[Cardiopulmonary function and exercise capacity in patients with morbid obesity]

Obesity accelerates cardiovascular ageing

A global obesity pandemic, coupled with an increasingly ageing population, is exacerbating the burden of cardiovascular disease. Indeed, clinical and experimental evidence underscores a potential connection between obesity and ageing in the pathogenesis of various cardiovascular disorders. This is further supported by the notion that weight reduction not only effectively reduces major cardiovascular events in elderly individuals but is also considered the gold standard for lifespan extension, in obese and non-obese model organisms. This review evaluates the intricate interplay between obesity and ageing from molecular mechanisms to whole organ function within the cardiovascular system. By comparatively analysing their characteristic features, shared molecular and cell biological signatures between obesity and ageing are unveiled, with the intent to shed light on how obesity accelerates cardiovascular ageing. This review also elaborates on how emerging metabolic interventions targeting obesity might protect from cardiovascular diseases largely through antagonizing key molecular mechanisms of the ageing process itself. In sum, this review aims to provide valuable insight into how understanding these interconnected processes could guide the development of novel and effective cardiovascular therapeutics for a growing aged population with a concerning obesity problem.

Preventive Screening of Young People from the Perspective of Vascular Aging Phenotypes: the Role of Body Weight

Aim. To study the cardiovascular stiffness index CAVI in relation to main risk factors (RF) in young people from the point of their vascular aging phenotype and gender.

Material and methods. 264 young people (93 boys and 171 girls) at age of 18 to 25 years were examined. Vascular screening was performed with evaluating of CAVI. All subjects were divided into tertile groups for this indicator, taking into account gender. Such interval analysis of gender- and age- homogeneous sample allows to identify carriers of the phenotypes of premature (upper CAVI-tercile), normal (middle CAVI-tercile), and favorable or healthy (low CAVI-tercile) vascular aging. The first of them is also called EVA (early vascular aging) syndrome. In these groups, the incidence of carriers of insufficient, normal body mass (BM) and overweight were estimated. In three groups formed by BM indicator, the parameters of CAVI, hemodynamic and metabolic status in response to changes in BM were determined.

Results. Among of the presented RF, the correlation was significant for CAVI with a weight -0.428 (p<0.001) for R-CAVI, -0.453 (p<0.001) for L- CAVI, and even more significant with the BM index - at the level of -0.410 (p<0.001) for R-CAVI and -0.462 (p<0.001) for L-CAVI. This connection is found in boys. Among boys and girls with excessive BM, the most favorable vascular aging phenotype is observed 2.7 and 2.2 times more often than the EVA syndrome. In contrast, among girls with insufficient BM, a favorable vascular phenotype is detected almost twice rarely as compared with EVA syndrome. In similar group of boys, a healthy vascular phenotype is not observed at all. Among normal-weight boys and girls, the occurrence of the two extreme vascular phenotypes is almost identical. The arterial rigidity decrease on the background of BM increase occurs despite the сhanges of hemo- dynamic and metabolic indicators. This changes are especially pronounced in girls. The difference between the extreme weight categories in terms of R- CAVI and L-CAVI for boys was 1.4, while for girls it was only 0.3 for R-CAVI and 0.4 for L-CAVI.

Conclusion. When carrying out preventive measures among young people, one should not limit oneself to evaluating only traditional RF. Based on the concept of vascular aging, angiological screening should be more widely implemented. It will allow for more individualized preventive interventions among young people in the future.

Effects and dose-response relationship of high-intensity interval training on cardiorespiratory fitness in overweight and obese adults: a systematic review and meta-analysis

This study aims to quantify the effects of high-intensity interval training (HIIT) on cardiorespiratory fitness (CRF) by considering potential moderators and to characterise dose-response relationships of HIIT variables that could maximise CRF improvements in overweight and obese adults. Following a comprehensive search through four electronic databases, 19 studies met eligibility criteria. Random-effects models were applied to weight all included studies and to compute the weighted mean standardised mean differences (SMD_wm). Meta-analysis showed that HIIT was a highly effective approach for improving CRF in overweight and obese adults (SMD_wm = 1.13). Effects were modified by sex and baseline CRF level. Dose-response relationship analysis provided some preliminary data regarding the training period, training intensity, and session duration. However, it is still not possible to provide accurate recommendations currently. Further studies are still needed to identify the most appropriate training variables to prescribe effective HIIT programmes for improving CRF in overweight and obese adults.

