Lipid profile, BMI, body fat distribution, and aerobic fitness in men with metabolic syndrome

The association of obesity and serum leptin levels with complete blood count and some serum biochemical parameters in Iranian overweight and obese individuals

Background: Obesity has been suggested to be well correlated with altered levels of complete blood count (CBC) parameters. In this study, the relationship of body mass index (BMI) and circulating leptin levels with CBC among obese and overweight adults was examined.

Methods: CBC and biochemical parameters, WBC and hematological profiles, leptin levels, related factors to liver, and kidney and lipid profiles were measured among 184 obese and overweight people aged 18–60 years. Statistical analysis was performed using SPSS software. To assess the normality of data, the Kolmogorov–Smirnov test was used. Logarithmic transformation was performed for some variables with non-normal distribution. The association between 2 quantitative variables was measured using bivariate correlation (Pearson or Spearman). Pearson correlations and multiple regression analysis were performed to assess the correlation between variables. Simple and multiple regression analyses were performed to predict some variables. P- value <0.05 was considered significant.

Results: Hematocrit, insulin, fasting blood sugar, uric acid, TG, LDL-C, VLDL-C, and ALT were positively correlated with BMI (p=0.041, r=0.149 for hematocrit; p≤0.001, r=0.520 for insulin; p≤0.001, r=0.363 for FBS; p≤0.001, r=0.309 for uric acid; p=0.015, r=0.189 for TG; p=0.030, r=161 for LDL-C; p=0.019, r=0.181 for VLDL-C; p≤0.001, r=0.299 for ALT), whereas urea and HDL-C were negatively correlated with BMI (p≤0.001, r=-0.368 for urea; p≤0.001, r=-0.297 for HDL-C). Moreover, LDL-C and insulin were positively correlated with leptin (P = 0.011, r = 0.194 for LDL-C, P = 0.013, r = 0.114 for insulin) and hematocrit, urea, creatinine, TG and VLDL-C were negatively correlated with leptin (p=0.040, r=-0.162 for hematocrit; p≤0.001, r=-0.305 for urea; p=0.007, r=-0.219 for creatinine; p=0.025, r=0.188 for TG; p=0.007, r=-0.218 for VLDL-C). Our analysis showed that white blood cell was positively correlated with leptin (β=17.36, p=0.048). Also, other CBC parameters had no significant correlations with BMI and leptin.

Conclusion: According to the findings of this study, BMI had a negative association with urea and HDL-C, while BMI had a positive association with insulin, hematocrit, FBS, uric acid, TG, VLDL-C, LDL-C, and ALT. Furthermore, leptin had a negative association with hematocrit, creatinine, and urea, TG, VLDL-C and a positive association with LDL-C and insulin among the participants of this study.

Effects of different exercise loads on the thyroid hormone levels and serum lipid profile in swimmers

Background

The aim of this study was to investigate the effects of different exercise loads (short, medium and long swimming distances) on the thyroid hormone (THs) levels and serum lipid profiles of male professional swimmers.

Materials and methods

The participants in this study were 20 healthy male professional swimmers aged 18–22 years, who all competed at an elite level. The THs levels [thyroid-stimulating hormone (TSH), triiodothyronine (T3) and thyroxine (T4)] and serum lipid profile were also obtained.

Results

It was determined that the TSH and T4 values increased after exercise (p < 0.05). When compared to the pretest values, the increase in the TSH and T4 values following the L400 tests was statistically significant (p < 0.001 and p < 0.05). It was also determined that the changes in the cholesterol, high-density lipoprotein (HDL) and total glucose (TG) values were significant after exercise (p < 0.001). There was no significant difference between the groups in terms of the low-density lipoprotein (LDL) values (p = 0.07). According to the results, the cholesterol counts for the M200 and L400 groups were lower than the pretest counts (p < 0.001). When compared to the pretest values, the decrease in the HDL counts for the M200 and L400 groups was higher than the pretest HDL counts (p < 0.001 and p < 0.05, respectively). Further, the triglycerides counts for the M200 and L400 groups were higher than the pretest counts (p < 0.001).

Conclusions

Different exercise loads can have a positive impact on the physical health of swimmers via their lipid profiles and THs. Additionally, swimming exercise could be considered an efficient protective strategy against metabolic disorders, as it serves to balance the serum lipid levels.

Predictive value of body mass index to metabolic syndrome risk factors in Syrian adolescents

BACKGROUND

Obesity has become a serious epidemic health problem in both developing and developed countries. There is much evidence that obesity among adolescents contributed significantly to the development of type 2 diabetes and coronary heart disease in adulthood. Very limited information exists on the prevalence of overweight, obesity, and associated metabolic risk factors among Syrian adolescents. Therefore, the purpose of this study was to determine the relationship between obesity determined by body mass index and the major metabolic risk factors among Syrian adolescents.

