Is Osteopenia a Health Risk in Professional Cyclists?

Bone mineral content (BMC) and bone mineral density (BMD) were measured by dual-energy X-ray absorptiometry Lunar DPX-NT, SV 4.0 in 23 professional male cyclists (age: 28.5+/-3.9 yr; height: 179+/-6.8 cm; weight: 70.9+/-7.1 kg(-1)). Eight subjects had normal L1-L4 T-score values (-0.19+/-0.62) and 15 had low values (-1.57+/-0.45). Correlations between: L1-L4 T-scores and body weight, fat mass (FM) and % FM (r=0.40, p<0.05; r=0.65, p<0.001; r=0.59, p<0.01). Regression analysis: L1-L4 T-score and FM (R2=0.42; p<0.001); total BMC and fat-free mass (FFM) (R2=0.60; p<0.0001); and total BMD and BMI (R2=0.25; p<0.05). Climbers had lower arms BMD (0.85+/-0.04; p<0.05). Flat-terrain cyclist had lower right leg FFM (9.7+/-0.8 kg; p<0.05). Time trialists had higher body weight (76.7+/-4.4 kg; p<0.05), total FFM (68.3+/-4.7 kg), total BMC (3.1+/-0.3; p<0.03), right and left leg BMC (0.60+/-0.1; 0.60+/-0.1; p<0.05), and spinal BMD (1.09+/-0.1; p<0.05). In conclusion, two-thirds of professional cyclists had abnormally low BMD values.     

Randomized prospective comparison between erythropoietin and androgens in CAPD patients

BACKGROUND: Anemia and malnutrition are significant complications in peritoneal dialysis (PD) patients. Previous studies in hemodialysis have shown that androgens are effective as therapy for anemia; however, this has not been tested in a randomized prospective trial in PD patients. Furthermore, the anabolic properties of androgens may exert additional benefits on the nutritional status in this population. METHODS: Twenty-seven stable male patients over 50 years who were under maintenance continuous ambulatory peritoneal dialysis (CAPD) therapy were randomized to receive recombinant human erythropoietin (rHuEPO; N = 14) or nandrolone decanoate (ND; 200 mg/week IM; N = 13) as therapy for anemia. The evolution of hematologic parameters and the impact on both nutritional anthorpometric and biochemical variables were evaluated after six months of treatment. RESULTS: Hemoglobin and hematocrit experienced similar increases in both groups: from 8.5 +/- 0.9 g/dL and 25.8 +/- 2.7% to 11.7 +/- 0.6 g/dL and 34.7 +/- 1.6% (P < 0.001) in patients receiving rHuEPO, and from 8.9 +/- 0.8 and 27 +/- 2.2% to 11.8 +/- 0.4 g/dL and 35.1 +/- 1.5% (P < 0.001) in subjects treated with ND. At the end of the study, out of the diverse nutritional variables included in this investigation, only weight and body mass index significantly increased in the rHuEPO group. Conversely, both anthropometric [weight, body mass index, triceps skinfold, mid-arm circumference (MAC) and mid-arm muscle circumference (MAMC)] and biochemical parameters (serum total proteins, albumin, prealbumin and transferrin) were significantly increased in patients treated with ND. In this group, serum urea nitrogen, urea net excretion and protein equivalent of nitrogen appearance significantly decreased. These facts, together with an increase in serum creatinine and no changes in dietary intake during the study, suggest a rise in muscle mass related to an anabolic effect of nandrolone decanoate. Interestingly, serum levels of insulin-like growth factor type 1 (IGF-1) increased in patients on the androgen group compared to subjects treated with rHuEPO. Moreover, there was a positive and significant correlation between the rise in IGF-1 concentrations and the increase in hemoglobin, hematocrit, MAC and MAMC. CONCLUSIONS: Androgens therapy improved the anemia in elderly male CAPD patients in a similar manner to that observed with rHuEPO. Furthermore, compared with rHuEPO, androgen administration was associated with beneficial effects on nutritional status. The mechanism of action of androgens on hematologic and nutritional parameters might be mediated, at least in part, by IGF-1.     

