Table 3.

Relationship between VIM of average BP across four study visits and various characteristics among participants without antihypertensive treatment or past history of CVD: INTERMAP, 1996–1999

	VIM of average BP
	Model 1		Model 3
	Beta	P-value	Beta	P-value
Age (5 years)	0.231	<0.001	0.229	<0.001
Women	0.631	<0.001	0.589	<0.001
Country
Japan	Reference		Reference
PRC	1.225	<0.001	1.276	<0.001
UK	−0.024	0.931	−0.025	0.931
US	0.235	0.392	0.262	0.365
BMI (kg/sq.m)	−0.038	0.001	−0.031	0.008
Pulse (10 beats/min)	−0.145	0.008	−0.122	0.029
Smoking
Non-smoker	Reference
Ex-smoker	−0.003	0.985
Smoker	0.075	0.548
Drinking
Non-drinker	Reference
Ex-drinker	−0.354	0.085
Moderate drinker	−0.185	0.218
Heavy drinker	−0.327	0.125
Mean inside temperature (°C)	0.003	0.919
Mean outside temperature (°C)	0.015	0.039	0.014	0.062
Physical activity (h/week)a	0.018	0.249
Years of education
6 years or less	Reference
12 years or less	0.025	0.909
More than 13 years	0.174	0.496
Family history of hypertension	−0.003	0.972
Urinary sodium (20 mmol/24 h)	−0.035	0.031	−0.022	0.192
Urinary potassium (10 mmol/24 h)	−0.036	0.203

The associations between VIMs of BP and participant characteristics were assessed using multiple linear regression analysis

BP blood pressure, VIM variation independent of mean, CVD cardiovascular disease, BMI body mass index, PRC People’s Republic of China, UK United Kingdom, US United States, h hour

^aPhysical activity was defined as number of hours with moderate and heavy physical activity per week. Model 1 included age, sex, countries and study centers. Model 3 included age, sex, countries, study centers and all variables associated with VIM of visit-to-visit BP variability (P 0.05) in Model 1