Inflammation and cardiorespiratory fitness in overweight women and men: the FATCOR study

Background

Women have more body fat compared to men, and adipose tissue is associated with chronic inflammation. Cardiorespiratory fitness has on the other hand been postulated to lower chronic inflammation. However, sex-specific associations of inflammation with cardiorespiratory fitness is less studied.

Purpose

To assess inflammatory markers in overweight and obese women and men according to cardiorespiratory fitness in the FAT associated CardiOvasculaR dysfunction (FATCOR) study.

Methods

Cardiorespiratory fitness was assessed by maximal oxygen uptake (VO2max) by cardiopulmonary exercise testing in 566 subjects (mean age was 48±9 years, 60% women) with body mass index (BMI) >27.0 kg/m2. Participants were grouped according to sex, and fitness status identified from sex and age specific VO2max thresholds. C-reactive protein (CRP) and serum amyloid A (SAA) were analysed using Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight mass spectrometry. Serum levels of the kynurenine:tryptophan ratio (KTR) and pyriodoxic acid ratio (PAr) were measured by liquid chromatography tandem mass spectrometry. All inflammatory markers were log transformed before inclusion in linear regression analyses.

Results

In the total study population, 63% had obesity and 74% were cardiorespiratory unfit. Unfit women had the highest fat percentage and the highest serum levels of CRP and SAA compared to the other groups (p<0.05), while serum levels of KTR and PAr were higher only compared to fit men (p<0.05). In multivariable linear regression analyses in women, higher CRP (β −0.15, p=0.001), SAA (β −0.10, p=0.03) and PAr (β −0.09, p=0.03) were associated with lower VO2max after adjusting for age, fat percentage, hypertension and metabolic syndrome. In men, only higher PAr (β −0.14, p=0.02) was associated with lower VO2max in multivariable analyses adjusted for age, fat percentage and metabolic syndrome. In multivariable analyses in obese women only (n=213), higher CRP (β −0.15, p=0.01) and PAr (β −0.13, p=0.03) remained associated with lower VO2max, while in obese men (n=144) there was no significant associations between inflammatory markers and VO2max.

Conclusion

Among overweight subjects participating in the FATCOR study, cardiorespiratory unfit women had the highest serum levels of inflammatory markers. The association of inflammation with reduced cardiorespiratory fitness was more pronounced in women than men, in particular when obesity was present.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Western Regional Health Authority of Norway

Myocardial work in overweight and obesity: impact of sex and central haemodynamics

Background

Women with increased body mass index (BMI) have better left ventricular (LV) global longitudinal strain (GLS) than men. LV global myocardial work index (GWI) is a novel measure of myocardial function that adjusts for afterload and offers the opportunity to differentiate between early systolic dysfunction and elevated myocardial workload.

Purpose

To investigate sex differences in myocardial work in women and men with increased BMI.

Methods

Clinical and echocardiographic data from 467 participants (61% women, average age 47±9 years) with a BMI above 27 kg/m2 and without cardiac disease was analysed. Central pulse wave analysis was assessed by applanation tonometry. GWI was calculated by GLS and post-echocardiography blood pressure (BP). Covariables of GWI were identified by linear regression analysis with collinearity tools.

Results

Women had higher BMI (31.4 vs. 31.0 kg/m2) and higher aortic augmentation pressure (12±7 vs. 8±6 mmHg), but lower clinic systolic BP (127±17 vs. 134±14 mmHg) compared to men (all P<0.05). Women also had higher LV GLS (20.0±2.8 vs. 18.8±2.8%) and GWI (2126±385 vs. 2047±389 mmHg%) (both P<0.05). In univariable regression analyses, higher GWI was significantly associated with higher age, clinic systolic BP, wall stress, ejection fraction, aortic augmentation pressure, left atrial size, and LV ejection time, and with lower waist circumference (all P<0.05), but not with BMI. In multivariable linear regression analyses, adjusting for these correlates, female sex was independently associated with higher GWI (Table 1, model 1). After additional adjustment for aortic augmentation pressure, the association between GWI and sex became non-significant (Table 1, model 2).