Metabolic and Nutritional Status Changes After 10% WeightLoss in Severely Obese Patients Treated with Laparoscopic Surgery vs Integrated Medical Treatment

BACKGROUND: Bariatric surgery is considered the most effective treatment for reducing excess body weight and maintaining weight loss (WL) in severely obese patients. There are limited data evaluating metabolic and body composition changes after different treatments in type III obese (body mass index [BMI] > 40 kg/m(2)). METHODS: Twenty patients (9 males, 11 females; 37.6 +/- 8 years; BMI = 50.1 +/- 8 kg/m(2)) treated with dietary therapy and lifestyle correction (group 1) have been compared with 20 matched patients (41.8 +/- 6 years; BMI = 50.4 +/- 6 kg/m(2)) treated with laparoscopic gastric bypass (LGBP; group 2). Patients have been evaluated before treatment and after >10% WL obtained on average 6 weeks after LGBP and 30 weeks after integrated medical treatment. Metabolic syndrome (MS) was evaluated using the Adult Treatment Panel III/America Heart Association (ATP III/AHA) criteria. Resting metabolic rate (RMR) and respiratory quotient (RQ) was assessed with indirect calorimetry; body composition with bioimpedance analysis. RESULTS: At entry, RMR/fat-free mass (FFM) was 34.2 +/- 7 kcal/24 h.kg in group 1 and 35.1 +/- 8 kcal/24 h.kg in group 2 and did not decrease in both groups after 10% WL (31.8 +/- 6 vs 34.0 +/- 6). Percent FFM and fat mass (FM) was 50.7 +/- 7% and 49.3 +/- 7% in group 1 and 52.1 +/- 6% and 47.9 +/- 6% in group 2, respectively (p = n.s.). After WL, body composition significantly changed only in group 1 (% FFM increased to 55.9 +/- 6 and % FM decreased to 44.1 +/- 6; p = 0.002). CONCLUSION: After >10% WL, MS prevalence decreases precociously in surgically treated patients; some improvements in body composition are observed in nonsurgically treated patients only. Further investigations are needed to evaluate long-term effects of bariatric surgery on body composition and RMR after stable WL.     

Estimating body fat and lean tissue distribution in hyperthyroidism by dual-energy X-ray absorptiometry.

Body composition (fat mass, lean tissue, and bone mineral content), was determined by dual-energy X-ray absorptiometry (DEXA) at baseline and 6, 12, and 24 mo after treatment of hyperthyroidism. Ten women with Graves' disease were included in this study. Suppressed serum TSH and high total serum thyroxine levels were found in all patients. The patients received antithyroid therapy (methimazol and/or (131) I radioiodine). Lean tissue, bone mass, and body weight increased after 2 yr of euthyroidism. Total body lean mass increased from 32.3+/-3.9 kg to 35.2+/-4.1 kg (p < 0.005). Total lean mass increased from 10.6 +/- 1.8 kg to 11.6 +/- 1.9 kg (p < 0.01) in the legs, from 3.6 +/- 0.8 kg to 4.0 +/- 0.7 kg (p < 0.02) in the arms, and 16.0 +/- 1.6 kg to 17.4+/-1.8 kg (p < 0.005) in the trunk. Total-body fat mass increased from 19.9 +/- 6.6 kg to 21.2 +/- 7.6 kg (ns). At 1-yr, regional analysis disclosed that fat mass had increased in the trunk from 8.9 +/- 2.9 kg to 10.9 +/- 3.9 kg (p < 0.04) and from 2.3 +/- 0.9 kg to 3.2 +/- 1.2 kg in the arms (p < 0.04). After 2 yr of treatment, fat tissue remained unchanged in all of the studied regions. The results obtained herein suggest that, compared to initial values, the treatment of hyperthyroidism restore body weight. This increase is mainly the result of recovery of lean mass, predominantly in the limbs and trunk. This study provides new data on the patterns of change in body composition occurring in hyperthyroid patients during a 24-mo follow-up after attaining euthyroidism.     

Increased rate of Cori cycle in obese subjects with NIDDM and effect of weight reduction

To determine the contribution of the rate of glucose recycling via the Cori cycle (glucose----3-carbon compounds----glucose) to the higher rate of endogenous glucose production (EGPR) in subjects with non-insulin-dependent diabetes mellitus (NIDDM), we studied eight obese, weight-stabilized diabetic Pima Indians before [93.1 +/- 5.4 kg, 38 +/- 2% body fat, fasting plasma glucose (FPG) 254 +/- 11 mg/dl] and after (87.7 +/- 4.7 kg, 36 +/- 2% body fat, FPG 153 +/- 17 mg/dl) a 5-wk weight-loss diet and eight obese Indians (95.0 +/- 4.2 kg, 36 +/- 2% body fat, FPG 97 +/- 1 mg/dl) with normal glucose tolerance. EGPR and glucose recycling rate were measured during a 4-h primed continuous tracer infusion of [1-13C]glucose, and the rate of reincorporation of 1-13C of glucose into C2-6 positions in glucose was quantified by gas chromatography mass spectrometry. Substrate utilization rates were measured by simultaneous indirect calorimetry. EGPR (corrected for measured rate of recycling) decreased in the diabetic subjects from 3.80 to 2.74 mg.min-1.kg-1 fat-free mass (FFM) (P less than .01) after weight loss, approaching the rate observed in nondiabetic subjects (2.09 mg.min-1.kg-1 FFM).(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of weight loss on regional fat distribution and insulin sensitivity in obesity

