Relationship between reduced serum IGF-I levels and accumulation of visceral fat in Japanese men

OBJECTIVE: To investigate whether the changes in IGF-I concentrations after weight reduction in Japanese overweight men are associated with changes in visceral and subcutaneous fat. DESIGN: Cross-sectional and longitudinal clinical intervention study with exercise education. SUBJECTS: One-hundred and twelve Japanese overweight men aged 30-59 y (body mass index (BMI) 28.4+/-2.5 kg/m(2)) and 33 normal-weight men aged 30-39 y (BMI 22.1+/-1.5 kg/m(2)) at baseline. From the participants, 56 randomly selected overweight men (BMI 28.8+/-2.8) were further enrolled into a 1 y exercise program. MEASUREMENTS: Fat distribution was evaluated by visceral fat (V) and subcutaneous fat (S) areas measured with computed tomography scanning at umbilical levels, metabolic parameters and hormones including insulin, leptin and IGF-I at baseline and after 1 y. RESULTS: In 112 overweight subjects at baseline, insulin (10.5+/-5.0 microU/ml) and leptin (6.4+/-3.7 ng/ml) significantly correlated with both V (r=0.260, P=0.0073; r=0.410, P<0.0001) and S areas (r=0.377, P<0.0001; r=0.613, P<0.0001), respectively. IGF-I (156.8+/-48.7 microU/ml) significantly and negatively correlated with V area (r=-0.242, P=0.0125) and age (r=-0.192, P=0.0480). In normal-weight men aged 30-39 y (n=33) and age-matched subjects (n=30) selected from the 112 overweight men, the serum IGF-I further tightly correlated with V area (r=-0.467, P<0.0001). Visceral fat area and age were independently related to serum IGF-I levels by multiple regression analysis. By intervention with exercise education, 56 overweight subjects showed an increase in daily steps (6224+/-2781 to 7898+/-4141 steps/day) and reduction of BMI (28.8+/-2.8 to 27.7+/-2.9). deltaIGF-I significantly correlated with deltaV area (r=-0.432, P=0.0009) but not with DeltaS area or deltaBMI. CONCLUSION: The present study indicated a negative correlation between IGF-I levels and visceral fat at baseline as well as an association between the reduction in visceral fat and increase in IGF-I levels after an exercise intervention.     

Changes in serum leptin concentrations in overweight Japanese men after exercise

AIM: To investigate the link between serum leptin concentrations and exercise. DESIGN: Cross-sectional and longitudinal studies of an exercise intervention. SUBJECTS: 110 Japanese overweight men aged 32-59 years were recruited. At baseline, the average body mass index (BMI) was 28.5 +/- 2.5 kg/m2. From this group, we used data of 36 overweight men (BMI, 28.9 +/- 2.3) for a 1-year exercise programme. MEASUREMENTS: Leptin was measured at baseline and after 1 year. Fat distribution was evaluated by visceral fat (V) and subcutaneous fat (S) areas measured with computed tomography (CT) scanning at umbilical levels. Anthropometric parameters, aerobic exercise level, muscle strength and flexibility were also investigated at baseline and after 1 year. RESULTS: In the first analysis, using cross-sectional data, leptin was significantly correlated with total body fat (r = 0.760, p < 0.01), V (r = 0.383, p < 0.01) and S (r = 0.617, p < 0.01) areas. In the second analysis, using longitudinal data, leptin was significantly reduced after 1 year (pre 6.7 +/- 4.0 ng/ml vs. post 5.1 +/- 3.1 ng/ml, p < 0.01). Results showed that steps per day were increased, and aerobic exercise level, weight-bearing index (WBI) and insulin resistance were significantly improved. Although, there was a positive correlation between Delta leptin(positive changes in leptin after 1 year) and anthropometric measurements such as Delta body weight, Delta BMI and Delta body fat, leptin/body weight, leptin/BMI and leptin/body fat ratios were significantly reduced during exercise intervention. CONCLUSION: The present study indicated exercise significantly lowers serum leptin concentrations, and thus it may improve the leptin resistance observed in overweight Japanese men.     

