(2)) were measured by BIA (Xitron Technologies) and DEXA (Hologic QDR 4500). A BIA equation to predict ASMM (kg) that included height(2)/resistance, weight, gender, age and reactance, was developed by means of multiple regressions. [table: see text] Mean difference (Bland-Altman) for volunteers was 0.1+/-1.1 kg, r =0.95, SEE 1.12 kg and for patients -0.4+/-1.5 kg, r =0.91, SEE 1.5 kg.Best fitted multiple regression equation was -4.211 + (0.267 x height2 / resistance) + (0.095 x weight)+(1.909 x sex (men = 1, women = 0)) + (-0.012 x age) + (0.058 x reactance). CONCLUSIONS: BIA permits the prediction of ASMM in healthy volunteers and patients between 22 and 94 years of age. A slightly larger, though clinically not significant, error was noted in patients.     

Malnutrition and impaired muscle strength in patients with Crohn's disease and ulcerative colitis in remission

OBJECTIVE: This prospective, controlled, and multicentric study evaluated nutritional status, body composition, muscle strength, and quality of life in patients with inflammatory bowel disease in clinical remission. In addition, possible effects of gender, malnutrition, inflammation, and previous prednisolone therapy were investigated. METHODS: Nutritional status (subjective global assessment [SGA], body mass index, albumin, trace elements), body composition (bioelectrical impedance analysis, anthropometry), handgrip strength, and quality of life were assessed in 94 patients with Crohn's disease (CD; 61 female and 33 male, Crohn's Disease Activity Index 71 +/- 47), 50 patients with ulcerative colitis (UC; 33 female and 17 male, Ulcerative Colitis Activity Index 3.1 +/- 1.5), and 61 healthy control subjects (41 female and 20 male) from centers in Berlin, Vienna, and Bari. For further analysis of body composition, 47 well-nourished patients with inflammatory bowel disease were pair-matched by body mass index, sex, and age to healthy controls. Data are presented as median (25th-75th percentile). RESULTS: Most patients with inflammatory bowel disease (74%) were well nourished according to the SGA, body mass index, and serum albumin. However, body composition analysis demonstrated a decrease in body cell mass (BCM) in patients with CD (23.1 kg, 20.8-28.7, P = 0.021) and UC (22.6 kg, 21.0-28.0, P = 0.041) compared with controls (25.0 kg, 22.0-32.5). Handgrip strength correlated with BCM (r = 0.703, P = 0.001) and was decreased in patients with CD (32.8 kg, 26.0-41.1, P = 0.005) and UC (31.0 kg, 27.3-37.8, P = 0.001) compared with controls (36.0 kg, 31.0-52.0). The alterations were seen even in patients classified as well nourished. BCM was lower in patients with moderately increased serum C-reactive protein levels compared with patients with normal levels. CONCLUSION: In CD and UC, selected micronutrient deficits and loss of BCM and muscle strength are frequent in remission and cannot be detected by standard malnutrition screening.     

Evaluation of handgrip strength as a nutritional marker and prognostic indicator in peritoneal dialysis patients

BACKGROUND: Serum albumin has limitations as a nutritional marker in patients undergoing peritoneal dialysis (PD) in that it is affected by inflammation, systemic disease, overhydration, and urinary and dialysate protein loss. Handgrip strength is a simple, easily performed bedside test that has been shown to correlate with lean body mass in patients close to inception of dialysis. OBJECTIVE: We evaluated the associations of handgrip strength with other clinical factors and examined its relations with mortality and cardiovascular death in PD patients. DESIGN: We prospectively enrolled 233 chronic PD patients and assessed handgrip strength and other variables at baseline and then followed the patients for a mean (+/-SD) of 30 +/- 14 mo. RESULTS: Baseline handgrip strength was significantly associated with age, sex, height, diabetes, residual glomerular filtration rate (GFR), and hemoglobin but not with C-reactive protein (CRP). After adjustment for age, sex, and height, handgrip strength was most strongly correlated with lean body mass on the basis of creatinine kinetics (r = 0.334, P < 0.001), followed by serum albumin and subjective global assessment. Both men and women who died had lower handgrip strengths than did those who remained alive (P < 0.001). After control for age, sex, diabetes, atherosclerotic vascular disease, GFR, hemoglobin, CRP, and serum albumin, greater handgrip strength was predictive of lower all-cause [hazards ratio (HR): 0.95 (95% CI: 0.92, 0.99); P = 0.005] and cardiovascular [HR: 0.94 (0.90, 0.98); P = 0.004] mortality. CONCLUSIONS: Handgrip strength not only is a marker of body lean muscle mass but also provides important prognostic information independent of other covariates, including CRP and serum albumin. Our data suggest that handgrip strength may be used in conjunction with serum albumin as a nutrition-monitoring tool in patients undergoing PD.     

