Nº de abstracts = 22

Modificado em 08 de Dezembro de 2010

The upper extremity of the professional tennis player: muscle volumes, fiber-type distribution and muscle strength

Sanchis-Moysi J, Idoate F, Olmedillas H, Guadalupe-Grau A, Alayón S, Carreras A, Dorado C, Calbet JA.: Scandinavian Journal of Medicine & Science in Sports, 2010, 20(3):524-34. Department of Physical Education, University of Las Palmas de Gran Canaria, Campus Universitario de Tafira s/n, Las Palmas de Gran Canaria, Spain.

The effects of professional tennis participation on dominant and non-dominant upper extremity muscle volumes, and on fiber types of triceps brachii (lateral head) and vastus lateralis muscles were assessed in 15 professional tennis players. Magnetic resonance imaging (MRI, n=8) examination and dual-energy x-ray absorptiometry (DXA, n=7) were used to assess muscle volumes and lean body mass. Muscle fiber-type distribution assessed by biopsy sampling was similar in both triceps brachii (2/3 were type 2 and 1/3 type 1 fibers). The VL was composed of 1/3 of type 2 and 2/3 of type 1 fibers. The dominant had 12-15% higher lean mass (DXA/MRI) than the non-dominant (P<0.05). Type 1, 2a and 2x muscle fibers of the dominant were hypertrophied compared with the non-dominant by 20%, 22% and 34% (all P<0.01), respectively. The deltoid, triceps brachii, arm flexors and forearm superficial flexor muscles of the dominant were hypertrophied (MRI) compared with the non-dominant by 11-15%. These muscles represented a similar fraction of the whole muscle volume in both upper extremities. Dominant muscle volume was correlated with 1RM on the one-arm cable triceps pushdown exercise (r=0.84, P<0.05). Peak power during vertical jump correlated with VL muscle fibers's cross-sectional area (r=0.82-0.95, P<0.05).

Alternatives to rapid weight loss in US wrestling.

Lambert C, Jones B.: International journal of Sports Medicine, 2010, 31(8):523-8. University of Louisville, Health and Sport Sciences, Louisville, United States.

Amateur wrestling at the high school and collegiate level in the United States often involves exercise and thermal dehydration as well as food and fluid restriction to "make weight". Available evidence suggests this is the opposite of what is optimal for high-intensity exercise performance. A high-intensity taper will substantially improve performance when conducted after a period of high-volume high intensity training. Additionally, dehydration of approximately 3-4% of body weight will most definitely impair muscular endurance during high-intensity exercise although it likely will not impair maximal muscular strength or power. Even more gradual weight loss practices over a few days, which result in a reduction of body weight by approximately 3.3 to 6% will result in impaired performance as assessed by wrestling specific tests. It would seem of paramount importance for wrestlers to maintain a high-carbohydrate diet of approximately 8-10 g carbohydrate/kg body weight/day to maintain training intensity and optimize performance during individual matches and tournaments. Thus, the evidence would suggest that, prior to competition, collegiate wrestlers should be: 1) tapered, 2) in the euhydrated state, and 3) have ingested a high carbohydrate diet, rather than undergo rapid weight loss prior to competition.

Effects of one year aerobic endurance training on resting metabolic rate and exercise fat oxidation in previously untrained men and women. Metabolic endurance training adaptations.

Scharhag-Rosenberger F, Meyer T, Walitzek S, Kindermann W.: International journal of sports medicine, 2010-07 31(7):498-504. University of Saarland, Institute of Sports and Preventive Medicine, Saarbrücken, Germany.

Although metabolic training adaptations are considered to be an important aim of recreational endurance exercise, effects of aerobic endurance training on metabolism have hardly been recorded over longer training periods. The aim of the study was therefore to record changes in resting metabolic rate (RMR), substrate oxidation at rest and maximal exercise fat oxidation rate (MFO) after one year of recreational endurance training within the ACSM-recommendations. Seventeen sedentary participants (7 male symbol/10 female symbol, 42+/-5 yr, pre-training characteristics: BMI: 24.6+/-2.2 kg.m (-2), VO(2max): 37.5+/-4.7 ml.min (-1).kg (-1)) completed a 12 months jogging/walking program 3 days/week for 45 min/session at a constant heart rate (HR) prescription of 60% HR-reserve. Resting measurements and maximal incremental treadmill tests were conducted before the training program, after 6 and 12 months of training. Indirect calorimetry was used to assess metabolic parameters. After 12 months of training, body weight remained unchanged ( P=0.16), however, body fat was significantly reduced by 3.4+/-2.1% ( P<0.001). Neither RMR ( P=0.42) nor substrate oxidation at rest ( P=0.25) changed significantly. MFO increased significantly over time by 0.07+/-0.08 g.min (-1) ( P<0.01) and occurred at significantly higher exercise intensities (35+/-6 vs. 44+/-15 vs. 50+/-14%VO(2max), P<0.01). In summary one year of recreational endurance training does therefore not appear to influence RMR or substrate oxidation at rest in previously untrained non-obese participants. In contrast, a constant training stimulus within the ACSM-recommendations elicits sustained improvements in MFO over at least one year of training.

