Human brain chemical shift imaging at age 60 to 90 - Analysis of the causes of the observed sex differences in brain metabolites

RATIONALE AND OBJECTIVES. To assess whether differences in cerebral atrophy and white matter lesions or in the presence of lactate and lipid signals c an explain the observed differences in brain choline, creatine, and N-acety laspartate levels between healthy elderly women and men. METHODS. In addition to standard magnetic resonance imaging of the brain, a n 8 x 8 x 2-cm(3) supraventricular transverse brain volume parallel to the canthomeatal line was examined by magnetic resonance spectroscopy (automate d H-1 chemical shift imaging) in 540 healthy elderly persons. RESULTS. At P = 0.01, 0.001, and 0.0001, choline differed between women and men in 14, 9, and 5 of 36 voxels, respectively. On correction for cerebral atrophy (more frequent in men than in women), white matter lesions (more f requent in women), and lactate and lipid (more frequent in women), the diff erences in choline were reduced to 13, 6, and 3. Sex differences for creati ne and N-acetylaspartate were similar but less numerous after correction. CONCLUSIONS. Elderly women and men in the general population show differenc es in the levels of creatine, N-acetylaspartate, and especially choline in portions of the brain. The sex-related differences in brain metabolite leve ls cannot be explained by differences in cerebral atrophy or other aging-re lated phenomena (white matter lesions, lactate, lipid).