METHODS

A cross-sectional study of a randomly selected sample of 2064 apparently healthy Syrian adolescents aged 18 to 19 years from Damascus city, in Syria, was performed. Body mass index and blood pressure were measured. Serum concentrations of glucose, triglycerides, total cholesterol, high-density lipoprotein-cholesterol, and low-density lipoprotein-cholesterol were determined. Metabolic syndrome was defined using the national criteria for each determined metabolic risk factor. Individuals with a body mass index 25 to 29.9 were classified as overweight, whereas individuals with a body mass index ≥30 were classified as obese. A receiver operating characteristics curve was drawn to determine appropriate cut-off points of the body mass index for defining overweight and obesity, and to indicate the performance of body mass index as a predictor of risk factors.

RESULTS

The obtained data showed that blood pressure and the overall mean concentrations of fasting blood sugar, triglycerides, cholesterol, low-density lipoprotein-cholesterol, and triglycerides/high-density lipoprotein-cholesterol were significantly higher in overweight and obese adolescent groups (p <0.0001) in comparison with the normal group. Based on receiver operating characteristics calculation for body mass index and some metabolic risks, the data suggest the best body mass index cut-offs ranged between 23.25 and 24.35 kg/m².

CONCLUSIONS

A strong association between overweight and obesity as determined by body mass index and high concentrations of metabolic syndrome components has been demonstrated. Although body mass index values were lower than the international cut-offs, these values were good predictors of some metabolic abnormalities in Syrian adolescents; body mass index is a good predictor of these abnormalities in this population.

Is cardiorespiratory fitness impaired in PCOS women? A review of the literature

PURPOSE

Polycystic ovary syndrome (PCOS) is a common and heterogeneous endocrine disorder, affecting 8-12% of reproductive-aged women. Insulin resistance and body fat excess are common features in these subjects. Increased physical activity and diet modifications are the first recommended approach in the management of these women, at least in overweight/obese subjects. Evaluation of cardiorespiratory fitness (CRF) is important in assessing exercise performance and in monitoring the effects of physical exercise interventions. Several studies have shown that CRF may be impaired in metabolic and endocrine disorders. However, there are little data on this issue in PCOS women. The aim of this narrative review is to critically evaluate whether aerobic capacity is altered in PCOS women, focusing on maximal oxygen uptake.

METHODS

An updated search of the literature was performed, identifying papers with maximal oxygen consumption measurements in women with PCOS compared to healthy controls.

RESULTS

We have identified six studies on this specific topic: four of them showed an alteration of maximal oxygen consumption in PCOS women, whereas two did not. However, taken together these studies suggest that CRF may be strikingly impaired in both normal-weight and overweight/obese subjects with this condition.

CONCLUSIONS

Women with PCOS appear to be characterized by a reduced cardiopulmonary fitness. However, further research on this topic is needed. This information may hopefully help clinicians and exercise specialist in planning individualized exercise programs aimed at improving the metabolic and endocrine outcomes in these women.

High-intensity aerobic interval training improves aerobic fitness and HbA1c among persons diagnosed with type 2 diabetes

PURPOSE

It remains to be established how high-intensity aerobic interval training (HAIT) affects risk factors associated with type 2 diabetes (TD2). This study investigated effects of HAIT on maximal oxygen uptake (VO_2max), glycated Hemoglobin type A1C (HbA1c), insulin resistance (IR), fat oxidation (FatOx), body weight (BW), percent body fat (%BF), lactate threshold (LT), blood pressure (BP), and blood lipid profile (BLP) among persons with T2D. Results were compared to the effects after a moderate-intensity training (MIT) program.

METHODS

Thirty-eight individuals with T2D completed 12 weeks of supervised training. HAIT consisted of 4 × 4 min of walking or running uphill at 85-95% of maximal heart rate, and MIT consisted of continuous walking at 70-75% of maximal heart rate.

RESULTS

A 21% increase in VO_2max (from 25.6 to 30.9 ml kg^-1 min^-1, p < 0.001), and a reduction in HbA1c by -0.58% points (from 7.78 to 7.20%, p < 0.001) was found in HAIT. BW and body mass index (BMI) was reduced by 1.9% (p < 0.01). There was a tendency towards an improved FatOx at 60% VO_2max (14%, p = 0.065). These improvements were significant different from MIT. Both HAIT and MIT increased velocity at LT, and reduced %BF, waist circumference, hip circumference, and BP, with no significant differences between the two groups. Correlations were found between change in VO_2max and change in HbA1c when the two intervention groups were combined (R = -0.52, p < 0.01).

