CLINICAL RESEARCH: OBESITY AND CARDIAC FUNCTION
Reversibility of Cardiac Abnormalities in Morbidly Obese Adolescents
Holly M. Ippisch, MD, MS*,*,
Thomas H. Inge, MD, PhD ,
Stephen R. Daniels, MD, PhD, FACC ,
Baiyang Wang, MS*,
Philip R. Khoury, MS*,
Sandra A. Witt, RDCS*,
Betty J. Glascock, RDCS*,
Victor F. Garcia, MD and
Thomas R. Kimball, MD, FACC*
* Division of Cardiology, Cincinnati Children’s Hospital, Medical Center and Department of Pediatrics, University of Cincinnati, Cincinnati, Ohio
Division of Pediatric General and Thoracic Surgery, Cincinnati Children’s Hospital, Medical Center and Department of Pediatrics, University of Cincinnati, Cincinnati, Ohio
Department of Pediatrics, The Children’s Hospital, Denver, Colorado.
Manuscript received May 24, 2007;
revised manuscript received December 17, 2007,
accepted December 18, 2007.
* Reprint requests and correspondence: Dr. Holly M. Ippisch, Cincinnati Children’s Hospital Medical Center, Division of Pediatric Cardiology, 3333 Burnet Avenue, MLC 2003, Cincinnati, Ohio 45229. (Email: Holly.Ippisch{at}cchmc.org).
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Abstract
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Objectives: The purpose of this study was to evaluate changes in cardiac geometry, systolic and diastolic function before and after weight loss in morbidly obese adolescents.
Background: Cardiac abnormalities are present in morbidly obese adolescents; however, it is unclear if they are reversible with weight loss.
Methods: Data from 38 adolescents (13 to 19 years; 29 females, 9 males, 33 Caucasians, 5 African Americans) were evaluated before and after bariatric surgery. Left ventricular mass (LVM), left ventricular (LV) geometry, systolic and diastolic function were assessed by echocardiography. Mean follow up was 10 ± 3 months.
Results: Weight and body mass index decreased post-operatively (mean weight loss 59 ± 15 kg, pre-operative body mass index 60 ± 9 kg/m2 vs. follow-up 40 ± 8 kg/m2, p < 0.0001). Change in LVM index (54 ± 13 g/m2.7 to 42 ± 10 g/m2.7, p < 0.0001) correlated with weight loss (r = 0.41, p = 0.01). Prevalence of concentric left ventricular hypertrophy (LVH) improved from 28% at pre-operative to only 3% at follow up (p = 0.007), and normal LV geometry improved from 36% to 79% at follow up (p = 0.009). Diastolic function also improved (mitral E/Ea lateral 7.7 ± 2.3 at pre-operative vs. 6.3 ± 1.6 at post-operative, p = 0.003). In addition, rate-pressure product improved suggesting decreased cardiac workload (p < 0.001).
Conclusions: Elevated LVM index, concentric LVH, altered diastolic function, and cardiac workload significantly improve following surgically induced weight loss in morbidly obese adolescents. Large weight loss due to bariatric surgery improves predictors of future cardiovascular morbidity in these young people.
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Abbreviations and Acronyms
| | BMI = body mass index | | CV = cardiovascular | | DBP-z = diastolic blood pressure z score | | IBW = ideal body weight | | IVSd = end-diastolic septal thickness | | LA = left atrium/atrial | | LVED = left ventricular end-diastolic dimension | | LVES = left ventricular end-systolic dimension | | LVH = left ventricular hypertrophy | | LVM = left ventricular mass | | LVPWd = end-diastolic left ventricular posterior wall thickness | | RWT = relative wall thickness | | SBP-z = systolic blood pressure z score | | SF = shortening fraction | | VCF = velocity of circumferential fiber shortening | | WS = wall stress |
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Morbid obesity (body mass index [BMI]  40 kg/m2) affects over 1 million adolescents and young adults (1), and being obese as an adolescent is predictive of remaining obese into adulthood (2,3). Little is known about the reversibility of cardiac abnormalities in morbidly obese adolescents. The purpose of this study was to determine whether cardiac abnormalities reverse with significant weight loss in adolescents. An important model for this evaluation is bariatric surgery, because rapid and profound weight loss occurs over a short period of time, such that plasticity, if present, might be demonstrated.