Weight loss (WL) decreases regional depots of adipose tissue and improves insulin sensitivity, two parameters that correlate before WL. To examine the potential relation of WL-induced change in regional adiposity to improvement in insulin sensitivity, 32 obese sedentary women and men completed a 4-month WL program and had repeat determinations of body composition (dual-energy X-ray absorptiometry and computed tomography) and insulin sensitivity (euglycemic insulin infusion). There were 15 lean men and women who served as control subjects. VO2max was unaltered with WL (39.2 +/- 0.8 vs. 39.8 +/- 1.1 ml x fat-free mass [FFM](-1) x min(-1)). The WL intervention achieved significant decreases in weight (100.2 +/- 2.6 to 85.5 +/- 2.1 kg), BMI (34.3 +/- 0.6 to 29.3 +/- 0.6 kg/m2), total fat mass (FM) (36.9 +/- 1.5 to 26.1 +/- 1.3 kg), percent body fat (37.7 +/- 1.3 to 31.0 +/- 1.5%), and FFM (59.2 +/- 2.3 to 55.8 +/- 2.0 kg). Abdominal subcutaneous and visceral adipose tissue (SAT and VAT) were reduced (494 +/- 19 to 357 +/- 18 cm2 and 157 +/- 12 to 96 +/- 7 cm2, respectively). Cross-sectional area of low-density muscle (LDM) at the mid-thigh decreased from 67 +/- 5 to 55 +/- 4 cm2 after WL. Insulin sensitivity improved from 5.9 +/- 0.4 to 7.3 +/- 0.5 mg x FFM(-1) x min(-1) with WL. Rates of insulin-stimulated nonoxidative glucose disposal accounted for the majority of this improvement (3.00 +/- 0.3 to 4.3 +/- 0.4 mg x FFM(-1) x min(-1)). Serum leptin, triglycerides, cholesterol, and insulin all decreased after WL (P < 0.01). After WL, insulin sensitivity continued to correlate with generalized and regional adiposity but, with the exception of the percent decrease in VAT, the magnitude of improvement in insulin sensitivity was not predicted by the various changes in body composition. These interventional weight loss data underscore the potential importance of visceral adiposity in relation to insulin resistance and otherwise suggest that above a certain threshold of weight loss, improvement in insulin sensitivity does not bear a linear relationship to the magnitude of weight loss.     

Relationships Among Bone Mineral Density,Body Composition,and Isokinetic Strength in Young Women

The purpose of this study was to examine the relationships among bone mineral density (BMD), body composition, and isokinetic strength in young women. Subjects were 76 women (age: 20 ± 2 yr, height: 164 ± 6 cm, weight: 57 ± 6 kg, body fat: 27 ± 4%) with a normal body mass index (18–25 kg/m²). Total body, nondominant proximal femur, and nondominant distal forearm BMD were measured with dual-energy x-ray absorptiometry. Isokinetic concentric (CON) and eccentric (ECC) strength of the nondominant thigh and upper arm were measured at 60 deg/sec. Fat-free mass (FFM) correlated (P < 0.001) with BMD of the total body (r = 0.56) and femoral neck (r = 0.52), whereas fat mass (FM) did not relate to BMD at any site. Leg FFM, but not FM, correlated with BMD in all regions of interest at the proximal femur. Weak associations were observed between arm FFM and forearm BMD. Isokinetic strength did not relate to BMD at any site after correcting for regional FFM. In conclusion, strong, independent associations exist between BMD and FFM, but not FM or isokinetic strength, in young women.     

Phenotypic characteristics associated with insulin resistance in metabolically obese but normal-weight young women.

Metabolically obese, normal-weight (MONW) individuals are a hypothesized subgroup of the general population. These normal-weight individuals potentially display a cluster of obesity-related features, although this has not been systematically tested in young women. We hypothesized that MONW young women would display higher levels of total and visceral fat and lower levels of physical activity than normal women. In a cohort of 71 healthy nonobese women (21-35 years old), we identified MONW women based on cut points for insulin sensitivity (normal = glucose disposal >8 mg x min(-1) x kg(-1) of fat-free mass [FFM], n = 58; impaired = glucose disposal <8 ml x min(-1) x kg(-1) of FFM, n = 13). Thereafter, we measured body composition (dual energy X-ray absorptiometry) and body fat distribution (computed tomography), cardiorespiratory fitness (VO2max on a treadmill), physical activity energy expenditure (doubly labeled water and indirect calorimetry), glucose tolerance (oral glucose tolerance test), serum lipid profile, and dietary intake. We found a higher body fat percentage (32 +/- 6 vs. 27 +/- 6%, P = 0.01) and higher subcutaneous (213 +/- 61 vs. 160 +/- 78 cm2, P = 0.03) and visceral (44 +/- 16 vs. 35 +/- 14 cm2, P < 0.05) abdominal adiposity in the MONW group versus the normal group. The MONW group showed a lower physical activity energy expenditure (2.66 +/- 0.92 vs. 4.39 +/- 1.50 MJ/day, P = 0.01), but no difference in cardiorespiratory fitness was noted between groups. In conclusion, despite a normal body weight, a subset of young, apparently healthy women displayed a cluster of risky phenotypic characteristics that, if left untreated, may eventually predispose them to type 2 diabetes and cardiovascular disease.     

