Higher Lean Body Mass Research Articles

Beneficial Effects of GH in Young Adults With Prader-Willi Syndrome: A 2-Year Crossover Trial.

Patients with Prader-Willi syndrome (PWS) are severely at risk to develop morbid obesity, diabetes mellitus type 2, and cardiovascular disease, leading to high mortality. They have an increased fat mass (FM) and decreased lean body mass (LBM). During childhood, GH treatment counteracts the natural course of increasing obesity. Discontinuation of GH treatment at attainment of adult height (AH) might deteriorate their improved clinical condition, whereas continuation might benefit them. To investigate the effects of GH versus placebo on body composition in young adults with PWS who were GH treated for many years during childhood and had attained AH. Two-year, randomized, double-blind, placebo-controlled crossover study with stratification for gender and body mass index in 27 young adults with PWS. PWS Reference Center in The Netherlands. Crossover intervention with GH (0.67 mg/m2 · d) and placebo, both during 1 year. Body composition, measured by dual-energy x-ray absorptiometry. During placebo, FM increased (relative change +21.5%; P < .001). Compared with placebo, GH treatment resulted in lower FM (-2.9 kg; P = .004) and higher LBM (+1.5 kg; P = .005), representing relative changes of -17.3% FM and +3.5% LBM. Both limb and trunk FM percentage were lower during GH versus placebo (relative change +17.3% and +15.6%; P < .001 and P = .007, respectively). No GH-related adverse events occurred. GH-treated young adults with PWS who have attained AH benefit from continuation of GH treatment. FM increases during placebo, whereas GH versus placebo results in lower FM and higher LBM. Thus, GH treatment maintains the improved body composition without safety concerns.

The response of muscle protein synthesis following whole‐body resistance exercise is greater following 40 g than 20 g of ingested whey protein

The currently accepted amount of protein required to achieve maximal stimulation of myofibrillar protein synthesis (MPS) following resistance exercise is 20–25 g. However, the influence of lean body mass (LBM) on the response of MPS to protein ingestion is unclear. Our aim was to assess the influence of LBM, both total and the amount activated during exercise, on the maximal response of MPS to ingestion of 20 or 40 g of whey protein following a bout of whole‐body resistance exercise. Resistance‐trained males were assigned to a group with lower LBM (≤65 kg; LLBM n = 15) or higher LBM (≥70 kg; HLBM n = 15) and participated in two trials in random order. MPS was measured with the infusion of 13C6‐phenylalanine tracer and collection of muscle biopsies following ingestion of either 20 or 40 g protein during recovery from a single bout of whole‐body resistance exercise. A similar response of MPS during exercise recovery was observed between LBM groups following protein ingestion (20 g – LLBM: 0.048 ± 0.018%·h−1; HLBM: 0.051 ± 0.014%·h−1; 40 g – LLBM: 0.059 ± 0.021%·h−1; HLBM: 0.059 ± 0.012%·h−1). Overall (groups combined), MPS was stimulated to a greater extent following ingestion of 40 g (0.059 ± 0.020%·h−1) compared with 20 g (0.049 ± 0.020%·h−1; P = 0.005) of protein. Our data indicate that ingestion of 40 g whey protein following whole‐body resistance exercise stimulates a greater MPS response than 20 g in young resistance‐trained men. However, with the current doses, the total amount of LBM does not seem to influence the response.

Effect of body composition, aerobic performance and physical activity on exercise-induced oxidative stress in healthy subjects.