Sport and training influence bone and body composition in women collegiate athletes.

Carbuhn AF, Fernandez TE, Bragg AF, Green JS, Crouse SF.: Journal of strength and conditioning research / National Strength & Conditioning Association, 2010, 24(7):1710-7. Department of Health and Kinesiology, Texas A&M University, College Station, Texas, USA.

This is a novel descriptive study to characterize off-season, preseason, and postseason bone and body composition measures in women collegiate athletes. From 2006 through 2008, 67 women collegiate athletes from 5 sports, softball (n = 17), basketball (n = 10), volleyball (n = 7), swimming (n = 16), and track jumpers and sprinters (n = 17) were scanned using dual energy X-ray absorptiometry (DXA) at 3 seasonal periods: (a) off-season = before preseason training, (b) preseason = after preseason training, and (c) postseason = after competitive season. Dual energy X-ray absorptiometry scans were analyzed for total body mass, lean mass (LM), fat mass (FM), percent body fat (%BF), bone mineral content, bone mineral density (BMD), arm BMD, leg BMD, pelvis BMD, and spine BMD. Data were analyzed between sports using analysis of variance (ANOVA) with Tukey post hoc follow-ups, and within each sport using repeated-measures ANOVA and LSD; alpha < 0.05. Significant off-season to preseason or postseason changes in %BF, LM, and BMD within each sport were as follows, respectively: softball, -7, +4, +1%; basketball, -11, +4, +1%; volleyball, unchanged, unchanged, +2%; swimming, unchanged, +2.5%, unchanged; track jumpers and sprinters, -7, +3.5, +1%. Comparisons among athletes in each sport showed bone measurements of swimmers averaged 4-19% lower than that of athletes in any other sport, whereas for track jumpers and sprinters, %BF and FM averaged 36 and 43% lower compared with other sports at all seasonal periods. Values for athletes playing basketball and volleyball were most similar, whereas softball athletes' values fell between all other athletes. These data serve as sport-specific reference values for comparisons at in-season and off-season training periods among women collegiate athletes in various sports.

Bone status in professional cyclists.

Campion F, Nevill AM, Karlsson MK, Lounana J, Shabani M, Fardellone P, Medelli J.: International journal of SportsMmedicine, 2010-07 31(7):511-5. Clinical and Molecular Osteoporosis Research Unit, Department of Clinical Sciences and Orthopaedic Surgery, Malmö University Hospital, Lund University, Malmö, Sweden.

Professional cycling combines extensive endurance training with non weight-bearing exercise, two factors often associated with lower bone mineral density (BMD). Therefore BMD was measured with dual-energy x-ray absorptiometry in 30 professional road cyclists (mean (SD) age: 29.1 (3.4) years; height: 178.5 (6.7) cm; weight: 71.3 (6.1) kg; %fat mass: 9.7 (3.2)%; VO (2)max: 70.5 (5.5) ml.kg (-1).min (-1)) and in 30 young healthy males used as reference (28.6 (4.5) years; 176.5 (6.3) cm; 73.4 (7.3) kg; 20.7 (5.8)%). Adjusting for differences in age, height, fat mass, lean body mass, and calcium intake by ANCOVA, professional cyclists had similar head BMD (p=0.383) but lower total body (1.135 (0.071) vs. 1.248 (0.104) g.cm (-2); p<0.001), arms (0.903 (0.075) vs. 0.950 (0.085), p=0.028), legs (1.290 (0.112) vs. 1.479 (0.138); p<0.001), spine (0.948 (0.100) vs. 1.117 (0.147) g.cm (-2); p<0.001), pelvis (1.054 (0.084) vs. 1.244 (0.142), p<0.001), lumbar spine (1.046 (0.103) vs. 1.244 (0.167), P<0.001), and femoral neck BMD (0.900 (0.115) vs. 1.093 (0.137), p<0.001) compared to reference subjects. Professional cycling appears to negatively affect BMD in young healthy and highly active males, the femoral neck being the most affected site (-18%) in spite of the elevated muscle contractions inherent to the activity.

Prevalence, magnitude, and methods of rapid weight loss among judo competitors.