Conclusions

Women with increased BMI have higher GWI compared to men, despite lower BP. Higher GWI in women is mainly explained by elevated workload due to higher central aortic stiffness.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Western Norwegian Regional Health Authorities

One-year impact of bariatric surgery on echocardiographic markers of vascular disease: results from the prospective FatWest study

Background

Aortic root plaque and aortic valve sclerosis (AVS) are known echocardiographic markers of atherosclerosis. Obesity increases the atherothrombotic risk, while large surgical weight loss improves the cardiovascular risk profile. It is unclear whether the severity of vascular disease associated with severe obesity changes after bariatric surgery.

Purpose

To assess the 1-year impact of bariatric surgery on aortic root wall thickness (ART) and AVS.

Methods

91 severely obese patients (43±10 years, preoperative body mass index [BMI] 41.7±4.9 kg/m2, 55% hypertensive, 17% diabetic) underwent echocardiography preoperatively and 14 months after Roux-en-Y bypass surgery in the prospective FatWest (Bariatric Surgery on the West Coast of Norway) study. We measured the end-diastolic maximum ART and categorized AVS as mild, moderate or severe based on combined aortic cusp thickness and hyperechoic valve lesions. Left ventricular (LV) structural remodelling was assessed by LV mass and geometry. In 52 patients with clinical signs of obstructive sleep apnea, preoperative polysomnography data including apnea-hypopnea index and mean nightly oxygen saturation were evaluated.

Results

Preoperatively, 39% had mild-moderate AVS, and an average ART of 4.9±1.7mm (Figures 1–2). Presence of AVS at baseline was associated with higher LV mass, while ART was higher in men, older patients and increased with lower nightly oxygen saturation (r=−0.29, p<0.05). During the first preoperative 14 months, patients experienced a 12.9±3.8kg/m2 BMI and 0.6±1.9mm ART reduction, and AVS prevalence lowered by 45% (Figures 1 and 2). In backward stepwise multivariate regression analyses with adjustment for changes in clinical variables, LV mass and geometry, less ART reduction at 14 months was independently predicted by higher age, higher postoperative BMI and presence of AVS (R2 0.53, all p<0.05). Persistent AVS was associated with higher age and preoperative diabetes (R2 0.24, p<0.05).

Conclusion

In patients undergoing bariatric surgery, a reduction in echocardiographic markers of vascular disease was observed 1 year postoperatively, particularly in younger, non-diabetic patients.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Helse Vest Figure 1Figure 2

Impact of chronic mitral regurgitation on 3D atrial size and mechanics. Insights from the prospective 3D-PRIME study

Background

Chronic mitral regurgitation (MR) leads to progressive left atrial (LA) dilation. Its relative contribution to 3-dimensional (3D) LA structural and functional remodelling and the impact of concomitant clinical and hemodynamic factors, has been less explored.

Aims

To assess 3D LA size and mechanics, as well as mean LA pressure estimated from the pulmonary vein flow, in relation to chronic MR severity.

Methods

In the prospective 3D-PRIME (3D Echocardiography and Cardiovascular Prognosis in Mitral Regurgitation) study, 46 patients with chronic MR (69±13 years, body mass index (BMI) 26.2±4.3kg/m2, 50% women, 26% with atrial fibrillation, 30% with severe MR) recruited at one heart valve center were investigated with 2D and 3D transthoracic and transesophageal echocardiography. MR severity was quantified by the regurgitant volume (RV) and MR classified as organic, atrial functional or ventricular functional, as by current recommendations. LA size was measured by 3D maximum volume (LAV) indexed for body surface area (LAVI), LA mechanics by 3D peak relative increase in longitudinal volume in the reservoir phase (Sr), and mitral size by 3D annulus area and total leaflet area. Pulmonary vein Doppler flow profile was recorded in both right and left upper veins, and mean LA pressure was estimated from the average pulmonary vein systolic/diastolic velocity time integral ratio.

Results

Average mitral RV was 38±26ml, LAVI 53ml/m2, and Sr 17±11%. Increased mitral RV correlated with higher LAV and mean LA pressure (Figure 1), larger mitral annulus area (r=0.42) and total leaflet area (r=0.38) (all p<0.01), but not with Sr. In backward stepwise multivariate linear regression analyses, increased LAVI was independently predicted by larger mitral RV, higher age and atrial fibrillation (R2=0.62), higher mean LAP by larger mitral RV, body mass index and atrial fibrillation (R2=0.55), while lower Sr was associated with higher age and atrial fibrillation (R2=0.62) (all p<0.001). Patients with atrial functional MR (30% of the total group) had the largest LAVs and lowest Sr despite slightly lower mitral RV (Figure 2).