Gender differences in gastrointestinal disturbances and plasma concentrations of tafenoquine in healthy volunteers after tafenoquine administration for post-exposure vivax malaria prophylaxis

In an open-label sequential cohort study, we compared gastrointestinal (GI) disturbances and plasma tafenoquine concentrations after administration of single-dose (400mg daily x 3 days; n=76 males, 11 females) and split-dose (200 mg twice daily x 3 days; n=73 males, 13 females) tafenoquine regimens in healthy Australian Defence Force volunteers for post-exposure malaria prophylaxis. The female and male volunteers had comparable demographic characteristics (age, weight, height) in the single- and split-dose treatment groups. GI disturbances were generally mild and self-limiting for both groups. The frequency of nausea and abdominal distress was over two-fold higher in females than in males for both treatment groups. Reporting of GI disturbances in the single-dose group differed significantly between males and females, but this gender difference was not seen for the split-dose group. In those volunteers who experienced GI disturbances, the mean plasma tafenoquine concentrations 12 h after the last dose of tafenoquine were approximately 1.3-fold higher in females than in males (means+/-SD: 737+/-118 ng/ml vs. 581+/-113 ng/ml). These preliminary findings suggest that further studies are required in a larger number of females to determine whether there is a need to reduce the dose of tafenoquine to minimise GI disturbances in females.     

学龄前儿童握力发展特点及与体成分的相关性

  目的  了解学龄前儿童握力的发育特点,并探讨握力与身高、体重和体成分指标的相关性。  方法  2020年9—10月,对北京4所幼儿园的900名学龄前儿童进行问卷调查,并进行身高、体重和握力测量,使用生物电阻抗方法检测体成分,采用偏相关、多元线性回归对握力与体成分指标的相关性进行分析。  结果  北京学龄前儿童握力随年龄增长逐渐升高,男童由(5.2±1.7)kg增至(9.3±2.5)kg,女童由(4.3±1.6)kg增至(7.9±2.5)kg(F值分别为57.93,48.77,P值均 < 0.01),男童握力高于女童(t=6.42,P < 0.01),肥胖男童握力高于超重和正常体重男童(F=5.35,P < 0.01)。调整身高、体重、出生体重、母亲文化程度及过去1周家中进食各类食物频率后,男童握力与瘦体重、上肢肌肉量呈正相关,与体脂肪呈负相关(r值分别为0.11,0.09,-0.18,P值均 < 0.05);女童握力与体脂肪呈负相关,与瘦体重呈正相关(r值分别为-0.09,0.09,P值均 < 0.05)。多元线性回归分析发现,年龄、瘦体重和上肢肌肉量对男童的握力影响有统计学意义(F=66.75,P < 0.01);年龄、瘦体重对女童的握力影响有统计学意义(F=150.81,P < 0.01)。  结论  学龄前期男童握力可以反映瘦体重和上肢骨骼肌水平的变化,女童可以反映瘦体重的变化。增加瘦体重可以提高学龄前儿童握力水平。     

Spontaneous activity responses to exercise in males and females

OBJECTIVE: This study examines the impact of a short-term exercise programme, prescribed on the basis of current exercise recommendations, on energy balance in males and females to assess whether this type of exercise induces compensatory changes in spontaneous activity energy expenditure (SAEE) and energy intake (EI). DESIGN: Individuals were monitored for 16 days, 8 days of habitual physical activity (C) and 8 days when exercise was imposed (E). Total energy expenditure (TEE) was calculated from individual relationships of VO2 and VCO2 to heart rate (HR) records of HR and physical activity obtained during waking hours of the C and E periods and basal metabolic rate (BMR) measurements (Deltatrac System, Datex Instrumentation). Changes in nude body mass (BM) were estimated by using a digital scale (Sartorius AG, Gottigen, Germany). SETTING: Laboratory and free-living. SUBJECTS: Eight lean females (body fat: 17.5+/-4.5%) and eight males of similar percentage body fat participated in this study. All subjects were Caucasian and aged between 20 and 25 years. INTERVENTION: During the E period, a supervised exercise session was conducted every second day, each consisting of a total net energy expenditure of 2092 kJ+BMR at 90% lactate threshold. RESULTS: During the E period, TEE was higher than C in males and females (exercise: 95.2+/-13.9, 78.3+/-15.9 MJ; control: 82.4+/-10.4, 68.8+/-16.7 MJ, respectively; P<0.00; P=0.02). SAEE, calculated as TEE minus the energy expended during exercise, was not significantly different between C (males: 82.4+/-4.8 MJ; females: 68.8+/-7.6 MJ) and E (males: 86.8+/-6.3 MJ; females: 70.0+/-7.2 MJ) periods in either gender. Males showed no change in BM over the C (pre-intervention: 83.4+/-7.2 kg; post-intervention: 83.1+/-6.8 kg) or E (pre-intervention: 83.4+/-6.8 kg; post-intervention: 83.4+/-6.8 kg) periods. Females' BM over the C period did not alter (pre-intervention: 63.3+/-2.8 kg; post-intervention 63.7+/-3.1 kg); however, there was a significant decrease (P<0.00) in BM over the E period (pre-intervention: 63.0+/-2.7 kg; post-intervention: 62.4+/-2.7 kg). CONCLUSION: The exercise programme was achieved in males and females without any impact on SAEE. Therefore, differences between genders in relation to BM reduction can be explained by differences in the EI response to exercise.     