CONCLUSION

HAIT is an effective exercise strategy to improve aerobic fitness and reduce risk factors associated with T2D.

Effect of walking exercise on abdominal fat, insulin resistance and serum cytokines in obese women

[Purpose]

The purpose of the study was to investigate the effect of 12-week walking exercise on abdominal fat, insulin resistance and serum cytokines in obese women.

[Methods]

Following baseline measurements, obese women (N = 20) who met obesity criterion of BMI at 25 kg/m² or greater were randomly assigned to the control (n = 10) or exercise groups (n = 10). Women assigned to the exercise group participated in a walking exercise (with an intensity of 50-60% of predetermined VO²max, a frequency of 3 days per week and duration of 50-70 minutes targeting 400 kcal of energy expenditure per session) for 12 weeks, while women assigned to the control group maintained their sedentary lifestyle. After the 12-week walking intervention, post-test measurements were conducted using the same procedure as the baseline measurement. Analyses of variance with repeated measures were used to evaluate any significant time by group interactions for the measured variables.

[Results]

With respect to body fat parameters, significant time-by-group interactions were found in the abdominal subcutaneous (p = < 0.001) and visceral adipose tissues (p = 0.011). The exercise group had significant reductions in both subcutaneous and visceral adiposity, and the control group had no significant changes in those parameters. Similarly, there were significant time by group interactions in fasting glucose (p = 0.008), HOMA-IR (p = 0.029), serum TNF-α (p = 0.027), and IL-6 (p = 0.048) such that the exercise group had significant reductions in those parameters, with no such significant changes found in the control group. The exercise group also had a significant increase in serum adiponectin (p = 0.002), whereas the control group had no significant change in the parameter.

[Conclusion]

In summary, the current findings suggest that walking exercise can provide a safe and effective lifestyle strategy against abdominal obesity and serum insulin resistance markers in obese women.

What enables size-selective trophy hunting of wildlife?

Although rarely considered predators, wildlife hunters can function as important ecological and evolutionary agents. In part, their influence relates to targeting of large reproductive adults within prey populations. Despite known impacts of size-selective harvests, however, we know little about what enables hunters to kill these older, rarer, and presumably more wary individuals. In other mammalian predators, predatory performance varies with knowledge and physical condition, which accumulates and declines, respectively, with age. Moreover, some species evolved camouflage as a physical trait to aid in predatory performance. In this work, we tested whether knowledge-based faculty (use of a hunting guide with accumulated experience in specific areas), physical traits (relative body mass [RBM] and camouflage clothing), and age can predict predatory performance. We measured performance as do many hunters: size of killed cervid prey, using the number of antler tines as a proxy. Examining ∼4300 online photographs of hunters posing with carcasses, we found that only the presence of guides increased the odds of killing larger prey. Accounting for this effect, modest evidence suggested that unguided hunters presumably handicapped with the highest RBM actually had greater odds of killing large prey. There was no association with hunter age, perhaps because of our coarse measure (presence of grey hair) and the performance trade-offs between knowledge accumulation and physical deterioration with age. Despite its prevalence among sampled hunters (80%), camouflage had no influence on size of killed prey. Should these patterns be representative of other areas and prey, and our interpretations correct, evolutionarily-enlightened harvest management might benefit from regulatory scrutiny on guided hunting. More broadly, we suggest that by being nutritionally and demographically de-coupled from prey and aided by efficient killing technology and road access, wildlife hunters in the developed world might have overcome many of the physical, but not knowledge-based, challenges of hunting.

Efeitos de um programa de exercicios fisicos sobre a pressao arterial e medidas antropometricas

