Table 2. Results of linear modeling of age progression of MRS metabolites relative to normative values.

Slope of age is the expected difference in metabolite concentration (in mM) for a one-year difference in age. CI: confidence interval. DF: degree of freedom. Glx: glutamine/glutamate/gamma-aminobutyric acid. NAA: n-acetylaspartate/n-acetylaspartyl glutamate. LCSO: left centrum semiovale. PGM: parietal gray matter.

Region	Metabolite	Slope of Age [95% CI]	Test Statistic for Age (DF = 25)
LCSO	Creatine	0.07 [0, 0.14]	t=2.02, p=0.05
	Myo-inositol	0.09 [−0.05, 0.23]	t=1.31, p=0.20
	Choline	0.03 [0, 0.06]	t=2.21, p=0.04
	NAA	−0.25 [−0.37, −0.13]	t=−3.96, p<.001
	Glx	−0.04 [−0.27, 0.19]	t=−0.32, p=0.75
PGM	Creatine	−0.27 [−0.39, −0.15]	t=−4.48, p<.001
	Myo-inositol	−0.08 [−0.18, 0.02]	t=−1.52, p=0.14
	Choline	0 [−0.03, 0.03]	t=−0.16, p=0.87
	NAA	−0.61 [−0.78, −0.45]	t=−7.44, p<.001
	Glx	−0.82 [−1.04, −0.6]	t=−7.36, p<.001