Conclusion

Chronic MR is associated with progressive increase in LA volume, mean LA pressure, and mitral annulus and total leaflet area. While MR is accompanied by low 3D LA longitudinal deformation, impaired LA mechanics is multifactorial and related closely to age and history of atrial arrythmias.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Haukeland University Hospital Figure 1Figure 2

Incomplete functional reverse remodelling of the left ventricle one year after bariatric surgery. Insights from the prospective FatWest study

Background

Patients with severe obesity are predisposed to development of left ventricular (LV) hypertrophy with subsequent increased myocardial oxygen demand and impaired myocardial function. Bariatric surgery leads to rapid weight loss and improves cardiovascular risk profile.

Purpose

To assess whether LV systolic function, wall mechanics, and cardiac power improve 1 year after bariatric surgery.

Methods

91 severely obese patients (43±10 years, 70% women, body mass index [BMI] 41.7±4.9 kg/m2, 55% with hypertension, 17% with diabetes mellitus) underwent echocardiography before, 6 and 14 months after Roux-en-Y gastric bypass surgery in the prospective FatWest (Bariatric Surgery on the West Coast of Norway) study. We assessed LV systolic function by biplane ejection fraction (EF), LV wall mechanics by midwall shortening (MWS) and global longitudinal strain (GLS), and cardiac power normalized for LV mass by 0.222 x cardiac output x mean blood pressure (BP)/LV mass.

Results

Surgery induced a significant reduction in BMI, heart rate, systolic BP, and LV mass (Figure 1). Prevalence of LV hypertrophy fell from 34 to 20% 14 months after surgery (p<0.001), while that of concentric geometry remained stable: 8 vs 10% (p=0.36). GLS improved by 28%, however LV EF and MWS did not change (Figure 2). LV power at rest decreased postoperatively, reflecting the lower BP and heart rate, but was unaltered when normalized for LV mass (Figure 2). In backward stepwise multivariate regression analyses, 1 year improvement in GLS was predicted by the systolic BP reduction (p<0.05) (R2 0.73, p<0.001), while low 1-year MWS was independently associated with female gender, concentric geometry and higher myocardial oxygen demand (all p<0.01) (Nagelkerke R2 0.44, p<0.001), and lower 1-year LV power-mass with female gender and LV hypertrophy (p<0.01) (R2 0.24, p<0.001).

Conclusion

In severely obese patients, LV longitudinal function normalizes 1 year after bariatric surgery, mainly due to the BP reduction. LV midwall mechanics and power do not improve, especially in women and patients with persistent LV geometric abnormalities.

Funding Acknowledgement

Type of funding sources: None. Figure 1Figure 2

Higher acceleration ejection time ratio predicts impaired prognosis in mild to moderate aortic stenosis

Introduction

Acceleration/ejection time (AT/ET) ratio is a marker of aortic stenosis (AS) severity, and a predictor of outcome in severe AS. The importance of ejection dynamics in mild and moderate AS has been less investigated.

Purpose

To investigate the impact of increased AT/ET ratio on prognosis in patients with mild-moderate AS.

Methods

Data from 1635 patients with asymptomatic mild-moderate AS with preserved ejection fraction enrolled in the Simvastatin and Ezetimibe in Aortic Stenosis study was analysed. Covariates of higher AT/ET ratio was identified in linear regression analysis. Outcome was assessed in Cox regression analyses and reported as hazard ratio (HR) and 95% confidence interval (CI) per 1 standard deviation (SD) higher AT/ET ratio. Median follow-up time was 4 years.

Results

The total study population included 38% female, mean age 67 years and average peak aortic jet velocity was 3.02 m/s. Higher AT/ET ratio was significantly associated with lower ejection fraction, higher LV mass, higher aortic jet velocity, lower systolic blood pressure, low stroke volume index and lower stress-corrected midwall shortening (all p<0.05). In Cox regression analyses, adjusting for these confounders including age and gender, 1 SD higher AT/ET ratio predicted a 29% increase in hazard for major cardiovascular events, 25% for cardiovascular death and hospitalization for heart failure and 23% increase in hazards for all-cause mortality (Table).

