Allometric correction of peak VO2 in obese adults undergoing cardiopulmonary exercise testing

2019 ◽  
Vol 15 (2) ◽  
pp. 77-83
Author(s):  
A.C. Matheus ◽  
A.R.T. Gagliardi ◽  
E.F. Sperandio ◽  
M. Romiti ◽  
R.L. Arantes ◽  
...  

We hypothesised that the reduction in cardiorespiratory fitness (CRF) of individuals with less severe obesity is small or non-existent when the allometric rather than the ratio standard is used for the comparison. We aimed to evaluate the influence of obesity on CRF, and to compare peak VO2 using allometric corrections in asymptomatic adults with a wide range of body mass index. The results of 780 adults (age 41±13 years) who underwent cardiopulmonary exercise testing (CPET) were evaluated. Participants were stratified according to body mass index (BMI): normal weight (n=227), overweight (n=198), and obese class 1 (n=155), 2 (n=131), and 3 (n=69). After cardiovascular risk assessment, the participants underwent CPET on a treadmill ramp protocol. The allometric exponents calculated were 0.60 and 0.62 for obese and non-obese groups respectively, with no significant differences. After using BMI strata in a multivariate analysis of covariance, we found an allometric exponent of 0.65. Peak VO2 using ratio standards significantly declined among all stratified groups. After allometric correction, peak VO2 remained significantly reduced only in women with obesity class 3 and men with obesity classes 2 and 3. When ratio standards were used to compare peak VO2, the effect of obesity on CRF was overestimated. Allometric correction of peak VO2 is more reasonable, and should be adopted as a routine for CPET.

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Caroline A Ball ◽  
Carolyn M Larsen ◽  
Virginia Hebl ◽  
Jeffrey B Geske ◽  
Kevin C Ong ◽  
...  

Introduction: Impaired peak VO2 and obesity are known predictors of morbidity and mortality in Hypertrophic Cardiomyopathy (HCM). The purpose of this study is to determine the degree of exercise impairment due to excess weight in patients with HCM. Methods: Adult HCM patients who underwent cardiopulmonary treadmill testing at our tertiary referral center from 2006 - 2012 and had consented to research participation were identified retrospectively. Percent predicted peak VO2 was calculated by the Astrand formula for men and the Jones formula for women which adjust for age and gender. Baseline echocardiographic features obtained within 1 week of exercise testing and % predicted peak VO2 were compared among four groups of patients stratified by body mass index (BMI). Results: 510 patients were identified, with a mean age at diagnosis of 44.3 ± 16.1 years, 186 (36.5%) female. Mean BMI at the time of cardiopulmonary exercise testing was 29.7 ± 5.3 and 227 (44.6%) patients had a BMI ≥ 30. Overweight and obese patients were older and were more likely to be male than their normal weight peers. However, there was no significant difference in ejection fraction (EF), resting left ventricular outflow tract gradient, right ventricular systolic pressure (RVSP), or septal thickness among the groups. HCM patients show impaired peak VO2 across all BMI groups. While peak VO2 increased progressively across BMI groups consistent with greater O2 demand generated by higher body weight, the adjusted peak VO2 in mL/kg/min fell progressively, indicating progressively greater performance impairment with increasing BMI despite similar degrees of cardiac impairment (p <0.0001) (Table 1). Conclusion: Increased BMI is associated with reduced exercise performance in a graded manner in HCM patients independent of cardiac impairment identified on echocardiography.


2009 ◽  
Vol 158 (4) ◽  
pp. S31-S36 ◽  
Author(s):  
Tamara B. Horwich ◽  
Eric S. Leifer ◽  
Clinton A. Brawner ◽  
Meredith B. Fitz-Gerald ◽  
Gregg C. Fonarow

2021 ◽  
Author(s):  
Szymon Price ◽  
Szczepan Wiecha ◽  
Igor Cieśliński ◽  
Daniel Śliż ◽  
Przemysław Seweryn Kasiak ◽  
...  

