The influence of smoking cessation and hypertriglyceridaemia on the progression of peripheral arterial disease and the onset of critical ischaemia.

OBJECTIVE: To investigate whether smoking and other cardiovascular risk factors were associated with deterioration of ankle/brachial pressure index or onset of critical ischaemia in patients with mild to moderate intermittent claudication.

DESIGN AND SETTING: Longitudinal study in a London teaching hospital.

SUBJECTS: 415 consecutive smokers, with symptoms of intermittent claudication and an ankle/brachial pressure index of <0.9, referred for a surgical opinion between April 1985 and December 1990, who were not considered for an immediate surgical procedure.

MAIN OUTCOME RESULTS: Reduction in ankle/brachial pressure index of >0.14, onset of critical limb ischaemia.

RESULTS: After one year of follow up 183 patients (44%) had stopped smoking (as evaluated by biochemical markers). With longer follow up only 110 patients (27%) had maintained smoking cessation. There were no differences in age, sex, and previous tobacco exposure between stoppers and smokers, but the proportion of diabetics among stoppers (20%) was greater than among those who continued smoking (10%) [p=0.01]. The annual rate of deterioration of ABPI was 21, 16 and 17% respectively in the first, second and third year of follow-up and the onset of critical ischaemia was observed in 52 patients (12.5%) during the period of follow-up. In univariate analyses, continued smoking, diabetes and presence of ischaemic heart disease were not associated with an increased risk of deterioration of ABPI, but hypertriglyceridaemia (> or = 2.2 mmol/l) was, [relative risk 1.7(95% CI 1.21-2.37), p=0.003], and patients having systolic blood pressure in the middle tertile (153-170 mmHg had a reduced risk of deterioration of ABPI, p=0.026. Hypertriglyceridaemia (> or = 2.2mmol/l) was the only independent factor associated with deterioration of ABPI in multivariate analysis [relative risk 1.8(95% CI:1.23-2.59), p=0.003] and also was associated with a relative risk of onset of critical ischaemia of 1.9 [(95% CI: 1.08-2.87), p=0.035], compared with triglyceride levels of <2.2mmol/l.

CONCLUSION: For those with mild to moderate claudication, the lack of immediate benefit from cessation of smoking appears to be associated with a gradual return to smoking. Hypertriglyceridaemia was identified as the most important independent factor associated with the progression of peripheral arterial disease and onset of critical ischaemia.