Homocysteine, fibrinogen and physical activity in human males with coronary artery disease

Abstract

Elevated homocysteine (Hcy) concentration has been identified as an independent risk factor for premature coronary artery disease (CAD). Associations between Hcy concentrations and established cardiovascular risk factors have occasionally, but not consistently, been demonstrated. Plasma fibrinogen and total Hcy concentrations, along with other risk factors, folate and B-vitamin supplements and medications, were recorded for 40 males (mean age±SD: 65±9.8 years) with CAD. Physical activity was assessed using the Modifiable Activity Questionnaire (MAQ), a written questionnaire which appraises leisure and occupational activities by recall for a 12-month period. Subjects in the upper tertile of physical activity had significantly lower fibrinogen concentrations than those in the lower tertile (274.7±38 mg/dl vs. 320.2±63, respectively,p-0.04). Univariate analyses revealed those subjects on beta-blocker therapy (n=12) had lower fibrinogen concentrations than those not on these medications (n=28) (277.7±16.7 vs. 316.1±10.9 mg/dl respectively,p=0.04). There was also a trend for those on beta-blockade to have lower Hcy concentrations (8.3±0.66 vs 9.7±0.43 μmol/l, respectively,p=0.058). Homocysteine concentration was found to be positively associated with age (p=0.0008). No significant associations were established with multivariate analyses among fibrinogen. Hcy, physical activity, age, BMI, B-vitamin and folate supplements, beta-blocker therapy, total cholesterol, high density lipoprotein (HDL), low density protein (LDL), triglycerides, and TC/HDL ratio. These results support the hypothesis that hyperhomocysteinaemia is independent of other CAD risk factors. Future studies should consider the favourable effects of beta-blockade, which may be a confounding factor, on Hcy and fibrinogen concentrations. Knowledge of associations may contribute towards understanding of the pathogenesis of CAD.