Non-contrast MRI of Brain White Matter in Young Male Patients with Childhood-onset Adult Growth Hormone Deficiency: A Diffusion Tensor Imaging Study

Abstract BACKGROUND The brain structure and function of adult growth hormone deficiency (AGHD) have not been fully investigated so far. No previous studies have evaluated alterations in brain white matter degree and integrity in AGHD. PURPOSE To evaluate alterations in brain white matter degree and integrity in AGHD compared to age and gender-matched healthy controls and further explore the correlation between endocrine hormone and brain white matter. METHODS 17 young AGHD patients and 17 healthy controls were assessed by 3D volumetric T1-weighted magnetic resonance imaging (MRI). Whole brain and white matter volume were compared between two groups. Fractional anisotropy (FA) and mean diffusivity (MD) of brain white matter were calculated for group comparison based on DTI. Effect of disease status and hormone levels on FA and MD of brain white matter were evaluated. RESULTS AGHD had significantly lower serum insulin-like growth factor 1 (IGF-1)，free triiodothyronine (FT3) and free thyroxine (FT4) levels compared with control (p<0.001). AGHD presents no significant change compared with control neither on the whole brain volume (p =0.2) nor the white matter volume (p =0.78). Comparing with controls, brain regions mainly including Middle cerebellar peduncle were decreased on FA and Middle cerebellar peduncle were increased on MD in AGHD. MD of the Left superior longitudinal fasciculus was prominently only associated with serum levels of FT4 in control adjusting for IGF-1 levels. CONCLUSIONS Young adult male AGHD patients presented alteration of brain white matter on MD and FA in some brain regions.