Phenotypes of early and favorable vascular aging in young people depending on the risk factors and presence of connective tissue dysplasia

Aim. To study the main risk factors and signs of connective tissue dysplasia (CTD) in young people according  to quartile analysis of cardioankle vascular index (CAVI).

Material and methods. The study involved 243 young people (men, 81; women, 162) aged 18-25 years. All subjects were divided into quartile groups  depending  on CAVI on both sides,  or CAVI-R and CAVI-L, determined  using the VaSera-1500 system (Fucuda Denshia,Japan). According to the latest guidelines, the 4th  quartile of this distribution among persons  of the same sex and age corresponds to early vascular aging (EVA) syndrome.  The 1st  quartile corresponds to favorable vascular aging. We analyzed the main RFs and CTD signs in each  of the 4 CAVI quartiles. Data processing  was carried out using the Statistica 10.0 software package (StatSoft Inc,USA).

Results. The minimum and maximum CAVI in the sample were 3,2 and 7,9. The overwhelming majority of studied risk factors in both sexes were not associated with the stiffness. Only body mass and body mass index increasedwith a decrease in vascular stiffness and vice versa. The average number of external stigmas of dysembryogenesis in young people increased from the 1st  to the 4th  CAVI quartile, with significant differences in the extreme groups. Such CTD signs as a carpal tunnel syndrome and thumb sign also significantly differed between the 1st  and 4th quartiles.

Conclusion. The presented results can be used for prevention among young people to form more individualized programs taking into account a comprehensive assessment of vascular aging phenotype and the level of external stigmatization of each young person.

Effect of obesity on cardiovascular responses to submaximal treadmill exercise in adult males

Context:

Obesity is a major risk factor for chronic diseases. Abnormal changes in cardiovascular responses to exercise indicate the alteration in autonomic activity in obese.

Aims:

To assess and compare the cardiovascular parameters before and after exercise among obese and nonobese adult males.

Subjects and Methods:

Thirty each obese and normal-weight males between the age group 18-45 years were selected as cases and controls, respectively. Heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), corrected QT intervals were measured before and after submaximal treadmill exercise (QT and QTc) were done according to Bruce protocol. HR, SBP, DBP, MAP, QT, and QTc were also measured during passive recovery at 1 min and 5 min after exercise.

Statistical Analysis Used:

One-way analysis of variance and t-test were used to assess changes before and after exercise.

Results:

Resting HR was significantly higher in obese when compared to nonobese (P < 0.05). SBP, DBP, MAP, QT, and QTc were significantly higher in obese when compared to nonobese (P < 0.001). Immediately after exercise HR, SBP, DBP, MAP, QT, and QTc were significantly higher in obese when compared to nonobese (P < 0.001) 1 min after exercise.

Conclusions:

Obese individuals had elevated resting cardiovascular parameters and showed increased responses to steady exercise which could be due to alteration in autonomic functions with sympathetic hyperactivity. Delayed rate of decrease in HR and BP after exercise was also observed in obese, which indicates that they are at risk of developing cardiovascular diseases.

Determinants of Cardiorespiratory Fitness After Bariatric Surgery: Insights From a Randomised Controlled Trial of a Supervised Training Program

BACKGROUND

Severely obese patients have decreased cardiorespiratory fitness (CRF) and poor functional capacity. Bariatric surgery-induced weight loss improves CRF, but the determinants of this improvement are not well known. We aimed to assess the determinants of CRF before and after bariatric surgery and the impact of an exercise training program on CRF after bariatric surgery.

