PLASMA VISCOSITY AND THE RISK OF CORONARY HEART-DISEASE - RESULTS FROM THE MONICA-AUGSBURG COHORT STUDY, 1984 TO 1992

Plasma viscosity is determined by various macromolecules, eg, fibrinog en, immunoglobulins, and lipoproteins. It may therefore reflect severa l aspects involved in cardiovascular diseases, including the effects o f classic risk factors, hemostatic disturbances, and inflammation. We examined the association of plasma viscosity with the incidence of a f irst major coronary heart disease event (CHD; fatal and nonfatal myoca rdial infarction and cardiac death; n=50) in 933 men aged 45 to 64 yea rs of the MONICA project of Augsburg, Germany. The incidence rate was 7.23 per 1000 person-years (95% confidence interval [CI], 5.37 to 9.53 ), and the subjects were followed up for 8 years. All suspected cases of an incident CHD event were classified according to the MONICA proto col, There was a positive and statistically significant unadjusted rel ationship between plasma viscosity and the incidence of CHD. The relat ive risk of CHD events associated with a 1-SD increase in plasma visco sity (0.070 mPa.s) was 1.60 (95% CI, 1.25 to 2.03), After adjustment f or age, total cholesterol, high density lipoprotein cholesterol, smoki ng, blood pressure, and body mass index, the relative risk was reduced only moderately (1.42; 95% CI, 1.09 to 1.86). The relative risk of CH D events for men in the highest quintile of the plasma viscosity distr ibution in comparison with the lowest quintile was 3.31 (95% CI, 1.19 to 9.25) after adjustment for the aforementioned variables. A large pr oportion of events (40%) occurred among men in the highest quintile. T hese findings suggest that plasma viscosity may have considerable pote ntial to identify subjects at risk for CHD events.