Impact of body fat mass extent on cardiac autonomic alterations in women.
BACKGROUND
Obesity has been associated with significant abnormalities of the cardiac autonomic regulation. However, the precise impact of increasing body weight on cardiac autonomic function and the metabolic and hormonal contributors to these changes are presently unclear. The aim of our study was to explore in subjects with increasing values of body mass index (BMI) the alterations of cardiac autonomic function and to establish the potential role of various metabolic and hormonal contributors to these alterations.


METHODS
We investigated time and frequency domain heart rate variability (HRV) parameters taken from 24-h Holter recordings, and several anthropometric, metabolic and hormonal parameters (plasma glucose, insulin, triglycerides, free fatty acids, leptin and adiponectin) in 68 normoglycaemic and normotensive women (mean age of 40 +/- 3 years), subdivided according to their BMI into 15 normal body weight (controls), 15 overweight, 18 obese and 20 morbidly obese.


RESULTS
Heart rate was increased and HRV was decreased in the morbidly obese group as compared with controls. In overall population, a negative association linked body fat mass (FM) to HRV indices. None of the metabolic and hormonal parameters were significantly related to the HRV indices, after they were adjusted for the body FM.


CONCLUSIONS
Morbidly obese, normoglycaemic and normotensive young women have increased HR and low HRV, indicating an abnormal cardiac autonomic function and representing a risk factor for adverse cardiovascular events. A decrease of HRV parameters is associated with a progressive increase of body FM. Other metabolic and hormonal factors, characterising obesity, do not show an independent influence on these HRV alterations.
Sztajzel
J
J
Cardiology Service, University Hospital, 24 rue Micheli-du-Crest, Geneva 4, Switzerland. juan.sztajzel@hcuge.ch
Golay
A
A
Makoundou
V
V
Lehmann
T N O
TN
Barthassat
V
V
Sievert
K
K
Pataky
Z
Z
Assimacopoulos-Jeannet
F
F
Bobbioni-Harsch
E
E
D000328:Adult; D000886:Anthropometry; D001341:Autonomic Nervous System / Q000378:metabolism / Q000503:physiopathology*; D001342:Autonomic Nervous System Diseases / Q000378:metabolism / Q000503:physiopathology* / Q000517:prevention & control; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D007333:Insulin Resistance; D009767:Obesity, Morbid / Q000378:metabolism / Q000503:physiopathology*; D012016:Reference Values; D012307:Risk Factors