Serum uric acid independently predicts cardiovascular events in older persons with isolated systolic hypertension. Monitoring serum uric acid change during diuretic treatment may help to identify patients who will most benefit from treatment.

Abstract-The treatment of hypertension with high-dose thiazide diuretics results in potassium depletion and a limited benefit for preventing coronary events. The clinical relevance of hypokalemia associated with low-dose diuretics has not been assessed. To determine whether hypokalemia that occurs with low-dose diuretics is associated with a reduced benefit on cardiovascular events, we analyzed data of 4126 participants in the Systolic Hypertension in the Elderly Program (SHEP), a 5-year randomized, placebo-controlled clinical trial of chlorthalidone-based treatment of isolated systolic hypertension in older persons. After 1 year of treatment, 7.2% of the participants randomized to active treatment had a serum potassium Ͻ3.5 mmol/L compared with 1% of the participants randomized to placebo (PϽ0.001). During the 4 years after the first annual visit, 451 participants experienced a cardiovascular event, 215 experienced a coronary event, 177 experienced stroke, and 323 died. After adjustment for known risk factors and study drug dose, the participants who received active treatment and who experienced hypokalemia had a similar risk of cardiovascular events, coronary events, and stroke as those randomized to placebo. Within the active treatment group, the risk of these events was 51%, 55%, and 72% lower, respectively, among those who had normal serum potassium levels compared with those who experienced hypokalemia (PϽ0.05). The participants who had hypokalemia after 1 year of treatment with a low-dose diuretic did not experience the reduction in cardiovascular events achieved among those who did not have hypokalemia.

In the Systolic Hypertension in the Elderly Program (SHEP) trial (1985-1990), active treatment reduced the incidence of cardiovascular events, but not that of dementia and disability, as compared with placebo. This study aims to evaluate if assessment of cognitive and functional outcomes was biased by differential dropout. Characteristics of subjects who did or did not participate in follow-up cognitive and functional evaluations were compared. The relative risks of incident cognitive impairment and disability were assessed in the two treatment groups, with the use of the reported findings and under the assumption that the proportions of cognitive and functional impairment among dropouts increased. Assignment to the placebo group and the occurrence of cardiovascular events independently predicted missed assessments. From the reported findings, the risk of cognitive and functional impairment was similar between the two treatment groups. However, when 20-30% and 40-80% of the subjects who missed the assessment were assumed to be cognitively and, respectively, functionally impaired, assignment to active treatment reduced the risk of these outcomes. In the SHEP, the cognitive and functional evaluations were biased toward the null effect by differential dropout. This might have obscured the appraisal of a protective effect of treatment on the cognitive and functional decline of older hypertensive adults.