INTRODUÇÃO: O número de pessoas com sobrepeso ou obesidade tem alcançado índices alarmantes no Brasil. Condutas não-medicamentosas devem ser a estratégia inicial para o tratamento de indivíduos com sobrepeso e hipertensão leve a moderada. OBJETIVO: Analisar os efeitos de um programa de condicionamento físico realizado por um período de 24 meses sobre pressão arterial e composição corporal em indivíduos normotensos e pré-hipertensos. MÉTODOS: Participaram do estudo 35 indivíduos randomizados como: (GI) normotensos (n = 16), 51 ± 1 anos, pressão arterial sistólica (PAS) < 120 e diastólica (PAD) < 80 mmHg; e (GII) pré-hipertensos (n = 19), 54 ± 1 anos, PAS de 139 e PAD de 89 mmHg. RESULTADOS: Após 24 meses de programa de condicionamento físico, os indivíduos do GII apresentaram redução na PAS (-3,6 ± 0,94 e -10 ± 0,94 mmHg, p < 0,05, respectivamente) e PAD (-6,5 ± 1 e -7,1 ± 0,9 mmHg, p < 0,05). Em ambos os grupos houve redução do perímetro de cintura (-1,74 ± 3,5 e -1,91 ± 4 cm, p < 0,05) e índice de adiposidade (-1,21 ± 2,6 e -1,35 ± 3,1%, p < 0,05), aumento da massa corporal (+1,27 ± 3 e +1,32 ± 3,8 kg, p < 0,05), IMC (+0,72 ± 0,4 e +0,54 ± 0,60 kg/m2, p < 0,05) e massa corporal isenta de gordura (+0,91 ± 0,5 e +0,77 ± 4,8 kg p < 0,05). CONCLUSÃO: Este programa reduziu PA, o perímetro de cintura e o índice de adiposidade em indivíduos pré-hipertensos, constituindo-se, portanto, numa estratégia segura e de baixo custo na prevenção de doenças cardiovasculares e melhoria da condição de saúde da população.

Dyslipidaemia and dysglycaemia in HIV-infected patients on highly active anti-retroviral therapy in Kumasi Metropolis

BACKGROUND

Diet and genetic predisposition significantly affect lipid metabolism in the individual. This metabolic effect is further challenged in patients infected with HIV and on HAART. The prolonged use of HAART is associated with lipodystrophy, dyslipidemia, and insulin resistance.

OBJECTIVE

To determine the prevalence of lipid dysregulation and dysglycaemia in HIV infected patients on HAART in the Kumasi metropolis.

METHODS

This cross sectional study was conducted between October 2009 and June 2010, and 305 HIV-infected patients consisting of 164 patients on HAART for at least six months and 141 HAART-naive patients constituted HIV-positive patients, not on HAART and whose CD4 were not below 320 cell/ml as the control. Data was analyzed using Graph Pad Prism (version 5.0). Unpaired t-test, linear and multivariate regression analyses, was used to predict glucose level from the various parameters. Anthropometric parameters consisting of body weight, waist and hip circumferences, height, bicep and triceps skin fold were measured with a pair of calipers. Lipid profile and fasting blood glucose were determined by enzymatic methods. CD4 counts and hemoglobin were determined.

RESULTS

Fasting plasma, glucose (3.81±0.08mmol/l, 4.48±0.17mmol/l), total cholesterol (3.05± 0.0 8mmol/l, 4.54±0.08mmol/l) LDL (2.24±0.07mmol/l, 2.87±0.07mmol/l) and HDL (0.85±0.04mmol/l, 0.97±0.03mmol/l) between the control and case respectively were significantly raised (P< 0.001), though within the physiological range. The significantly increased hip and waist circumferences, waist-to-hip ratio (0.85±0.22, 0.88±0.01) of the control and case correlated with lipodystrophy.

CONCLUSION

HAART was associated with lipodystrohy and, the risk of developing type II diabetes among the HAART experienced group was 5 times higher than the HAART naive group.

Predictors of effects of lifestyle intervention on diabetes mellitus type 2 patients

The main aim of the study was to identify predictors of the effects of lifestyle intervention on diabetes mellitus type 2 patients by means of multivariate analysis. Data from a previously published randomised clinical trial, which compared the effects of a rehabilitation programme including standardised education and physical training sessions in the municipality's health care centre with the same duration of individual counseling in the diabetes outpatient clinic, were used. Data from 143 diabetes patients were analysed. The merged lifestyle intervention resulted in statistically significant improvements in patients' systolic blood pressure, waist circumference, exercise capacity, glycaemic control, and some aspects of general health-related quality of life. The linear multivariate regression models explained 45% to 80% of the variance in these improvements. The baseline outcomes in accordance to the logic of the regression to the mean phenomenon were the only statistically significant and robust predictors in all regression models. These results are important from a clinical point of view as they highlight the more urgent need for and better outcomes following lifestyle intervention for those patients who have worse general and disease-specific health.

Pericardial fat loss in postmenopausal women under conditions of equal energy deficit

Weight loss induced by caloric restriction (CR) or aerobic exercise can reduce pericardial fat, and these reductions may help improve cardiovascular health.

PURPOSE

We examined whether combining CR with aerobic exercise enhances pericardial fat loss compared with a CR-only intervention designed to elicit equivalent reductions in body weight. We also examined the relationship between changes in pericardial fat and changes in maximal oxygen consumption (V˙O2max), a measure of cardiorespiratory fitness.

