Table 4.

Categorical data analysis: HRs and 95% CIs of high vs. low short-term blood pressure variability for 20-year cardiovascular mortality (n = 1,257) in categories of normotension and hypertension by unadjusted and adjusted Cox proportional hazards regression models

	Unadjusted	Model 1	Model 2
	HR (95% CI)	HR (95% CI)	HR (95% CI)
Normotension and low ARVd	1 (reference)	1 (reference)	1 (reference)
Normotension and high ARVd	3.86 (1.37–10.84)	2.63 (0.91–7.59)	2.47 (0.85–7.14)
Hypertension and low ARVd	4.96 (1.97–12.50)	1.93 (0.70–5.38)	2.12 (0.80–5.67)
Hypertension and high ARVd	15.12 (6.53–35.00)	3.91 (1.47–10.42)	4.19 (1.65–10.64)
Hypertension and low ARVd	1 (reference)	1 (reference)	1 (reference)
Hypertension and high ARVd	3.05 (1.80–5.15)	2.11 (1.23–3.62)	2.04 (1.19–3.51)
Normotension and low ARVs	1 (reference)	1 (reference)	1 (reference)
Normotension and high ARVs	2.56 (1.11–5.93)	1.21 (0.50–2.93)	1.04 (0.43–2.53)
Hypertension and low ARVs	3.10 (1.32–7.30)	1.03 (0.39–2.74)	1.25 (0.50–3.11)
Hypertension and high ARVs	9.47 (4.85–18.5)	1.66 (0.68–4.07)	1.88 (0.82–4.27)
Hypertension and low ARVs	1 (reference)	1 (reference)	1 (reference)
Hypertension and high ARVs	3.05 (1.61–5.80)	1.77 (0.90–3.45)	1.70 (0.87–3.34)

Model 1: adjusted independent variables: age, sex, smoking, total cholesterol, high-density lipoprotein cholesterol, fasting blood glucose and office SBP; Model 2: adjusted independent variables: age, sex, smoking, total cholesterol, high-density lipoprotein cholesterol, fasting blood glucose and 24-hour SBP; cut points: ARVd ≥ 8.8mm Hg (median) ARVs ≥ 9.3mm Hg (median). All bold values indicate significant P value < 0.05.

Abbreviations: ARVd, average real variability of 24-hour DBP; ARVs, average real variability of 24-hour SBP; CIs, confidence intervals; DBP, diastolic blood pressure; HRs, hazard ratios; SBP, systolic blood pressure.