Artioli GG, Gualano B, Franchini E, Scagliusi FB, Takesian M, Fuchs M, Lancha AH.: Medicine and Science in Sports and Exercise, 201003 42(3):436-42. Laboratory of Applied Nutrition and Metabolism, School of Physical Education and Sports, University of São Paulo, São Paulo, Brazil.

Purpose: To identify the prevalence, magnitude, and methods of rapid weight loss among judo competitors. Methods: Athletes (607 males and 215 females; age = 19.3 T 5.3 yr, weight = 70 T 7.5 kg, height = 170.6 T 9.8 cm) completed a previously validated questionnaire developed to evaluate rapid weight loss in judo athletes, which provides a score. The higher the score obtained, the more aggressive the weight loss behaviors. Data were analyzed using descriptive statistics and frequency analyses. Mean scores obtained in the questionnaire were used to compare specific groups of athletes using, when appropriate, Mann-Whitney U-test or general linear model one-way ANOVA followed by Tamhane post hoc test. Results: Eighty-six percent of athletes reported that have already lost weight to compete. When heavy weights are excluded, this percentage rises to 89%.Most athletes reported reductions of up to 5% of body weight (mean T SD: 2.5 T 2.3%). The most weight ever lost was 2%-5%, whereas a great part of athletes reported reductions of 5%-10% (mean T SD: 6 T 4%). The number of reductions underwent in a season was 3 T 5. The reductions usually occurred within 7 T 7 d. Athletes began cutting weight at 12.6 T 6.1 yr. No significant differences were found in the score obtained by male versus female athletes as well as by athletes from different weight classes. Elite athletes scored significantly higher in the questionnaire than non elite. Athletes who began cutting weight earlier also scored higher than those who began later. Conclusions : Rapid weight loss is highly prevalent in judo competitors. The level of aggressiveness in weight management behaviors seems to not be influenced by the gender or by the weight class, but it seems to be influenced by competitive level and by the age at which athletes began cutting weight.

Body composition of 161-km ultramarathoners.

Hoffman MD, Lebus DK, Ganong AC, Casazza GA, Van Loan M.: International Journal of Sports Medicine, 201002 31(2):106-9. Department of Veterans Affairs, Northern California Health Care System, and University of California Davis Medical Center, Department of Physical Medicine & Rehabilitation, Sacramento, California 95655-1200, USA.

This study compares body composition characteristics with performance among participants in a 161-km trail ultramarathon. Height, mass, and percent body fat from bioimpedance spectroscopy were measured on 72 starters (17 women, 55 men). Correlation analyses were used to compare body characteristics with finish time, and unpaired t-tests were used to compare characteristics of finishers with non-finishers. Mean (+/-SD) BMI (kg x m(-2)) was 24.8+/-2.7 (range 19.1-32.2) for the men and 21.2+/-2.1 (range 18.1-26.7) for the women. Among the three fastest runners, BMI values ranged from 22.1 to 23.4 for men and 21.5 to 22.9 for women. Mean (+/-SD) percent body fat values for men and women were 17+/-5 (range 5-35) and 21+/-6 (range 10-29) , and ranged from 6 to 14 and 14 to 27 among the fastest three men and women. There was a significant positive correlation (r(2)=0.23; p=0.0025) between percent body fat and finish time for men but not for women, and percent body fat values were lower for finishers than non-finishers for men (p=0.03) and women (p=0.04). We conclude that despite wide variations in BMI and percent body fat among ultramarathon participants, the faster men have lower percent body fat values than the slower men, and finishers have lower percent body fat values than non-finishers.

Anthropometric and fitness characteristics of international, professional and amateur male graduate soccer players from an elite youth academy.

le Gall F, Carling C, Williams M, Reilly T.: Journal of Science and Medicine in Sport / Sports Medicine Australia, 201001 13(1):90-5. Institut National du Football, Centre Technique National Fernand-Sastre, Clairefontaine-en-Yvelines, France.

We compared anthropometric and fitness performance data from graduate male youth players from an elite soccer academy who on leaving the institution were either successful or not in progressing to higher standards of play. Altogether, 161 players were grouped according to whether they achieved international or professional status or remained amateur. Measures were taken across three age categories (under 14, 15 and 16 years of age). Players were assessed using standard measures of anthropometric and fitness characteristics. The skeletal age of players was also measured to determine maturity status. Multivariate analysis (MANCOVA) identified a significant (p<0.001) effect for playing status. Univariate analysis revealed a significant difference in maturity status in amateurs and professionals versus internationals (p<0.05), in body mass in professionals versus amateurs (d=0.56, p<0.05), in height (d=0.85, p<0.01) and maximal anaerobic power (d=0.79, p<0.01) in both professionals and internationals versus amateurs. There was also a significant difference in counter-movement jump (d=0.53, p<0.05) and 40-m sprint time (d=0.50, p<0.05) in internationals versus amateurs, as well as a significant main effect for age and playing position (p<0.001). Significant differences were reported for maturity status, body mass, height, peak concentric torque, maximal anaerobic power, and sprint and jump performance with results dependant on age category and playing position. These results suggest that anthropometric and fitness assessments of elite youth soccer players can play a part in determining their chances of proceeding to higher achievement levels.