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Methods
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Subjects and inclusion criteria.
All morbidly obese (BMI 99th percentile) (4,5) adolescents ( 19 years old) undergoing bariatric surgery at Cincinnati Children’s Hospital Medical Center were eligible for inclusion. All patients were physician-referred and then evaluated by a multidisciplinary team before undergoing surgery (6).
To be included in the analysis, echocardiograms had to be obtained pre-operatively and at least 4 to 18 months post-operatively, and image quality had to be visually discernible for measurements. The number of subjects included (n = 38) who had both an adequate pre-operative and post-operative echocardiogram is less than the total number of operations performed (n = 67) on this age group during this timeframe. When multiple echocardiograms had been performed on a subject, the 2 echocardiograms chosen for analysis were the pre-operative echocardiogram closest to the surgery date and the post-operative echocardiogram with the longest follow-up period. This analysis represents all patients who met the aforementioned criteria between August 2002 and December 2006.
Exclusion criteria.
Patients with congenital heart disease were excluded.
Institutional oversight.
Institutional review board-approval for retrospective analysis of these clinical data was required.
Anthropometric and demographic measures.
Patient weight, height, race, gender, age, and blood pressure were recorded at the time of the echocardiogram. Weights were obtained without shoes, in light clothing, with a digital scale. Heights were measured with a calibrated wall-mounted stadiometer. Body mass index was calculated as weight (kg)/height x height (m2). Because the Centers for Disease Control and Prevention growth curves for standard weight and BMI are based on a normal population distribution, the accurate calculation of the outermost BMI percentiles less than the third percentile or less than the 97th percentile (z-scores below –2 [2.3rd percentile] or above 2 [97.9th percentile]) are felt to be beyond the capabilities of the growth curve data. Therefore, to account for the morbid obesity of these participants, ideal body weight (IBW) was also calculated for each patient and their weight was indexed to IBW as "percent over IBW." The IBW was defined as the weight at the 50th percentile of BMI for the patient’s gender and age. Percent over IBW was then calculated as: (100 x [patient’s weight in kg/IBW]) – 100.
Heart rate was obtained from averaging 3 RR intervals during the echocardiogram. The rate-pressure product (an indirect index of myocardial oxygen consumption) was calculated as heart rate x average systolic blood pressure (7,8).
Echocardiographic technique.
The cardiovascular (CV) system was assessed with a GE Vivid 5 or 7 (Milwaukee, Wisconsin) or a Philips Sonos 5500 (Andover, Massachusetts) ultrasound system. All echocardiographic images were obtained with the patient in the left decubitus position to obtain the following images: parasternal long- and short-axis and apical 4-chamber. Measurements were performed off-line with a Cardiology Analysis System (Digisonics, Houston, Texas). A total of 3 to 5 measurements for each variable were obtained per patient.
Echocardiographic indexes.
Left Ventricular Geometry
Measurements were obtained by 2-dimensional directed M-mode for left ventricular end-diastolic dimension (LVED), left ventricular end-systolic dimension (LVES), short-axis left ventricular (LV) end-diastolic cavity area, end-diastolic septal thickness (IVSd), and posterior wall thickness (LVPWd) (9). Left ventricular mass (LVM) was calculated with the method of Devereux et al. (10).
 | (1) |
The LV mass was indexed by dividing by height in meters2.7 as described by de Simone (11). Relative wall thickness (RWT) was calculated by: RWT = (LVPWd + IVSd)/LVED. Cardiac geometry was subdivided on the basis of LVM and RWT into: concentric hypertrophy (increased LVM and increased RWT), eccentric hypertrophy (increased LVM and normal RWT), concentric remodeling (normal LVM and increased RWT), and normal geometry (normal LVM and normal RWT) (12,13). For RWT, a common adult threshold of >0.43 cm was used to determine abnormal RWT (14,15). For indexed LVM, an adult threshold of 51 g/m2.7 was used, owing to the association with predicting future cardiac morbidity in adults (16). For statistical analysis, patients were stratified by LV geometry subtype.