Enhanced fat oxidation through physical activity is associated with improvements in insulin sensitivity in obesity

Skeletal muscle insulin resistance entails dysregulation of both glucose and fatty acid metabolism. This study examined whether a combined intervention of physical activity and weight loss influences fasting rates of fat oxidation and insulin-stimulated glucose disposal. Obese (BMI >30 kg/m(2)) volunteers (9 men and 16 women) without diabetes, aged 39 +/- 4 years, completed 16 weeks of moderate-intensity physical activity combined with caloric reduction. Body composition was determined by dual-energy X-ray absorptiometry and computed tomography. Glucose disposal rates (R(d)) were measured during euglycemic hyperinsulinemia (40 mU x m(-2) x min(-1)), and substrate oxidation was determined via indirect calorimetry. Fat mass and regional fat depots were reduced and VO(2max) improved by 19%, from 38.8 +/- 1.2 to 46.0 +/- 1.0 ml x kg fat-free mass (FFM)(-1) x min(-1) (P < 0.05). Insulin sensitivity improved 49 +/- 10% (6.70 +/- 0.40 to 9.51 +/- 0.51 mg x min(-1) x kg FFM(-1); P < 0.05). Rates of fat oxidation following an overnight fast increased (1.16 +/- 0.06 to 1.36 +/- 0.05 mg x min(-1) x kg FFM(-1); P < 0.05), and the proportion of energy derived from fat increased from 38 to 52%. The strongest predictor of the improved insulin sensitivity was enhanced fasting rates of fat oxidation, accounting for 52% of the variance. In conclusion, exercise combined with weight loss enhances postabsorptive fat oxidation, which appears to be a key aspect of the improvement in insulin sensitivity in obesity.     

Anabolic therapy with growth hormone accelerates protein gain in surgical patients requiring nutritional rehabilitation.

OBJECTIVE: The authors investigated the effects of exogenous growth hormone (GH) on protein accretion and the composition of weight gain in a group of stable, nutritionally compromised postoperative patients receiving standard hypercaloric nutritional therapy. SUMMARY BACKGROUND DATA: A significant loss of body protein impairs normal physiologic functions and is associated with increased postoperative complications and prolonged hospitalization. Previous studies have demonstrated that standard methods of nutritional support enhance the deposition of fat and extracellular water but are ineffective in repleting body protein. METHODS: Fourteen patients requiring long-term nutritional support for severe gastrointestinal dysfunction received standard nutritional therapy (STD) providing approximately 50 kcal/kg/day and 2 g of protein/kg/day during an initial 7-day equilibrium period. The patients then continued on STD (n = 4) or, in addition, received GH 0.14 mg/kg/day (n = 10). On day 7 of the equilibrium period and again after 3 weeks of treatment, the components of body weight were determined; these included body fat, mineral content, lean (nonfat and nonmineral-containing tissue) mass, total body water, extracellular water (ECW), and body protein. Daily and cumulative nutrient balance and substrate oxidation studies determined the distribution, efficiency, and utilization of calories for protein, fat, and carbohydrate deposition. RESULTS: The GH-treated patients gained minimal body fat but had significantly more lean mass (4.311 +/- 0.6 kg vs. 1.988 +/- 0.2 kg, p < or = 0.03) and more protein (1.417 +/- 0.3 kg vs. 0.086 +/- 0.1 kg, p < or = 0.03) than did the STD-treated patients. The increase in lean mass was not associated with an inappropriate expansion of ECW. In contrast, patients receiving STD therapy tended to deposit a greater proportion of body weight as ECW and significantly more fat than did GH-treated patients (1.004 +/- 0.3 kg vs. 0.129 +/- 0.2 kg, p < 0.05). GH administration altered substrate oxidation (respiratory quotient = 0.94 +/- 0.02 GH vs. 1.17 +/- 0.05 STD, p < or = 0.0002) and the use of available energy, resulting in a 66% increase in the efficiency of protein deposition (13.37 +/- 0.8 g/1000 kcal vs. 8.04 g +/- 3.06 g/1000 kcal, p < or = 0.04). CONCLUSIONS: GH administration accelerated protein gain in stable adult patients receiving aggressive nutritional therapy without a significant increase in body fat or a disproportionate expansion of ECW. GH therapy accelerated nutritional repletion and, therefore, may shorten the convalescence of the malnourished patient requiring a major surgical procedure.     