METHODS

Fifty-eight severely obese patients (46.1 ± 6.1 kg/m², 78% women) were randomly assigned to either an exercise group (n = 39) or usual care (n = 19). Exercise training was conducted from the 3rd to the 6th months after surgery. Anthropometric measurements, abdominal and mid-thigh computed tomographic scans, resting echocardiography, and maximal cardiopulmonary exercise testing was performed before bariatric surgery and 3 and 6 months after surgery.

RESULTS

Weight, fat mass, and fat-free mass were reduced significantly at 3 and 6 months, without any additive impact of exercise training in the exercise group. From 3 to 6 months, peak aerobic power (V̇O_2peak) increased significantly (P < 0.0001) in both groups but more importantly in the exercise group (exercise group: from 18.6 ± 4.2 to 23.2 ± 5.7 mL/kg/min; control group: from 17.4 ± 2.3 to 19.7 ± 2.4 mL/kg/min; P value, group × time = 0.01). In the exercise group, determinants of absolute V̇O_2peak (L/min) were peak exercise ventilation, oxygen pulse, and heart rate reserve (r² = 0.92; P < 0.0001), whereas determinants of V̇O_2peak indexed to body mass (mL/kg/min) were peak exercise ventilation and early-to-late filling velocity ratio (r² = 0.70; P < 0.0001).

CONCLUSIONS

A 12-week supervised training program has an additive benefit on cardiorespiratory fitness for patients who undergo bariatric surgery.

Improvement in 6-min Walk Test Distance Following Treatment for Behavioral Weight Loss and Disinhibited Eating: an Exploratory Secondary Analysis

BACKGROUND

Poor functional exercise capacity is common among those with obesity; however, objective measures of exercise capacity are rarely examined in behavioral treatments targeting obese individuals. We examined whether a 4-week acceptance and commitment therapy (ACT) intervention for disinhibited eating or a behavioral weight loss (BWL) intervention improved exercise capacity and explored demographic and disinhibited eating variables related to exercise capacity.

METHODS

Veterans (n = 61), randomized to receive ACT or BWL, completed an assessment of exercise capacity via the 6-min walk test (6MWT) at baseline and 6-month follow-up. Measures of disinhibited eating patterns and body mass index (BMI), at baseline and post-treatment, were also collected. Change in 6MWT distance and treatment group differences were examined using mixed ANOVAs. Characteristics related to baseline 6MWT and predictors of improvement in 6MWT at 6 months were examined with hierarchical multiple regression.

RESULTS

There were overall significant improvements on the 6MWT from baseline to 6-month follow-up (F(1,59) = 11.14, p = .001, η_p² = .159) but no differences between the ACT and BWL groups. Baseline BMI (β = - .33, p = .005) was the only variable related to baseline 6MWT. Improvements on the 6MWT were related to younger age (β = - .41, p = 0.001), female gender (β = .36, p = .001), and treatment-related increases in dietary restraint behaviors (β = .42, p = .001).

CONCLUSIONS

Functional exercise capacity improved among participants completing behavioral interventions for weight and disinhibited eating. Improvements in dietary behavior regulatory skills may have generalized to improved regulation in other behavioral domains associated with exercise capacity.

[Profile of body composition in women with class III obesity by multipolar bioimpedance method]

OBJECTIVE

To analyze a body composition profile in women with class III obesity using the multipolar bioimpedance method.

METHODS

Thirteen sedentary women aged between 20 and 40 years were evaluated.

RESULTS

The results show that the patients had a fat percentage of 51.9±1.50 % and lean mass of 48.1±1.50 %. Regarding fat mass and lean mass per body region, figures of 26.3±3.62kg and 26.2±2.91kg in the upper body, 9.1±0.06kg and 8.4±0.14kg in the lower limbs, and 3.3±0.02kg and 7.6±0.01kg in the upper limbs were obtained. Patients had a good symmetry between the left and right sides in both upper and lower limbs, besides of a muscular mass of 32.1±5.08kg, with a muscular mass index of 12.7±1.05kg/m2.