LV Systolic Function
Shortening fraction (SF = [(LVED – LVES)/LVED]) and heart rate-corrected velocity of circumferential fiber shortening (VCF) (VCF = SF/LVETc) were calculated where LVETc is the heart rate corrected ejection time. Left ventricular end-systolic meridional wall stress (WS) was determined by (17,18):
 | (2) |
where P = LV end-systolic pressure (mm Hg), and LVPWs = end-systolic LV posterior wall thickness (cm).
Finally, contractility was assessed by calculating VCF difference (i.e., VCF diff = measured VCF – the predicted VCF for the measured WS) (19,20).
Diastolic Function
There is no single measurement for evaluation of LV diastolic function. Instead, multiple measures are generally evaluated, and therefore the following were included in this analysis: - Left Atrial Size Assessment:
- Measurements of the left atrium (LA) were obtained by 2-dimensional directed M-mode.
- Pulsed Doppler Assessment:
- Mitral inflow velocities were obtained with pulsed wave Doppler in the apical 4-chamber view. The Doppler cursor was placed parallel to mitral inflow. The maximal velocity was measured with the sample volume at the mitral valve leaflet tips. The mitral peak E (early filling) and A (inflow with atrial contraction) waves were measured off-line, and an E/A ratio was calculated.
- Tissue Doppler Imaging:
- Myocardial flow velocities were acquired in the apical 4-chamber view. The peak and late velocities of mitral annular flow were recorded at both the septal annulus (Ea–sept, Aa–sept) and lateral annulus (Ea-lat, Aa-lat). The Ea/Aa ratios were calculated in addition to E/Ea-lat and E/Ea-sept ratios. The E/Ea ratio corrects for myocardial relaxation in transmitral flow (E) and has been shown to correlate with LV end-diastolic pressure (21). In adults, an E/Ea-lat of >10 is predictive of elevated LV filling pressures, and <6 is normal (21–23).
Surgical procedure.
Laparoscopic Roux-en-Y gastric bypass was performed on all patients as described in Figure 1
(24).
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Figure 1 Roux-en-Y Procedure
Diagram of Roux-en-Y gastric bypass surgery. In this procedure, a small stomach pouch is created at the gastroesophageal junction (arrow, A), resulting in restricted intake. In addition, the jejunum is brought up and sewn to the new stomach pouch (arrow, B), bypassing the majority of the absorptive stomach and duodenum, creating a mildly malabsorptive state. The proximal jejunum is then anastamosed to the side of the distal jejunum (arrow, C), creating the jejunojejunostomy and allowing for egress of secretory fluids and bile acids. (Artist illustration by Jan Warren, Cincinnati Children’s Hospital Medical Center).
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Statistical analysis.
Analyses were performed with SAS version 9.1 (SAS Institute, Inc., Cary, North Carolina). In preliminary analyses, all variables were examined for missing values and outliers with cross (e.g., scattergrams) and range checks. Continuous variables were tested for normality with the Kolmogorov-Smirnov D statistic as well as visual inspection of the univariate distributions. Chi-square statistics were used to determine difference in proportions between categorical variables. Descriptive statistics (mean, SD) were generated for the demographic characteristics. To compare differences before and after surgery for normally distributed continuous variables, Student t tests for paired data were performed. The Wilcoxon signed-rank test, the nonparametric equivalent, was used to assess changes in the following variables: height, age, heart rate, Ea ratio, and Ea-sept. Statistical significance was determined at a p value of <0.05. Spearman’s and Pearson’s correlations were calculated to further determine which factors were associated with measures of change in cardiac structure and change in cardiac function after weight loss. Specifically, the dependent variables were change in: indexed LVM, E/A, Ea/Aa-lat, E/Ea-lat, LA size, and indexed LA size. The variables included in correlation analysis as potential independent risk factors were: gender, race, and change in: weight, BMI z-score, BMI, kilograms over ideal body weight (IBW), percent over IBW, heart rate, systolic blood pressure z score (SBP-z), diastolic blood pressure z score (DBP-z), indexed LVM, IVSd, LVPWd, LVED, RWT, SF, and VCF difference. Multivariate regression models were built with the results from Pearson’s analysis to explore potential determinants of change in indexed LVM. These models were built by selecting either clinically or statistically significant independent variables from the univariate correlation analyses. The following independent variables were included in the model: gender, race, change in percent over IBW, change in SBP-z, and change in DBP-z. As an additional analysis, the pre-operative values for indexed LV mass and LV geometry were added to the aforementioned independent variables. Analysis of covariance was performed to further elaborate upon the results of the regression analyses, where appropriate. No regression models were built for changes in diastolic function, because there were no significant correlations in univariate analyses.