Oxidative stress could be the result of an increase in ATP resynthesis during exercise. The aim of the study was to compare prooxidant-antioxidant balance (PAB) disturbances induced by exercise at maximal intensity in young men with differing body compositions. Thirty-nine subjects were selected from 1549 volunteers aged 18-30, based on lean body mass (LBM) and body fat percentage (%BF), and then assigned into one of the following groups: control group (CON), including subjects with average LBM (59.0-64.3 kg) and average %BF (14.0-18.5%); high body fat (HBF) group, including subjects with high %BF (>21.5%) and average LBM; and high lean body mass (HLBM) group, including subjects with high LBM (>66.3 kg) and average %BF. Participants' physical activity was determined. A running test with a gradually increased load was used. Before and 3 minutes after exercise, total oxidative status (TOS) and total antioxidant capacity (TAC) were determined in the plasma, and the Oxidative Stress Index (OSI = TOS/TAC) was calculated. Maximal oxygen uptake (VO2max) was comparable in the HBF and HLBM groups (53.12±1.51 mL/kg and 50.25±1.27 mL/kg, respectively) and significantly lower compared to the CON group (58.23±1.62 mL/kg). The CON, HBF and HLBM groups showed similar significant (P<0.05) increases in TOS levels (36%, 35% and 31%, respectively). Post-exercise TAC increased by 8% in the HBF and HLBM groups (P<0.05), compared to the 3% increase in the CON group (P>0.05). There was significant negative correlation between OSI, measured before and after exercise, and participants' physical activity. There was no correlation between OSI and VO2max, BM, LBM, %BF and BMI. Exercise at maximal intensity causes a similar increase in TOS and in TAC in subjects with increased %BF and elevated content of LBM and regardless of body composition, the ratios of TOS/TAC concentrations before and after maximal-intensity exercise, have lower values in people with higher physical activity levels and are not dependent on aerobic performance (VO2max).

Exercise‐induced muscle damage in healthy men with low choline intake

Both very low choline intake and intense exercise in healthy men can trigger peak muscle soreness a few days later and a rise of creatine kinase (CK) activity in peripheral blood indicating muscle damage.We wanted to know whether men susceptible to exercise‐induced muscle damage have lower dietary choline intake than men with more robust muscles and whether their heightened muscle fragility is associated with low lean body mass.We investigated in 58 healthy Caucasian men the increase of CK activity three days after 12 eccentric elbow flexors (Biodex 4, Biodex Medical Systems Inc., Shirley, NY) with the non‐dominant arm. This single bout of exercise took little more than one minute to complete. The dynamometer tracked the patient's torque and provided instant feedback throughout the exercises. The same measurements and exercises were done on the non‐dominant arm at the initial visit and three days later. Participants indicated on an analog scale after each exercise test the level of discomfort or pain they had experienced. A whole body dual energy x‐ray absorptiometry scan (Lunar iDXA, GE Healthcare) was used for the assessment of body composition and to estimate total and regional lean body masses. A trained dietitian supervised the automated 24‐hour diet recall assessments on days 1 and 4 for each subject with the ASA24 online system, demonstrated food models for improved accuracy of portion sizes, confirmed reported food items and probed for missing food items prior to submission, and asked additional quality control questions to promote comprehensive reporting. The recall on day 2 was reviewed and discussed with the participant over the phone.The study was registered at Clinicaltrials.gov (NCT01722448).The median change of CK activity three days after the initial bout of exercise was +49 U/L (+36%). We classified a significant minority (9 of 58) of the investigated men as high responders (HR) because they had exceptionally high CK activity after the exercise (between 4 and 27 times of the upper reference limit). At the other end of the spectrum were men (19 of 58) with no increase of CK activity (non‐responders, NR); their median change of CK activity was −22 U/L (−20%).The single bout of eccentric arm flexor exercise greatly reduced arm strength in HR when assessed three days later, but changed strength very little in NR. Average power in HR was 32% lower than initially (p&lt;0.0005), while NR had an average decrease of 7%. The difference in response between the two groups was statistically highly significant (p&lt;0.00001). Lean body mass was 10% lower in HR than in NR (17.1 vs. 19.1 kg/m2, p&lt;0.04).More HR reported low choline intake (less than an average of 330 mg/day or 60% of adequate intake, AI) than NR (7 of 9 vs. 6 of 19, p&lt;0.05). Men with higher choline intake also tended to have less muscle soreness (r = −0.261, p&lt;0.05), better muscle performance after exercise (r = 0.310, p&lt;0.02), and higher lean body mass (r = 0.383, p&lt;0.005).These findings support our initial hypothesis that men susceptible to exercise‐induced muscle damage are more likely to have low choline intake than men with more resilient muscles. Increased vulnerability to intense exercise may discourage HR men to engage in physical activities and limit their ability to build up and maintain high muscle mass.Support or Funding InformationSupported by a grant from the UNC Nutrition Research Institute

Lean Body Mass and Survival in Hemodialysis Patients and the Roles of Race and Ethnicity

