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Metabolic Syndrome and Left Ventricular Structure and Functional Abnormalities
AJH
2006; 19:206 –207
Reviewer Critique
Metabolic Syndrome and Left Ventricular Structure and Functional Abnormalities Vittorio Palmieri and Jonathan N. Bella
M
etabolic syndrome is a pro-atherothrombotic condition predisposing to cardiovascular events. In their study, Grandi et al1 explored correlations of metabolic syndromes with subclinical cardiovascular organ damage, such as increased left ventricular mass and systolic and diastolic dysfunction. Such a target is relevant because left ventricular structural and functional abnormalities are independent predictors of cardiovascular events including congestive heart failure. Grandi et al suggested considering metabolic syndrome as a distinct condition requiring aggressive treatment strategies because the study showed that metabolic syndrome was more strongly correlated than its components with subclinical cardiovascular target organ damage. In the study by Grandi et al,1 subjects with metabolic syndrome had higher left ventricular mass indexed for body surface area (g/m2) than those without metabolic syndrome (see Table 3 in that article). Therefore it appears that higher left ventricular mass associated with metabolic syndrome is not simply driven by obesity. In fact, indexation of left ventricular mass by body surface accounts for obesity-related increase in fat-free mass,2 which in turn is a strong correlate of left ventricular mass in the general population.3 Although all patients in this study were hypertensive, mean blood pressure (BP) measured in the clinic setting was higher in the metabolic syndrome group. In both regression models (see Table 4 of that article), 24-h systolic BP was a strong correlate of nonindexed left ventricular mass but did not exclude the correlation between metabolic syndrome (or body mass index) with left ventricular mass. Insulin resistance is supposed to be a relevant additive factor to left ventricular mass increase in such a context; however a recent study in a populationbased sample found no correlation between insulin resis-
See related article on page 199
Received October 9, 2005. First decision October 28, 2005. Accepted October 28, 2005. From the Department of Clinical and Experimental Medicine (VP), “Federico II” University School of Medicine, Naples, Italy; and Weill Medical College of Cornell University (VP, JNB), New York, New 0895-7061/06/$30.00 doi:10.1016/j.amjhyper.2005.10.012
tance and left ventricular mass after accounting for body size.4 Use of left ventricular mass indexed for body height (in meters) to the 2.7 power (g/m2.7) would have allowed more precise identification of the relative contribution of obesity, BP, and metabolic factors to left ventricular mass. Grandi et al also showed that metabolic syndrome was associated with left ventricular diastolic dysfunction independent of left ventricular mass, midwall systolic function, and age. However, it was recognized that concentric left ventricular geometry is a relevant correlate of abnormal left ventricular relaxation.5 Indeed, Grandi et al found higher relative wall thickness in the subjects with metabolic syndrome; however, concentric geometry was not accounted for in multivariate models exploring correlations of metabolic syndrome with left ventricular diastolic function. Coexistence of several cardiovascular risk factors, such as those involved in the definition of metabolic syndrome, requires the greatest attention, even more in subjects with target organ damage as guidelines clearly indicate.6 However the greatest challenge is to avoid underestimation of cardiovascular risk in patients with apparently low cardiovascular risk, such as subjects with high-normal BP who are overweight.
References 1.
2.
Grandi et al: Metabolic syndrome and morphofunctional characteristics of the left ventricle in clinically hypertensive nondiabetic subjects. Am J Hypertens 2006;19:199 –205. Palmieri V, de Simone G, Arnett DK, Bella JN, Kitzman DW, Oberman A, Hopkins PN, Province MA, Devereux RB: Relation of various degrees of body mass index in patients with systemic hypertension to left ventricular mass, cardiac output, and peripheral resistance (The Hypertension Genetic Epidemiology Network Study). Am J Cardiol 2001;88:1163–1168.
York; and Bronx-Lebanon Hospital Center and Albert Einstein College of Medicine, Bronx, New York (JNB). Address correspondence and reprint requests to Dr. Vittorio Palmieri, “Federico II” University Hospital, Internal Medicine, via Pansini 5 Building 1A, Room 421, Naples, 80131, Italy; e-mail: [email protected] © 2006 by the American Journal of Hypertension, Ltd. Published by Elsevier Inc.
AJH–February 2006 –VOL. 19, NO. 2
3.
4.
Bella JN, Devereux RB, Roman MJ, O’Grady MJ, Welty TK, Lee ET, Fabsitz RR, Howard BV: Relations of left ventricular mass to fat-free and adipose body mass. The Strong Heart Study Investigators. Circulation 1998;98:2538 –2544. Devereux RB, de Simone G, Palmieri V, Oberman A, Hopkins P, Kitzman DW, Rao DC, Arnett DK: Relation of insulin to left ventricular geometry and function in African American and white hypertensive adults: the HyperGEN study. Am J Hypertens 2002; 15:1029 –1035.
METABOLIC SYNDROME
5.
6.
207
de Simone G, Kitzman DW, Chinali M, Oberman A, Hopkins PN, Rao DC, Arnett DK, Devereux RB: Left ventricular concentric geometry is associated with impaired relaxation in hypertension: the HyperGEN study. Eur Heart J 2005;26:1039 –1045. Chobanian AV, Bakris GL, Black HR, Cushman WC, Green LA, Izzo JL Jr, Jones DW, Materson BJ, Oparil S, Wright JT Jr, Roccella EJ: Seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Hypertension 2003;42:1206 –1252.
