ACTIVATED PROTEIN-C RESPONSE AND CARDIOVASCULAR RISK-FACTORS IN THE ELDERLY - THE ROTTERDAM STUDY

Background and objective A low activated protein C (APC) response incr eases the risk of venous thrombosis, and possibly arterial disease, Ap art from the factor V Leiden mutation, other factors may determine the level of APC response. In most studies on the association with arteri al disease, cardiovascular risk factors were not appropriately control led for as possible confounders. We studied the association of APC res ponse to cardiovascular risk factors in a sample of the general popula tion. Methods The Rotterdam Study is a cohort study among 7983 subject s aged 55 years or over, living in the Ommoord suburb in Rotterdam, Th e Netherlands, APC response was measured in 928 subjects as part of tw o case-control studies (subjects with and without symptomatic cardiova scular disease (CVD) and with and without dementia), APC response was determined in double centrifuged platelet poor plasma. Those on antico agulants were excluded. Linear regression analyses were done in age st rata (55-64, 65-74, 75-84, greater than or equal to 85), with adjustme nt for age, sex, CVD, and dementia. Results APC response was lower in women than in men (difference 0.56 (p<0.01)). In men, APC response dec reased with age (0.15 per decade (p=0.02)), In women, a non-significan t rise was seen (0.05 per decade (p=0.27)), Associations with cardiova scular risk factors differed by age, not gender. In those aged 55-64 y ears inverse associations were found with total cholesterol (0.14 decr ease per 1 mmol/l increase, p=0.03) and diastolic pressure (0.12 decre ase per 10 mmHg increase, p=0.06). In those aged greater than or equal to 85 years a positive association was seen with smoking (0.76 increa se, p=0.01). No associations were found with systolic pressure and bod y mass index. Conclusion These findings suggest that in the elderly ag e, gender, serum lipids, diastolic pressure and smoking may influence APC response, the extent of which may differ by age, These factors sho uld be allowed for in studies on the association between APC response and arterial disease.