Lean body mass (LBM) represents the "fat-free" muscle mass in hemodialysis (HD) patients and is an important nutritional measure. Previous studies have found that both higher LBM and body mass index (BMI) were related to greater survival in HD patients. Additional studies have shown differences in survival across racial-ethnic groups of HD patients. However, the association of LBM and mortality across racial-ethnic subgroups has not been examined. We hypothesize that racial differences in LBM affect the mortality in HD patients. Chronic HD patients from a large dialysis organization in the United States. Estimated LBM (eLBM), self-identified racial subgroups. 5-year survival. We examined the association between baseline eLBM and survival using Cox proportional hazard models adjusted for demographics, comorbidities, and laboratory measures. Associations were examined across subgroups of race-ethnicity (non-Hispanic white, African American, and Hispanic) and BMI. The final cohort included 117,683 HD patients, who were 62±15 (mean±standard deviation) years old, 43% women and 59% with diabetes mellitus. Higher eLBM was linearly associated with lower mortality. Compared with the reference group (48.4-<50.5kg), patients with the lowest eLBM (<41.3kg) had a 1.4-fold higher risk of mortality (hazard ratio: 1.37; 95% confidence interval: 1.30-1.44) in the fully adjusted model. A similar linear association was seen among patients with BMI < 35kg/m(2) and in non-Hispanic whites and African American subgroups. However, higher eLBM was not associated with improved survival in Hispanic patients or patients with BMI ≥ 35kg/m(2). Potential residual confounding. Higher eLBM is associated with a lower mortality risk in HD patients, especially among non-Hispanic white and African American groups. Hispanic patients do not demonstrate a similar inverse relationship. The association between LBM and mortality among different racial groups of HD patients deserves additional study.

Early Protein Intake Is Associated with Body Composition and Resting Energy Expenditure in Young Adults Born with Very Low Birth Weight1–3

Background: Suboptimal nutrition during fetal life and early childhood may be important in early programming of health and disease. Preterm infants born with very low birth weight (VLBW; <1500 g) frequently receive inadequate neonatal nutrition; the long-term consequences are poorly known.Objective: We evaluated the association between early macronutrient intake and body composition in young adults born with VLBW.Methods: We collected comprehensive information on daily nutritional intake during the initial hospital stay for 127 participants of the Helsinki Study of Very Low Birth Weight Adults. We calculated mean daily intakes of energy, protein, fat, and carbohydrate during the first 9 wk of life. At the mean age of 22.5 y, the subjects underwent measurements of weight, height, body composition by dual-energy X-ray absorptiometry, and resting energy expenditure. The associations were examined by linear regression.Results: We found that energy, protein, and fat intakes during the first 3 wk of life, all below current recommendations, predicted adult body composition. When adjusted for sex, age, birth weight SD score, and gestational age, a 1 g · kg−1 · d−1 higher protein intake predicted 11.1% higher lean body mass (LBM) (95% CI: 3.7%, 18.9%) and 8.5% higher resting energy expenditure (REE) (95% CI: 0.2%, 17.0%). Among those born before 28 wk of gestation, the numbers were 22.5% (95% CI: 1.9%, 47.4%) for LBM and 22.1% (95% CI: 3.6%, 44.0%) for REE. Similar associations were seen with energy (P = 0.01, P = 0.05) and fat (P < 0.01, P = 0.03) but not with carbohydrate. Energy intake was also associated with BMI (P = 0.01) and fat intake with BMI (P < 0.01) and percentage body fat (P = 0.05). The results were little changed when adjusted for prenatal and postnatal characteristics.Conclusions: At relatively low neonatal protein intake levels, additional protein intake is reflected in a healthier body composition, accompanied by a higher metabolic rate, in young adults born with VLBW 20 y earlier.

