Longitudinal associations between plasma viscosity and cardiovascular risk factors in a middle-aged French population.

A recent prospective study has suggested that increased plasma viscosity may be associated with higher risk of coronary heart disease. A longitudinal approach was used to investigate associations between plasma viscosity and conventional risk factors in an apparently healthy French population aged 45-56 years (637 men and 431 women) over a 2-year follow-up period. In univariate analysis, change in plasma viscosity was significantly related to changes in smoking status, systolic and diastolic blood pressure, gamma glutamyl transferase (gamma GT), body mass index and triglycerides only in men, and to changes in total cholesterol, low-density lipoprotein (LDL) cholesterol and apolipoprotein (apo) B in both sexes. Change in plasma viscosity was also significantly associated with changes in fibrinogen and hemoglobin levels in both sexes. No association was found with age, high-density lipoprotein (HDL) cholesterol or apo A1 in both sexes, or with changes in smoking and menopausal status in women. In multiple stepwise regression analysis, independent determinants of change in plasma viscosity were changes in smoking status, systolic blood pressure, gamma GT, total cholesterol, fibrinogen and hemoglobin in men, and changes in fibrinogen and apo B in women. These results strengthen the hypothesis that increased plasma viscosity may be one of the mechanisms linking conventional risk factors to the risk of cardiovascular disease and suggest that its decrease may be obtained by appropriate life-style changes.