CONCLUSION

Higher fat accumulation was observed in the upper body region, followed by lower and upper limbs. Total muscular mass was apparently preserved, although sarcopenic obesity was not verified. Since this is a group of people that is still understudied, there is a need for further research on genetic and physical profile and caloric expenditure during exercise and rest.

Improvement in lung function and functional capacity in morbidly obese women subjected to bariatric surgery

OBJECTIVE

To determine whether weight loss in women with morbid obesity subjected to bariatric surgery alters lung function, respiratory muscle strength, functional capacity and the level of habitual physical activity and to investigate the relationship between these variables and changes in both body composition and anthropometrics.

METHODS

Twenty-four women with morbid obesity were evaluated with regard to lung function, respiratory muscle strength, functional capacity, body composition, anthropometrics and the level of habitual physical activity two weeks prior to and six months after bariatric surgery.

RESULTS

Regarding lung function, mean increases of 160 mL in slow vital capacity, 550 mL in expiratory reserve volume, 290 mL in forced vital capacity and 250 mL in forced expiratory volume in the first second as well as a mean reduction of 490 mL in inspiratory capacity were found. Respiratory muscle strength increased by a mean of 10 cmH2O of maximum inspiratory pressure, and a 72-meter longer distance on the Incremental Shuttle Walk Test demonstrated that functional capacity also improved. Significant changes also occurred in anthropometric variables and body composition but not in the level of physical activity detected using the Baecke questionnaire, indicating that the participants remained sedentary. Moreover, correlations were found between the percentages of lean and fat mass and both inspiratory and expiratory reserve volumes.

CONCLUSION

The present data suggest that changes in body composition and anthropometric variables exerted a direct influence on functional capacity and lung function in the women analyzed but exerted no influence on sedentarism, even after accentuated weight loss following bariatric surgery.

Comparison between pre-exercise casein peptide and intact casein supplementation on glucose tolerance in mice fed a high-fat diet

We hypothesized that along with exercise, casein peptide supplementation would have a higher impact on improving glucose tolerance than intact casein. Male 6-week-old ICR mice were provided a high-fat diet to induce obesity and glucose intolerance. The mice were randomly divided into 4 treatment groups: control (Con), endurance training (Tr), endurance training with intact casein supplementation (Cas+Tr), and endurance training with casein peptide supplementation (CP+Tr). The mice in each group were orally administrated water, intact casein, or casein peptide (1.0 mg/g body weight, every day), and then subjected to endurance training (15-25 m/min, 60 min, 5 times/week for 4 weeks) on a motor-driven treadmill 30 min after ingestion. Our results revealed that total intra-abdominal fat was significantly lower in CP+Tr than in Con (p < 0.05). Following an oral glucose tolerance test, the blood glucose area under the curve (AUC) was found to be significantly smaller for CP+Tr than for Con (p < 0.05). Moreover, in the soleus muscle, glucose transporter 4 (GLUT4) protein levels were significantly higher in CP+Tr than in Con (p < 0.01). However, intra-abdominal fat, blood glucose AUC, and GLUT4 protein content in the soleus muscle did not alter in Tr and Cas+Tr when compared with Con. These observations suggest that pre-exercise casein peptide supplementation has a higher effect on improving glucose tolerance than intact casein does in mice fed a high-fat diet.

The Influence of Body Composition on Pulmonary Rehabilitation Outcomes in Chronic Obstructive Pulmonary Disease Patients

INTRODUCTION

Alterations in body composition are commonly present in chronic obstructive pulmonary disease (COPD). The hypothesis of this study is that COPD patients would achieve clinical benefits after pulmonary rehabilitation (PR) independent of muscle mass depletion or body weight.