学龄儿童握力水平与体成分的相关性研究

目的 研究学龄儿童青少年体成分与握力的相关性,对学龄肥胖儿童干预过程中维持合适的体成分具有重要意义。方法 2018年对北京市15 118名6~16岁学龄儿童进行问卷调查(生活方式、膳食、运动)、生物电阻抗体成分检测和优势手握力检测,并采用偏相关、多元线性回归对握力与体成分指标的相关性进行分析。结果 北京市儿童青少年的握力水平随年龄增长逐渐升高,男童正常体重组握力水平由6~8岁组的(9.7±2.6)kg增长到15~16岁组的(40.0±7.1)kg,女童正常体重组由6~8岁组的(8.9±2.6)kg增长到15~16岁组的(25.0±4.4)kg,与上肢骨骼肌质量指数变化趋势一致;男生高于女生;调整相关因素后,瘦体重质量指数及上肢骨骼肌质量指数与握力水平均呈正相关(男童:r=0.597,0.258;女童:r=0.424,0.102,P<0.05)。结论 握力可反映骨骼肌水平变化趋势。增加瘦体重,减少脂肪可提高握力水平。     

Relationships between structural and functional measures of nutritional status in a normally nourished population

BACKGROUND AND AIMS: Both anthropometric and functional measurements have been used in nutritional assessment and monitoring. Hand dynamometry is a predictor of surgical outcome and peak expiratory flow rate has been used as an index of respiratory muscle function. This study aims to measure in normal subjects the relationship between anthropometric measurements, voluntary muscle strength by hand grip dynamometry and respiratory muscle function by peak expiratory flow rate. METHODS: Ninety-eight subjects (46 male, 52 female) with a mean age of 45.9 years were studied. Hand grip strength was measured in the dominant and non-dominant hands with a portable strain-gauge dynamometer. Peak expiratory flow rate was measured using a mini-Wright peak flow meter. Three readings were taken, each 1 min apart, and the average recorded. Midarm muscle circumference (MAMC) was derived from triceps skin fold thickness and midarm circumference (MAC) using standard anthropometric techniques. Statistical relationships were measured with Pearson's coefficient of correlation. RESULTS: In both sexes there was significant correlation between hand grip strength in the dominant and non-dominant hands and peak expiratory flow rate (P<0.001). In men, there was a positive correlation between MAMC, hand grip strength (P<0.001) and peak expiratory flow rate (P<0.001). In women muscle function correlated with height (P<0.001) but not MAMC (P>0.05). CONCLUSIONS: In normal subjects bedside tests of skeletal and respiratory muscle function correlated with each other in both sexes, and with muscle mass in men but not in women.     

Body composition estimated by bioelectrical impedance in the Swedish elderly. Development of population-based prediction equation and reference values of fat-free mass and body fat for 70- and 75-y olds

OBJECTIVE: To develop a bioelectrical impedance (BIA) prediction equation for fat-free mass (FFM(BIA)) and present reference values of FFM and body fat (BF) for healthy Swedish elderly from population-based representative samples. SUBJECTS: This study is based on 823 (344 males, 479 females) participants from two systematic samples of birth cohorts in G?teborg aged 70 (cohort H70V, 201 males and 299 females) and 75 (cohort NORA75, 143 males and 180 females). METHODS: Body composition was measured with BIA (BIA-101, RJL system, Detroit) in both cohorts and was estimated by a four-compartment (4C) model from total body water (TBW) and total body potassium (TBK) in a sub-sample of the NORA75 cohort. The FFM(BIA) was validated against the FFM from the 4C model (FFM(4C)). RESULTS: The FFM(BIA) correlated well with FFM(4C) (r=0.95, SEE=2.64 kg). The FFM(BIA) (kg) in 70-y-old males and females were 58.5+/-5.4 and 43.4+/-4.4, and for 75-y-old males and females were 56.1+/-4.7 and 42.5+/-4, respectively. The body fat in kg (FM) among 70-y-old males and females were 25.2+/-8.1 and 25.7+/-8.4, and for 75-y-old males and females were 21.7+/-7.1 and 22.8+7.2, respectively. The percent body fat (BF%) among 70-y-old males and females were 29.5+/-5.8 and 36.3+/-6.4, and for 75-y-old males and females were 27.3+/-6 and 34.1+/-6.1, respectively. CONCLUSION: The FFM, FM and BF% from this study might be used as reference values for Swedish elderly aged 70 and 75 y.