Age- and sex-specific reference intervals for visceral fat mass in adults

Dual-energy X-ray absorptiometry (DXA) is becoming a method of choice for the assessment of visceral adipose tissue (VAT) but the lack of robust reference ranges presents a challenge to the interpretation of VAT in clinical practice, research settings, and the athletic environment. The objective of this study was to develop age- and sex-specific reference intervals for DXA-derived VAT mass.

The reference group comprised 3219 adults (1886 general population, 42% women; 1333 athletes, 11% women) in the United Kingdom, aged 18-83 years. Total body scans were performed using a GE Lunar iDXA and VAT analyses were enabled through Corescan software (Encore version 15.0). Age-specific reference ranges were derived in samples stratified by sex and general population/ athlete status. We modelled the mean and SD of Box-Cox transformed VAT mass as a function of age with a generalised least squares method using fractional polynomials (Stata® -xrigls- program). Centile values were then back-transformed to provide reference intervals on the original scale.

In general population samples, average VAT mass increases with age up until around 65-70 years, and then begins to decline at older ages, though data are relatively sparse at the upper end of the age range. In athletes, on average, VAT mass increases with advancing age in men and women. Both 95 and 98% reference ranges are presented in 5-year increments in all samples, and we provide equations to enable the calculation of any centile, for any age within the range.

These reference data can aid the interpretation of VAT mass specific to an individual's sex, age, and athletic status, increasing the utility and applicability of DXA-derived VAT assessments. Additional research is needed in adults over 65 years and female athletes, with different DXA devices, across different ethnic groups and specific sports.