Increased resting metabolic rates in obese subjects with non-insulin-dependent diabetes mellitus and the effect of sulfonylurea therapy

Obese subjects with non-insulin-dependent diabetes mellitus (NIDDM) lose weight soon after diagnosis and tend to gain weight during hypoglycemic therapy. One explanation for these weight shifts is the change in caloric loss from glycosuria. We compared 24 obese Pima Indians with NIDDM to 24 Pima Indians with normal glucose tolerance to determine whether resting metabolic rate changes may be an additional factor influencing the weight shifts. The diabetic and nondiabetic subjects were equally obese, body fat 38 +/- 1% versus 37 +/- 1% (mean +/- SEM), respectively, as determined by densitometry. In the morning after an overnight fast, resting metabolic rate (RMR) was measured by indirect calorimetry. The mean RMR of the diabetic subjects, 32.9 +/- 0.5 kcal/day X kg fat-free mass (FFM), was 5% higher than that of the nondiabetic subjects, 31.4 +/- 0.5 kcal/day X kg FFM (P less than 0.05). In nine of the diabetic subjects, 6 wk of tolazamide therapy was associated with reductions in mean FPG, 253 +/- 16 to 144 +/- 14 mg/dl (P less than 0.01), mean daily urine glucose loss, 128 +/- 26 to 11 +/- 4 g (P less than 0.01), and mean RMR, 31.9 +/- 0.8 to 30.2 +/- 0.6 kcal/day X kg FFM (P less than 0.04). Weight of the subjects was maintained constant from beginning to end of therapy (106.5 +/- 9.6 versus 108.1 +/- 9.9 kg) by decreasing daily calorie intake from 3070 +/- 103 to 2784 +/- 163 kcal (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)     

Hormone replacement therapy dissociates fat mass and bone mass, and tends to reduce weight gain in early postmenopausal women: a randomized controlled 5-year clinical trial of the Danish Osteoporosis Prevention Study.

The aim of this study was to study the influence of hormone replacement therapy (HRT) on weight changes, body composition, and bone mass in early postmenopausal women in a partly randomized comprehensive cohort study design. A total of 2016 women ages 45-58 years from 3 months to 2 years past last menstrual bleeding were included. One thousand were randomly assigned to HRT or no HRT in an open trial, whereas the others were allocated according to their preferences. All were followed for 5 years for body weight, bone mass, and body composition measurements. Body weight increased less over the 5 years in women randomized to HRT (1.94 +/- 4.86 kg) than in women randomized to no HRT (2.57 +/- 4.63, p = 0.046). A similar pattern was seen in the group receiving HRT or not by their own choice. The smaller weight gain in women on HRT was almost entirely caused by a lesser gain in fat. The main determinant of the weight gain was a decline in physical fitness. Women opting for HRT had a significantly lower body weight at inclusion than the other participants, but the results in the self-selected part of the study followed the pattern found in the randomized part. The change in fat mass was the strongest predictor of bone changes in untreated women, whereas the change in lean body mass was the strongest predictor when HRT was given. Body weight increases after the menopause. The gain in weight is related to a decrease in working capacity. HRT is associated with a smaller increase in fat mass after menopause. Fat gain protects against bone loss in untreated women but not in HRT-treated women. The data suggest that women's attitudes to HRT are more positive if they have low body weight, but there is no evidence that the conclusions in this study are skewed by selection bias.     

Impaired oxidation of plasma-derived fatty acids in type 2 diabetic subjects during moderate-intensity exercise