METHODS

Thirty-two abdominally obese postmenopausal women (mean age=58 yr; 78% Caucasian) were randomly assigned to one of three interventions of equal energy deficit (∼2800 kcal·wk) for 20 wk: CR only (n=8), CR + moderate-intensity exercise (n=15), or CR + vigorous-intensity exercise (n=9). The volume of pericardial fat around the coronary arteries was measured by computed tomography.

RESULTS

Women in the CR, CR + moderate-intensity, and CR + vigorous-intensity groups had similar baseline characteristics. The mean ± SD value for pericardial fat before weight loss was 79.07 ± 32.90 cm (range=34.04-152.74 cm), with no difference among groups (P=0.89). All three interventions significantly reduced body weight (15%), waist circumference (10%), and abdominal visceral fat (28%) to a similar degree. There was also a 17% reduction in pericardial fat (-12.75 ± 6.29 cm, P<0.0001), which did not differ among groups (P=0.84). Changes in pericardial fat were inversely correlated with changes in V˙O2max (r=-0.37, P=0.05), but not after adjusting for intervention group and change in body weight.

CONCLUSIONS

Weight loss interventions of equal energy deficit have similar effects on pericardial fat in postmenopausal women, regardless of whether the energy deficit is due to CR alone or CR plus aerobic exercise.

Effects of Aerobic Exercise vs. Resistance Training on Endothelial Function in Women with Type 2 Diabetes Mellitus

BACKGROUND

There is controversy over whether aerobic or resistance exercise is more effective for improving endothelial function in type 2 diabetes mellitus (T2DM). This study was aimed to investigate the effects of an aerobic and resistance training program on endothelial function, and the influences of glycemic control, body weight changes, and aerobic capacity in T2DM.

METHODS

Total 40 overweight women with T2DM were assigned into 3 groups: an aerobic exercise group (AEG, n=13), resistance exercise group (REG, n=12), and control group (CG, n=15), and followed either brisk walking for the AEG or resistance band training for the REG, 60 minutes per day, 5 days per week for 12 weeks with monitoring daily activity using accelerometers. We assessed endothelial function by flow-mediated dilation (FMD), and aerobic capacity by oxygen uptake at anaerobic threshold (AT_VO(2)) at baseline and following training program.

RESULTS

The mean participants' age was 57.0±6.8 years, and body mass index (BMI) was 27.0±2.3 kg/m(2). After intervention, FMD increased by 2.2±1.9% in AEG, which differed from REG and CG (P=0.002), despite of decreased body weight (BW) in both AG and RG (2.8±2.5%, P=0.002; 1.6±2.0%, P=0.017, respectively). A significant increased AT_VO(2) and decreased HbA1c were found only in AEG. In all participants, FMD was changed with the significant relations to the AT_VO(2) (r=0.348, P=0.035), but not to HbA1c levels or BW.

CONCLUSION

Aerobic exercise appears to be more beneficial than resistance exercise for improving endothelial function in T2DM. In addition, aerobic capacity could be a better predictor of changes in FMD than BW and glycemic control.

Upright water-based exercise to improve cardiovascular and metabolic health: a qualitative review

Research regarding the benefits of exercise for cardiovascular and metabolic health is extensive and well-documented. However, weight-bearing exercise may not be suitable for individuals with orthopaedic or musculoskeletal limitations, excess adiposity or other medical conditions. Water-based exercise may provide an attractive alternative to land-based exercise for achieving improved health and fitness in these populations. Although swimming is a popular form of water-based exercise it requires specific skills and is often undertaken at intensities that may not be safely prescribed in patient populations. Therefore upright, water-based exercise has been suggested as a viable water-based alternative. However, surprisingly little is known about the effects of upright water-based exercise on improvements in cardiovascular and metabolic health. Limited evidence from water-based studies indicate that regular deep or shallow water exercise can exert beneficial effects on cardiorespiratory fitness, strength, and body fat distribution. However, the impacts of water-based exercise on lipid profile, bodyweight, and carbohydrate metabolism are still unclear. Further studies are warranted to establish the effects of non-swimming, water-based exercise on cardiometabolic risks in humans.

Comparison of aerobic exercise capacity and muscle strength in overweight women with and without polycystic ovary syndrome

OBJECTIVE

To assess maximal aerobic capacity (VO2max) and muscle strength in overweight and obese women with polycystic ovary syndrome (PCOS) and determine their relationship with metabolic and hormonal factors.

DESIGN

Cross-sectional study.

