Table 2.

Variables by quartile of plasma amyloid-β1–42 at 2000–02 and 2009 in the Pittsburgh GEMS cohort

Plasma amyloid-β1–42	HIP volume				Cortical thickness (mm)				PiB score				WMH
	n	Mean	SD	Median	n	Mean	SD	Median	n	Mean	SD	Median	n	Mean	SD	Median
At 2000–02
1Q: ≤6.23	39	0.255	0.028	0.249	39	3.00	0.33	3.05	39	1.93	0.49	1.91	39	0.009	0.005	0.009
2Q: 6.24–9.35	41	0.253	0.028	0.251	41	3.07	0.38	3.06	41	1.69	0.43	1.53	41	0.010	0.006	0.008
3Q: 9.36–13.92	41	0.254	0.039	0.252	41	2.99	0.52	3.11	41	1.75	0.46	1.59	41	0.007	0.005	0.006
4Q: >13.92	38	0.257	0.035	0.261	37	3.20	0.33	3.20	38	1.63	0.43	1.49	38	0.009	0.004	0.009
	P = 0.932, age-adjusted P = 0.924				P = 0.092, age-adjusted P = 0.097				P = 0.028, age-adjusted P = 0.023				P = 0.013, age-adjusted P = 0.007
At 2009
1Q: ≤5.81	31	0.254	0.036	0.244	31	3.00	0.43	3.06	31	1.75	0.45	1.68	31	0.010	0.005	0.009
2Q: 5.82–9.34	34	0.254	0.025	0.249	34	3.05	0.33	3.08	34	1.80	0.42	1.86	34	0.009	0.007	0.007
3Q: 9.35–14.01	34	0.254	0.032	0.253	34	3.09	0.43	3.11	34	1.58	0.43	1.47	34	0.010	0.006	0.008
4Q: >14.01	34	0.253	0.035	0.256	33	3.21	0.41	3.28	34	1.62	0.42	1.49	34	0.008	0.004	0.008
	P = 1.000, age-adjusted P = 0.998				P = 0.198, age-adjusted P = 0.199				P = 0.099, age-adjusted P = 0.080				P = 0.396, age-adjusted P = 0.461

WMH comparisons were based on log-transformed values. Q = quartile; WMH = white matter hyperintensities.