Are there gender differences in abdominal fat distribution in healthy teenagers?

Francois Duboeuf; Stephanie Boutroy; Tiphanie Ginhoux; Jean-Paul Roux; Roland Chapurlat; Justine Bacchetta

doi:10.1530/boneabs.6.P157

Background: While the relationship between visceral (VFAT) and subcutaneous (SFAT) fat mass with cardiometabolic risk has been demonstrated in adults, fat mass evolution during teenagehood remains poorly explored and usually assessed with irradiative (CT) or expensive (MRI) techniques. Our aim was to evaluate a novel technique derived from DXA to assess VFAT and SFAT in healthy teenagers.

Subjects and methods: Healthy teenagers from the VITADOS study underwent whole body DXA scans for body composition analysis (Discovery A, HOLOGIC Inc; Bedford, MA). Outcome parameters were considered on the sub-total body (total body without head) and included mass (M), fat mass (FM), lean mass (LM), bone mineral density (BMD), as well as the android-gynoid ratio (And/Gyn). Abdominal fat mass, including VFAT and SFAT, was assessed on the same scan using APEX V4.0.2, on a 5 cm-wide region placed across the entire abdomen just above the iliac crest approximatively at the level of the 4th lumbar vertebra.

Results: Ninety-two volunteers were included: 44 girls (G) and 48 boys (B), age: 13.9±1.9 and 13.6±2.4 yrs, body weight (BW): 49.6±10.0 and 47.9±14.4 kg, height: 158.8±9.0 and 159.3±15.0 cm, BMI: 19.4±2.5 and 18.4±2.9 kg/m², respectively. Age, Height, BW and BMI were not significantly different between genders in the total cohort. In the Tanner 5 sub-group, age, BW and BMI were not different between genders; in contrast, height, FM, LM, And/Gyn and BMD were all significantly different (Table 1). Interestingly, VFAT and SFAT were significantly different between genders from Tanner 2 stages onwards: VFAT was significantly greater in boys whilst SFAT was significantly greater in girls.

Discussion: Using a non-irradiative and inexpensive technique, VFAT and SFAT are significantly different between genders as early as Tanner stage 2 in healthy teenagers. The clinical consequences of such differences should be determined, but could explain some of the differences in cardiovascular risk observed between genders later in life.

Table 1.
Tanner stage (Boys: N/Girls:N)	Tanner 1 (B:14/G:2)	Tanner 2 (B:8/G:7)	Tanner 3 (B:5/G:13)	Tanner 4 (B:7/G:7)	Tanner 5 (B:10/G:19)
Height	−5.5	−1.1	0.1	−5.5	−6.7*
Weight	−2.1	3.1	−8.6	−7.7	−10.9
BMI	10.0	5.6	−7.6	3.0	2.6
Lean Mass (LM)	−7.7	−5.2	−6.6	−19.0*	−23.1**
Fat Mass (FM)	13.5	42.8	−21.8	52.4	54.9*
Mass (M)	−3.1	3.3	−10.5	−8.3	−11.6
Android Gynoid Ratio (And/Gyn)	6.5	−2.0	−13.1	−18.2	−18.5*
BMD	−5.3	−0.3	1.5	−6.7	−11.9*
Visceral fat (VFAT)	−31.1	−44.0*	−50.5*	−55.6*	−35.2*
Subcutaneous fat (SFAT)	108.6	196.4**	10.0*	129.1*	111.7*
*P≤0.001; P≤0.05

Disclosure: The authors declared no competing interests.

Bone Abstracts

P157