2006; 19:206 –207
Reviewer Critique
Metabolic Syndrome and Left Ventricular Structure and Functional Abnormalities Vittorio Palmieri and Jonathan N. Bella
M
etabolic syndrome is a pro-atherothrombotic condition predisposing to cardiovascular events. In their study, Grandi et al1 explored correlations of metabolic syndromes with subclinical cardiovascular organ damage, such as increased left ventricular mass and systolic and diastolic dysfunction. Such a target is relevant because left ventricular structural and functional abnormalities are independent predictors of cardiovascular events including congestive heart failure. Grandi et al suggested considering metabolic syndrome as a distinct condition requiring aggressive treatment strategies because the study showed that metabolic syndrome was more strongly correlated than its components with subclinical cardiovascular target organ damage. In the study by Grandi et al,1 subjects with metabolic syndrome had higher left ventricular mass indexed for body surface area (g/m2) than those without metabolic syndrome (see Table 3 in that article). Therefore it appears that higher left ventricular mass associated with metabolic syndrome is not simply driven by obesity. In fact, indexation of left ventricular mass by body surface accounts for obesity-related increase in fat-free mass,2 which in turn is a strong correlate of left ventricular mass in the general population.3 Although all patients in this study were hypertensive, mean blood pressure (BP) measured in the clinic setting was higher in the metabolic syndrome group. In both regression models (see Table 4 of that article), 24-h systolic BP was a strong correlate of nonindexed left ventricular mass but did not exclude the correlation between metabolic syndrome (or body mass index) with left ventricular mass. Insulin resistance is supposed to be a relevant additive factor to left ventricular mass increase in such a context; however a recent study in a populationbased sample found no correlation between insulin resis-
See related article on page 199
Received October 9, 2005. First decision October 28, 2005. Accepted October 28, 2005. From the Department of Clinical and Experimental Medicine (VP), “Federico II” University School of Medicine, Naples, Italy; and Weill Medical College of Cornell University (VP, JNB), New York, New 0895-7061/06/$30.00 doi:10.1016/j.amjhyper.2005.10.012
tance and left ventricular mass after accounting for body size.4 Use of left ventricular mass indexed for body height (in meters) to the 2.7 power (g/m2.7) would have allowed more precise identification of the relative contribution of obesity, BP, and metabolic factors to left ventricular mass. Grandi et al also showed that metabolic syndrome was associated with left ventricular diastolic dysfunction independent of left ventricular mass, midwall systolic function, and age. However, it was recognized that concentric left ventricular geometry is a relevant correlate of abnormal left ventricular relaxation.5 Indeed, Grandi et al found higher relative wall thickness in the subjects with metabolic syndrome; however, concentric geometry was not accounted for in multivariate models exploring correlations of metabolic syndrome with left ventricular diastolic function. Coexistence of several cardiovascular risk factors, such as those involved in the definition of metabolic syndrome, requires the greatest attention, even more in subjects with target organ damage as guidelines clearly indicate.6 However the greatest challenge is to avoid underestimation of cardiovascular risk in patients with apparently low cardiovascular risk, such as subjects with high-normal BP who are overweight.
References 1.
2.
Grandi et al: Metabolic syndrome and morphofunctional characteristics of the left ventricle in clinically hypertensive nondiabetic subjects. Am J Hypertens 2006;19:199 –205. Palmieri V, de Simone G, Arnett DK, Bella JN, Kitzman DW, Oberman A, Hopkins PN, Province MA, Devereux RB: Relation of various degrees of body mass index in patients with systemic hypertension to left ventricular mass, cardiac output, and peripheral resistance (The Hypertension Genetic Epidemiology Network Study). Am J Cardiol 2001;88:1163–1168.
York; and Bronx-Lebanon Hospital Center and Albert Einstein College of Medicine, Bronx, New York (JNB). Address correspondence and reprint requests to Dr. Vittorio Palmieri, “Federico II” University Hospital, Internal Medicine, via Pansini 5 Building 1A, Room 421, Naples, 80131, Italy; e-mail: [email protected] © 2006 by the American Journal of Hypertension, Ltd. Published by Elsevier Inc.
AJH–February 2006 –VOL. 19, NO. 2
3.
4.
Bella JN, Devereux RB, Roman MJ, O’Grady MJ, Welty TK, Lee ET, Fabsitz RR, Howard BV: Relations of left ventricular mass to fat-free and adipose body mass. The Strong Heart Study Investigators. Circulation 1998;98:2538 –2544. Devereux RB, de Simone G, Palmieri V, Oberman A, Hopkins P, Kitzman DW, Rao DC, Arnett DK: Relation of insulin to left ventricular geometry and function in African American and white hypertensive adults: the HyperGEN study. Am J Hypertens 2002; 15:1029 –1035.
METABOLIC SYNDROME
5.
6.
207
de Simone G, Kitzman DW, Chinali M, Oberman A, Hopkins PN, Rao DC, Arnett DK, Devereux RB: Left ventricular concentric geometry is associated with impaired relaxation in hypertension: the HyperGEN study. Eur Heart J 2005;26:1039 –1045. Chobanian AV, Bakris GL, Black HR, Cushman WC, Green LA, Izzo JL Jr, Jones DW, Materson BJ, Oparil S, Wright JT Jr, Roccella EJ: Seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Hypertension 2003;42:1206 –1252.