SETTING

Clinical Research Unit.

POPULATION

Overweight and obese women with PCOS (n = 10) and age-and weight-matched healthy controls (n = 16).

METHODS

VO2max was measured during an incremental treadmill test and maximal isometric (ImS) and isokinetic knee extensor strength (IkS) (120 degrees/second) were assessed by isokinetic dynamometry.

MAIN OUTCOME MEASURES

VO2max, ImS, IkS, waist circumference, blood lipids, glucose, insulin, insulin resistance (homeostatic model assessment [HOMA2]), C-reactive protein (CRP), hormonal profile.

RESULTS

PCOS women had higher levels of testosterone and free testosterone (P < or = 0.05), but there were no significant differences in any cardiovascular disease (CVD) risk markers between the groups. VO2max was similar in women with PCOS and healthy controls (PCOS 26.0 +/- 4.1 ml/kg/minute, controls 25.7 +/- 3.8 ml/kg/minute; P = 0.90), as was ImS (PCOS 1.50 +/- 0.54 Nm/kg, controls 1.50 +/- 0.47 Nm/kg; P = 0.96) and IkS (PCOS 1.04 +/- 0.32 Nm/kg, controls 1.16 +/- 0.23 Nm/kg; P = 0.32). VO2max was inversely related to waist circumference, insulin, HOMA2 and CRP. Waist circumference was inversely associated with ImS and IkS. No significant associations between exercise parameters and hormonal variables were identified.

CONCLUSIONS

Compared to age- and weight-matched healthy overweight and obese women with similar insulin resistance and CVD risk profiles, women with PCOS had similar aerobic capacity and muscle strength. This suggests PCOS, at least in the absence of an adverse metabolic profile is unlikely to limit physical function. Larger studies examining the effects of PCOS on exercise tolerance in a diverse range of PCOS phenotypes is required.

Anti-aging therapy through fitness enhancement

Physical exercise is proposed as a highly effective means of treating and preventing the main causes of morbidity and mortality – most of which are associated with aging – in industrialized countries. Low physical fitness is an important risk factor for cardiovascular and all-causes morbidity and mortality; indeed, it is even a predictor of these problems. When properly measured, the assessment of physical fitness can be a highly valuable indicator of health and life expectancy and, therefore, should be performed routinely in the clinical setting. Individually adapted training programs could be prescribed based on fitness assessment results and an adequate knowledge of patient lifestyle and daily physical activity. Such training programs would allow people to develop their maximum physical potential, improve their physical and mental health, and attenuate the negative consequences of aging.

Relationship of insulin sensitivity to aerobic capacity in Standardbred mares and geldings

The objective of this study was to determine the relationship between insulin sensitivity and aerobic capacity and serum adipocytokine (leptin, adiponectin) concentrations in 14 mature, unconditioned Standardbred horses (eight mares, six geldings). Each horse underwent a euglycaemic–hyperinsulinaemic clamp (EHC) and a frequently sampled intravenous glucose tolerance test (FSIGT) for assessment of insulin sensitivity. Aerobic capacity was determined by measurement of the peak rate of oxygen uptake (V˙O2peak) during an incremental exercise test (IET). Serum leptin and adiponectin concentrations were measured in baseline samples obtained before tests of insulin sensitivity. Mean body weight, condition score, V˙O2peak and run time during the IET did not differ between the sex groups. However, minimal model analysis of the FSIGT showed that insulin sensitivity (SI, ×10−4 l mU−1 min−1) was higher (P = 0.002) in geldings (4.21±0.78) than in mares (2.43±0.95), while the acute insulin response to glucose (AIRg) and glucose utilization independent of insulin (SG) were significantly higher in mares. Similarly, glucose uptake (M) per unit of serum insulin (I) during the EHC (M/I ratio) tended (P = 0.08) to be higher in geldings than in mares (×10−2 mg kg−1 min−1 per μU ml−1: 2.41±0.64 vs. 1.80±0.51). There was no significant relationship between V˙O2peak and measures of insulin sensitivity. Stepwise multiple linear regression modelling determined that sex (65%) and leptin concentrations (13.7%) accounted for 78.7% of the variance in SI, while 46% of the variance in M/I could be attributed to sex. It was concluded that aerobic capacity is not an important determinant of insulin-mediated glucose disposal in mature, untrained Standardbred horses. Further studies are needed to examine the influence of gender on insulin sensitivity in horses.