The present study was intended to investigate the different components of fatty acid utilization during a 60-min period of moderate-intensity cycling exercise (50% of VO2max) in eight male type 2 diabetic subjects (aged 52.6 +/- 3.1 years, body fat 35.8 +/- 1.3%) and eight male obese control subjects (aged 45.1 +/- 1.4 years, body fat 34.2 +/- 1.3%) matched for age, body composition, and maximal aerobic capacity. To quantitate the different components of fatty acid metabolism, an isotope infusion of [U-13C]-palmitate was used in combination with indirect calorimetry. In separate experiments, the 13C label recovery in expired air was determined during infusion of [1,2-13C]-acetate (acetate recovery factor). There were no differences in energy expenditure or carbohydrate and total fat oxidation between the groups. The rate of appearance (Ra) of free fatty acid (FFA) (P < 0.05) and the exercise-induced increase in Ra of FFA were significantly lower (P < 0.05) in type 2 diabetic subjects compared with control subjects (baseline vs. exercise [40-60 min]; type 2 diabetes 11.9 +/- 0.9 vs. 19.6 +/- 2.2 micromol x kg(-1) fat-free mass [FFM] x min(-1) and control 15.8 +/- 1.8 vs. 28.6 +/- 2.1 micromol x kg(-1) FFM x min(-1)). The oxidation of plasma-derived fatty acids was significantly lower in type 2 diabetic subjects during both conditions (P < 0.05, baseline vs. exercise [40-60 min]; type 2 diabetes 4.2 +/- 0.5 vs. 14.1 +/- 1.9 micromol x kg(-1) FFM x min(-1) and control 6.2 +/- 0.6 vs. 20.4 +/- 1.9 micromol x kg(-1) FFM x min(-1)), whereas the oxidation of triglyceride-derived fatty acids was higher (P < 0.05). It is hypothesized that these impairments in fatty acid utilization may play a role in the etiology of skeletal muscle and hepatic insulin resistance.     

Altered tissue distribution in adults with cystic fibrosis

BACKGROUND: Regional body composition was determined in adults with cystic fibrosis (CF). Our hypothesis was that dual energy x ray absorptiometry (DXA) scanning could assess the fat free mass, bone mineral content, and fat mass and determine the distribution of the changes. METHOD: Height squared indices were derived for fat mass (FMI), fat free mass (FFMI), and bone mineral content (BMCI) of the arm, leg, and trunk by DXA in 51 patients and 18 age/sex matched healthy subjects. RESULTS: The arm and leg FFMI in patients were less than in healthy controls (p<0.05); the deficit was leg>arm>trunk (-18.19%, -14.86%, +0.09%, p<0.02) and was related to severity of lung disease. Patients with a normal BMI and low total FFM (hidden loss) had a lower arm, leg and trunk FFMI than those with a normal BMI and total FFM (p<0.05). The BMCI for all body segments was lower in patients than in controls (p<0.001). The BMCI was lower in the leg and trunk (p<0.01) in patients with severe disease than in those with mild lung disease. In those with hidden FFM loss the BMCI was lower (p<0.05 in leg and trunk). There was no difference in the BMCI deficit between body segments. Fat mass in patients was not reduced. CONCLUSION: Preferential loss of FFM is related to severity of lung disease and occurs in patients with a normal BMI. A similar loss of BMC occurs while FM is preserved. A hierarchical pattern of FFM loss of legs>arms>trunk was shown; BMC loss was evenly distributed.     

Four-year follow-up of body compostion in lung transplant patients

BACKGROUND: Both undernutrition and overnutrition can affect the quality of life and survival of patients with pulmonary disease and lead to quantitative and functional alterations of fat-free mass (FFM). This longitudinal study determines the changes in weight, FFM, and body fat before and up to 4 years after lung transplant (LTR). METHODS: Height, weight, and body composition measurements (bioelectrical impedance) were obtained in 37 LTR patients. FFM and body fat were measured before and at 1, 3, 6, 9, 12, 18, 24, 36, and 48 months after LTR. RESULTS: Weight changed by +16.6%, +3.2%, -0.2%, and -3.2% and FFM by +14.0%, +2.5%, -0.3%, and -1.0% during years 1, 2, 3, and 4, respectively. A diagnosis of obliterative bronchiolitis after LTR was associated with loss of body weight, FFM, and body fat, compared with stable weight or gain in weight, FFM, and body fat in obliterative bronchiolitis-negative subjects; 76.2% and 85.7%, and 28% and 38% of men and women, respectively, demonstrated low FFM at 1 month and at 2 years after LTR, respectively. The FFM change was higher (39% of weight) during year 1 than during year 2 (25%) or year 3 (21%). CONCLUSIONS: After LTR, patients gained weight, FFM, and body fat, and two-thirds reached normal levels of FFM by year 2. A weight increase resulted in an FFM increase. Contrary to studies after heart or liver transplantation, our results suggest that despite posttransplant infections and grafts rejection, LTR permits FFM recovery.     

Effect of prescribing a high protein diet and increasing the dose of dialysis on nutrition in stable chronic haemodialysis patients: a randomized, controlled trial.