Conclusion

In asymptomatic mild-moderate AS patients free from diabetes and known cardiovascular disease, higher AT/ET ratio was associated with increased risk for major cardiovascular events, cardiovascular death and hospitalization for heart failure and all-cause mortality independent of traditional risk markers.

Funding Acknowledgement

Type of funding source: None

P1514 Increased myocardial oxygen demand is associated with impaired left ventricular strain in patients with morbid obesity referred for bariatric surgery

Background

Obesity predisposes for left ventricular (LV) hypertrophy and systolic dysfunction. Higher myocardial oxygen demand in LV hypertrophy is associated with higher risk for cardiovascular events, while the association with LV systolic function has been less explored.

Purpose

To assess the association of myocardial oxygen demand with LV systolic function in morbidly obese subjects without known heart disease.

Methods

Clinical and echocardiographic data from 110 obese subjects referred for gastric bypass surgery (mean age 42 ± 11 years, 74% women, mean body mass index [BMI] 41.9 ± 4.8 kg/m², 33% with hypertension, 15% with diabetes) in the prospective FatWest (Bariatric Surgery on the West Coast of Norway) study was used. LV function was assessed by ejection fraction (EF) by Simpson"s biplane method and endocardial global longitudinal strain (GLS) by 2D vector velocity imaging using a 16-segment model (Image Arena 4.6, Tomtec, Unterschleissheim, Germany). Myocardial oxygen demand was estimated from LV mass - wall stress - heart rate product according to a previously validated formula.

Results

Myocardial oxygen demand was higher in men (1884 vs. 1579 x 10³ g x kdyne/cm² x bpm, p < 0.05), and associated with higher BMI (r = 0.24) and pulse pressure (r = 0.28), and with lower EF (r = -0.22) and lower GLS (r = 0.26, all p < 0.05). In multiple regression analysis, higher myocardial oxygen demand was associated with lower LV GLS (Beta = 0.21, p < 0.05) independent of age, gender, BMI, pulse pressure, diabetes, and EF (Table).

Conclusion

In obese patients without known heart disease referred for bariatric surgery, higher myocardial oxygen demand was associated with lower LV systolic function measured by GLS independent of confounders.

Covariates of lower GLS in multivariable Variable β correlation coefficient p LV mass - wall stress - heart rate product (g x kdyne/cm² x bpm x 10³) 0.21 0.04 Age (years) -0.12 0.22 Gender 0.34 <0.01 BMI (kg/m²) 0.25 <0.01 Pulse pressure (mmHg) -0.04 0.71 Diabetes -0.17 0.09 LV EF (%) -0.01 0.90

Does fitness improve the cardiovascular risk profile in obese subjects?

BACKGROUND AND AIMS

Good cardiorespiratory fitness has been suggested to reduce the risk of cardiovascular disease in obesity. We explored the association of fitness with the prevalences of major cardiovascular risk factor like hypertension (HT), diabetes and metabolic syndrome (MetS) in overweight and obese subjects.

METHODS AND RESULTS

Clinical data from 491 participants in the FAT associated CardiOvasculaR dysfunction (FATCOR) study were analyzed. Physical fitness was assessed by ergospirometry, and subjects with at least good level of performance for age and sex were classified as fit. HT subtypes were identified from clinic and 24-h ambulatory blood pressure in combination. Diabetes was diagnosed by oral glucose tolerance test. MetS was defined by the American Heart Association and National Heart, Lung and Blood Institute criteria. The participants were on average 48 years old (60% women), and mean body mass index (BMI) was 32 kg/m². 28% of study participants were classified as fit. Fitness was not associated with lower prevalences of HT or HT subtypes, diabetes, MetS or individual MetS components (all p > 0.05). In multivariable regression analysis, being fit was characterized by lower waist circumference, BMI < 30 kg/m², non-smoking and a higher muscle mass (all p < 0.05).

CONCLUSION

In the FATCOR population, fitness was not associated with a lower prevalence of major cardiovascular risk factors like HT, diabetes or MetS. Given the strong association of cardiovascular risk factor burden with risk of clinical cardiovascular disease, these findings challenge the notion that fitness alone is associated with lower risk of cardiovascular disease in obesity.