Excess visceral and hepatic adipose tissue in Turner syndrome determined by magnetic resonance imaging: estrogen deficiency associated with hepatic adipose content.

ABSTRACT

Obesity, predominantly centrally distributed, is common in women with Turner syndrome (TS) and is thought to contribute to the increased risk of atherosclerosis; however, insulin concentrations are unexpectedly low. To explore this discrepancy, we assessed fat content and distribution by magnetic resonance imaging (MRI) and bioelectrical impedance (BI). Six nondiabetic, estrogen-treated women with TS were compared with six age-matched normal controls of similar body mass index. Clinical history, anthropometric measurements, biochemical markers, and MRI and BI measures of adiposity were assessed. TS women had increased intrahepatocellular lipids (IHCL) on MRI. After height adjustment, they also had an excess of total and visceral compared with sc adipose tissue (AT) than controls, without elevated insulin concentrations. BI and MRI measures correlated strongly for total and sc, but not visceral, AT in TS. IHCL was associated with cumulative estrogen-deficient years (r = 0.928; P = 0.008). Women with TS depart from the classical picture of metabolic syndrome despite an excess of total and visceral AT on MRI. Elevated IHCL in TS is associated with estrogen deficiency. BI may be useful to estimate total body fat, but does not reliably localize fat depots in TS.