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Results
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Demographic data.
A total of 38 morbidly obese adolescents were evaluated (Table 1). The average age at surgery was 16 ± 1 years (range 13 to 19 years). There were 29 girls and 9 boys, of whom 33 were Caucasian and 5 were African American. As expected, BMI, weight, and percent over IBW significantly decreased after gastric bypass. Follow-up echocardiograms were performed at a mean post-operative period of 10 ± 3 months.
Hemodynamic assessment.
An effect was seen between pre-operative and post-operative measurements of hemodynamic variables, including a significant decrease in both heart rate and systolic blood pressure (p < 0.0001) (Table 1). In addition, the rate-pressure product significantly improved (pre-operative mean 9,832 ± 2,843 vs. post-operative 6,937 ± 1,637, p < 0.001). These changes demonstrate a shift toward a more favorable autonomic status and possibly reflect a decreased cardiac workload (7,8).
LV mass.
After weight loss there were significant improvements in indexed LVM, LVPW, interventricular septal thickness, and RWT (Table 2). In univariate analysis, change in indexed LVM correlated with change in percent over IBW (r = 0.41, p = 0.01). Multiple stepwise regression analysis with backward stepping was performed to evaluate predictors of change in indexed LVM. The following variables were included in the model as potential independent predictors: gender, race, change in SBP-z and DBP-z, and change in percent over IBW. The only predictor of change in indexed LVM was change in percent over IBW (r = 0.41, p = 0.01). This suggests that, as weight improved, indexed LVM improved (Fig. 2). As an additional analysis, the pre-operative values for indexed LV mass and LV geometry were added to the aforementioned independent variables. Change in percent over IBW and type of pre-operative LV geometry were the only 2 independent risk factors associated with change in indexed LVM at follow-up (p = 0.001 and p = 0.002, respectively, model R2 = 0.49). Analysis of covariance showed that the subjects with pre-operative concentric LVH and eccentric LVH geometry had a significantly greater mean decrease in indexed LVM when compared with those with normal geometry.
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Figure 2 Change in Indexed LV Mass Versus Change in Percent Over Ideal Body Weight
The larger the decrease in percent over ideal body weight, the larger the decrease in indexed left ventricular (LV) mass.
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LV geometry subtypes.
Concentric LVH was seen in 28% pre-operatively, whereas post-operatively only 3% had concentric LVH. The percentage with normal LV geometry improved from 36% pre-operatively to 79% at follow-up. The overall geometry distribution was significantly improved in the post-operative period (p < 0.0001) (Fig. 3). In addition, none of the patients with normal LV geometry pre-operatively regressed into abnormal LV geometry at follow-up. All changes in LV geometry after weight loss were uniformly in the direction of improvement.
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Figure 3 Effects of Weight Loss on LV Geometry Patterns
With weight loss, the percent of patients with concentric left ventricular hypertrophy (CLVH) decreased from 28% pre-operatively to 3% post-operatively and the percent of patients with normal left ventricular (LV) geometry improved from 36% pre-operatively to 79% post-operatively. The overall post-operative (post-op) geometry distribution was significantly improved compared with the pre-operative (pre-op) distribution (p < 0.0001). *p < 0.05. CR = concentric remodeling; ELVH = eccentric left ventricular hypertrophy.
