Abstract
BACKGROUND:
Left ventricular mass (LVM) is an important predictor of cardiovascular risk. In adolescence, LVM is commonly indexed to height2.7, although some evidence suggests that this may not fully account for sex differences.
METHODS:
We investigated appropriate allometric scaling of LVM to height, total lean mass, and body surface area, in a UK birth cohort of 2039 healthy adolescents (17±1 years). Allometric relationships were determined by linear regression stratified by sex, following log transformation of x and y variables [log(y)=a+b×log(x)], b is the allometric exponent.
RESULTS:
Log (LVM) showed linear relationships with log(height) and log(lean mass). Biased estimates of slope resulted when the sexes were pooled. The exponents were lower than the conventional estimate of 2.7 for males (mean [95% CI]=1.66 [1.30–2.03]) and females (1.58 [1.27–1.90]). When LVM was indexed to lean mass, the exponent was 1.16 (1.05–1.26) for males and 1.07 (0.97–1.16) for females. When LVM was indexed to estimated body surface area, the exponent was 1.53 (1.40–1.66) for males and 1.34 (1.24–1.45) for females.
CONCLUSIONS:
Allometric exponents derived from pooled data, including men and women without adjustment for sex were biased, possibly due to sex differences in body composition. We suggest that when assessing LVM, clinicians should consider body size, body composition, sex, and age. Our observations may also have implications for the identification of young individuals with cardiac hypertrophy.
Left ventricular mass (LVM) is an important predictor of cardiovascular risk. In adolescence, LVM is commonly indexed to height2.7, although some evidence suggests that this may not fully account for sex differences.
METHODS:
We investigated appropriate allometric scaling of LVM to height, total lean mass, and body surface area, in a UK birth cohort of 2039 healthy adolescents (17±1 years). Allometric relationships were determined by linear regression stratified by sex, following log transformation of x and y variables [log(y)=a+b×log(x)], b is the allometric exponent.
RESULTS:
Log (LVM) showed linear relationships with log(height) and log(lean mass). Biased estimates of slope resulted when the sexes were pooled. The exponents were lower than the conventional estimate of 2.7 for males (mean [95% CI]=1.66 [1.30–2.03]) and females (1.58 [1.27–1.90]). When LVM was indexed to lean mass, the exponent was 1.16 (1.05–1.26) for males and 1.07 (0.97–1.16) for females. When LVM was indexed to estimated body surface area, the exponent was 1.53 (1.40–1.66) for males and 1.34 (1.24–1.45) for females.
CONCLUSIONS:
Allometric exponents derived from pooled data, including men and women without adjustment for sex were biased, possibly due to sex differences in body composition. We suggest that when assessing LVM, clinicians should consider body size, body composition, sex, and age. Our observations may also have implications for the identification of young individuals with cardiac hypertrophy.
| Original language | English |
|---|---|
| Pages (from-to) | 2033-2042 |
| Number of pages | 10 |
| Journal | Hypertension |
| Volume | 80 |
| Issue number | 10 |
| DOIs | |
| Publication status | Published - 7 Aug 2023 |
Bibliographical note
Funding Information:The UK Medical Research Council and Wellcome (grant ref: 217065/Z/19/Z) and the University of Bristol provide core support for ALSPAC (Avon Longitudinal Study of Parents and Children). This publication is the work of the authors and C.M. Park will serve as guarantor for the contents of this article. This research was funded in part, by the Wellcome Trust (grant number 092731). For the purpose of Open Access, the author has applied a CC BY public copyright license to any Author Accepted Manuscript version arising from this submission. A. Fraser and L.D. Howe are funded by UK Medical Research Council Post-doctoral research fellowships (MR/M009351/1/1 and MR/M020894/1, respectively). A.D. Hughes and N. Chaturvedi receive support from a Biomedical Research Center Award to University College London Hospital and a British Heart Foundation (BHF) Accelerator award to UCL (AA/18/6/34223). Additional funding for this study came from the Wellcome Trust (067100 and 086676/7/08/Z) and BHF (PG/06/145 and CS/15/6/31468 and SP/F/21/150020). N.J. Timpson is a Wellcome Trust Investigator (202802/Z/16/Z), the PI of the Avon Longitudinal Study of Parents and Children (MRC and WT 217065/Z/19/Z), is supported by the University of Bristol National Institute for Health and Care Research Biomedical Research Center, the MRC Integrative Epidemiology Unit (MC_UU_00011/1), and works within the Cancer Research UK Integrative Cancer Epidemiology Program (C18281/A29019).
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