BACKGROUND: Protein requirements in stable, adequately dialysed haemodialysis patients are not known and recommendations vary. It is not known whether increasing the dialysis dose above the accepted adequate level has a favourable effect on nutrition. The aim of this study was to determine whether prescribing a high protein diet and increasing the dose of dialysis would have a favourable effect on dietary protein intake and nutritional status in stable, adequately dialysed haemodialysis patients. Effects on hyperphosphataemia and acidosis were also studied. METHODS: Patients were randomized to a high dialysis dose (HDD) group (target Kt/V(eq) of 1.4) or a regular dialysis dose (RDD) group (target Kt/V(eq) of 1.0). All patients were prescribed a high protein (HP) diet [1.3 g/kg of ideal body weight (IBW)/day] and a regular protein (RP) diet (0.9 g/kg/day), each during 40 weeks in a crossover design. In 50 patients, 23 in the HDD and 27 in the RDD group follow-up was > or =10 weeks. These patients, aged 56+/-15 years, were included in the analysis. Nutritional status was assessed by anthropometry, plasma albumin and a nutritional index. RESULTS: Delivered Kt/V(eq) in the HDD group (1.26+/-0.14) was significantly higher than in the RDD group (1.02+/-0.08). Protein intake estimated from total nitrogen appearance (PNA) measurements and food records (DPI) was significantly higher during the HP diet (PNA(IBW), 1.01+/-0.18 g/kg/day; DPI(IBW), 1.15+/-0.18 g/kg/day) than during the RP diet (PNA(IBW), 0.90+/-0.14 g/kg/day; DPI(IBW), 0.94+/-0.11 g/kg/day). Increasing the dialysis dose did not increase protein intake either during the HP or RP diet. Plasma albumin (41.9+/-3.0 g/l) lean body mass (107+/-15% of normal values) and the nutritional index did not differ between the dialysis dose groups or protein diets and remained stable overtime. Dry body weight (97+/-14%) and total fat mass increased over time in the HDD group, but remained stable in the RDD group suggesting an effect of dialysis dose on energy balance. There was no effect of the protein diets on dry body weight or total fat mass. Plasma phosphate levels and oral bicarbonate supplements were lower in the HDD group, but were comparable between the protein diets. CONCLUSIONS: Prescribing a HP diet resulted in a modest increase in actual protein intake, but increasing dialysis dose did not have a contributing effect. A HP diet or increasing the dialysis dose did not have a favourable effect on the nutritional status. A dietary protein intake of at least 0.9 g/kg IBW/day appears to be sufficient for adequately dialysed haemodialysis patients without overt malnutrition.     

Changes in the body composition of the surgical infant in the early postoperative period

The purpose of this study was to evaluate the effects of postoperative nutritional management on the body composition of infants after major surgery. We studied 13 full-term surgical infants (mean initial weight 2.88 +/- 0.19 kg; mean days postsurgery 5.0 +/- 0.5). Ten infants were receiving total parenteral nutrition and three were orally fed (mean caloric intake 84 +/- 4 kcal/kg/d; mean fluid intake 145 +/- 4 mL/kg/d). Total body water (TBW) was measured by isotope dilution using heavy oxygen (18O) labeled water (H2(18)O). Total body fat (TBF) was estimated from anthropometric data. Lean body mass (LBM) was calculated as follows: LBM = weight--TBF. Protein, fat, and carbohydrate accretion were determined by energy and macronutrient balance in conjunction with open-circuit indirect calorimetry. Body composition was reevaluated after an interval of seven days. Body weight increased from 2.88 +/- 0.19 to 3.00 +/- 0.19 kg, representing a mean growth velocity of 5.9 g/kg/d. Increments were observed in all body compartments but only the increase in TBF reached statistic significance (12.9 v 14% of body weight, P less than .05). TBW ranged from an initial value of 76.2 +/- 1.4% to a value of 75.5 +/- 1.4% at the end of the study. Protein, fat, and carbohydrate accretion (g/kg/d) during the seven-day study period were 1.62 +/- 0.13; 1.44 +/- 0.41, and 0.96 +/- 0.70, respectively. These data indicate that in the early postoperative period, the weight gain is secondary to both water and solid tissue accretion. Fat represents the major form of energy storage in the new tissues synthesized.(ABSTRACT TRUNCATED AT 250 WORDS)     

The arch index: a measure of flat or fat feet?

BACKGROUND: Studies using footprint-based estimates of arch height have indicated that obesity results in a lowered medial longitudinal arch in children. However, the potentially confounding effect of body composition on indirect measures of arch height, such as the arch index, has not been investigated. METHODS: This study assessed the body composition of 12 male and 12 female adults (mean age: 39.9 +/- 8.1 years, height: 1.724 +/- 0.101 m; weight: 95.1 +/- 13.7 kg, and BMI: 31.9 +/- 3.0 kg/m(2)) using bioelectrical impedance analysis to produce a two-component model of fat mass (FM) and fat-free mass (FFM). The dynamic arch index also was determined from electronic footprints captured during gait using a capacitive pressure distribution platform with a resolution of 4 sensors/cm(2). RESULTS: While significant correlations were noted between FFM and the area of both the hindfoot (r =.75, p <.05) and forefoot (r =.72, p <. 05), the midfoot area was correlated only with FM (r =.54, p <.05). Similarly, the arch index was significantly correlated with the FM percentage (r =.67, p <.05). CONCLUSIONS: The findings of this pilot study suggest that body composition influences arch index values in overweight and obese subjects. Consequently, body composition may be a confounding factor in interpreting footprint based estimates of arch height and, as such, these estimates would best be used with supplementary measures of body composition.     