Citrulline Supplementation Induces Changes in Body Composition and Limits Age-Related Metabolic Changes in Healthy Male Rats1–3

Background: Aging is associated with profound metabolic disturbances, and citrulline may be of use to limit them.Objective: The aim of this work was to evaluate the long-term effect of citrulline supplementation on metabolism in healthy aged rats.Methods: Twenty-month-old male rats were randomly assigned to be fed (ad libitum) for 12 wk with either a citrulline-enriched diet (1 g⋅kg−1⋅ d−1) or a standard diet [rendered isonitrogenous by addition of nonessential amino acids (NEAAs)]. Motor activity and muscle strength were measured, body composition was assessed, and muscle metabolism (protein structure, mitochondrial exploration, and transductional factors) and lipid metabolism (lipoprotein composition and sensitivity to oxidative stress) were explored.Results: Compared with the NEAA-treated group, citrulline supplementation was associated with lower mortality (0% vs. 20%; P = 0.05), 9% higher lean body mass (P < 0.05), and 13% lower fat mass (P < 0.05). Compared with the NEAA-treated group, citrulline-treated rats had greater muscle mass (+14–48% depending on type of muscle; P < 0.05 for tibialis, gastrocnemius, and plantaris). Susceptibility to oxidation of lipoproteins, as measured by the maximal concentration of 7-ketocholesterol after copper-induced VLDL and LDL oxidation, was lower in citrulline-treated rats than in NEAA-treated rats (187 ± 8 μmol/L vs. 243 ± 7 μmol/L; P = 0.0005).Conclusions: Citrulline treatment in male aged rats favorably modulates body composition and protects against lipid oxidation and, thus, emerges as an interesting candidate to help prevent the aging process.

Energy intake and expenditure assessed ‘in-season’ in an elite European rugby union squad

Rugby union (RU) is a complex high-intensity intermittent collision sport with emphasis placed on players possessing high lean body mass and low body fat. After an 8 to 12-week pre-season focused on physiological adaptations, emphasis shifts towards competitive performance. However, there are no objective data on the physiological demands or energy intake (EI) and energy expenditure (EE) for elite players during this period. Accordingly, in-season training load using global positioning system and session rating of perceived exertion (sRPE), alongside six-day assessments of EE and EI were measured in 44 elite RU players. Mean weekly distance covered was 7827 ± 954 m and 9572 ± 1233 m with a total mean weekly sRPE of 1776 ± 355 and 1523 ± 434 AU for forwards and backs, respectively. Mean weekly EI was 16.6 ± 1.5 and 14.2 ± 1.2 megajoules (MJ) and EE was 15.9 ± 0.5 and 14 ± 0.5 MJ. Mean carbohydrate (CHO) intake was 3.5 ± 0.8 and 3.4 ± 0.7 g.kg−1 body mass, protein intake was 2.7 ± 0.3 and 2.7 ± 0.5 g.kg−1 body mass, and fat intake was 1.4 ± 0.2 and 1.4 ± 0.3 g.kg−1 body mass. All players who completed the food diary self-selected a ‘low’ CHO ‘high’ protein diet during the early part of the week, with CHO intake increasing in the days leading up to a match, resulting in the mean EI matching EE. Based on EE and training load data, the EI and composition seems appropriate, although further research is required to evaluate if this diet is optimal for match day performance

Variation in C-reactive protein following weight loss in obese insulin resistant postmenopausal women: is there an independent contribution of lean body mass?

We showed that obese insulin resistant postmenopausal women are characterized by higher lean body mass and elevated C-reactive protein. Although counterintuitive, we hypothesized that losses in muscle mass following caloric restriction and increase in muscle quality will be associated with improvements in glucose homeostasis through decreases in C-reactive protein. To determine 1) if improvements in C-reactive protein concentrations occurs through losses in lean body mass; and 2) if decreases in C-reactive protein levels contribute to improvements in insulin sensitivity. 50 postmenopausal women (body mass index>26 kg/m(²)) with impaired glucose disposal (<7.5 mg/kg/min) completed a 6-month caloric restriction program. Outcome measures were: Glucose disposal rate: M value (by hyperinsulinemic-euglycemic clamp), body composition (total, trunk, and appendicluar). LBM and FM by DXA), LBM index (LBM (kg)/height (m(2)), body fat distribution (VAT and SAT by CT scan) and plasma high-sensitive C-reactive protein (hsCRP) and interleukin-6 (Il-6). Significant correlations were observed between Δ hsCRP levels with Δ Il-6 (r=0.33, p≤0.05), Δ total LBM index (r=0.44, p≤0.01), Δ trunk LBM (r=0.38, p≤0.01) Δ SAT (r=0.35, p≤0.05) and ∆ glucose disposal rate (r=- 0.44, p≤0.01). After including all the correlated variables in Stepwise linear regression model, Δ LBM index was the only independent predictor of the reduction in hsCRP levels (R(2)=0.20, p≤0.01). Losses in total lean body mass are independently associated with improvements in inflammatory state (CRP levels) in obese postmenopausal women with impaired glucose disposal.

