RELATIONSHIP OF TACHYCARDIA WITH HIGH BLOOD-PRESSURE AND METABOLIC ABNORMALITIES - A STUDY WITH MIXTURE ANALYSIS IN 3 POPULATIONS

Faster resting heart rate has been shown to be associated with a highe r risk of developing hypertension and a greater incidence of cardiovas cular morbidity and mortality. The aim of this study was to investigat e the distribution of heart rate and its relationship with blood press ure and other cardiovascular risk factors in three populations. One Eu ropean general population (Belgian study), one North American general population (Tecumseh study), and one European hypertensive population (HARVEST trial) were studied. Within each population, mixture analysis was used to investigate whether a mixture of two normal distributions explained the variance in heart rate better than a single distributio n. In the men of all populations, mixture analysis identified a larger subpopulation of subjects with normal heart rate and a smaller one wi th fast heart rate. The subgroups with tachycardia had higher blood pr essure and lipid levels than those with normal heart rate. In the popu lations in which they were measured, fasting insulin and postload gluc ose were also higher in the men with faster heart rate. A subgroup wit h tachycardia could also be singled out among the women from Tecumseh, but no relation between heart rate and blood pressure could be found. These findings show that in Western societies, high heart rate pertai ns to a distinct subgroup of subjects, who are more frequently men and exhibit the characteristic features of the insulin resistance syndrom e. Sympathetic overactivity is likely to be the mechanism underlying t his clinical condition.