Table 4.

Mean ankle-brachial index and odds ratio for peripheral arterial disease according to duration of smoking cessation

	Current smokers (n = 603)	Duration of smoking cessation (years since quitting smoking)c				Never smokers (n = 616)	P-trendd
		≤ 3 years (n = 185)	4-10 years (n = 398)	11-20 years (n = 303)	≥ 21 years (n = 357)
Mean ankle-brachial index
Unadjusted	1.118 (0.004)	1.127 (0.007)	1.130 (0.005)	1.140 (0.006)**	1.138 (0.005)**	1.156 (0.004)***	<0.001
Age-adjusted	1.116 (0.004)	1.125 (0.007)	1.129 (0.005)*	1.141 (0.006)***	1.141 (0.005)***	1.157 (0.004)***	<0.001
Multivariate-adjusteda	1.123 (0.004)	1.132 (0.008)	1.134 (0.005)	1.139 (0.006)*	1.138 (0.005)*	1.147 (0.005)***	<0.001
Peripheral arterial diseaseb
Prevalence, n (%)	36 (6.0)	6 (3.2)	17 (4.3)	10 (3.3)	16 (4.5)	12 (1.9)
Unadjusted OR	1.00 (reference)	0.53 (0.22-1.27)	0.70 (0.39-1.27)	0.54 (0.26-1.10)	0.74 (0.40-1.35)	0.31 (0.16-0.61)**	0.002
Age-adjusted OR	1.00 (reference)	0.49 (0.20-1.19)	0.59 (0.32-1.08)	0.41 (0.20-0.84)*	0.47 (0.25-0.88)*	0.23 (0.12-0.45)**	<0.001
Multivariate-adjusteda OR	1.00 (reference)	0.47 (0.19-1.17)	0.57 (0.30-1.06)	0.41 (0.19-0.86)*	0.49 (0.24-0.98)*	0.25 (0.11-0.55)**	<0.001

Data are presented as mean (standard error) or odds ratio (95% confidence interval).

^aAdjusted for age, body mass index, systolic blood pressure, fasting blood glucose, total cholesterol, HDL cholesterol, uric acid, alcohol consumption, physical exercise, use of medications for hypertension, diabetes, and hyperlipidemia, and pack-year of smoking.

^bDefined as an ankle-brachial index lesser than 0.90 in either leg.

^cFifty-five former smokers were excluded due to lack of information about years since quitting smoking.

^dP-trend estimated from analysis of covariance or logistic regression using the categories of years since quitting smoking as an ordinal variable.

*P < 0.05, **P < 0.01, ***P < 0.001; compared with current smokers.