Incidence of Myocardial Infarction and Death in Relation to Walking-Induced Calf Pain and Plasma Levels of Inflammation-Sensitive Proteins

Abstract

Walking-induced calf pain as well as levels of different inflammation-sensitive plasma proteins (ISPs) are related to cardiovascular disease (CVD). This prospective cohort study explored the relationship between ISPs and walking-related calf pain and the interrelationships between ISPs and calf pain in the prediction of death and incidence of coronary events (CE). In 5,725 apparently healthy men, 46 ±3.0 years old, plasma concentrations of orosomucoid (a1-acid glycoprotein), a1-antitrypsin, haptoglobin, fibrinogen, and ceruloplasmin were measured. Walking-induced calf pain was assessed by questionnaire. Mortality and incidence of CE were monitored over a mean follow-up of 18 years in subjects defined by the presence of calf pain and ISP level (0 to 1 or 2 to 5 ISP(s) in the top quartile). The prevalence of calf pain (7.3%) was significantly related to age, lifestyle, and traditional risk factors of CVD and ISP levels. The risk factor-adjusted relative risks for CE, CVD- and all-cause mortality were 1.89 (CI: 1.27 to 2.82), 2.90 (CI: 1.82 to 4.62), and 2.67 (CI: 1.97 to 3.57), respectively, for men with calf pain and high ISP levels (reference: no calf pain and low ISP levels). The corresponding risk for those with calf pain and low ISP levels were 1.34 (CI: 0.91 to 1.97), 1.47 (CI: 0.90 to 2.41), and 1.31 (CI: 0.95 to 1.81), respectively. These results indicate, on the one hand, that walking-induced calf pain is associated with high ISP levels and, on the other, that the risk of CVD in men with calf pain is substantially higher in those with high ISP levels than in those with low levels.