Table 3.

Mean ankle-brachial index and odds ratio for peripheral arterial disease according to cumulative smoking exposure

	Never smokers (n = 616)	Cumulative smoking exposure (pack-years of smoking)c			P-trendd
		Light smokers [0.1-20.0 pack-years] (n = 745)	Moderate smokers [20.1-40.0 pack-years] (n = 687)	Heavy smokers [> 40.0 pack-years] (n = 438)
Mean ankle-brachial index
Unadjusted	1.156 (0.004)	1.138 (0.004)**	1.125 (0.004)***	1.118 (0.005)***	<0.001
Age-adjusted	1.156 (0.004)	1.138 (0.004)**	1.124 (0.004)***	1.119 (0.005)***	<0.001
Multivariate-adjusteda	1.150 (0.004)	1.137 (0.004)*	1.128 (0.004)***	1.123 (0.005)***	<0.001
Peripheral arterial diseaseb
Prevalence, n (%)	12 (1.9)	30 (4.0)	31 (4.5)	30 (6.8)
Unadjusted OR	1.00 (reference)	2.11 (1.07-4.16)*	2.38 (1.21-4.67)*	3.70 (1.87-7.31)***	<0.001
Age-adjusted OR	1.00 (reference)	2.32 (1.17-4.59)*	2.85 (1.44-5.64)**	3.69 (1.86-7.31)***	<0.001
Multivariate-adjusteda OR	1.00 (reference)	2.15 (1.06-4.38)*	2.24 (1.08-4.65)*	2.93 (1.41-6.09)**	0.008

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 current smoking (yes/no).

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

^cThirty-one smokers were excluded due to lack of information about pack-years of smoking.

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

*P < 0.05, **P < 0.01, ***P < 0.001; compared with never smokers.