METHODS

We conducted a retrospective cohort study using single-frequency bioelectrical impedance analysis (BIA) for assessment of fat-free mass (FFM) depletion (muscle depletion). Patients were stratified into three categories based on (1) obesity BMI ≥ 30 kg/m², (2) non-obesity BMI < 30 kg/m², and (3) combined cachexia (BMI < 21 kg/m² and FFM index < 16 kg/m²) and muscle atrophy (BMI ≥ 21 kg/m² and FFMI < 16 kg/m²). PR outcomes were defined as the improvement in exercise capacity (maximal exercise capacity, 6-min walk, constant workload cycle exercise duration) and quality of life determined by Chronic Respiratory Questionnaire after PR.

RESULTS

We studied 72 patients with available FFM measured by BIA. Patients were predominantly elderly man (N = 71; 98%), with a mean age of 72 years with COPD GOLD stage I-IV. The groups were balanced in terms of age, comorbidities, baseline FEV1, exercise capacity, and quality of life. The absolute changes in patients with muscle depletion or obesity compared to those without muscle depletion or obesity were not statistically different as was the percentage of patients reaching the minimal clinically important difference (MCID) after PR.

CONCLUSION

A comprehensive PR program in COPD patients improved exercise tolerance and quality of life independent of muscle mass depletion or obesity. Similarly, muscle depletion or obesity had no effect on the percentage of patients achieving the MCID for measures of quality of life and exercise tolerance after PR.

Feasibility and effect of in-home physical exercise training delivered via telehealth before bariatric surgery

Optimal physical activity (PA) interventions are needed to increase PA in individuals with severe obesity, and optimize the results of bariatric surgery (BS). The aim of this study was to assess the feasibility and effect of Pre-Surgical Exercise Training (PreSET) delivered in-home via telehealth (TelePreSET) in subjects awaiting BS. Six women following the TelePreSET were compared to the women from a previous study (12 performing the PreSET in a gymnasium and 11 receiving usual care). In-home TelePreSET (12-weeks of endurance and strength training) was supervised twice weekly using videoconferencing. Physical fitness, quality of life, exercise beliefs, anthropometric measures and telehealth perception were assessed before and after 12-weeks. Satisfaction was evaluated with questionnaires at the end of the intervention. The TelePreSET participants attended 96% of the exercise sessions, and were very satisfied by the TelePreSET. The baseline telehealth perception score was high, and increased significantly after the intervention. The TelePreSET group significantly increased their physical fitness compared to the usual care group. No significant change was noted in other outcomes. The TelePreSET is feasible and seems effective to improve the physical fitness of women awaiting BS. Further studies are needed to confirm beneficial effects of this innovative mode of delivery.

Results of a Multimodal Program During Hospitalization in Obese COPD Exacerbated Patients

The objective of this study was to analyze the results of a multimodal therapeutic program during hospitalization in obese AECOPD patients. This was a randomized, single-blind clinical trial conducted at two university hospitals in Granada, Spain. Forty-nine patients hospitalized due to AECOPD were randomly allocated to a control group (CG), in which patients received standard care, or to an intervention group (IG), in which patients were included in a multimodal therapeutic program, added to the standard care. The main outcome measures were pulmonary, physical (strength and exercise capacity) and perceived (dyspnea, quality of life and psychological distress) variables. Within-group significant improvements (p < 0.05) were found in physical and perceived variables in the IG after the treatment. In the CG, a significant decrease was found in lower limb strength and a significant improvement in dyspnea and in three subscales of the EuroQol-5D questionnaire. The between-groups analysis showed significant differences after the treatment on lower limb strength and exercise capacity values (p < 0.05), in three of the EuroQol-5D subscales, and in the total score and the depression subscale of the Hospital Anxiety and Depression Scale. A multimodal therapeutic program has a beneficial effect on physical functioning and perceived variables in hospitalized obese patients with AECOPD.

Effects of lifestyle interventions that include a physical activity component in class II and III obese individuals: a systematic review and meta-analysis

BACKGROUND

In class II and III obese individuals, lifestyle intervention is the first step to achieve weight loss and treat obesity-related comorbidities before considering bariatric surgery. A systematic review, meta-analysis, and meta-regression were performed to assess the impact of lifestyle interventions incorporating a physical activity (PA) component on health outcomes of class II and III obese individuals.