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Systolic function.
Systolic function and contractility were normal pre-operatively and did not significantly change at follow-up (Table 2). There were no significant changes in end-systolic wall stress or stress-velocity relationship.
Diastolic function.
Compared with normative diastolic data in adolescents ages 14 to 18 years old (25), the pre-operative values for E/Ea-lateral and Ea-lateral for this cohort were abnormal (Table 3). The normal range for E/Ea-lateral ratio is 4.7 ± 1.3, and Ea-lateral velocity is 20.6 ± 3.8 as previously described by Eidem et al. (25). Post-operatively, there were no significant changes in LA diameter; however, there were significant improvements in other variables of diastolic function, including: improved E/A ratio, Ea/Aa ratio, and E/Ea lateral ratios. The lack of improvement in LA diameter might be secondary to small sample size or lack of sufficient time for remodeling of LA chamber size. In addition, the LA diameter was limited to m-mode measurements and did not include planimetry. The improvements in Doppler indexes of diastolic function suggest that some features of LV diastolic function are capable of improving after significant weight loss in morbidly obese adolescents. Univariate correlations were performed to analyze the change in Doppler indexes of diastolic function after weight loss. Change in diastolic Doppler indexes were not correlated with change in: weight, BMI z-score, percent over IBW, heart rate, SBP-z, DBP-z, indexed LVM, IVSd, LVPWd, LVED, RWT, SF, and VCF difference.
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Discussion
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The significant findings of this study are that abnormal cardiac geometry and altered diastolic function in morbidly obese adolescents improve with significant weight loss. These results are important, because reversal of abnormal cardiac geometry might improve predictors of future CV morbidity in these young people.
Over one-quarter of adolescents in this data set had already developed high-risk concentric hypertrophy before bariatric surgery. In 1 adult study of hypertensive patients, 53% with concentric hypertrophy had CV events, compared with 10% of those with eccentric hypertrophy (26).
In this adolescent population, concentric hypertrophy largely reversed. In addition, prevalence of normal LV geometry improved from 36% pre-operatively to 79% after surgical weight loss. In a study in adults, improvements in indexed LVM (g/m) were seen after surgical weight loss, but no significant change was observed in LVED or posterior wall and septal thicknesses (27). By comparison, this study shows the posterior wall and septal thicknesses in adolescents can significantly improve after weight loss, demonstrating remodeling of the myocardium. This might be an argument for intervention at an earlier age. Although likely related to age and duration of obesity, these differences between adults and adolescents might also be due to sample size, variable weight changes, or variability in length of follow-up.
Because these adolescents are anthropometrically similar to adults, we chose adult thresholds for determining LV geometry subtypes. But as our results demonstrate, even by adult standards, a significant number of adolescents seem to be at increased risk for future cardiac morbidity on the basis of LV mass and geometry. Using pediatric criteria would have reflected an even higher prevalence of abnormal cardiac geometries (15).
Reversal in LV geometry patterns and improvement in LV mass carries prognostic importance. Data suggest that in hypertensive adults, LVM >51 g/m2.7 indicates a >4-fold risk of CV morbidity (16). The adolescent population in our analysis had an average indexed LVM of 54 g/m2.7 (maximum of 86 g/m2.7). The LVH of this magnitude suggests that adolescents with morbid obesity are at elevated risk for future adverse cardiac events.
Interestingly, even in the face of continued obesity, the indexed LVM improved with weight loss and the prevalence of concentric LVH nearly resolved. One hypothesis to explain these observations is that weight loss translates into a reduction in cardiac workload that thereby decreases LVM. This possibility is supported by the reduction in heart rate, decrease in systolic blood pressure, and decrease in rate-pressure product.
Initial increases in LV mass might be physiologic (28), and in obesity this might be due to increased body mass, yet the concern is that long-term exposure to LVH might result in poor outcomes. In 1970, the Framingham Heart Study reported the risk of cardiac morbidity and mortality in men with significant LVH, even after adjustment for hypertension (29,30). Results from another study showed that improvements in LVH were associated with lower CV morbidity and mortality, also independent of blood pressure (31). In addition, Devereux et al. (32) reported that lower LVM was associated with better outcomes, as demonstrated by lower rates of CV death, myocardial infarction, and stroke.