Quantification of training load, energy intake, and physiological adaptations during a rugby preseason: a case study from an elite European rugby union squad.

Rugby Union (RU) is a high-speed collision sport consisting of an intermittent activity profile. Given the extreme physical demands of the sport, significant emphasis is placed on players possessing high lean body mass while minimizing body fat. Anecdotally, the most significant changes in body composition are observed during the preseason; however, there are no objective data on the physiological demands and energy intake during this time. We therefore monitored 45 elite European RU players over the 10-week preseason period by assessing training load using Global Positioning System and session rate of perceived exertion (sRPE) while also assessing changes in anthropometry and physical performance. For forwards and backs, respectively, mean weekly distance covered was 9,774 m (1,404) and 11,585 m (1,810) with a total mean weekly sRPE of 3,398 (335) arbitrary units and 2,944 (410) arbitrary units. Mean daily energy intake was 14.8 MJ (1.9) and 13.3 MJ (1.9), carbohydrate (CHO) intake was 3.3 (0.7) and 4.14 (0.4) g·kg body mass, protein intake was 2.52 (0.3) and 2.59 (0.6) g·kg body mass, and fat intake was 1.0 (0.3) and 0.95 (0.3) g·kg body mass for forwards and backs, respectively. Markers of physical performance (1 repetition maximum strength, speed, and repeated sprint tests) and anthropometry (body fat and estimated lean mass) improved in all players. Interestingly, all players self-selected a "low" CHO "high" protein diet. Based on physiological improvements the training load and energy intake seems appropriate, although further research is required to evaluate if such energy intakes would also be suitable for match day performance.

Influence of increased body mass and body composition on cycling anaerobic power.

Recent evidence suggests that not only body fat (BF) but high lean body mass (HLBM) adversely affects aerobic performance and may reduce aerobic endurance performance as well. However, the influence of body composition on anaerobic performance remains controversial. This study aimed to examine the effects of increased body mass (BM) and body composition on cycling anaerobic power. Peak power (PP) and mean power (MP) measurements were conducted in 2 groups of men with similar total BM but different body compositions resulting from (a) high level of BF [HBF group] or (b) high level of lean body mass [HLBM group] and in a control group. Peak power and MP were calculated in absolute values, relative to BM and lean body mass (LBM), and using allometric scaling. Absolute PP and MP were significantly higher in the HLBM group compared with the control and HBF groups. However, PP and MP relative to BM and using allometric scaling were similar in the HLBM and control groups, yet significantly higher than in the HBF group. There were no significant differences between groups in PP and MP when presented relative to LBM. Therefore, it seems that it is not BM but rather body composition that affects PP. Increased BM, resulting from increased LBM, does not adversely affect cycling anaerobic power, but a BM increase resulting from an increase in BF may adversely affect PP. Therefore, coaches and athletes should avoid excess BF to maximize cycling anaerobic power.

Clinical determinants of reduced physical activity in hemodialysis and peritoneal dialysis patients.

