Table 1.

Sociodemographic and clinical characteristics of the study population. Values are means (standard deviations) unless otherwise stated

Characteristic	Alzheimer's disease (n=48)	No dementia (n=1352)	P value	Participants (n=1409)	Non-participants (n=591)	P value (t test)
Male/female (%)	40/60	38/62	0.73*	38/62	36/64	0.57*
Duration of follow up (years)	20.6 (4.5)	20.9 (4.9)	0.75	20.9 (4.9)
Age (years):
Midlife	54.0 (4.7)	50.2 (6.0)	<0.001	50.4 (6.0)	51.2 (5.9)	0.007
Re-examination	74.7 (3.8)	71.1 (4.0)	<0.001	71.3 (4.0)
Education (years)	6.7 (2.7)	8.5 (3.5)	<0.001	8.4 (3.5)	7.4 (2.9)	<0.001
Mini-mental state examination	20.4 (3.0)	26.1 (2.0)	<0.001	25.9 (2.4)
Body mass index (kg/m2):
Midlife	27.6 (4.0)	26.5 (3.7)	0.038	26.6 (3.7)	27.2 (4.5)	0.002
Re-examination	27.8 (4.4)	27.8 (4.3)	0.994	27.8 (4.3)
Systolic blood pressure (mm Hg):
Midlife	152.7 (18.2)	143.9 (19.8)	0.002	144.3 (19.9)	150.2 (21.7)	<0.001
Re-examination	150.4 (23.5)	151.5 (23.4)	0.747	151.4 (23.3)
Diastolic blood pressure (mm Hg):
Midlife	91.2 (9.5)	89.1 (10.9)	0.182	89.2 (10.9)	91.7 (11.3)	<0.001
Re-examination	80.4 (11.5)	80.5 (11.2)	0.965	80.4 (11.2)
Cholesterol (mmol/l):
Midlife	7.2 (1.0)	6.7 (1.2)	0.001	6.7 (1.2)	7.0 (1.3)	<0.001
Re-examination	6.0 (1.0)	5.8 (1.0)	0.234	5.8 (1.0)

^*χ² test was used.