METHODS

An electronic search was conducted in 4 databases (Medline, Scopus, CINAHL and Sportdiscus). Two independent investigators selected original studies assessing the impact of lifestyle interventions with PA components on anthropometric parameters, cardiometabolic risk factors (fat mass, blood pressure, lipid and glucose metabolism), behaviour modification (PA and nutritional changes), and quality of life in adults with body mass index (BMI) ≥ 35 kg/m2. Estimates were pooled using a random-effect model (DerSimonian and Laird method). Heterogeneity between studies was assessed by the Cochran's chi-square test and quantified through an estimation of the I².

RESULTS

Of the 3,170 identified articles, 56 met our eligibility criteria, with a large majority of uncontrolled studies (80%). The meta-analysis based on uncontrolled studies showed significant heterogeneity among all included studies. The pooled mean difference in weight loss was 8.9 kg (95% CI, 10.2-7.7; p < 0.01) and 2.8 kg/m² in BMI loss (95% CI, 3.4-2.2; p < 0.01). Long-term interventions produced superior weight loss (11.3 kg) compared to short-term (7.2 kg) and intermediate-term (8.0 kg) interventions. A significant global effect of lifestyle intervention on fat mass, waist circumference, blood pressure, total cholesterol, LDL-C, triglycerides and fasting insulin was found (p<0.01), without significant effect on HDL-C and fasting blood glucose.

CONCLUSIONS

Lifestyle interventions incorporating a PA component can improve weight and various cardiometabolic risk factors in class II and III obese individuals. However, further high quality trials are needed to confirm this evidence, especially beyond weight loss.

Reproducibility of the incremental shuttle walk test for women with morbid obesity

OBJECTIVE

The incremental shuttle walk test (ISWT) is a valuable tool for the assessment of functional capacity. However, few studies have used the ISWT in individuals with obesity or have determined its reproducibility in this population.

PURPOSE

The aim of the present study was to evaluate the reproducibility of the ISWT in women with morbid obesity.

METHODS

Twenty-three women with a body mass index >40 kg/m(2) (mean age: 39.1 ± 7.7) performed the ISWT twice on the same day.

RESULTS

The mean distance traveled was 313.3 ± 100.2 m on the first test and 322.5 ± 98.9 on the second test, with no significant difference between tests. The intraclass correlation coefficient (0.91) indicated excellent reproducibility. Reliability determined through Bland-Altman analysis revealed a small mean difference between tests (-9.2 m).

CONCLUSION

The practice of repeating the ISWT appears to be unnecessary for women with morbid obesity, as demonstrated by the excellent reproducibility of the test.

The relationship between exercise capacity and masked hypertension in sedentary patients with diabetes mellitus

AIM

Although exaggerated blood pressure responses (EBPR) to exercise have been related to future hypertension and masked hypertension (MHT), the relationship between exercise capacity and MHT remains unclear. A sedentary life style has been related to increased cardiovascular mortality, diabetes mellitus (DM), and hypertension. In this study, we aimed to examine the relationship between exercise capacity and MHT in sedentary patients with DM.

METHODS

This study included 85 sedentary and normotensive patients with DM. Each patient's daily physical activity level was assessed according to the INTERHEART study. All patients underwent an exercise treadmill test, and exercise duration and capacity were recorded. Blood pressure (BP) was recorded during all exercise stages and BP values ≥ 200/110 mmHg were accepted as EBPR. MHT was diagnosed in patients having an office BP <140/90 mmHg and a daytime ambulatory BP >135/85 mmHg. Patients were divided into two groups according to their ambulatory BP monitoring (MHT and normotensive group).