Daily exercise lowers blood pressure and reduces visceral adipose tissue areas in overweight Japanese men

OBJECTIVE: To investigate the link between a reduction in blood pressure (BP) and daily exercise. DESIGN: Cross-sectional and longitudinal clinical intervention study with exercise education. SUBJECTS: 43 overweight Japanese men aged 32-59 years (BMI, 29.0+/-2.3 kg/m2) at baseline. Among the participants, a randomly selected 23 overweight men (BMI, 28.5+/-1.7) were further enrolled into the 10 months exercise program. MEASUREMENTS: BP was measured every week and steps per day were also recorded every day throughout the observation period. Fat distribution was evaluated by visceral fat (V) and subcutaneous fat (S) areas measured with computed tomography (CT) scanning at umbilical level, at before, 5 months and after intervention. Anthropometric parameters were also measured at same point. Aerobic exercise level, muscle strength, flexibility and calorie intake and insulin resistance (HOMA index) were investigated at before and after the study. RESULTS: In a cross sectional analysis, systolic BP (SBP) and diastolic BP (DBP) were significantly correlated with body composition. In a second longitudinal analysis, SBP was significantly reduced at 2 months and DBP was also reduced at 3 months, and almost maintained until the end of the observation period. Increasing daily walking was observed in 3 months and maintained until 10 months. Body composition, aerobic exercise level, muscle strength, flexibility and insulin resistance were significantly improved. There was positive correlation between DeltaDBP and Deltavisceral fat area (1-5, 5-10, 1-10 months). By stepwise multiple regression analysis, only Deltavisceral fat area was independently related to DeltaDBP at a significant level (1-10 months: DeltaDBP=-0.608+0.105Deltavisceral fat area, r2=0.227, P=0.0334). CONCLUSION: The present study indicated daily exercise lowers BP and visceral fat area is the critical factor for BP change.     

Hemodynamic basis of the reduced oxygen uptake relative to work rate during incremental exercise in patients with chronic heart failure

BACKGROUND: The ratio of the increase in oxygen uptake to the increase in work rate (DeltaVO2/DeltaWR) during incremental exercise is reduced in patients with severe chronic heart failure (CHF). However, the pathophysiological basis of the reduced O2 uptake relative to work rate has not been elucidated. METHODS: To elucidate the hemodynamic basis of the reduced ratio of DeltaVO2/DeltaWR during exercise in severe CHF, 48 patients with CHF (15 patients in class I, 21 in class II and 12 in class III) performed maximal ergometer exercise with respiratory gas analysis. Cardiac output and systemic O2 extraction were measured at 1-min intervals during exercise. RESULTS: Both peak VO2 and peak cardiac output decreased as the severity of CHF advanced. Patients in class III showed significantly reduced DeltaVO2/DeltaWR than those in class I (8.2+/-0.9 vs. 9.8+/-1.5 ml/min/W, P<0.01). Cardiac output at rest was significantly lower, and O2 extraction at rest was significantly higher in class III than class I. The ratio of the increase in cardiac output to the increase in work rate (DeltaCO/DeltaWR) was significantly lower in class III than class I (42.5+/-14.5 vs. 60.6+/-10.3 ml/min/W), and the ratio of the increase in O2 extraction to the increase in work rate (DeltaO2 extraction/DeltaWR) was significantly higher in class III than class I (0.45+/-0.13 vs. 0.34+/-0.08%/W). The DeltaVO2/DeltaWR was significantly correlated with the DeltaCO/DeltaWR (r=0.67, P<0.01), and the DeltaCO/DeltaWR was inversely correlated with DeltaO2 extraction/DeltaWR (r=-0.65, P<0.01). CONCLUSIONS: Decreased O2 supply due to reduced cardiac output was not fully compensated by the increased O2 extraction. Reduced ratio of DeltaVO2/DeltaWR in advanced CHF reflected the severely attenuated cardiac output response to exercise.     

Effects of a weight reduction program with and without aerobic exercise in the metabolic syndrome