Cardiorespiratory Fitness Is Related to Physical Inactivity, Metabolic Risk Factors, and Atherosclerotic Burden in Glucose-Intolerant Renal Transplant Recipients

The mechanisms of reduced cardiorespiratory fitness (CF) in renal transplant recipients (RTR) have not been studied closely. This study evaluated the relationships between CF and specific cardiovascular risk factors (metabolic syndrome [MS], physical inactivity, myocardial ischemia, and atherosclerotic burden) in glucose-intolerant RTR. Data were recorded on 71 glucose-intolerant RTR (mean age 55 yr; 55% male; median transplant duration 5.7 yr). MS was defined using National Cholesterol Education Programme Adult Treatment Panel III criteria. Resting and exercise stress echocardiography were performed, and myocardial ischemia was identified by new or worsening wall motion abnormalities. Cardiorespiratory fitness was determined using peak oxygen uptake (VO(2)) by expired gas analysis. Atherosclerotic burden was assessed by carotid intima-media thickness (IMT). Mean peak VO(2) was 19 +/- 7 ml/kg per min and was significantly lower than predicted peak VO(2) (29 +/- 6 ml/kg per min; P < 0.001). Patients with MS (63%) had reduced CF (17 +/- 6 versus 22 +/- 8 ml/kg per min; P = 0.001) and were more likely to be physically inactive (76 versus 48%; P = 0.02). CF was reduced in 14 patients with myocardial ischemia (15 +/- 3 versus 20 +/- 7 ml/kg per min; P = 0.05). CF was positively correlated with male gender, height, and physical activity and inversely correlated with number of MS risk factors and IMT (adjusted R(2) = 0.66). Carotid IMT added incremental value to clinical variables in determining VO(2) (adjusted R(2) = 0.65 versus 0.63; P = 0.04). Reduced CF is associated with physical inactivity, MS, and atherosclerotic burden in glucose-intolerant RTR. Further studies should address whether increasing exercise and modifying MS risk factors improve CF in RTR.

Waist circumference and BMI are independently associated with the variation of cardio-respiratory and neuromuscular fitness in young adult men

OBJECTIVE

To test two hypotheses: (1) cardiorespiratory (CRF) and neuromuscular (NMF) fitness is associated with body mass index (BMI) and waist circumference (WC), independent of each other and of leisure-time physical activity; (2) individuals with high CRF and NMF have lower WC for a given BMI, compared with those with low CRF and NMF.

DESIGN

Cross-sectional study.

SETTING

Men participating in refresher training organized by the Finnish Defence Forces.

PARTICIPANTS

A total of 951 men (mean age 29.1, s.d. 4.2 years; BMI 25.3 kg/m(2), s.d. 3.8; WC 91, s.d. 11 cm).

MAIN OUTCOME MEASURES

Body mass index, WC, maximal oxygen uptake (VO(2)max), height of vertical jump, number of push-ups and sit-ups during a 1-min test, static back extension endurance, isometric grip strength, self-reported leisure-time vigorous physical activity. Multiple linear regressions were used to explain the variation in fitness.

RESULTS

Waist circumference had significant (P<0.001) negative association with all test results (standardized beta coefficients from -0.23 to -0.77), except for grip strength. Body mass index had significant negative association with VO(2)max (-0.12; P<0.05), but positive association (P<0.01) with grip strength (0.28), vertical jump (0.21) and push-ups (0.55). For a given BMI, the estimated WC was highest among those with the poorest results for VO(2)max, vertical jump, sit-ups and push-ups.

CONCLUSIONS

Despite stronger isometric grip strength, the functional muscle fitness of the upper body, trunk and lower extremities is impaired in individuals with abdominal obesity. Although the known loss of CRF is a serious consequence of obesity, the deterioration of NMF deserves increased attention.

Usefulness of arterial compliance in the thigh in predicting exercise capacity in individuals without coronary heart disease

This study examined the relation between arterial compliance of the lower extremities and aerobic capacity in patients with a broad spectrum of cardiovascular risk but without overt coronary heart disease (CHD). Local arterial compliance was noninvasively measured in the thigh and calf in 104 men and 99 women using air plethysmography. Subjects also underwent maximal exercise treadmill testing as a measure of aerobic capacity. In univariate analysis, age (r = -0.49, p <0.001), systolic blood pressure at rest (r = -0.27, p <0.001), pulse pressure (r = -0.39, p <0.001), total cholesterol (r = -0.25, p <0.001), triglycerides (r = -0.025, p <0.001), non-high-density lipoprotein cholesterol (r = -0.23, p <0.001), high-sensitivity C-reactive protein (r = -0.21, p = 0.002), and low-density lipoprotein cholesterol (r = -0.15, p = 0.03) all demonstrated a significant inverse association with treadmill time. Thigh and calf compliance demonstrated a significant positive association with treadmill time (r = 0.48, p <0.001; r = 0.46, p <0.001). In multivariate analysis, thigh compliance (p = 0.003), age (p <0.001), gender (p = 0.005), and triglycerides (p = 0.017) were independent predictors of treadmill time. In conclusion, thigh compliance measured with a simple-to-use, fully automated device independently predicts aerobic fitness in patients with a wide range of cardiovascular risk but without CHD.

