Body composition in premature adrenarche by structural MRI, 1H MRS and DXA

Abstract

Background: Premature adrenarche (PA) is recognized to be a possible precursor of polycystic ovarian syndrome, type 2 diabetes mellitus and cardiovascular disease. Visceral adiposity and increased intramyocellular lipid (IMCL) are associated with insulin resistance and increased risk of cardiovascular disease.

Aim: To determine whether prepubertal girls with PA have altered visceral adiposity and/or increased muscle lipid content compared to prepubertal girls without PA using proton magnetic resonance imaging (MRI) and spectroscopy (1H MRS).

Patients and methods: We performed total body dual energy X-ray absorptiometry (DXA) scans, MRI of the trunk, and MRS of the tibialis anterior muscle in the right calf on six girls with PA and eight prepubertal controls.

Results: Amount of visceral adipose tissue (VAT), abdominal subcutaneous adipose tissue (SAT), and VAT to SAT ratio did not differ significantly between the PA and control girls. Those with PA, however, had significantly greater IMCL than controls (p = 0.004).

Conclusions: This study adds further evidence that PA is not a benign condition, and future studies investigating early intervention with dietary and exercise counseling may help diminish potential risk for diabetes mellitus and/or cardiovascular disease.

Fig. 1

Representative ¹H spectra from a 10×10×10 mm³ voxel in the tibialis anterior (TA) muscle (see voxel location in inset) of (A) an 8 year-old girl with premature adrenarche and (B) a weight- and age-matched normal control. Detected are resonances for intramyocellular lipid (IMCL), extramyocellular lipid (EMCL) and total muscle creatine (tCr). Sample frequency-domain non-linear least-squares Gauss-Lorentzian lineshape model-fitting of the TA muscle spectra for deriving IMCL, EMCL and tCr peak areas are also shown: (a) measured spectra; (b) calculated ‘best-fit’ spectra and (dashed lines) individual components of the ‘best-fit’ spectra; and (c) residual of the difference between the measured and calculated ‘best-fit’ spectra.