The phenotype associated to reduced physical activity (PA) in dialysis patients is poorly documented. We here evaluate weekly PA in two independent cohorts. Cross-sectional study with PA assessed by the number of steps/day measured by pedometer in two cohorts of prevalent dialysis patients: (1) peritoneal dialysis (PD) patients (n = 64; 62 ± 14 years; 70 % men) from Stockholm, Sweden using the pedometer for 7 consecutive days; (2) hemodialysis (HD) patients (n = 78; 63 ± 12 years; 65% men) from a single center in Madrid, Spain using the pedometer for 6 consecutive days: 2 HD days, 2 non-HD midweek days and 2 non-HD weekend days. In both cohorts, comorbidities, body composition, nutritional status, and related biomarkers were assessed. Cohorts were not merged; instead data were analyzed separately serving as reciprocal replication analyses. Most patients (63% of PD and 71% of HD) were considered sedentary (<5,000 steps/day). PD patients had on average 4,839 ± 3,313 steps/day. HD patients had 3,767 ± 3,370 steps/day on HD-free days, but fewer steps/day on HD days (2,274 ± 2,048 steps/day; p < 0.0001). In both cohorts, and across increasing PA tertiles, patients were younger and had less comorbidities. Higher PA was also accompanied by better nutritional status (depicted by albumin, pre-albumin, creatinine and normalized protein catabolic rate in HD, and by albumin and subjective global assessment [SGA] in PD), higher lean body mass, and lower fat body mass (bioimpedance and/or dual-energy X-ray absorptiometry [DEXA]). Higher levels of PA were accompanied by lower levels of C-reactive protein in PD. Age and lean body mass were the strongest multivariate predictors of PA in both cohorts. There is a high prevalence of sedentary behavior in dialysis patients. Better physical activity was consistently associated with younger age, lower presence of comorbidities and better nutritional status. Pedometers represent a simple and inexpensive tool to objectively evaluate physical activity in this patient population.

Sports anthropological and somatotypical investigation of female handball players of different performance classes

The present study examines anthropometric and somatotypical differences between female handball players of the first and the second national league (n = 24, the age range 16–31 years) on the one side and female handball players of the district league (n = 24, age range 18–48 years) on the other side. Anthropometric data and computed constitutional and somatotypical parameters correspond to international standards.For the body height there is a highly significant difference in both leagues, as well as for the arm span in favor of higher performance classes. Finally, the arm length determines essential leverage ratios and throwing power and hence the performance in handball. Also for most of the rest of the height parameters the national leagues are dominating the district leagues.Within the study cohort, the goalkeepers are the largest, followed by the backcourt.The national league handball players have the expected smaller percentage of body fat and a higher lean body mass than the district players. The body weight of the female national league players surpasses the body mass of the district players by 3.6 kg. In the chess-board pattern graphic after CONRAD the players of the national leagues are more hyperplastic.The average somatotypes after PARNELL (1958) for the female handball players of the national leagues are 4-3-3 and for the district league 5-3-2. The corresponding somatotypes after HEATH and CARTER are 4.3-3.5-1.8 and 4.9-3.9-1.8.

Lean mass in obese adult subjects correlates with higher levels of vitamin D, insulin sensitivity and lower inflammation.

Several chronic metabolic alterations are present in obese subjects. While it is well known about the detrimental effect of abdominal adipose tissue on chronic metabolic clinical condition, less is known on the role of lean mass in obese subjects. Thus, the aim of our study was to evaluate the potential correlation of muscle mass, metabolic condition and inflammation status in obese individuals. The study included 426 obese subjects (86 men and 340 female; mean age 44.8 ± 14 years; BMI: 34.9 ± 6.1 kg/m(2)). Exclusion criteria were chronic medical conditions or use of medications affecting bone metabolism, alterations of hormonal and nutritional status, vitamin D supplementation, recent weight loss and prior bariatric surgery. Patients underwent measurements of bone mineral density (lumbar and hip) and body composition (lean mass, total and trunk fat mass) by dual X-ray absorptiometry and were evaluated for hormonal and metabolic profile and inflammatory markers. Higher lean body mass (LM%) was inversely correlated with homeostasis model assessment of insulin resistance (p < 0.0091; r(2) 0.03938) and associated with lower fibrinogen levels (p < 0.0001; r(2) 0.1263). Interestingly, in obese subjects, LM% was associated with higher levels of vitamin D (p < 0.0001, r(2) 0.1140), osteocalcin (p < 0.0001, r(2) 0.2401) and insulin-like growth factor-1 (IGF-1) (p < 0.0002, r(2) 0.1367). Our results show for the first time that in obese patients, higher amounts of lean mass are directly linked to a lower inflammatory profile and to better insulin sensitivity, but also to the presence of higher level of vitamin D and IGF-1. Moreover, these data suggest that higher levels of lean mass in obese people correlate with a better metabolic profile and, thus, strongly suggest the need to develop programs to facilitate an increase in physical activity in obese people.