Hyperinsulinemia in african-american children: decreased insulin clearance and increased insulin secretion and its relationship to insulin sensitivity

African-American (AA) children are hyperinsulinemic and insulin resistant compared with American White (AW) children. This study investigated 1) whether AA/AW differences in insulinemia are associated with differences in insulin clearance; 2) whether dietary patterns, mainly carbohydrate and fat intake, play a role; and 3) whether the quantitative relationship between insulin sensitivity and secretion is similar between AA and AW children. Forty-four prepubertal children (22 AA and 22 AW) with comparable body composition and visceral adiposity were studied. All underwent a 3-h hyperinsulinemic (40 mU x m(-2) x min(-1))-euglycemic clamp to calculate insulin sensitivity and insulin clearance and a 2-h hyperglycemic clamp (12.5 mmol/l) to assess first- and second-phase insulin responses. Twenty-four-hour food recalls were analyzed for macronutrient intake. Insulin clearance (19.5 +/- 0.7 vs. 22.9 +/- 1.1 ml x min(-1) x kg(-1) fat-free mass [FFM]; P = 0.011) and insulin sensitivity were lower in AA versus AW children (14.8 +/- 1.0 vs. 18.9 +/- 1.4 micro mol x min(-1) x kg(-1) FFM; P = 0.021). Both insulin clearance and insulin sensitivity correlated inversely with dietary fat/carbohydrate ratio, which was higher in AA than in white children. Fasting C-peptide and insulin were higher in AA children with no difference in proinsulin levels. First- and second-phase insulin concentrations and glucose disposition index (insulin sensitivity x first-phase insulin) were higher in AA than in white children (12.8 +/- 2.1 vs. 7.2 +/- 0.6 micro mol. min(-1) x kg(-1) FFM; P = 0.019). In conclusion, the hyperinsulinemia observed in AA children is due to both lower insulin clearance and higher insulin secretion compared with their white peers. The quantitative relationship between insulin secretion and sensitivity is upregulated in AA children. This suggests that increased insulin secretion in AA children is not merely a compensatory response to lower insulin sensitivity. Dietary factors may have a role. Additional studies are needed to determine whether metabolic/nutritional factors, possibly mediated through free fatty acids, may play a role in the hyperinsulinism observed in AA children.     

Increased plasma leptin/fat ratio in patients with chronic renal failure: a cause of malnutrition?

Background: Protein-energy malnutrition occurs in patients with chronic renal failure primarily due to loss of appetite. The ob gene protein, leptin, which is secreted by adipocytes, regulates body composition by lowering food intake. We have measured plasma leptin in undialysed and dialysed patients and in controls and the concentrations have been related to body composition, dietary intake, and biochemistry. Methods: Plasma leptin was measured by radioimmunoassay in 93 individuals in groups of undialysed, peritoneal dialysed, and haemodialysed patients and controls. Body composition was determined by DEXA. Results: Protein-energy malnutrition was evident in non-dialysed and dialysed patients from low lean or fat tissues, plasma albumin and transferrin. A third of the dialysis patients were eating less than prescribed intakes. Leptin relative to total fat mass (ng/ml/kg) was significantly greater for patients than for controls, particularly the dialysed patients. Leptin was highly correlated with total, arm, leg, and all other fat measurements, e.g. r for leptin vs% total fat was: undialysed 0.88, PD 0.81, HD 0.93, and controls 0.83 (P <0.0001 for all). Dialysis patients with the highest leptin/fat mass ratio had low protein intakes and significantly lower lean tissue mass. Leptin/fat ratio correlated inversely with dietary intake e.g. with protein intake in g/day an marginally in g/kg of ideal weight/day. Leptin concentration was unrelated to plasma creatinine or residual renal function or to the protein 'nutritional indices', albumin and transferrin. Conclusion: Our data suggests that leptin is markedly increased in some patients with chronic renal failure. The association of increased leptin with low protein intake and loss of lean tissue is consistent with leptin contributing to malnutrition but a definitive role cannot be substantiated by this study. Key words: body composition; chronic renal failure; dialysis; dietary intake; fat; leptin