BACKGROUND: In the setting of a rural, primary care practice, evidence for the efficacy of intentional weight loss with or without aerobic exercise training (AET) in hypertensive patients with the metabolic syndrome remains controversial. DESIGN OF STUDY, METHODS: We analysed data of 52 hypertensives with the metabolic syndrome, who attended a weight management program with or without AET (diet/exercise group, n = 18; diet group, n = 20) for 36 months. Patients with a similar risk profile, who declined antihypertensive therapy beyond ACE inhibition, served as controls (n = 14). RESULTS: Body mass index (BMI) was significantly reduced over time in the diet and diet/exercise group (DeltaBMI: -7.2 +/- 1.1 and -6.6 +/- 1.5 kg/m2) vs. the control group (DeltaBMI: +0.4 +/- 1.3 kg/m2; p < 0.001 at 36 m). While systolic and diastolic blood pressures (BPs) did not change over time in controls (175 +/- 5/89 +/- 7 mm Hg), BPs were significantly reduced in the diet group (151 +/- 8/75 +/- 10 mm Hg) and in the diet/exercise group (139 +/- 12/71 +/- 8 mm Hg; p < 0.001 vs. diet group). Metabolic abnormalities were significantly improved over time in the diet group vs. controls, while AET did not add further benefits. However, heart rate recovery after acute exercise was improved and body cell mass (BCM) was increased in the diet/exercise group vs. patients without AET (p < 0.001 vs. others). CONCLUSIONS: Weight management significantly improves the lipid and nonlipid abnormalities of the metabolic syndrome, which is associated with reduced blood pressure. Addition of AET does not add further benefits on metabolic parameters, but improves blood pressure regulation. Effective lifestyle modifications are feasible even in the setting of a rural practice.     

Impact of changes in myocardial velocity assessed by tissue Doppler imaging during exercise on dynamic mitral regurgitation in patients with nonischemic cardiomyopathy

BACKGROUND: We evaluated the myocardial contractile reserve related to exercise-induced changes in functional mitral regurgitation (MR) by tissue Doppler imaging (TDI). METHODS: Supine bicycle exercise was performed in 35 patients with nonischemic cardiomyopathy (age 51 +/- 12 years; EF < 40%) and resting, and peak exercise 2D echocardiographic parameters, and TDI data were obtained. V(avg) was defined as the average of peak systolic velocities of six basal LV segments by TDI. Myocardial contractile reserve, which was calculated by [peak exercise V(avg)- baseline V(avg)], was represented as DeltaV(avg). Dyssynchrony index was derived from the standard deviation of the time to the peak systolic velocity of 12 LV segments. RESULTS: During exercise (9.7 +/- 2.4 minutes), the mean V(avg) increased from 4.0 +/- 0.8 cm/s to 5.5 +/- 1.0 cm/s. The effective regurgitant orifice area (ERO) and the ratio of MR jet area to the left atrial area (JLA%) were 1.9 +/- 2.9 mm(2) and 12 +/- 12%, respectively. During exercise, ERO and JLA% significantly increased to 6.2 +/- 6.4 mm(2) and 21 +/- 13% (P < 0.05), respectively, with individually variable changes. Tenting area was found to be an independent factor that showed a relationship with the baseline severity of MR (r = 0.561, P < 0.001). Dyssynchrony index and DeltaV(avg) were found to correlate with both maximal MR severity at peak exercise and changes in MR during exercise. By multivariate analysis, DeltaV(avg) was found to be an independent determinant of exercise-induced changes in ERO (DeltaERO; r =-0.707, P< 0.001) and changes in JLA% (DeltaJLA%; r =-0.663, P< 0.001). CONCLUSION: In patients with nonischemic cardiomyopathy, impaired contractile reserve assessed by TDI velocity data may be an independent determinant affecting exercise-induced changes in dynamic MR.     

Abdominal obesity predicts declining insulin sensitivity in non-obese normoglycaemics: the Insulin Resistance Atherosclerosis Study (IRAS)

AIM: Cross-sectional studies have demonstrated a relationship between obesity and insulin sensitivity (S(I)); however, there is a lack of evidence from longitudinal studies. METHODS: The Insulin Resistance Atherosclerosis Study (IRAS) estimated S(I) (x10(-4)/min.microU/ml) directly using a frequently sampled intravenous glucose tolerance test with minimal model analysis in 504 normoglycaemic subjects. Partial correlation coefficients (r) were calculated to compare the relationship of change in S(I) from baseline to 5 years later (DeltaS(I)) with baseline waist circumference (waist) as a measure of abdominal obesity and body mass index (BMI) as a measure of overall obesity. Mean DeltaS(I) was -1.06 (SD = 1.85). RESULTS: Higher baseline waist (r = -0.16; p = 0.0005), but not BMI (r = -0.005; p = 0.91), was associated with (-) DeltaS(I) in models including sex, ethnicity, clinical centre and baseline S(I), BMI, waist, age and physical activity. The waist-DeltaS(I) relationship differed across the levels of baseline BMI, being significant only in normal weight (r = -0.21) and overweight subjects (r = -0.16), but not in obese subjects. DeltaS(I) was correlated with a 5-year change in either obesity measure (Deltawaist: r = -0.22 and DeltaBMI: r = -0.20; p = 0.0001). CONCLUSIONS: Among non-diabetics, waist circumference was a strong predictor of declining S(I) among lean subjects, a modest predictor among overweight subjects, but was not predictive among obese individuals. Waist circumference should be considered, in addition to BMI, when identifying individuals at high risk of diabetes or the insulin resistance syndrome.     