Validation of bioelectrical impedance analysis to hydrostatic weighing in male body builders.

Volpe SL, Melanson EL, Kline G:: Acta Diabetologica, 2010, 47(1):55-8 . Division of Biobehavioral and Health Sciences, School of Nursing, University of Pennsylvania, Philadelphia, PA 19104-4217, USA.

The Purpose of this study was to compare bioelectrical impedance analysis (BIA) to hydrostatic weighing (HW) in male weight lifters and body builders. Twenty-two male body builders and weight lifters, 23 +/- 3 years of age (mean +/- SD), were studied to determine the efficacy of BIA to HW in this population. Subjects were measured on two separate occasions, 6 weeks apart, for test-retest reliability Purposes. Participants recorded 3-day dietary intakes and average work-out times and regimens between the two testing periods. Subjects were, on average, 75 +/- 8 kg of body weight and 175 +/- 7 cm tall. Validation results were as follows: constant error for HW-BIA = 0.128 +/- 3.7%, r for HW versus BIA = -0.294. Standard error of the estimate for BIA = 2.32% and the total error for BIA = 3.6%. Percent body fat was 7.8 +/- 1% from BIA and 8.5 +/- 2% from HW (P > 0.05). Subjects consumed 3,217 +/- 1,027 kcals; 1,848 +/- 768 kcals from carbohydrates; 604 +/- 300 kcals from protein; and 783 +/- 369 kcals from fat. Although work-outs differed among one another, within subject training did not vary. These results suggest that measurement of percent body fat in male body builders and weight trainers is equally as accurate using BIA or HW.

Effects of resistance or aerobic exercise training on interleukin-6, C-reactive protein, and body composition.

Donges CE, Duffield R, Drinkwater EJ.: Medicine and Science in Sports and Exercise, 2010, 42(2):304-13. School of Human Movement Studies, Charles Sturt University, Bathurst, Australia.

Purpose: To determine the effects of 10 wk of resistance or aerobic exercise training on interleukin-6 (IL-6) and C-reactive protein (CRP). Further, to determine pretraining and posttraining associations between alterations of IL-6 and CRP and alterations of total body fat mass (TB-FM), intra-abdominal fat mass (IA-FM), and total body lean mass (TB-LM). Methods: A sample of 102 sedentary subjects were assigned to a resistance group (n = 35), an aerobic group (n = 41), or a control group (n = 26). Before and after intervention, subjects were involved in dual-energy x-ray absorptiometry, muscular strength and aerobic fitness, measurements and further provided a resting fasted venous blood sample for measures of IL-6, CRP, cholesterol profile, triglycerides, glucose, insulin, and glycosylated hemoglobin. The resistance and the aerobic groups completed a respective 10-wk supervised and periodized training program, whereas the control group maintained sedentary lifestyle and dietary patterns. Results: Both exercise training programs did not reduce IL-6; however, the resistance and the aerobic groups reduced CRP by 32.8% (P or = -0.24). Compared with the resistance and the control groups, the aerobic group exhibited significant (P < 0.05) improvements in all aerobic fitness measures and significant reductions in IA-FM (7.4%) and body mass (1.1%). Compared with the aerobic and the control groups, the resistance group significantly (P < 0.05) improved TB-FM (3.7%) and upper (46.3%) and lower (56.6%) body strength. Conclusion: Despite no alteration in baseline IL-6 and significantly smaller reductions in measures of adipose tissue as compared with the aerobic training group, only resistance exercise training resulted in significant attenuation of CRP concentration.

Diet, body composition, and bone mass in well-trained cyclists.

Penteado VS, Castro CH, Pinheiro Mde M, Santana M, Bertolino S, de Mello MT, Szejnfeld VL

Journal of Clinical Densitometry, 2010, 13(1):43-50. Rheumatology Division, Universidade Federal de São Paulo-Escola Paulista de Medicina, São Paulo, Brazil.

