Relative fat-free mass deficiency and left ventricular adaptation to obesity: the Strong Heart Study.
BACKGROUND
Relative fat-free mass (FFM) deficiency (RFFMD) can also occur in obesity, but the impact on left ventricular (LV) mass is unknown.


METHODS
We assessed relations among reduced FFM, obesity and LV mass in a population with high prevalence of obesity. Echocardiograms were performed in 2625 participants (1694 women, 1199 non-obese) of the Strong Heart Study cohort, free of prevalent cardiovascular disease and kidney failure. FFM was estimated by bioelectric impedance and analyzed in the non-obese subpopulation in relation with sex, BMI and waist-to-hip ratio (WHR). RFFMD was estimated in the obese subpopulation as the percent of observed/predicted FFM<20th percentile of the non-obese distribution.


RESULTS
RFFMD was more frequent in women than men. LV mass indices (by either height(2.7) or FFM) were greater in obese with than in those without RFFMD, even after adjusting for sex and diabetes (both p<0.0001). The greater LV mass index in obesity with RFFMD was related mostly to increased LV diastolic dimension paralleling increased stroke index and cardiac index, in the presence of normal ejection fraction. RFFMD remained associated with greater LV mass index (p<0.0001) even independently of older age, greater BMI, higher systolic and lower diastolic blood pressure (all p<0.007), with negligible effect of sex, waist/hip ratio and diabetes.


CONCLUSIONS
In obese SHS participants, RFFMD is associated with higher levels of LV mass, an effect related to adiposity more than central fat distribution and typical of female gender. Biological mechanisms of this association have to be better explored.
Federico II University, Naples, Italy; Weill Cornell Medical College, New York, NY, United States. Electronic address: simogi@unina.it.
Giovanni
G
de Simone
Fabrizio
F
Pasanisi
Aldo L
AL
Ferrara
Mary J
MJ
Roman
Elisa T
ET
Lee
Franco
F
Contaldo
Barbara V
BV
Howard
Richard B
RB
Devereux
D000222:Adaptation, Physiological / Q000502:physiology*; D000368:Aged; D001794:Blood Pressure / Q000502:physiology; D015992:Body Mass Index; D015331:Cohort Studies; D005260:Female; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology*; D011159:Population Surveillance / Q000379:methods; D049629:Waist-Hip Ratio / Q000379:methods