Does waist circumference predict fat gain in children?

OBJECTIVE: The aim of this study was to identify in a group of 8-y-old prepubertal children the anthropometric parameter with the highest prediction power of overweight, measured 4 y later. SUBJECTS: One-hundred and twelve Caucasian children (54 males, 58 females), aged 8.7+/-0.9 y, were studied. RESULTS: An analysis of the association between relative body mass index (BMI) at follow-up (%) and some indexes of adiposity like relative BMI (%), waist circumference, subscapular and triceps skinfolds, the sum of four skinfolds and percentage fat mass measured at baseline, showed that relative BMI (relBMI) at baseline had the highest association with relBMI at follow-up (r=0.77; P<0.001); waist circumference had a slightly lower significant association with relBMI at follow-up (r=0.74; P<0.001). In a multiple regression analysis, waist circumference (adjusted for age) accounted for approximately 64% of the variation of relBMI at follow-up (P<0.001). RelBMI measured at baseline accounted for approximately 59% of the variation of relBMI at follow-up (P<0.001). Multiple logistic regression analysis included waist circumference, adjusted for age, mother's BMI and relBMI measured at baseline as independent variables in the final equation. In particular, each centimeter increase of waist circumference at the age of 8 y doubled the risk of having a relBMI greater than 120% at the age of 12 y. CONCLUSION: The results of this study, the first which has approached this investigation in children, showed that waist circumference measured at the age of 8 y, which is simple to perform and easy to reproduce, may be a promising index to assess adiposity as well as to predict overweight at puberty.     

Acylation-stimulating protein: effect of acute exercise and endurance training

INTRODUCTION: Acylation-stimulating protein (ASP) is an adipocyte-derived protein that contributes to fatty acid clearance. Regular exercise training improves fatty acid handling. OBJECTIVE: To examine the effect of acute exercise and short-term endurance training on ASP levels. SUBJECTS: Eight untrained men (age: 23.5+/-3.4 y; maximal power output (Wmax): 3.7+/-0.6 W/kg body weight). DESIGN: Subjects were trained for 2 weeks. Before and after training, blood was sampled during a 3-h exercise test, and insulin sensitivity was assessed by an insulin tolerance test. RESULTS: Before training, ASP levels decreased during exercise (from 17.9+/-2.9 to 15.5+/-3.7 nmol/l at t=0 vs 180, P<0.05). Endurance training decreased fasting ASP levels significantly (17.9+/-2.9 vs 13.4+/-2.3 nmol/l pre- and post-training, P<0.001). Interestingly, after 2 weeks of endurance training, ASP levels tended to increase during exercise (from 13.4+/-2.3 to 17.2+/-4.5 nmol/l at t=0 vs 180, P=0.09). Baseline ASP levels correlated negatively with insulin sensitivity both before (r=-0.86, P<0.01) and after training (r=-0.82, P<0.05). CONCLUSION: Short-term endurance training reduces baseline ASP levels. These data fit with the hypothesis that reduced ASP levels indicate improved ASP sensitivity.     

Exercise training-induced triglyceride lowering negatively correlates with DHEA levels in men with type 2 diabetes