Without weight loss intervention, these morbidly obese children (BMI 99th percentile) will likely remain obese in adulthood (2,3). In recent adult studies, bariatric surgery for severe obesity is associated with decreased overall mortality (33,34). Although this type of evidence is currently lacking in adolescent studies, at the very least, significant LVH should be considered a relative indication for more aggressive weight loss interventions.
In this analysis, there were also several measures of diastolic function that improved after weight loss, including mitral Ea-lat velocity and increased E/Ea-lat ratio, with post-operative results comparing more favorably with normal adolescents (25). The adult published reports examining diastolic function after gastric bypass have shown conflicting findings (27,35,36). Again, the improvements seen in this adolescent population might reflect advantages to earlier age at intervention. Additional studies are needed to determine the effect of other confounding factors, including: sample size, length of follow-up, and magnitude of weight loss.
Study limitations.
This study was limited by the analysis of only 38 of the 67 patients who were 19 years old and underwent bariatric surgery during this study period. The remaining 29 patients were not evaluated, because either no pre- or post-operative images were available for comparison or the image quality was insufficient for analysis. Of note, there were no significant differences between pre-operative and follow-up weights between those included versus excluded (pre-operative BMI 60 vs. 60 kg/m2 and follow-up BMI 41 vs. 40 kg/m2, respectively). Therefore it is doubtful that a selection bias was introduced on the basis of weight. It is recognized that other comorbidities associated with morbid obesity could be playing a role in the observed changes of cardiac structure and function, including changes in: metabolic parameters, obstructive sleep apnea, dyslipidemia, body fat distribution, and hypertension. Although patients receiving medications were not excluded from the analysis, there were only 5 of the 38 that were taking cardiac medications. Two of those were receiving lipid-lowering medications, and 3 were receiving antihypertensive drugs. All were able to discontinue medications within 1 to 5 months post-operatively, with the exception of 1 patient taking an antilipidemic drug. Four patients were taking glucophage pre-operatively, and all were discontinued within 6 weeks post-operatively. There was 1 type I diabetic patient controlled on an insulin pump, with a glycosylated hemoglobin (HbA1c) value of 6.2%. The population as a whole was not hypertensive before or after surgery despite significant obesity.
Summary.
We demonstrate for the first time in morbidly obese adolescents the plasticity of pathologic LV geometry patterns with weight loss. The abnormalities of cardiac structure and function that can be reversed include: abnormal LV mass, high-risk forms of LV geometry, cardiac workload, and abnormal diastolic function. Weight loss interventions during adolescence might be more likely to change cardiac parameters than adults who have been exposed to long-term effects of obesity. This might be an argument for earlier intervention at younger ages in severely obese young people.
Future directions.
Long-term follow-up studies in adolescents are needed to determine whether these improvements in LVM and cardiac geometry persist and whether these findings translate into long-term reduction in their future CV morbidity during adulthood.
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Footnotes
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This evaluation was supported in part by the following grant: National Institutes of Health-T32-ES10957.
