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Myocardial Oxygen Consumption Change Predicts Left Ventricular Relaxation Improvement in Obese Humans After Weight Loss
Author(s) -
Lin C. Huie,
Kurup Suraj,
Herrero Pilar,
Schechtman Kenneth B.,
Eagon J. Christopher,
Klein Samuel,
DávilaRomán Víctor G.,
Stein Richard I.,
DornII Gerald W.,
Gropler Robert J.,
Waggoner Alan D.,
Peterson Linda R.
Publication year - 2011
Publication title -
obesity
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.438
H-Index - 199
eISSN - 1930-739X
pISSN - 1930-7381
DOI - 10.1038/oby.2011.186
Subject(s) - weight loss , medicine , diastole , insulin resistance , cardiology , obesity , endocrinology , blood pressure
Obesity adversely affects myocardial metabolism, efficiency, and diastolic function. Our objective was to determine whether weight loss can ameliorate obesity‐related myocardial metabolism and efficiency derangements and that these improvements directly relate to improved diastolic function in humans. We studied 30 obese (BMI >30 kg/m 2 ) subjects with positron emission tomography (PET) (myocardial metabolism, blood flow) and echocardiography (structure, function) before and after marked weight loss from gastric bypass surgery ( N = 10) or moderate weight loss from diet ( N = 20). Baseline BMI, insulin resistance, hemodynamics, left ventricular (LV) mass, systolic function, myocardial oxygen consumption (MVO 2 ), and fatty acid (FA) metabolism were similar between the groups. MVO 2 /g decreased after diet‐induced weight loss ( P = 0.009). Total MVO 2 decreased after dietary ( P = 0.02) and surgical weight loss ( P = 0.0006) and was related to decreased BMI ( P = 0.006). Total myocardial FA utilization decreased ( P = 0.03), and FA oxidation trended lower ( P = 0.06) only after surgery. FA esterification and LV efficiency were unchanged. After surgical weight loss, LV mass decreased by 23% (Doppler‐derived) E/E' by 33%, and relaxation increased (improved) by 28%. Improved LV relaxation related significantly to decreased BMI, insulin resistance, total MVO 2 , and LV mass but not FA utilization. Decreased total MVO 2 predicted LV relaxation improvement independent of BMI change ( P = 0.02). Weight loss can ameliorate the obesity‐related derangements in myocardial metabolism and LV structure and diastolic function. Decreased total MVO 2 independently predicted improved LV relaxation, suggesting that myocardial oxygen metabolism may be mechanistically important in determining cardiac relaxation.