OBJECTIVE: To investigate the effect of an exercise training program on lipid profile in correlation with DHEA level and body weight and body composition in type 2 diabetic men. DESIGN: Longitudinal, controlled clinical intervention study with exercise training consisting of an 8 week supervised program of aerobic exercise (75% VO(2) peak, 45 min), twice a week and intermittent exercise, once a week, on a bicycle ergometer. SUBJECTS: Sixteen men (age 45.4+/-7.2 y (mean+/-s.d.), HbA1c 8.15+/-1.7%, body mass index (BMI) 29.6+/-4.6 kg/m(2)) were randomly divided into two groups: trained group (n=8) and control group (n=8). MEASUREMENTS: Lipid, apo- and lipoprotein and DHEA concentrations. Cross-sectional areas of subcutaneous and visceral adipose tissue and mid-thigh muscle by magnetic resonance imaging. RESULTS: Training decreased visceral (153.25+/-38.55 vs 84.20+/-21.30 cm(2), P<0.001), subcutaneous (241.55+/-49.55 vs 198.00+/-39.99 cm(2), P<0.001) adipose tissue area and triglyceride levels (2.59+/-1.90 vs 1.79+/-1.08 nmol/l, P<0.05) and increased mid-thigh muscle cross-sectional area (148.30+/-36.10 vs 184.35+/-35.85 cm(2), P<0.001), and DHEA levels (11.00+/-3.10 vs 14.25+/-4.10 nmol/l, P<0.05) with no modification in body weight. Changes in triglycerides were negatively correlated with changes in DHEA (r=-0.81, P=0.03). This correlation was independent of changes in abdominal fat distribution. CONCLUSION: Training decreases abdominal fat depots, improves muscular mass and affects favourably triglyceride and DHEA levels. Changes in triglycerides and DHEA were inversely related.     

The effects of changing exercise levels on weight and age-related weight gain

OBJECTIVE: To determine prospectively whether physical activity can prevent age-related weight gain and whether changing levels of activity affect body weight. DESIGN/SUBJECTS: The study consisted of 8,080 male and 4,871 female runners who completed two questionnaires an average (+/-standard deviation (s.d.)) of 3.20+/-2.30 and 2.59+/-2.17 years apart, respectively, as part of the National Runners' Health Study. RESULTS: Changes in running distance were inversely related to changes in men's and women's body mass indices (BMIs) (slope+/-standard error (s.e.): -0.015+/-0.001 and -0.009+/-0.001 kg/m(2) per Deltakm/week, respectively), waist circumferences (-0.030+/-0.002 and -0.022+/-0.005 cm per Deltakm/week, respectively) and percent changes in body weight (-0.062+/-0.003 and -0.041+/-0.003% per Deltakm/week, respectively, all P<0.0001). The regression slopes were significantly steeper (more negative) in men than women for DeltaBMI and Delta%body weight (P<0.0001). A longer history of running diminished the impact of changing running distance on men's weights. When adjusted for Deltakm/week, years of aging in men and years of aging in women were associated with increases of 0.066+/-0.005 and 0.056+/-0.006 kg/m(2) in BMI, respectively, increases of 0.294+/-0.019 and 0.279+/-0.028% in Delta%body weight, respectively, and increases of 0.203+/-0.016 and 0.271+/-0.033 cm in waist circumference, respectively (all P<0.0001). These regression slopes suggest that vigorous exercise may need to increase 4.4 km/week annually in men and 6.2 km/week annually in women to compensate for the expected gain in weight associated with aging (2.7 and 3.9 km/week annually when correct for the attenuation due to measurement error). CONCLUSIONS: Age-related weight gain occurs even among the most active individuals when exercise is constant. Theoretically, vigorous exercise must increase significantly with age to compensate for the expected gain in weight associated with aging.     

Correlation between BMI, leisure habits and motor abilities in childhood (CHILT-project)

INTRODUCTION: The prevalence of childhood obesity is increasing with its negative medical and psychosocial consequences. This paper examines the association between body mass index (BMI), motor abilities and leisure habits of 668 children within the CHILT (Children's Health InterventionaL Trial) project. METHOD: A total of 668 children (51.0% boys; 49.0% girls) and their parents were questioned on sport and leisure behaviour of the children. The anthropometric data were measured. Motor abilities were determined by a body gross motor development test for children (K?perkoordinationstest für Kinder; KTK) and a 6-min run. RESULTS: The children were 6.70 +/- 0.42 y old, 122.72 +/- 5.36 cm tall and weighed 24.47 +/- 4.59 kg, the average BMI was 16.17 +/- 2.27 kg/m2. KTK showed an average motor quotient (MQ) of 93.49 +/- 15.01, the 6-min run an average of 835.24 +/- 110.87 m. Both tests were inversely correlated with BMI (KTK and BMI r=-0.164 (P<0.001); 6-min run and BMI r=-0.201 (P<0.001)); the group of overweight/obese children showed poorer results than the normal/underweight ones, even after adjustment for gender and age (in each case P<0.001). Children with the greatest extent of exercise achieve the highest MQ (P=0.035). SUMMARY: Overweight/obesity is associated with a poorer body gross motor development and endurance performance. On the other hand, an active lifestyle is positively correlated with a better gross motor development in first-grade children. Therefore, to prevent the negative consequences of physical inactivity and overweight/obesity early intervention to support exercise and movement is recommended.     

