Effects of isolated obesity on systolic and diastolic left ventricular function
- 1Endocrinology and Nutrition Department, University Hospital Virgen de la Arrixaca, Murcia, Spain
- 2Cardiology Department, University Hospital Virgen de la Arrixaca
- 3Cardiology Department, General University Hospital, Murcia, Spain
- Correspondence to:
Dr Mariano Valdés, C/Portillo San Antonio 8, 5° D, 30005 Murcia, Spain;
- Accepted 13 March 2003
Background: Obesity is associated with increased cardiovascular morbidity and mortality. A direct effect of isolated obesity on cardiac function is not well established.
Objective: To determine the direct effect of different grades of isolated obesity on echocardiographic indices of systolic and diastolic left ventricular function.
Methods: 48 obese and 25 normal weight women were studied. They had no other pathological conditions. Obesity was classed as slight (n = 17; body mass index (BMI) 25–29.9 kg/m2), moderate (n = 20; BMI 30–34.9 kg/m2), or severe (n = 11; BMI ⩾ 35 kg/m2). Echocardiographic indices of systolic and diastolic function were obtained, and dysfunction was assumed when at least two values differed by ⩾ 2 SD from the normal weight group.
Results: Ejection fraction (p < 0.05), fractional shortening (p < 0.05), and mean velocity of circumferential shortening (p < 0.05) were increased in slight and moderate obesity. Left ventricular dimensions were increased (p < 0.001) but relative wall thickness was unchanged. No obese patients met criteria for systolic dysfunction. In obese subjects, the mitral valve pressure half time (p < 0.01) and the left atrial diameter (p < 0.001) were increased and the deceleration slope was decreased (p < 0.01); all other diastolic variables were unchanged. No differences were found between obesity subgroups. Subclinical diastolic dysfunction was more prevalent among obese subjects (p = 0.002), being present in two with slight obesity (12%), seven with moderate obesity (35%), and five with severe obesity (45%). BMI correlated significantly with indices of left ventricular function.
Conclusions: Subclinical left ventricular diastolic dysfunction is present in all grades of isolated obesity, correlates with BMI, and is associated with increased systolic function in the early stages of obesity.
- A, maximum velocity of active mitral filling
- AA, area under the curve of the velocity range corresponding to active mitral filling
- AE, area under the curve of the velocity range corresponding to passive mitral filling
- BMI, body mass index
- E, maximum velocity of passive mitral filling
- E/A, ratio of passive to active filling velocity
- EDD, end diastolic diameter
- EDV, end diastolic volume
- EP, ejection period
- ESD, end systolic diameter
- ESV, end systolic volume
- FS, fractional shortening
- IVRT, isovolumic relaxation time
- MV½T, mitral valve pressure half time
- PEP, pre-ejection period
- PWT, posterior wall thickness
- RWT, relative wall thickness
- VCS, velocity of circumferential fibre shortening