Cycling is believed to be associated with low bone mass. In this study, we investigate food intake, body composition, and bone mass in well-trained young adult cyclists compared with those in sedentary controls. Four-day estimated diet records were used to study dietary intake in 31 cyclists and 28 sedentary controls (all male, 24yr old on average), together with maximal oxygen uptake (VO(2max)), body composition, and bone mass measurements (dual-energy X-ray absorptiometry). The VO(2max) values were twice as high as those in the cyclists, whereas no significant difference in bone mass was observed between cyclists and controls. A total of 10 cyclists and 9 controls had low bone mass. Total-body lean mass and appendicular skeletal muscle mass were higher in cyclists (p<0.001), whereas percentage of body fat was lower (p<0.001) compared with that of the controls. Energy and macro- and micronutrient intake was higher in the cyclists than in the controls (p<0.01). Energy consumption was considered adequate in the cyclists, whereas lipid and protein intake was higher than the American College of Sports Medicine recommendation. Lipid consumption negatively correlated with bone mass in the athletes. Our results demonstrate that cycling was associated with greater aerobic conditioning and lean mass without significant association with bone mass compared with sedentary controls. PMID: 19942468

Association between fitness and changes in body composition and muscle strength.

Koster A, Visser M, Simonsick EM, Yu B, Allison DB, Newman AB, van Eijk JT, Schwartz AV, Satterfield S, Harris TB.: Journal of the American Geriatrics Society, 2010, 58(2):219-26. Laboratory of Epidemiology, Demography, and Biometry, National Institute on Aging, 7201 Wisconsin Ave, 3C309, Bethesda, MD 20892, USA.

Objectives: To examine the association between physical fitness, assessed according to ability and time to complete a 400-m walk, on changes in body composition and muscle strength over a 7-year period. DESIGN: Prospective observational cohort study. Setting: Memphis, Tennessee, and Pittsburgh, Pennsylvania. Participants: Two thousand nine hundred forty-nine black and white men and women aged 70 to 79 participating in the Health, Aging and Body Composition Study. Measurements: Body composition (fat and bone-free lean mass) was assessed using dual-energy X-ray absorptiometry in Years 1 to 6 and 8. Knee extension strength was measured using isokinetic dynamometry and grip strength using isometric dynamometry in Years 1, 2, 4, 6, and 8. Results: Less fit people weighed more and had a higher total percentage of fat and a lower total percentage of lean mass than very fit men and women at baseline (P<.001). Additionally, the least fit lost significantly more weight, fat mass, and lean mass over time than the very fit (all P<.01). Very fit people had the highest grip strength and knee extensor strength at baseline and follow-up; decline in muscle strength was similar in every fitness group. Conclusion: Low fitness in old age was associated with greater weight loss and loss of lean mass than with high fitness. Despite having lower muscle strength, the rate of decline in the least fit persons was similar to that in the most fit. In clinical practice, a long-distance walk test as a measure of fitness might be useful to identify people at risk for these adverse health outcomes.

The effect of concurrent training on blood lipid profile and anthropometrical characteristics of previously untrained men.

Ghahramanloo E, Midgley AW, Bentley DJ.: Journal of Physical Activity & Health, 2009 6(6):760-6. Health and Exercise Science, University of New South Wales, Sydney, Australia.

Background: There is little information regarding the effects of concurrent training (endurance and resistance training performed in the same overall regimen) on blood lipid profile in sedentary male subjects. This study compared the effects of 3 different 8-wk training programs [endurance training (ET), strength training (ST) and concurrent training (CT)] on blood lipid profile and body composition in untrained young men. Methods: A total of 27 subjects were randomly allocated to an ET, ST or CT group which performed either progressive treadmill (ET), free weight (ST) or both the endurance and strength training requirements for 8 weeks. Results: High-density lipoprotein and low-density lipoprotein profiles significantly improved in the ET and CT groups (P < .01) but not in the ST group. Triglyceride and total cholesterol profiles significantly improved in all 3 training groups. Total fat mass significantly decreased in the ET and CT groups (P < .001) but not in the ST group, whereas fat free mass significantly increased in the ST and CT groups (P < .01) but not in the ET group. Conclusion: These results indicate that CT can be used to simultaneously improve both the serum lipid profile and body composition of previously untrained, apparently health young men.

The effects of resistance training on metabolic health with weight regain.

Warner SO, Linden MA, Liu Y, Harvey BR, Thyfault JP, Whaley-Connell AT, Chockalingam A, Hinton PS, Dellsperger KC, Thomas TR.: Journal of Clinical Hypertension (Greenwich, Conn.), 2010, 12(1):64-72. Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO 65211, USA.

