BMI and an Anthropometry-Based Estimate of Fat Mass Percentage Are Both Valid Discriminators of Cardiometabolic Risk : A Comparison with DXA and Bioimpedance

Abstract EN

Objective.

To determine whether categories of obesity based on BMI and an anthropometry-based estimate of fat mass percentage (FM% equation) have similar discriminative ability for markers of cardiometabolic risk as measurements of FM% by dual-energy X-ray absorptiometry (DXA) or bioimpedance analysis (BIA).

Design and Methods.

A study of 40–79-year-old male (n=205) and female (n=388) Finns.

Weight, height, blood pressure, triacylglycerols, HDL cholesterol, and fasting blood glucose were measured.

Body composition was assessed by DXA and BIA and a FM%-equation.

Results.

For grade 1 hypertension, dyslipidaemia, and impaired fasting glucose >6.1 mmol/L, the categories of obesity as defined by BMI and the FM% equation had 1.9% to 3.7% (P<0.01) higher discriminative power compared to DXA.

For grade 2 hypertension the FM% equation discriminated 1.2% (P=0.05) lower than DXA and 2.8% (P<0.01) lower than BIA.

Receiver operation characteristics confirmed BIA as best predictor of grade 2 hypertension and the FM% equation as best predictor of grade 1 hypertension.

All other differences in area under curve were small (≤0.04) and 95% confidence intervals included 0.

Conclusions.

Both BMI and FM% equations may predict cardiometabolic risk with similar discriminative ability as FM% measured by DXA or BIA.