LOW BLOOD-PRESSURE IS NOT AN INDEPENDENT DETERMINANT OF SURVIVAL IN AN ELDERLY POPULATION

The object of the study was to determine whether the increased mortali ty associated with low blood pressure in elderly people arises because of the adverse effects of hypotension or because of confounding varia bles. A community sample of 782 people aged 70 years and older was fol lowed for 3 years. Blood pressure measurements were taken on initial a ssessment and hypotension was defined separately for systolic and dias tolic pressures as a pressure less than the tenth percentile for the s ample (systolic less than or equal to 122 mmHg, diastolic less than or equal to 68 mmHg). After 3 years 135 participants had died and of the se 31 had low systolic or diastolic blood pressure at baseline. Low di astolic pressure was associated with an increased mortality over the 3 years (hazard ratio 1.85, 95% Confidence Interval 1.18-2.91). This in crease in risk was explained by confounding variables. Low systolic pr essure was not associated with increased mortality. The increased mort ality of those with low blood pressure is explained by concurrent illn ess.