Abstract Cardiopulmonary exercise testing (CPET) is the method of choice to assess aerobic fitness. Previous research was ambiguous as to whether treadmill (Tr) and cycle ergometry (CE) results are transferrable or different between testing modalities in triathletes. The aim of this paper was to investigate the differences in HR and VO2 at maximum exertion and at anaerobic threshold (AT) and respiratory compensation point (RCP) and evaluate their association with body fat (BF), fat free mass (FFM), and body mass index (BMI). 143 adult (n = 18 female), amateur, Caucasian triathletes had both Tr, and CE CPET performed. The male group was divided into < 40 years (n = 80) and > 40years (n = 45). Body composition was measured with bioelectrical impedance before tests. Differences were evaluated using paired T-tests and associations were evaluated in males using multiple linear regression (MLR). Significant differences were found in VO2 and HR at maximum exertion, at AT and at RCP between CE and Tr testing, in both males and females. VO2AT was 38.8(± 4.6) ml/kg/min in Tr vs 32.8(± 5.4) in CE in males and 36.0(± 3.6) vs 32.1(± 3.8) in females (p < 0.001). HRAT was 149 (± 10) bpm in Tr vs 136 (± 11) in CE in males and 156 (± 7) vs 146 (± 11) in females (p < 0.001). VO2max was 52 (± 6) ml/kg/min vs 49 (± 7) in CE in males and 45.3 (± 4.9) in Tr vs 43.9 (± 5.2) in females (p < 0.001). HRmax was 183 (± 10) bpm in Tr vs 177 (± 10) in CE in males and 183 (± 9) vs 179 (± 10) in females (p < 0.001). MLR showed that BMI, BF and FFM are significantly associated with differences in HR and VO2 at maximum, AT and RCP in males aged > 40. Both tests should be used independently to achieve optimal fitness assessment and further training planning.


Cancers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2202 ◽  
Author(s):  
Sarah Friis Christensen ◽  
Robyn Marie Scherber ◽  
Nana Brochmann ◽  
Martin Goros ◽  
Jonathan Gelfond ◽  
...  

Elevated body mass index (BMI) is a global health problem, leading to enhanced mortality and the increased risk of several cancers including essential thrombocythemia (ET), a subtype of the Philadelphia-chromosome negative myeloproliferative neoplasms (MPN). Furthermore, evidence states that BMI is associated with the severity of symptom burden among cancer patients. MPN patients often suffer from severe symptom burden. The purpose of this study was to examine whether deviations from a normal BMI in an MPN population are associated with higher symptom burden and reduced quality of life (QoL). A combined analysis of two large cross-sectional surveys, the Danish Population-based Study, MPNhealthSurvey (n = 2044), and the international Fatigue Study (n = 1070), was performed. Symptoms and QoL were assessed using the validated Myeloproliferative Neoplasm Symptom Assessment Form (MPN-SAF). Analysis of covariance was used to estimate the effects of different BMI categories on symptom scores while adjusting for age, sex, and MPN subtype. A U-shaped association between BMI and Total Symptom Burden was observed in both datasets with significantly higher mean scores for underweight and obese patients relative to normal weight (mean difference: underweight 5.51 (25.8%), p = 0.006; obese 5.70 (26.6%) p < 0.001). This is an important finding, as BMI is a potentially modifiable factor in the care of MPN patients.


2016 ◽  
Vol 134 (4) ◽  
pp. 330-334 ◽  
Author(s):  
Felipe Pucci ◽  
Guilherme Machado ◽  
Edcarlo Solera ◽  
Fernanda Cenovicz ◽  
Christian Arruda ◽  
...  

ABSTRACT CONTEXT AND OBJECTIVE: Increased life expectancy among people with Down syndrome (DS) has introduced new environmental factors that may affect blood pressure (BP) and/or lead to obesity in this population. The aim here was to investigate BP levels and body mass index (BMI) in adults with DS, correlating these data with the patients' sex and age. DESIGN AND SETTING: Analytical cross-sectional observational study conducted in special schools in Curitiba (PR), Brazil. METHODS: 97 adult patients were included. BP was measured in accordance with the established guidelines. BMI was calculated by dividing the weight by the height squared (kg/m2). RESULTS: Sex had no influence on BMI; nor did systolic BP (SBP) or diastolic BP (DBP). The age range was from 18 to 56 years. No correlation was observed between increasing age and greater BMI or BP. Eighty-six individuals (88.7%) presented normal BP, eleven (11.3%) prehypertension and none hypertension. Twenty patients (20.4%) presented BP lower than 90 × 60 mmHg. BMI ranged from 18 to 48 kg/m2 (mean of 28.8 ± 3.92 kg/m2): 21.9% had normal weight; 40.7% were overweight; and 25.3% had obesity class I, 9.9% class II and 2.2% class III. Higher BMI was associated with significantly greater SBP and DBP (P = 0.0175 and P = 0.0015). CONCLUSION: Sex and age did not influence SBP, DBP or BMI in Brazilian adults with DS. Higher BMI was associated with greater BP (both systolic and diastolic).


