A marked decline in the prevalence and incidence of intermittent claudication in Icelandic men 1968-1986: a strong relationship to smoking and serum cholesterol--the Reykjavik Study.

The epidemiology of peripheral vascular disease has been studied much less extensively than the epidemiology of coronary heart disease (CHD). The prospective Reykjavik Study gave an opportunity to monitor secular trends from 1968 to 1986 of clinical intermittent claudication (IC) amongst Icelandic males, aged 34-80 and to assess the importance of possible risk factors. Both prevalence and incidence of IC decreased sharply after 1970 in all age groups, and this decline occurred a few years earlier than the decline of CHD in Iceland. The only significant risk factors for intermittent claudication, in addition to age, were smoking which increased the risk of IC 8- to 10-fold and serum cholesterol level. Approximately one-half of the striking decline in the incidence of IC can be explained by decreased smoking and cholesterol levels amongst Icelandic men. A follow-up study verified that IC patients stood twice the risk of cardiovascular and total mortality as non-IC patients, indicating that IC is a high risk group which should receive all possible preventive measures.