Compared with participants without HA , those with HA had marginally significant less atrophy ( less decrease in TBV ) from baseline to 40 months ( -9.55 [ 95 % CI -15.21 , -3.90 ] vs. -15.38 [ 95 % CI -16.64 , -14.12 ] , P = 0.051 ) , and no significant increase of AWM volume ( 2.06 [ 95 % CI 1.71 , 2.49 ] vs. 1.84 [ 95 % CI 1.76 , 1.91 ] , P = 0.247 ) .