Serum leptin level as an indicator to predict the clinical efficacy of troglitazone in patients with type 2 diabetes mellitus

Troglitazone is effective in approximately 50% in patients with type 2 diabetes (NIDDM). In this study, we investigated the relations between serum leptin levels and clinical efficacy of troglitazone. Forty-five type 2 diabetic patients (23 men and 22 women) from our outpatient clinic were treated with troglitazone 400 mg daily for 12 weeks. Fasting plasma glucose (FPG), HbA1c, body weight, serum insulin and leptin concentrations were measured before and after troglitazone treatment. After 12 weeks of troglitazone treatment, FPG (before versus after, 179+/-33 vs. 138+/-26 mg/dl, mean+/-SD), HbA1c (7.8+/-1.3 vs. 6.9+/-1.0%), IRI (8.3+/-4.3 vs. 6.3+/-3.4 microU/ml) and HOMA-R index (homeostasis model assessment of insulin resistance) (3.8+/-2.4 vs. 2.2+/-1.3) decreased significantly, while body mass index (BMI) slightly increased (26.3+/-3.5 vs. 26.6+/- 3.6 kg/m(2)), and serum leptin remained unchanged (8.5+/-7.2 vs. 9.1+/-8.7 ng/ml). Reduction in FPG (DeltaFPG) after troglitazone treatment were correlated with reduction in HOMA-R (DeltaHOMA-R) (r=0.721, P<0.0001). DeltaFPG was correlated with serum leptin (r=0.441, P<0.01), HOMA-R (r=0.460, P<0.01) and FPG (r=-0.781, P<0.0001) at baseline, but not with BMI and serum IRI at baseline. Furthermore, serum leptin at baseline was significantly correlated with DeltaHOMA-R (r=0.634, P<0.01). Leptin concentration before treatment therefore, can be used as an predictor for clinical efficacy of troglitazone in patients with type 2 diabetes.     

Leisure-time physical activity and regular walking or cycling to work are associated with adiposity and 5 y weight gain in middle-aged men: the PRIME Study.

OBJECTIVE: To examine the influence of physical activity on body mass index (BMI), waist circumference (W) and body mass changes (DeltaBMI) in middle-aged men, with special regard to moderate-intensity activities. DESIGN: Longitudinal study of adults who participated in the PRIME Study. SUBJECTS: A cohort of 8865 men aged 50-59 y, free of coronary heart disease. MEASUREMENTS: BMI and W at baseline, body mass changes over a 5 y period. Detailed baseline assessment of net energy expenditure due to physical activity (PAE) in the preceding year, according to category of activity, by means of the MOSPA Questionnaire. PAE was expressed in weekly metabolic equivalent scores (MET h/week). RESULTS: After adjustment for confounders, the multiple regression analyses indicated that BMI, W and DeltaBMI were inversely associated with PAE spent in getting to work (P<10(-5), <10(-5) and 0.04, respectively) and practice of high-intensity (>or=6 MET) recreational activities (<0.01, <10(-5) and <0.01). Men who regularly spent more than 10 MET h/week in walking or cycling to work had a mean BMI, W and DeltaBMI respectively 0.3 kg/m(2), 1 cm and 0.06 kg/m(2) lower than those who did not expend energy in getting to work. In the subgroup of subjects who did not perform high-intensity activities, the level of recreational PAE was inversely associated with BMI and W but not with subsequent weight-gain. CONCLUSION: These findings indicate that, in middle-aged men, physical activities of moderate-intensity, which are probably easier to promote than more vigorous activities and, in particular, a more current daily activity, walking or cycling to work, may have a favourable effect on body fat markers and body mass gain.     