To determine whether resistance training effectively maintains improvements in cardiometabolic syndrome risk factors during weight regain, 9 individuals lost 4% to 6% of their body weight during an 8- to 12-week diet- and aerobic exercise-induced weight loss phase followed by a controlled weight regain phase (8-12 weeks), during which they regained approximately 50% of the lost weight while participating in a supervised resistance training program. Following weight loss (6.0%+/-0.3%), body mass index, body fat percentage, waist circumference, all abdominal adipose tissue depots, total cholesterol, low-density lipoprotein cholesterol, insulin, and homeostasis model assessment (HOMA) were significantly reduced, while quantitative insulin-sensitivity check index (QUICKI) and cardiorespiratory fitness (maximal oxygen consumption) significantly increased. During weight regain (48.3%+/-3.3% of lost weight), body fat percentage, waist circumference, and maximal oxygen consumption were maintained and muscular strength and lean body mass significantly increased. Abdominal adipose tissue depots, insulin, HOMA, and QUICKI did not significantly change after weight regain. Resistance training was effective in maintaining improvements in metabolic health during weight regain.

Abdominal obesity, insulin resistance, and the metabolic syndrome: contribution of physical activity/exercise.

Ross R, Després JP.: Obesity, 2009, 17 Suppl 3:S1-2. School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada.

The metabolic syndrome, a constellation of metabolic abnormalities, which include abdominal obesity, insulin resistance, an atherogenic dyslipidemia, elevated blood pressure, a prothrombotic profile, and inflammation is associated with an increased risk of type 2 diabetes (1), cardiovascular disease (2), and mortality (3). The prevalence of individuals with these clustering abnormalities has been steadily increasing over the past two decades, is now estimated to affect at least a quarter of the US population, and is particularly prevalent among older adults (4). Similarly, abdominal obesity, as crudely estimated by an elevated waist circumference, is the most prevalent manifestation of the metabolic syndrome and affects 36% of men and 52% of women, according to the 1999-2000 US National Health and Nutrition Examination Study (5).

Fat distribution, aerobic fitness, blood lipids, and insulin sensitivity in African-American and European-American women.

Hunter GR, Chandler-Laney PC, Brock DW, Lara-Castro C, Fernandez JR, Gower BA. Obesity (Silver Spring, Md.), 18(2):274-81, 2009.

Department of Nutrition Sciences, University of Alabama at Birmingham, Birmingham, Alabama, USA. 

The purpose of this study was to determine independent relationships of intra-abdominal adipose tissue (IAAT), leg fat, and aerobic fitness with blood lipids and insulin sensitivity (S(i)) in European-American (EA) and African-American (AA) premenopausal women. Ninety-three EA and ninety-four AA with BMI between 27 and 30 kg/m(2) had IAAT by computed tomography, total fat and leg fat by dual-energy X-ray absorptiometry, aerobic fitness by a graded exercise test, African admixture (AFADM) by ancestry informative markers, blood lipids by the Ektachem DT system, and S(i) by glucose tolerance test. Independent of age, aerobic fitness, AFADM, and leg fat, IAAT was positively related to low-density lipoprotein-cholesterol (LDL-C), cholesterol-high-density lipoprotein (HDL) ratio, triglycerides (TGs), and fasting insulin (standardized beta varying 0.16-0.34) and negatively related to HDL-cholesterol (HDL-C) and S(i) (standardized beta -0.15 and -0.25, respectively). In contrast, independent of age, aerobic fitness, AFADM, and IAAT, leg fat was negatively related to total cholesterol, LDL-C, cholesterol-HDL ratio, TGs, and fasting insulin (standardized beta varying -0.15 to -0.21) and positively related to HDL-C and S(i) (standardized beta 0.16 and 0.23). Age was not independently related to worsening of any blood lipid but was related to increased S(i) (standardized beta for S(i) 0.25, insulin -0.31). With the exception of total cholesterol and LDL-C, aerobic fitness was independently related to worsened blood lipid profile and increased S(i) (standardized beta varying 0.17 to -0.21). Maintenance of favorable fat distribution and aerobic fitness may be important strategies for healthy aging, at least in premenopausal EA and AA women.

Development and validation of two equations estimating body composition for overweight and obese postmenopausal women.

Kanellakis S, Kourlaba G, Moschonis G, Vandorou A, Manios Y. Maturitas, 65(1):64-8, 2009.

Department of Dietetics and Nutritional Science, Harokopio University, 17671, Kallithea, El Venizelou 70, Athens, Greece.