Differences in strength, flexibility and stability in freestyle and Greco-Roman wrestlers

Wrestling includes a variety of functional properties: muscular strength, flexibility, neuromuscular coordination, and static and dynamic balance. The aim of the study was to identify differences in the strength, flexibility, postural stability and core stabilization of young national and international wrestlers in different weight groups. Eighty-one male wrestlers (17-21 years old) were divided into 6 groups according to their body mass (light, middle and heavy) and wrestling style. The lumbosacral flexion, extension and lateral flexion range of motion, hamstring extensibility, back and leg muscle strength, postural stability, and core stabilization were assessed. Greco-Roman wrestlers had a higher lean body mass (6-12%) compared with freestyle wrestlers. However, the trunk lateral flexion flexibility was better in the Greco-Roman wrestlers (6-7%) than in the freestyle wrestlers, and the absolute back strength (BS) and leg strength (LS) were similar for both styles of wrestling. The BS/LBM and LS/LBM in the freestyle wrestlers were greater than in the Greco-Roman wrestlers, and the Light weight Greco-Roman wrestlers had the highest BS/LBM. The heavy weight Greco-Roman wrestlers and the light weight freestyle wrestlers had the greatest LS/LBM values. The postural control was similar for the two styles of wrestlers; however, the heavy weight Greco-Roman wrestlers had greater postural control in all directions compared with the light and middle weight Greco-Roman wrestlers. The core stabilization did not differ for the Greco-Roman and freestyle wrestlers except in the lateral bridge. The style of wrestling demonstrates different strength, flexibility and stability demands on the body. The differences between Greco-Roman and freestyle wrestlers may be due to the wrestling style differences in training and to competition-related demands. Comparative study, level lV (case series).

Adiposity measures, lean body mass, physical activity and mortality: NHANES 1999-2004.

BackgroundObesity and physical inactivity are major public health problems. We studied the associations between measures of adiposity, lean body mass, leisure time physical activity (LTPA), and death in those with and without chronic kidney disease (CKD).MethodsAssociations between body mass index (BMI), waist circumference (WC), percent body fat, lean body mass (assessed with Dual-Energy X-ray Absorptiometry[DEXA]), leisure time physical activity (LTPA) and death were examined using the National Health and Nutrition Examination Surveys (NHANES 1999–2004). All-cause mortality was ascertained by linkage of NHANES files with the National Death Index.Results9,433 non-CKD participants and 2,153 CKD participants who had fat mass measured using DEXA, BMI, WC, LTPA and mortality data were included. After adjusting for demographics, comorbid conditions, kidney function measures, C-Reactive Protein (CRP), and sodium intake there was no significant risk for death noted with higher WC, fat mass and BMI in those with and without CKD. When examining normal, overweight, and obese groups based on BMI criteria, being overweight (BMI 25–29.9 kg/m2) was associated with lower risk of death in those without CKD (Hazard ratio 0.62, 95% CI 0.40, 0.95). Higher lean body mass was associated with lower risk for death in those without kidney disease but not in the CKD population. There was a significantly higher risk for death among those who did not meet the minimum LTPA goals compared to those who met or exceeded the recommended activity levels (>450 MET/min/week) in those with and without CKD (CKD Hazard ratio: 1.36, 95% CI 1.003, 1.85; non-CKD HR 1.65, 95% CI 1.21, 2.26).ConclusionsIn a representative sample of the US population, higher LTPA levels and lean body mass were associated with lower mortality in those without kidney disease. In CKD, higher LTPA was associated with lower risk of death. There was no association between adiposity measures and death in those with and without CKD except for lower mortality associated with overweight among those without CKD. The data suggests the need to develop programs to facilitate an increase in physical activity in people with and without kidney disease.

Effect of Body Composition on Respiratory Compensation Point During an Incremental Test

Body mass (BM) and composition are considered to be significant determinants of aerobic endurance. The purpose of this study was to examine the influence of BM and its composition makeup on endurance performance. Thirty-nine men were divided into 3 groups of significantly different BM and mass composition: a control group, a group with high body fat (HBF), and a group with high lean body mass (HLBM). Participants in the HBF and HLBM groups had similar BM, which was significantly greater than observed in the control group. All participants performed an incremental treadmill test to volitional failure. Endurance performance was assessed on the basis of respiratory compensation point (RCP). The HBF and HLBM groups exceeded RCP at a much lower work intensity, expressed as %HRmax and %VO2max, compared with the control group. When considered relative to BM and lean body mass, oxygen consumption values at RCP were significantly less in the HBF and HLBM groups compared with the control group. Increased BM, regardless of its composition, substantially reduced aerobic endurance performance. Therefore, athletes and coaches should pay attention to not only the percentage of body fat but also to the amount of lean body mass because any gain may adversely affect aerobic endurance performance.