Effect of resistance exercise (body building) training on serum leptin levels in young men. Implications for relationship between body mass index and serum leptin

Available data about the influence of exercise on leptin level are controversial, and there are no studies concerning leptin levels in trained men with low fat mass plus large increase of muscle. 65 healthy young male matched for age were separated in three groups. 1) 25 non-professional body builders; 2) 21 mild overweight sedentary subjects; 3) 19 normal weight sedentary controls. Body composition was determined by bioelectrical impedance. Serum leptin was measured in duplicate by RIA. Statistics: Student's t and Pearson's test. Athletes showed similar BMI than overweight subjects: 26.98+/-0.49 vs 27.12+/-0.41 but lower fat mass: 12.53+/-0.96 vs 16.16+/-1.01 % (p=0.0064) and lower leptin: 4.66+/-0.51 vs 7.31+/-0.76 microg/l (p=0.014). Athletes showed higher BMI than controls: 26.98+/-0.49 vs 23.08+/-0.30 (p<0.0001) but similar fat mass: 12.53+/-0.96 vs 12.48+/-0.73% and leptin: 4.66+/-0.51 vs 4.79+0.58 microg/l. Overweight subjects showed higher BMI than controls: 27.12+/-0.41 vs 23.08+/-0.30 (p<0.0001), higher fat mass: 16.16+/-1.01 vs 12.48+/-0.73% (p=0.0064) and higher leptin: 7.31+/-0.76 vs 4.79+/-0.589 microg/l (p=0.014). When leptin was calculated by fat mass no differences were observed between the three groups. There was a significant correlation between leptin and fat mass in all groups. Leptin correlated with BMI in overweight subjects (r=0.438, p=0.0463), but this correlation was not observed either in athletes or in controls. In conclusion 1) regardless of the high BMI characteristic of body builders, no correlation was observed with leptin; 2) trained state induced by resistance exercise does not influence leptin production independently of variations in body composition.     

Cardiopulmonary evidence of exercise-induced silent ischaemia.

BACKGROUND: Exercise-induced ST changes, suggestive of cardiac ischaemia, are found in asymptomatic patients. METHODS: Gas exchange kinetics were studied during exercise to help to separate patients affected by epicardial coronary disease from those without. Forty-eight patients, without angina symptoms and showing significant changes of ST during exercise, underwent a coronarography and maximal cardiopulmonary exercise test. Thirty-five healthy individuals of matched age and sex underwent a cardiopulmonary exercise test as controls. RESULTS: Patients were grouped according to the presence (group 1, n = 35) or the absence (group 2, n = 13) of significant coronary lesions at angiography. When corrected for predicted oxygen consumption (VO2) at peak exercise and at anaerobic threshold, results showed a low VO2 at peak exercise and anaerobic threshold in group 1 (68 +/- 19 and 84 +/- 17% of predicted, respectively) compared with normal subjects (91 +/- 19 and 96 +/- 24% of predicted VO2) and group 2 patients (86 +/- 17 and 96 +/- 18%). Also the ischaemic threshold, when normalized for predicted workload at peak exercise, occurred earlier in group 1 (67 +/- 22%) than in group 2 (87 +/- 19%). The time-related (Delta)VO2/Deltawork relationship showed a significant flattening above the anaerobic threshold in group 1 (7.4+/-2.2 versus 9.4+/-1.4 ml/watt per minute, P < 0.01), but not in controls or in group 2. Also the DeltaVO2/Deltawork relationship, above the ischaemic threshold, flattened in group 1, but not in group 2. CONCLUSION: The suggestion of major coronary disease in patients with exercise-induced ST changes is given by: (i) a flattening of the DeltaVO2/Deltawork relationship, above both the ischaemic and anaerobic thresholds; and (ii) low VO2 values at anaerobic and ischaemic thresholds.     

Milk intake is inversely related to obesity in men and in young women: data from the Portuguese Health Interview Survey 1998-1999