Objective: The aim of this study was to develop and validate two equations that best predict body composition of overweight and obese postmenopausal women. Methods: Bioelectrical impedance analyses (BIAs) and anthropometric data such as circumferences and skinfolds were incorporated in the development of these two equations, respectively, while dual energy X-ray absorptiometry (DXA) was used as the reference method. A total number of 196 overweight and obese Greek postmenopausal women were used (131 subjects to develop the equations, and 65 to validate them). Results: The BIA equation was: (FFM)=38.475+0.207xWt-0.092xRz/Ht(2)+0.291xXc/Ht(2) (R(2)=0.800, p<0.0001) and the anthropometry equation was FM=-31.913+0.333xGC+0.840xbody mass index (BMI)+0.064x(biceps+triceps skinfold) (R(2)=0.835, p<0.0001). Both equations were found to result in unbiased estimates. Regarding reliability, BIA equation was found to be more reliable compared to existing ones when applied to this population. Additionally, BIA equation was more reliable compared to the anthropometric equation (+/-3.12642kg vs. +/-5.2342kg limits of agreement, respectively). Conclusion: These conclude that the equations developed in the current study are more reliable than the existing ones in the literature, and could be applied for assessing body composition in clinical practice and research.

Association of long-term change in waist circumference with insulin resistance.

Park K, Lee DH, Erickson DJ, Himes JH, Shikany JM, Jacobs DR. Obesity (Silver Spring, Md.).18(2):370-6, 2009.

Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis, Minnesota, USA.

Recent studies have shown that fat accumulation is associated with insulin resistance; however, the risks associated with long-term changes and fluctuations in central fatness are less clear. This study examined the longitudinal relationship between waist circumference (WC) and insulin resistance using three dimensions of WC: baseline WC, slope of linear changes in WC, and fluctuation of WC around the slope during 20 years of follow-up. Anthropometry, insulin resistance (homeostasis model assessment (HOMA(IR))), and lifestyle factors were obtained in a population-based, prospective observational study (Coronary Artery Risk Development in Young Adults (CARDIA)) during 1985-2006, excluding participants who had been diagnosed with diabetes at any examination. After adjusting for socio-demographic and lifestyle factors, the evolution of HOMA(IR) from CARDIA year 15 to 20 was 6.9% higher per standard deviation of year 0 WC (P trend <0.0001) and 6.3% higher per standard deviation increase in the change in WC over the long term (P trend <0.0001). However, WC fluctuations around the linear change were not associated with insulin resistance or its evolution. The level of HOMA(IR) increased substantially with steeper linear WC slope among initially thinner participants at baseline, whereas this association tended to be weaker in those with higher initial WC (P interaction <0.0001). We conclude that year 0 WC and long-term increment in WC are associated with worsening insulin resistance. However, the association of HOMA(IR) with slope of WC change may vary across the range of initial WC.

Prediction of body composition from spine and hip bone densitometry. Leslie, W. D.: Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada.Journal of clinical densitometry : the official journal of the International Society for Clinical Densitometry, 12(4):428-33, 2009.

Body mass index (BMI) is used to assess overweight and obesity, but it does not account for the distribution or composition of excess weight. Dual-energy X-ray absorptiometry (DXA) is widely used for the assessment of osteoporosis. We hypothesized that measures of regional fat tissue composition from spine and hip DXA done for osteoporosis assessment could be used to estimate body composition more accurately than with BMI. We identified 427 adult patients who underwent DXA evaluation of the lumbar spine, hip, and whole body at the same visit. The population was randomly divided into 2 equal-sized subgroups: one used to derive prediction equations for whole-body fat tissue, whole-body lean tissue, and trunk fat tissue, and the other for independent validation. The estimates were compared with the actual measurements from the whole-body scans. In all analyses, prediction using the regional DXA scans outperformed prediction using BMI or its component variables, height and weight. When the predicted and actual measurements were compared in the validation cohort, regression slopes did not differ significantly from unity and the intercepts did not differ significantly from zero. We conclude that regional DXA scans of the spine and hip can be used to accurately measure body composition. Further research is needed to see whether these measures can in turn predict the metabolic complications associated with overweight and obesity.

