Normalization for body size and population-attributable risk of left ventricular hypertrophy: the Strong Heart Study.
BACKGROUND
Left ventricular hypertrophy (LVH) is identified by left ventricular mass (LVM) normalized by body surface area (BSA) or height (in meters) also raised to allometric powers. The presence of LVH detected by these indices predicts increased cardiovascular (CV) events. Whether different indexations of LVH differ in their ability to predict excess risk is unknown.


METHODS
A total of 2400 subjects, (1589 women and 811 men), 59 +/- 8 years of age and without prevalent CV disease, valve disease or wall motion abnormalities and high prevalence of obesity were followed for an average of 86 months. Reference values (mean +/- 1.96 SD) for LVM/BSA, LVM/BSA(1.5), LVM/m, LVM/m(2.7), and LVM/m(2.13) were obtained in 251 normal participants and population-attributable risk percent (PAR%) for fatal and nonfatal CV events were calculated from prevalence of LVH and hazard ratios (HR).


RESULTS
In the entire population or in hypertensive participants, prevalence of LVH was higher for LVM/m(2.7) (20% and 28%) and LVM/m(2.13) (18% and 25%) than for BSA (7% and 11%). Age and sex-adjusted PAR% for LVM/m(2.7) or LVM/m(2.13) were on average 1.8-fold greater than for LVM/BSA in the entire population, and 1.6-fold greater in hypertensive participants, differences that were statistically significant.


CONCLUSIONS
The presence of LVH identified by LVM normalized for height to allometric powers is associated with a higher proportion of incident CV events than is LVH detected by normalization for BSA and is convenient for identification of individuals at high risk and in need of preventive intervention in populations with high prevalence of obesity. Allometric power methods allow detection of prognostically adverse, obesity-related LVH, which is unidentified using BSA.
de Simone
Giovanni
G
Division of Cardiology, The New York Presbyterian Hospital-Weill Medical College of Cornell University, New York, New York 10021, USA. simogi@unina.it
Kizer
Jorge R
JR
Chinali
Marcello
M
Roman
Mary J
MJ
Bella
Jonathan N
JN
Best
Lyle G
LG
Lee
Elisa T
ET
Devereux
Richard B
RB
D001827:Body Height; D049628:Body Size; D001830:Body Surface Area; D002318:Cardiovascular Diseases / Q000453:epidemiology / Q000209:etiology* / Q000401:mortality; D015331:Cohort Studies; D004452:Echocardiography; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications; D017379:Hypertrophy, Left Ventricular / Q000150:complications* / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000473:pathology; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications; D015995:Prevalence; D011379:Prognosis; D016016:Proportional Hazards Models; D018570:Risk Assessment