Although body mass index is criticized for not distinguishing fat from lean mass, its ability to detect subclinical cardiometabolic abnormalities was on par with more sophisticated body scanning technology, according a recent analysis.
BMI and dual-energy x-ray absorptiometry (DXA) had similar associations with cardiometabolic traits associated with coronary heart disease in individuals evaluated at 10 and 18 years of age in a population-based birth cohort study, the study investigators said.
Changes over time in BMI and DXA also were strongly associated with changes in blood pressure, cholesterol, and other markers, according to Joshua A. Bell, PhD, of MRC Integrative Epidemiology Unit, University of Bristol, England, and his coinvestigators.
“Altogether, the results support abdominal fatness as a primary driver of cardiometabolic dysfunction and BMI as a useful tool for detecting its effects,” Dr. Bell and his colleagues said in a report on the study appearing in the Journal of the American College of Cardiology.
In their analysis, Dr. Bell and coinvestigators used Pearson correlation coefficients to compare BMI and total and regional fat indexes from DXA in offspring participants from ALSPAC, (the Avon Longitudinal Study of Parents and Children), in which BMI and DXA measurements were collected at 10 and 18 years of age.
Researchers identified a total of 2,840 participants with at least one measurement at each of those time points. The mean BMI was 17.5 kg/m2 at 10 years of age and 22.7 kg/m2 at 18 years of age, with greater than 10% of participants classified as obese at each of those time points.
High BMI and high total fat mass index were similarly associated with a variety of cardiometabolic traits, including systolic and diastolic blood pressure, higher low-density lipoprotein (LDL) and very-low-density lipoprotein (VLDL) cholesterol levels and lower high-density lipoprotein (HDL) cholesterol levels, and more inflammation, investigators found.
BMI was strongly correlated with DXA total and regional fat indexes at 10 years of age, and again at 18 years of age, they reported.
Moreover, gains in BMI from 10 to 18 years of age were strongly associated with higher blood pressure, higher LDL and VLDL cholesterol, lower HDL cholesterol, and other cardiometabolic traits, while associations between DXA measurements and those traits closely tracked those of BMI in pattern and magnitude, investigators added.
Fatness is most often measured in populations using BMI, and causal analyses suggest linkage between higher BMI and coronary heart disease and its intermediates, including blood pressure, LDL and remnant cholesterol, and glucose; despite that, BMI is often disparaged as a tool for assessing cardiometabolic abnormalities because it does not distinguish fat from lean mass and cannot quantify fat distribution, investigators said.
However, based on results of this analysis, it is reasonable to depend on BMI to indirectly measure body and abdominal fatness in future studies, they said in their report.
Dr. Bell and his colleagues reported that they had no relationships relevant to the study publication.
SOURCE: Bell JA et al. J Am Coll Cardiol. 2018 Dec 18;72(24):3142-54.