Plasma viscosity and related cardiovascular risk factors in a Spanish Mediterranean population

Plasma viscosity (PV) constitutes an independent important predictor of initial and recurrent cardiac events and mortality. It has been suggested that there is a geographical variation in PV values related to coronary event rates. Little information exists regarding PV in Spain. Therefore, our objective was to determine PV in a large sample of randomly selected subjects from the Spanish population and to study which demographic or cardiovascular risk factors (CVRF) influence levels of PV in this population.

1277 subjects (503 males, 774 females) aged 43+/-14 years (range: 20-70) were randomly selected from an Eastern Spanish population. These subjects were free of cardiovascular diseases and other major diseases. PV was measured at 37 degrees C by means of the Fresenius GmbH plasma viscosimeter. In addition, total cholesterol, triglycerides, glucose and fibrinogen were measured.

In the crude analysis, no differences in PV were observed regarding gender (males: 1.235+/-0.061 cP; females: 1.236+/-0.059 cP, P=0.952). Women older than 50 years showed higher PV:1.248+/-0.057 cP than those aged less than 50 years: 1.232+/-0.059 cP, P=0.001. No differences in PV by age groups were observed in men (P=0.842). Furthermore, we evaluated the prevalence of the following CVRF: hypercholesterolemia, hypertriglyceridemia, hypertension, diabetes, tobacco smoking, obesity, and high fibrinogen levels. Prevalence of these factors was: 28%, 4.3%, 8%, 2.3%, 33%, 8.8% and 15% respectively. As some of these CVRF were correlated with PV levels, we carried out a multivariate analysis to adjust PV levels for the potential confounding effect of each one of these factors. After multivariate adjustment, PV was positively associated with high fibrinogen (>320 mg/dL) levels in both men and women (P<0.001). In addition, in women, but not in men, PV levels were independently associated with obesity (P<0.001) and hypertriglyceridemia (P=0.01). After the multivariate adjustment, the association between PV and age older than 50 in women did not remain statistically significant, revealing a confusing effect of the CVRF in the crude analysis.