Mejora de la forma física como terapia antienvejecimiento

Several recent important studies have clearly shown that a low physical fitness represents a potent risk factor and even a predictor of both cardiovascular and all-causes morbidity and mortality. As a consequence, physical fitness assessment should be performed at the clinical level since, when properly assessed, it is a highly valuable health and life expectancy indicator. Based on the results of fitness assessment in a particular person and knowing his/her life style and daily physical activity, an individually adapted training program can be prescribed. This training program will allow that person to develop his/her maximal physical potential while improving his/her physical and mental health and attenuating the deleterious consequences of aging. In fact, physical exercise is today proposed as a highly effective means to treat and prevent major morbidity and mortality causes in industrialized countries. Most of these causes are associated with the aging process. In order to be effective, this type of intervention should be directed to improve the aerobic capacity and strength. In addition, it should be complemented with work directed to improve the general coordination and flexibility. Finally, diet optimization and use of nutritional supplements and legal ergogenic aids are key elements to improve the functional capacity and health, all of which is synonymous of anti-aging interventions.

Metabolic Profile and Exercise Capacity Outcomes

PURPOSE

Obesity remains a significant health problem for cardiac rehabilitation patients. The purpose of this study was to examine the relation of overweight and obesity to cardiovascular risk factors in patients, and to compare the change in cardiovascular risk factor profiles in patients with coronary artery disease undergoing cardiac rehabilitation at a tertiary care hospital center in Ontario, Canada.

METHODS

Retrospective analysis of cross-sectional data for 3542 patients, ages 63 +/- 11 years, stratified by body mass index (BMI), was performed.

RESULTS

The findings showed that 81% of the patients had a BMI exceeding 25 kg/m(2), and that 35% of the patients were obese (BMI > or =30 kg/m(2)). After adjustment for age, sex, smoking, hypertension, diabetes, and peak power output, BMI was a significant independent predictor of a higher total cholesterol level, higher fasting blood glucose and triglyceride levels, and lower levels of high-density lipoprotein cholesterol. The Adult Treatment Panel III criteria were used to examine the prevalence of the metabolic syndrome for each BMI group. At baseline, 77% of the obese males in classes 2 and 3 had three or more risk factors for the metabolic syndrome, as compared with 68% of the obese females in classes 2 and 3. After 24 weeks of intervention, the outcome data for 1353 patients showed that despite no change in body weight, all the BMI groups demonstrated significant improvements in metabolic profiles and peak exercise capacity.

CONCLUSIONS

Cardiac rehabilitation results in significant improvement in the cardiovascular risk profile at all levels of BMI, independently of weight loss. Future studies should examine whether targeting weight loss in cardiac rehabilitation further improves outcomes and the overall cardiovascular risk profile.

The metabolic syndrome in obese postmenopausal women: relationship to body composition, visceral fat, and inflammation

The purpose of this study was to investigate whether aerobic fitness, body composition, body fat distribution, and inflammation are different in obese postmenopausal women with and without the metabolic syndrome (MS), and whether the severity of MS is associated with these characteristics. Fifty-eight women (age, 59 +/- 1 yr; body mass index, 33.0 +/- 0.6 kg/m2)completed testing of maximal aerobic capacity, body composition (fat mass, lean mass, and percent body fat), body fat distribution (sc and visceral fat areas, and regional adipocyte sizes), and inflammation (C-reactive protein, IL-6, and TNF-alpha,and their soluble receptors). Lean mass (44.4 +/- 0.9 vs. 41.2 +/- 0.9 kg; P < 0.05), visceral fat area (180 +/- 10 vs. 135 +/- 7 cm2; P <0.001), and plasma soluble TNF receptor 1 (sTNFR1; 860 +/- 25 vs. 765 +/- 42 pg/ml; P < 0.05) were higher in women with the MS(n = 27) than in those without the MS (n = 31). The number of MS components was directly related to weight, body mass index, fat mass, lean mass, visceral fat area, and plasma sT-NFR1. We conclude that obese older women with the MS are characterized by high lean mass, high visceral fat, and elevated sTNFR1, and the severity of the MS is associated with body composition, visceral adiposity, and inflammation.