Table 2.

Heritability of cerebral blood flow parameters in the Rotterdam Study.

		Model 1		Model 2
Parameter	N	h2 (SE)	P	h2 (SE)	P
Total cerebral blood flow	3485	16.1 (9.8)	0.048	17.8 (9.8)	0.033
Flow rate
Basilar artery	3489	21.8 (9.8)	0.011	24.1 (9.8)	0.0056
Left carotid	3480	9.5 (9.8)	0.17	10.4 (9.8)	0.15
Right carotid	3481	13.8 (9.9)	0.081	9.9 (9.8)	0.16
Vessel area
Basilar artery	3475	9.0 (9.2)	0.14	9.7 (9.2)	0.13
Left carotid	3482	0.0 (9.4)	0.50	0.0 (9.4)	0.50
Right carotid	3482	0.0 (9.6)	0.50	0.0 (9.6)	0.50
Flow velocity
Basilar artery	3451	12.1 (9.8)	0.10	13.4 (9.8)	0.082
Left carotid	3445	7.5 (9.9)	0.23	8.5 (10.0)	0.20
Right carotid	3449	3.5 (9.6)	0.36	3.5 (9.6)	0.36

Note: Heritability estimates of cerebral blood flow parameters under two models: adjusting for age, age², sex, intracranial volume (model 1) and additional for brain volume (model 2).

h2 = heritability; N = sample size; SE = standard error.