Large-scale analysis reveals a functional single-nucleotide polymorphism in the 5'-flanking region of PRDM16 gene associated with lean body mass.

Genetic factors are important for the development of sarcopenia, a geriatric disorder characterized by low lean body mass. The aim of this study was to search for novel genes that regulate lean body mass in humans. We performed a large-scale search for 250K single-nucleotide polymorphisms (SNPs) associated with bone mineral density (BMD) using SNP arrays in 1081 Japanese postmenopausal women. We focused on an SNP (rs12409277) located in the 5′-flanking region of the PRDM16 (PRD1-BF-1-RIZ1 homologous domain containing protein 16) gene that showed a significant P value in our screening. We demonstrated that PRDM16 gene polymorphisms were significantly associated with total body BMD in 1081 postmenopausal Japanese women. The rs12409277 SNP affected the transcriptional activity of PRDM16. The subjects with one or two minor allele(s) had a higher lean body mass than the subjects with two major alleles. Genetic analyses uncovered the importance of the PRDM16 gene in the regulation of lean body mass.

The influence of increased body fat or lean body mass on aerobic performance.

PurposeThe purpose of this study was to determine aerobic performance in men with an increased body mass due to (a) high body fat (>21.5%) but with a average (59.0–64.3 kg) lean body mass (HBF group) and (b) high lean body mass (>66.3 kg), but with average body fat (14.0–18.5%) (HLBM group).MethodsThe men in the HBF and HLBM had similar absolute body mass and body mass index (BMI). The aerobic performance was also determined in control group. Methods: Study participants comprised 39 men aged 21.3±1.9 years who did not participate in competitive sports but were recreationally physically active. Participants were divided into three groups. Each group comprised 13 persons. The study involved anthropometric measurements, assessing aerobic performance (VO2max) using an incremental test on a mechanical treadmill. VO2max was expressed in absolute values, relative to body mass (VO2max⋅BM−1), relative to lean body mass (VO2max⋅LBM−1), and relative to BM raised by the exponents of 0.75 and 0.67. Body composition was measured using bioelectrical impedance analysis.ResultsNo statistically significant differences in relative values of VO2max were found between the HBF and HLBM groups, in VO2max⋅BM−1 (50.24±4.56 vs. 53.11±5.45 mL⋅kg−1), VO2max⋅LBM−1 (65.33±5.63 vs. 63.86±7.13 mL⋅kgLBM−1), and VO2max⋅BM−0.75 (150.29±13.5 vs. 160.39±16.15 mL⋅kg−0.75). Values of VO2max⋅BM−1 were significantly lower in the HBF and HLBM groups than in the control group (58.23±5.84 mL⋅kg−1).ConclusionHigh body mass, regardless of the cause decreases VO2max⋅BM−1.

Body fat, body fat distribution, lean body mass and atrial fibrillation and flutter. A Danish cohort study

It is recognized that higher height and weight are associated with higher risk of atrial fibrillation or flutter (AF) but it is unclear whether risk of AF is related to body fat, body fat location, or lean body mass. This article reports the Danish population-based prospective cohort Diet, Cancer and Health study conducted among 55,273 men and women 50-64 years of age at recruitment. The associations between bioelectrical impedance derived measures of body composition and combinations of anthropometric measures of body fat distribution and risk of an incident record of AF in the Danish Registry of Patients were investigated. During follow-up (median 13.5 years) AF developed in 1,669 men and 912 women. Higher body fat at any measured location was associated with higher risk of AF. The adjusted hazard ratio (HR) per 1 sex-specific standard deviation (SD) increment in body fat mass was 1.29 (95% confidence interval [CI], 1.24-1.33). Higher lean body mass was also associated with a higher risk of AF. The adjusted HR for 1 sex-specific SD increment was 1.40 (95% CI, 1.35-1.45). Higher body fat and higher lean body mass were both associated with higher risk of AF.