Ventricular hypertrophy and cavity dilatation in relation to body mass index in women with uncomplicated obesity.
OBJECTIVE
The traditionally accepted mechanism for ventricular adaptation to obesity suggests that cavity dilatation in response to increased blood volume and elevated filling pressure results in ventricular hypertrophy as a compensatory mechanism. Our hypothesis was that, instead, initiation of ventricular hypertrophy in obesity may be explained by changes in hormonal milieu and not by cavity dilatation.


METHODS
88 female subjects without identifiable cardiovascular risk factors, covering a wide range of body mass indices (BMI), from normal (21.2 ± 1.6 kg/m(2)) to severely obese (45.0 ± 4.6 kg/m(2)), underwent cardiovascular MRI to determine left ventricular (LV) and right ventricular (RV) mass and volumes.


RESULTS
BMI correlated positively with LV and RV mass and end-diastolic volumes (EDV). However overweight is associated with a significant LV and RV hypertrophy (LV: 78 ± 11 g vs 103 ± 16 g, p<0.01; RV: 26 ± 7 g vs 40 ± 11 g, p<0.01) was observed in the absence of differences in LV and RV volumes (LV: EDV 119 ± 15 vs 121 ± 21 ml, p>0.99, RV: 131 ± 17 vs 130 ± 24 ml; p>0.99). Furthermore, significant increases of serum leptin occurred at this pre-obese stage (15.6 ± 19 vs 36.5 ± 22 ng/ml; p=0.013).


CONCLUSIONS
In a cohort of healthy female subjects with a wide range of BMIs, ventricular hypertrophy occurs without associated cavity dilatation in overweight individuals, while in manifest obesity, both cavity dilatation and ventricular hypertrophy occur. Elevated leptin levels may have a role in this effect on ventricular mass.
Rider
Oliver J
OJ
Department of Cardiovascular Medicine, University of Oxford Centre for Clinical Magnetic Resonance Research, University of Oxford, Oxford, UK.
Petersen
Steffen E
SE
Francis
Jane M
JM
Ali
Mohammed K
MK
Hudsmith
Lucy E
LE
Robinson
Monique R
MR
Clarke
Kieran
K
Neubauer
Stefan
S
D000328:Adult; D015992:Body Mass Index; D006332:Cardiomegaly / Q000097:blood / Q000209:etiology* / Q000473:pathology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000097:blood / Q000209:etiology / Q000473:pathology; D017380:Hypertrophy, Right Ventricular / Q000097:blood / Q000209:etiology / Q000473:pathology; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance / Q000502:physiology; D020738:Leptin / Q000097:blood; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009765:Obesity / Q000097:blood / Q000150:complications* / Q000503:physiopathology; D016277:Ventricular Function, Left / Q000502:physiology; D016278:Ventricular Function, Right / Q000502:physiology
D007328:Insulin; D020738:Leptin