RESULTS

The prevalence of MHT was 28.2%. Exercise duration and capacity were lower in the MHT group than in the normotensive group (p<0.05) and were negatively correlated with age, HbA1c, mean daytime BP, and mean 24 hour BP. Peak exercise systolic BP and the frequency of EBPR were both increased in the MHT group (25.0% and 8.1%, respectively, p=0.03). According to a multivariate regression, exercise capacity (OR: 0.61, CI95%: 0.39-0.95, p=0.03), EBPR (OR: 9.45, CI95%: 1.72-16.90, p=0.01), and the duration of DM (OR: 0.84, CI95%: 0.71-0.96, p=0.03) were predictors of MHT.

CONCLUSION

Exercise capacity, EBPR, and the duration of DM were predictors of MHT in sedentary subjects with DM.

Does obstructive sleep apnea impair the cardiopulmonary response to exercise?

STUDY OBJECTIVES

The aim of this study was to evaluate cardiopulmonary exercise performance in lean and obese patients with obstructive sleep apnea (OSA) compared with controls.

DESIGN

Case-control study.

SETTING

The study was carried out in Sao Paulo Sleep Institute, Sao Paulo, Brazil.

PATIENTS AND PARTICIPANTS

INDIVIDUALS WITH SIMILAR AGES WERE ALLOCATED INTO GROUPS: 22 to the lean OSA group, 36 to the lean control group, 31 to the obese OSA group, and 26 to the obese control group.

INTERVENTIONS

The participants underwent a clinical evaluation, polysomnography, a maximum limited symptom cardiopulmonary exercise test, two-dimensional transthoracic echocardiography, and spirometry.

MEASUREMENTS AND RESULTS

The apnea-hypopnea index, arousal index, lowest arterial oxygen saturation (SaO2) and time of SaO2 < 90% were different among the groups. There were differences in functional capacity based on the following variables: maximal oxygen uptake (VO2max), P < 0.01 and maximal carbon dioxide production (VCO2max), P < 0.01. The obese patients with OSA and obese controls presented significantly lower VO2max and VCO2max values. However, the respiratory exchange ratio (RER) and anaerobic threshold (AT) did not differ between groups. Peak diastolic blood pressure (BP) was higher among the obese patients with OSA but was not accompanied by changes in peak systolic BP and heart rate (HR). When multiple regression was performed, body mass index (P < 0.001) and male sex in conjunction with diabetes (P < 0.001) independently predicted VO2max (mL/kg/min).

CONCLUSIONS

The results of this study suggest that obesity alone and sex, when associated with diabetes but not OSA, influenced exercise cardiorespiratory function.

The influence of obesity on pulmonary rehabilitation outcomes in patients with COPD

Although obesity is increasing in prevalence, relatively little attention has been given to its impact on outcomes in patients with chronic obstructive pulmonary disease (COPD) completing pulmonary rehabilitation. We conducted a retrospective chart review of 114 patients with COPD who completed outpatient pulmonary rehabilitation at our center. Body habitus categories were determined based on body mass index (BMI). Underweight patients (BMI < 21 kg/m2) were excluded from the analysis. Normal weight and overweight patients were classified as non-obese. Obese patients (BMI >30 kg/m2) were compared with non-obese patients in the following areas: forced expiratory volume in 1 s (FEV1) percent predicted, the 6-min walk distance (6MWD), health status, the number of unsupported arm lifts per minute, and functional performance. Health status was determined using the Self-Reported Chronic Respiratory Questionnaire (CRQ-SR), which has dimensions of dyspnea, fatigue, emotion, and mastery. Functional performance was determined using the Pulmonary Functional Status Scale Daily Activities subscore. Compared with non-obese patients, obese patients had a higher FEV1 percent-predicted (44 ± 15% vs 52 ± 16%; P = 0.01), yet had lower 6MWD (269 ± 11 vs 203 ± 13; P = 0.0002), lower functional status, and greater fatigue at initial evaluation. However, the two groups had similar walk-work, which adjusts for differences in weight. Despite the baseline differences, both groups improved similarly following pulmonary rehabilitation (change in 6MWD was 52 ± 7 m in the non-obese patients versus 47 ± 9 in the obese patients; P = 0.65). Our study suggests that obese COPD patients are referred to pulmonary rehabilitation at an earlier spirometric stage of their disease, but have a poorer exercise performance, a greater degree of functional impairment and greater fatigue levels. This is probably, largely because of the effect of an increased weight burden. However, obesity did not seem to adversely affect the pulmonary rehabilitation outcomes.