OBJECTIVE: To assess the relationships between milk intake and body mass index (BMI) in a representative sample of the mainland Portuguese population. DESIGN: Cross-sectional study. SETTING: National Health Interview Survey 1998-1999. Average daily milk intake was calculated by a frequency questionnaire that also assessed the average volume of one serving. BMI was derived from the subject's reported height and weight. SUBJECTS: A total of 17,771 men and 19 742 women aged > or =18 y. RESULTS: In men, milk intake was inversely related to BMI (r = -0.10, P < 0.001), whereas the relationship in women was weaker (r = -0.06, P < 0.001). In men, prevalence of milk consumers was lower in obese (62%) and in overweight (68%) than in normal weight subjects (71%, P < 0.001). After adjusting for age, region, physical activity, smoking, number of meals and educational level, milk intake decreased with increasing BMI (adjusted mean +/- s.e.: 280 +/- 5, 266 +/- 5 and 246 +/- 7 ml/day for normal, overweight and obese subjects, respectively, P < 0.001), even after excluding subjects who did not consume milk (368 +/- 5, 353 +/- 6 and 346 +/- 8 ml/day, P < 0.02). In women, prevalence of milk consumers was lower in obese (71%) and in overweight (72%) than in normal weight subjects (76%, P < 0.001). In women younger than 55 y, milk intake decreased with increased BMI categories (291 +/- 9, 271 +/- 10 and 269 +/- 11 ml/day for normal, overweight and obese subjects, respectively, P < 0.001), whereas no relationship was found in the older group. CONCLUSIONS: Increased calcium intake is slightly but significantly negatively related with BMI in men and premenopausal women. The lack of relationship in older women might be due to the hormonal status, but awaits further investigation.     

Adiponectin levels do not change with moderate dietary induced weight loss and exercise in obese postmenopausal women

OBJECTIVE: The purpose of this study was to determine changes in adiponectin levels with moderate weight loss, weight loss plus aerobic exercise, or weight loss plus resistive exercise in overweight and obese, sedentary postmenopausal women. DESIGN: Longitudinal, clinical intervention study of 6-month (3 x /week) program of either weight loss (WL, n=15), weight loss + aerobic exercise (WL+AEX, n=16), or weight loss + resistive exercise (WL+RT, n=9) SUBJECTS: We studied 40 sedentary, overweight and obese (body mass index, BMI=32+/-1 kg/m(2), X+/-s.e.m.) postmenopausal (57+/-1y) women. MEASUREMENTS: Fat mass and fat-free mass (FFM) by dual-energy X-ray absorptiometry, plasma insulin, leptin, and adiponectin by radioimmunoassay. RESULTS: Age, body weight, BMI, waist and hip circumferences, waist-to-hip ratio, VO(2)max, percent fat, total body fat mass, FFM, and fasting plasma glucose, insulin, leptin, and adiponectin concentrations were similar among WL, WL+AEX, and WL+RT groups before the interventions. In all women combined, body weight, BMI, and waist and hip circumferences decreased (P < 0.001). There was a significant absolute decrease in percent body fat from 47 to 44%, representing a 13% decrease in total fat mass and a -1.6% change in FFM. Fasting concentrations of plasma adiponectin did not change (40+/-16%, P=NS), whereas fasting plasma glucose, insulin, and leptin all decreased (P<0.001). CONCLUSIONS: Plasma adiponectin levels do not change with a 6-month moderate weight reduction program even when accompanied by aerobic or resistive exercise training in overweight and obese postmenopausal women.     

Decreased plasma adiponectin is associated with insulin resistance and HDL cholesterol in overweight subjects

The purpose of this study was to investigate plasma adiponectin concentration and its relation with metabolic parameters in overweight and normal weight subjects. The study was carried out in 46 overweight subjects (20 male, 26 female; mean age 39.4 +/- 10.2 years) and 48 (19 male, 29 female; mean age 36.1 +/- 10.6 years) sex- and age-matched normal weight subjects. Anthropometric measurements were recorded and adiponectin, glucose, insulin, lipid profile, total homocysteine (tHcy) and fibrinogen levels were measured. The insulin resistance index was assessed by homeostasis model assessment for insulin resistance (HOMA-IR). Plasma mean adiponectin concentrations of the overweight subjects were significantly lower than those of normal weight subjects (15.0 +/- 4.2 vs 17.3 +/- 5.6 ng/ml) (P<0.05). In overweight subjects, adiponectin levels negatively correlated with body weight (r = -0.35, P<0.001), body mass index (BMI) (r = -0.28, P<0.006), systolic blood pressure (r = -0.21, P<0.04), fasting insulin (r = -0.19, P<0.01) and HOMA-IR (r = -0.20, P<0.01) and positively with high-density lipoprotein cholesterol (HDL-C) (r = 0.27, P<0.009). Overweight subjects with low HDL-C levels had significantly decreased plasma adiponectin levels compared to those with high HDL-C levels (P<0.05). Multiple regression analysis revealed that BMI, HOMA-IR and HDL-C explained 12%, 20% and 15% variance of the adiponectin concentrations. These findings may suggest that circulating adiponectin is associated with insulin resistance and HDL-C levels independent from BMI in overweight subjects.