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References
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1. Gordon-Larsen P, Adair LS, Nelson MC, Popkin BM. Five-year obesity incidence in the transition period between adolescence and adulthood: the National Longitudinal Study of Adolescent Health Am J Clin Nutr 2004;80:569-575.[Abstract/Free Full Text]2. Whitaker RC, Wright JA, Pepe MS, Seidel KD, Dietz WH. Predicting obesity in young adulthood from childhood and parental obesity N Engl J Med 1997;337:869-873.[Abstract/Free Full Text] 3. Guo SS, Roche AF, Chumlea WC, Gardner JD, Siervogel RM. The predictive value of childhood body mass index values for overweight at age 35 y Am J Clin Nutr 1994;59:810-819.[Abstract/Free Full Text] 4. Freedman DS, Mei Z, Srinivasan SR, Berenson GS, Dietz WH. Cardiovascular risk factors and excess adiposity among overweight children and adolescents: the Bogalusa Heart Study J Pediatr 2007;15012-7.e12. 5. Xanthaxos SA, Inge TH. Extreme pediatric obesity: weighing the health dangers J Pediatr 2007;150:3-5.[Web of Science][Medline] 6. Inge TH, Garcia V, Daniels S, et al. A multidisciplinary approach to the adolescent bariatric surgical patient J Pediatr Surg 2004;39:442-447.[CrossRef][Web of Science][Medline] 7. Nelson RR, Gobel FL, Jorgensen CR, Wang K, Wang Y, Taylor HL. Hemodynamic predictors of myocardial oxygen consumption during static and dynamic exercise Circulation 1974;50:1179-1189.[Abstract/Free Full Text] 8. Noel M, Jobin J, Poirier P, Dagenais GR, Bogaty P. Different thresholds of myocardial ischemia in ramp and standard bruce protocol exercise tests in patients with positive exercise stress tests and angiographically demonstrated coronary arterial narrowing Am J Cardiol 2007;99:921-924.[CrossRef][Web of Science][Medline] 9. Sahn DJ, DeMaria A, Kisslo J, Weyman A. Recommendations regarding quantitation in M-mode echocardiography: results of a survey of echocardiographic measurements Circulation 1978;58:1072-1083.[Abstract/Free Full Text] 10. Devereux RB, Alonso DR, Lutas EM, et al. Echocardiographic assessment of left ventricular hypertrophy: comparison to necropsy findings Am J Cardiol 1986;57:450-458.[CrossRef][Web of Science][Medline] 11. de Simone G, Daniels SR, Devereux RB, et al. Left ventricular mass and body size in normotensive children and adults: assessment of allometric relations and impact of overweight J Am Coll Cardiol 1992;20:1251-1260.[Abstract] 12. Krumholz HM, Larson M, Levy D. Prognosis of left ventricular geometric patterns in the Framingham Heart Study J Am Coll Cardiol 1995;25:879-884.[Abstract] 13. Daniels SR, Loggie JM, Khoury P, Kimball TR. Left ventricular geometry and severe left ventricular hypertrophy in children and adolescents with essential hypertension Circulation 1998;97:1907-1911.[Abstract/Free Full Text] 14. Ganau A, Saba PS, Roman MJ, de Simone G, Realdi G, Devereux RB. Ageing induces left ventricular concentric remodelling in normotensive subjects J Hypertens 1995;13:1818-1822.[Web of Science][Medline] 15. de Simone G, Daniels SR, Kimball TR, et al. Evaluation of concentric left ventricular geometry in humans: evidence for age-related systematic underestimation Hypertension 2005;45:64-68.[Abstract/Free Full Text] 16. de Simone G, Devereux RB, Daniels SR, Koren MJ, Meyer RA, Laragh JH. Effect of growth on variability of left ventricular mass: assessment of allometric signals in adults and children and their capacity to predict cardiovascular risk J Am Coll Cardiol 1995;25:1056-1062.[Abstract] 17. Grossman W, Jones D, McLaurin LP. Wall stress and patterns of hypertrophy in the human left ventricle J Clin Invest 1975;56:56-64.[Web of Science][Medline] 18. Lang RM, Borow KM, Neumann A, Janzen D. Systemic vascular resistance: an unreliable index of left ventricular afterload Circulation 1986;74:1114-1123.[Abstract/Free Full Text] 19. Kimball TR, Daniels SR, Khoury P, Meyer RA. Age-related variation in contractility estimate in patients less than or equal to 20 years of age Am J Cardiol 1991;68:1383-1387.