Inverse relation between dietary fiber intake and visceral adiposity in overweight Latino youth. Davis, J. N., Alexander, K. E., et al: Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.The American journal of clinical nutrition, 90(5):1160-5, 2009. BACKGROUND: To date, no studies have assessed the longitudinal changes of dietary intake on metabolic risk factors in Latino youth. OBJECTIVE: We assessed the relation between changes in dietary intake, specifically sugar and fiber intakes, with changes in adiposity and risk factors for type 2 diabetes in a longitudinal analysis of overweight Latino youth. DESIGN: Overweight Latino youth (n = 85; aged 11-17 y) underwent the following measures over 2 y [mean (+/-SD) time difference was 1.5 +/- 0.5 y]: dietary intake by 2-d diet recalls, body composition by dual-energy X-ray absorptiometry and magnetic resonance imaging, and glucose and insulin indexes by oral- and intravenous-glucose-tolerance tests. Partial correlations and repeated-measures analysis of covariance assessed the relation between changes in dietary intake with changes in adiposity and glucose and insulin indexes, independent of the following a priori covariates: sex, Tanner stage, time between visits, and baseline dietary and metabolic variables of interest. RESULTS: Increases in total dietary fiber (g/1000 kcal) and insoluble fiber (g/1000 kcal) were associated with decreases in visceral adipose tissue (VAT) (r = -0.29, P = 0.02, and r = -0.27, P = 0.03, for total dietary and insoluble fiber, respectively), independent of baseline covariates and change in subcutaneous abdominal adipose tissue. Participants who had decreased total dietary fiber (mean decrease of 3 g . 1000 kcal(-1) x d(-1)) had significant increases in VAT compared with participants who had increased total dietary fiber (21% compared with -4%; P = 0.02). No other changes in dietary variables were related to changes in adiposity or metabolic variables. CONCLUSION: Small reductions in dietary fiber intake over 1-2 y can have profound effects on increasing visceral adiposity in a high-risk Latino youth population.

Activity energy expenditure and change in body composition in late life. Manini, T. M., Everhart, J. E. et al: University of Florida, Department of Aging and Geriatric Research, Gainesville, FL 32611-0107, USA.The American journal of clinical nutrition, 90(5):1336-42, 2009. BACKGROUND: Change in body composition, specifically loss of fat-free mass and gain in fat mass, in older adults is a major pathway leading to the onset of functional decline and physical disability. OBJECTIVE: The objective was to determine the association of activity-related energy expenditure with change in body mass and composition among older men and women. DESIGN: Total energy expenditure (TEE) was assessed over 2 wk by using the doubly labeled water method in 302 community-dwelling older adults aged 70-82 y. Resting metabolic rate (RMR) was measured by using indirect calorimetry, and the thermic effect of meals was estimated at 10% of TEE. Activity energy expenditure (AEE) was calculated as [TEE(0.9) - RMR]. Total body mass, fat-free mass (FFM), and fat mass (FM) were assessed by dual-energy X-ray absorptiometry annually over a mean (+/-SD) of 4.9 +/- 1.3 y. RESULTS: In multivariate models adjusted for baseline age, smoking status, and race, men and women had a decline (in kg/y) in body mass (men: -0.34, 95% CI: -0.71, 0.02; women: -0.45, 95% CI: -0.71, -0.19) and FFM (men: -0.48, 95% CI: -0.67, -0.29; women: -0.14, 95% CI: -0.026, -0.03). No changes (in kg/y) were observed in FM (men: 0.14, 95% CI: -0.10, 0.38; women: -0.28, 95% CI: -0.49, -0.07). In men and women, higher AEE at baseline was associated with greater FFM. The average change in these outcomes (ie, slope), however, was similar across tertiles of AEE. CONCLUSIONS: These data suggest that accumulated energy expenditure from all physical activities is associated with greater FFM, but the effect does not alter the trajectory of FFM change in late life.

A 5-year cohort study of the effects of high protein intake on lean mass and BMC in elderly postmenopausal women. Meng, X. et al: Curtin Health Innovation Research Institute and School of Public Health, Curtin University of Technology, Perth, Western Australia, Australia.Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research, 24(11):1827-34, 2009. Long-term effects of high dietary protein intake on muscle and bone structure in the elderly are not clear. The aim of this study was to investigate the relationship between baseline protein intake and lean mass and BMC 5 yr later in a cohort of elderly postmenopausal women. A total of 862 community-dwelling women 75 +/- 3 yr of age provided baseline data including nutrient intake assessed by a food frequency questionnaire. At 5 yr, upper arm muscle area (UAMA) and body composition using DXA were measured. Baseline protein intake was 81 +/- 28 g/d (1.2 +/- 0.4 g/kg/d), contributing 19 +/- 3% of total energy intake. There were positive correlations between baseline protein intake and whole body and appendicular bone-free lean mass and BMC (r = 0.14-0.18, p < 0.001) and UAMA (r = 0.08, p < 0.05). Compared with those in the lowest tertile of protein intake (87 g/d) had 5.4-6.0% higher whole body and appendicular lean mass and UAMA and 5.3-6.0% higher whole body and appendicular BMC. These effects remained after adjusting for potential confounders. However, the effect on BMC disappeared after further adjustment for lean mass. This study shows that high protein intake is associated with long-term beneficial effects on muscle mass and size and bone mass in elderly women. The protein effect on bone may be partly mediated by its effects on muscle.