2022 ◽  
Vol 13 (1) ◽  
pp. 3-7
Author(s):  
Savita Gupta ◽  
Varun Goel ◽  
Nazia Nazir ◽  
Saurabh Srivastava ◽  
Anurag Srivastava

Background: Increased body mass index (BMI) is a known risk factor for respiratory infection and is being recognized as a predisposing factor in the COVID‐19 pandemic caused by the severe acute respiratory syndrome coronavirus‐2. Aims and Objectives: This study aimed to assess the association between different body mass index categories with severe COVID-19 patients leading to death. Materials and Methods: This retrospective study of six months included the laboratory-confirmed COVID-19 patients admitted to an ICU of a tertiary care academic health care organization. The medical records were reviewed at least 14 days after admission.  Results: 484 patients were included, and BMI data were available for 306 patients. 40.19% had a normal weight, 26.79% were overweight, 17.97% had BMI 30-34.9 Kg/m2 and 15.03% had BMI ≥ 35 Kg/m2. Overall, 58 patients (18.95%) died within 14 days of ICU admission, 50.98% were discharged alive or referred from the hospital within 14 days, and 30.06% remained hospitalized at 14 days. After controlling for all covariates, there was a significantly increased risk of mortality in the patients with obesity class I (RR 2.03, 95% CI 1.07-3.85, P = 0.030) and patients with obesity class II & III (RR 2.83, 95% CI 1.54–5.22, P <0.001) compared with those with normal BMI. Conclusions: Obesity was associated with an unfavorable outcome among patients with COVID-19. Patients with obesity should be more closely monitored when hospitalized for COVID-19 as there is increasing evidence of relation of severity of COVID-19 and obesity which appears to be a factor in the health risks.


Sports ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 103 ◽  
Author(s):  
Pantelis Nikolaidis ◽  
Eleni Kintziou ◽  
Georgios Georgoudis ◽  
José Afonso ◽  
Rodrigo Vancini ◽  
...  

Although the beneficial role of exercise for health is widely recognized, it is not clear to what extent the acute physiological responses (e.g., heart rate (HR) and oxygen uptake (VO2)) to a graded exercise test are influenced by nutritional status (i.e., overweight vs. normal-weight). Therefore, the main objectives of the present narrative review were to examine the effect of nutritional status on acute HR, and VO2 responses of children to exercise testing. For this purpose, we examined existing literature using PubMed, ISI, Scopus, and Google Scholar search engines. Compared with their normal-body mass index (BMI) peers, a trend of higher HRrest, higher HR during submaximal exercise testing, and lower HRmax was observed among overweight and obese children (according to BMI). Independent from exercise mode (walking, running, cycling, or stepping), exercise testing was metabolically more demanding (i.e., higher VO2) for obese and overweight children than for their normal-weight peers. Considering these cardiometabolic differences according to BMI in children might help exercise specialists to evaluate the outcome of a graded exercise test (GXT) (e.g., VO2max, HRmax) and to prescribe optimal exercise intensity in the context of development of exercise programs for the management of body mass.


RMD Open ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. e001203
Author(s):  
Sytske Anne Bergstra ◽  
Cornelia F Allaart ◽  
David Vega-Morales ◽  
Marieke De Buck ◽  
Elizabeth Murphy ◽  
...  

ObjectivesTo study whether there is an association between body mass index (BMI) category and survival of various tumour necrosis factor inhibitors (TNFi) in rheumatoid arthritis (RA) patients in a real-life longitudinal international registry.MethodsData from 5230 patients with RA starting treatment with any TNFi were selected from the METEOR registry. Patients were divided into six BMI categories: 3.7% underweight, BMI<18.5 kg/m2; 46% normal weight, BMI 18.5–25 kg/m2; 32% pre-obesity, BMI 25–30 kg/m2; 13% obesity class I, BMI 30–35 kg/m2; 3.4% obesity class II, BMI 35–40 kg/m2; and 1.6% obesity class III, BMI >40 kg/m2. Time on treatment in the different BMI categories was compared for all TNFi combined and for the infliximab, adalimumab and etanercept separately, using Kaplan–Meier curves and Cox regression analyses. Cox regression analyses were adjusted for potential confounders, with follow-up censored at 5000 days.ResultsPatients in obesity class II (HR 1.28, 95% CI 1.06 to 1.54) and III (HR 1.67, 95% CI 1.29 to 2.18) and underweight patients (HR 1.30, 95% CI 1.07 to 1.58) showed statistically significantly shorter TNFi survival than normal weight patients. The effect in underweight patients was strongest for infliximab (HR 1.82, 95% CI 1.20 to 2.76), the effect in overweight patients was strongest for infliximab (category II (HR 1.49, 95% CI 0.98 to 2.26); category III (HR 1.46, 95% CI 0.79 to 2.71)) and etanercept (category II (HR 1.27 95% CI 0.98 to 1.65); category III (HR 1.79, 95% CI 1.25 to 2.55)). No significant effect modification from reported pain was found.ConclusionBoth underweight and overweight patients discontinued TNFi treatment earlier than normal weight patients, without evidence of reported pain as the main determinant. It remains uncertain what determines TNFi survival in individual patients.


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