Acquired obesity and poor physical fitness impair expression of genes of mitochondrial oxidative phosphorylation in monozygotic twins discordant for obesity

Defects in expression of genes of oxidative phosphorylation in mitochondria have been suggested to be a key pathophysiological feature in familial insulin resistance. We examined whether such defects can arise from lifestyle-related factors alone. Fourteen obesity-discordant (BMI difference 5.2 +/- 1.8 kg/m(2)) and 10 concordant (1.0 +/- 0.7 kg/m(2)) monozygotic (MZ) twin pairs aged 24-27 yr were identified among 658 MZ pairs in the population-based FinnTwin16 study. Whole body insulin sensitivity was measured using the euglycemic hyperinsulinemic clamp technique. Transcript profiles of mitochondrial genes were compared using microarray data of fat biopsies from discordant twins. Body composition of twins was determined using DEXA and maximal oxygen uptake (Vo(2max)) and working capacity (W(max)) using a bicycle ergometer exercise test with gas exchange analysis. The obese cotwins had lower insulin sensitivity than their nonobese counterparts (M value 6.1 +/- 2.0 vs. 9.2 +/- 3.2 mg x kg LBM(-1) x min(-1), P < 0.01). Transcript levels of genes involved in the oxidative phosphorylation pathway (GO:0006119) in adipose tissue were lower (P < 0.05) in the obese compared with the nonobese cotwins. The obese cotwins were also less fit, as measured by Vo(2max) (50.6 +/- 6.5 vs. 54.2 +/- 6.4 ml x kg LBM(-1) x min(-1), for obese vs. nonobese, P < 0.05), W(max) (3.9 +/- 0.5 vs. 4.4 +/- 0.7 W/kg LBM, P < 0.01) and also less active, by the Baecke leisure time physical activity index (2.8 +/- 0.5 vs. 3.3 +/- 0.6, P < 0.01). This implies that acquired poor physical fitness is associated with defective expression of the oxidative pathway components in adipose tissue mitochondria.

Increased exercise capacity after surgically induced weight loss in morbid obesity

OBJECTIVE

To investigate the effects of surgically induced weight loss on exercise capacity in patients with morbid obesity (MO).

RESEARCH METHODS AND PROCEDURES

A prospective 1-year follow-up study was carried out, with patients being their own controls. A symptom-limited cardiopulmonary exercise stress test was performed in 31 MO patients (BMI > 40 kg/m2) before and 1 year after undergoing bariatric surgery.

RESULTS

At 1 year after surgery, weight was reduced from 146 +/- 33 to 95 +/- 19 kg (p < 0.001), and BMI went from 51 +/- 4 to 33 +/- 6 kg/m2 (p < 0.001). After weight loss, obese patients performed each workload with lower oxygen consumption, heart rate, systolic arterial pressure, and ventilatory volume (p < 0.001). This reduced energy expenditure allowed them to increase the duration of their effort test from 13.8 +/- 3.8 to 21 +/- 4.2 minutes (p < 0.001). Upon finishing the exercise, MO patients before surgery were able to reach only 83% of their age-predicted maximal heart rate, and their respiratory exchange ratio was 0.87 +/- 0.06. After weight loss, those values were 90% and 1 +/- 0.08, respectively (p < 0.01). When we compared the peak O2 pulse corrected by fat free mass before and after surgery, no significant differences between the groups were found.

DISCUSSION

After surgically induced weight loss, MO patients markedly improved their exercise capacity. This is due to the fact that they were able to perform the external work with lower energy expenditure and also to increase cardiovascular stress, optimizing the use of cardiac reserve. There were no differences in cardiac function before and after surgery.