Body composition and fat distribution influence systemic hemodynamics in the absence of obesity: the HyperGEN Study.
BACKGROUND
We have shown that increased cardiac output is related to both fat-free mass and fat mass in obesity.


OBJECTIVE
We studied the association of body fat distribution and body composition with flow-resistance relations in overweight.


METHODS
We studied 521 overweight, nonobese participants in the Hypertension Genetic Epidemiology Network (HyperGEN) Study-a component of the National Heart, Lung, and Blood Institute Family Blood Pressure Program, designed to assess the genetic basis of hypertension. Participants had normal ventricular function and no cardiovascular disease: 261 with central fat distribution (CFD) (waist girth >88 cm in women and >102 cm in men) and 260 with peripheral fat distribution (PFD). Fat-free mass (FFM) and fat mass (FM) were measured by bioelectric impedance. Body composition was estimated as FM/FFM. Echocardiographic stroke volume (SV) and cardiac output (CO) were measured.


RESULTS
Hypertension was present in 73% of the subjects with PFD and in 78% with CFD. Overweight with CFD was associated with greater FM/FFM in both normotensive and hypertensive participants. After FFM, age, sex, and race were controlled for, SV and CO were higher in subjects overweight with CFD than in those with PFD, whereas peripheral resistance was not significantly different. Differences in CO between CFD and PFD were reduced after further adjustment for FM. After the covariates were controlled for, hypertensive subjects had higher peripheral resistance and lower arterial compliance than did normotensive participants, but cardiac output was not significantly different.


CONCLUSIONS
CFD is associated with more severe abnormalities in body composition and with higher CO independently of FFM in overweight, nonobese subjects.
de Simone
Giovanni
G
Department of Medicine, The New York Presbyterian Hospital, Weill Medical College of Cornell University, New York, NY, USA. simogi@unina.it
Devereux
Richard B
RB
Kizer
Jorge R
JR
Chinali
Marcello
M
Bella
Jonathan N
JN
Oberman
Albert
A
Kitzman
Dalane W
DW
Hopkins
Paul N
PN
Rao
D C
DC
Arnett
Donna K
DK
D000273:Adipose Tissue / Q000378:metabolism*; D001823:Body Composition; D001835:Body Weight; D002302:Cardiac Output; D005260:Female; D006801:Humans; D006973:Hypertension / Q000209:etiology* / Q000235:genetics; D008297:Male; D008875:Middle Aged