Postural hand tremor and incident hypertension in young to middle-aged adults: The Bogalusa heart study

Background: Hand tremor and blood pressure (BP) are both increased by adrenergic stimulation and reduced by β-blockade, indicating that they may share a common underlying pathophysiology. Methods: We prospectively examined the relationship between postural hand tremor and incident hypertension in a community-based cohort of 715 (184 blacks and 531 whites) adults without hypertension and not using medications to control tremor (e.g. β-blockers). At baseline, tremor was measured with participants holding a laser pointer aimed at a sheet of Polaroid film 8 feet away with arm outstretched for 8s in a darkened room, and characterized by the width of the circle diameter encompassing all exposures and enumeration of exposure dots in the same area. Incident hypertension was defined as new elevation of BP (SBP≥140 or DBP≥90mmHg, based on an average of six readings over two visits) or antihypertensive medication use. Results: During a median follow-up of 6.4 years, 198 (69 blacks and 129 whites) participants developed hypertension. Tremor measurements (by quartile) were positively associated with incident hypertension after adjustment for baseline demographics, lifestyle characteristics, and BP. There was significant interaction by race (P=0.01). Among whites, tremor was positively associated with incident hypertension [hazard ratio highest vs. lowest quartile: 2.50 (95% confidence interval: 1.40-4.48) dot method and 3.24 (1.78-5.90) circular method; both P trend <0.01]. Among blacks, tremor was not associated with hypertension. Conclusion: In this community-based cohort, postural hand tremor was strongly associated with the risk of incident hypertension among whites and merits further study as a potential indicator of risk for hypertension.