[CrossRef][Web of Science][Medline] 20. Kimball TR, Daniels SR, Meyer RA, et al. Effect of digoxin on contractility and symptoms in infants with a large ventricular septal defect Am J Cardiol 1991;68:1377-1382.[CrossRef][Web of Science][Medline] 21. De Boeck BW, Cramer MJ, Oh JK, van der Aa RP, Jaarsma W. Spectral pulsed tissue Doppler imaging in diastole: a tool to increase our insight in and assessment of diastolic relaxation of the left ventricle Am Heart J 2003;146:411-419.[CrossRef][Web of Science][Medline] 22. Nagueh SF, Middleton KJ, Kopelen HA, Zoghbi WA, Quinones MA. Doppler tissue imaging: a noninvasive technique for evaluation of left ventricular relaxation and estimation of filling pressures J Am Coll Cardiol 1997;30:1527-1533.[Abstract] 23. Ommen SR, Nishimura RA, Appleton CP, et al. Clinical utility of Doppler echocardiography and tissue Doppler imaging in the estimation of left ventricular filling pressures: a comparative simultaneous Doppler-catheterization study Circulation 2000;102:1788-1794.[Abstract/Free Full Text] 24. Inge TH, Krebs NF, Garcia VF, et al. Bariatric surgery for severely overweight adolescents: concerns and recommendations Pediatrics 2004;114:217-223.[Abstract/Free Full Text] 25. Eidem BW, McMahon CJ, Cohen RR, et al. Impact of cardiac growth on Doppler tissue imaging velocities: a study in healthy children J Am Soc Echocardiogr 2004;17:212-221.[CrossRef][Web of Science][Medline] 26. Muiesan ML, Salvetti M, Monteduro C, et al. Left ventricular concentric geometry during treatment adversely affects cardiovascular prognosis in hypertensive patients Hypertension 2004;43:731-738.[Abstract/Free Full Text] 27. Willens HJ, Chakko SC, Byers P, et al. Effects of weight loss after gastric bypass on right and left ventricular function assessed by tissue Doppler imaging Am J Cardiol 2005;95:1521-1524.[CrossRef][Web of Science][Medline] 28. Katz AM. Cardiomyopathy of overload. A major determinant of prognosis in congestive heart failure. N Engl J Med 1990;322:100-110.[Web of Science][Medline] 29. Gardin JM, Lauer MS. Left ventricular hypertrophy: the next treatable, silent killer? JAMA 2004;292:2396-2398.[Free Full Text] 30. Kannel WB, Gordon T, Castelli WP, Margolis JR. Electrocardiographic left ventricular hypertrophy and risk of coronary heart disease. The Framingham study. Ann Intern Med 1970;72:813-822.[Abstract/Free Full Text] 31. Okin PM, Devereux RB, Jern S, et al. Regression of electrocardiographic left ventricular hypertrophy during antihypertensive treatment and the prediction of major cardiovascular events JAMA 2004;292:2343-2349.[Abstract/Free Full Text] 32. Devereux RB, Wachtell K, Gerdts E, et al. Prognostic significance of left ventricular mass change during treatment of hypertension JAMA 2004;292:2350-2356.[Abstract/Free Full Text] 33. Adams TD, Gress RE, Smith SC, et al. Long-term mortality after gastric bypass surgery N Engl J Med 2007;357:753-761.[Abstract/Free Full Text] 34. Sjostrom L, Narbro K, Sjostrom CD, et al. Effects of bariatric surgery on mortality in Swedish obese subjects N Engl J Med 2007;357:741-752.[Abstract/Free Full Text] 35. Leichman JG, Aguilar D, King TM, et al. Improvements in systemic metabolism, anthropometrics, and left ventricular geometry 3 months after bariatric surgery Surg Obes Relat Dis 2006;2:592-599.[CrossRef][Medline] 36. Ikonomidis I, Mazarakis A, Papadopoulos C, et al. Weight loss after bariatric surgery improves aortic elastic properties and left ventricular function in individuals with morbid obesity: a 3-year follow-up study J Hypertens 2007;25:439-447.[Web of Science][Medline]
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Circulation,
November 11, 2008;
118(20):
2091 - 2102.
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A. E. Malavazos, F. Ermetici, L. Morricone, A. Delnevo, C. Coman, B. Ambrosi, and M. M. Corsi
Response to Cardiotrophin-1 in Adolescents: Impact of Obesity and Blood Pressure
Hypertension,
August 1, 2008;
52(2):
e7 - e7.
[Full Text]
[PDF]
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Abstract
Methods