Metabolic rate of major organs and tissues in young adult South Asian women.
Level 4 - case-series / case-control
Cross-sectional physiological estimation study in a single demographic cohort
PubMed 30405209 · doi:10.1038/s41430-018-0362-0
What was done
In a cross-sectional study of 70 healthy young adult South Asian women, researchers measured brain and visceral organ volumes by MRI, skeletal muscle mass by dual-energy X-ray absorptiometry (DXA), fat mass by a 4-component model, and whole-body resting energy expenditure by indirect calorimetry. Organ- and tissue-specific metabolic rate coefficients (Ki values) were indirectly modeled using linear regression through the origin, both before and after applying a literature-based 22.5% downward adjustment to correct for heart mass overestimation.
What was found
The abstract reports no absolute numerical values, standard errors, or p-values. Qualitatively, the relative distribution of derived Ki values across organs and tissues matched standard in vivo reference values, though initial absolute estimates were systematically lower. Applying the 22.5% heart mass reduction correction markedly improved alignment with standard published values.
Why it matters
Most organ-specific metabolic rate models are derived from populations of European descent; this study evaluates whether observed ethnic variations in whole-body resting metabolic rate reflect distinct tissue-level metabolic intensities or methodological artifacts in organ mass estimation.
Limits
The sample is limited to 70 young, healthy women of South Asian ancestry, precluding generalization to men, older cohorts, or other ethnicities. Organ metabolic rates were derived indirectly via statistical modeling rather than direct in vivo measurement of tissue arteriovenous differences. The final model required an empirical correction factor for heart mass estimation error, and exact numerical estimates were omitted from the abstract.
Cited by
- supports Per unit of mass, skeletal muscle has a relatively low metabolic rate compared to other lean tissues like the liver and gut.