Cold-activated brown adipose tissue is an independent predictor of higher bone mineral density in women

SummaryIn animals, defective brown adipogenesis leads to bone loss. Whether brown adipose tissue (BAT) mass relates to bone mineral density (BMD) in humans is unclear. We determined the relationship between BAT mass and BMD by cold-stimulated positron-emission tomography (PET) and dual-energy X-ray absorptiometry (DXA) in healthy volunteers. Higher BAT mass was associated with higher BMD in healthy women, but not in men, independent of age and body composition.IntroductionContrary to the traditional belief that BAT is present only in infants, recent studies revealed significant depots of BAT present in adult humans. In animals, defective brown adipogenesis leads to bone loss. While white adipose tissue mass is a known determinant of BMD in humans, the relationship between BAT and BMD in humans is unclear. We thus examined the relationship between BAT and BMD in healthy adults.MethodsBAT volume (ml) and activity (standard uptake value) were determined by 18F-fluorodeoxyglucose PET after overnight mild cold exposure at 19 °C, and BMD was determined by DXA.ResultsAmong 24 healthy adults (age 28 ± 1 years, F = 10), BAT volumes were 82.4 ± 99.5 ml in women and 49.7 ± 54.5 ml in men. Women manifested significantly higher BAT activity, by 9.4 ± 8.1 % (p = 0.03), than men. BAT volume correlated positively with total and spine BMD (r 2 = 0.40 and 0.49, respectively, p