Hypokalemia associated with diuretic use and cardiovascular events in the Systolic Hypertension in the Elderly Program.

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 <3.5 mmol/L compared with 1% of the participants randomized to placebo (P<0.001). 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 (P<0.05). 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.

Coffee consumption and blood pressure: a randomized, crossover clinical trial.

OBJECTIVE: To examine the effect of moderate coffee consumption on blood pressure over a prolonged period of time. Previous work in this area has used primarily purified caffeine. DESIGN: A prospective, randomized, crossover clinical trial. SETTING: A hypertension specialty outpatient clinic at the University of Tennessee, Memphis. PATIENTS: Healthy, young, white men who were moderate coffee drinkers (less than 6 cups/day) were recruited. Twenty-four subjects were randomized and 21 (average age 35.5 years) completed the trial. INTERVENTIONS: Subjects were randomized to one of two groups: Group A drank three or more cups of coffee/day for two months, then crossed over to abstaining from coffee for two months; group B abstained from coffee first, then crossed over to drinking coffee. Only filter-brewed coffee was used. Subjects were seen at monthly intervals for blood pressure measurements. MEASUREMENTS AND MAIN RESULTS: The average coffee consumption was 3.6 cups/day during the coffee-drinking phases. There was no difference between the coffee-drinking phase and the abstention phase in either systolic blood pressure (110.1 mmHg vs. 108.0 mmHg, respectively; 95% CI of difference -7.3, 2.5) or diastolic blood pressure (67.2 mmHg vs. 69.6 mmHg, respectively; 95% CI of difference -2.2, 6.4). CONCLUSIONS: Moderate daily consumption of coffee does not elevate blood pressure.

Coffee consumption and serum lipids: a randomized, crossover clinical trial.

PURPOSE: The purpose of this study was to determine the effect of consuming three or more cups of filter-brewed coffee per day on levels of serum lipids. SUBJECTS AND METHODS: A prospective, randomized crossover clinical trial was performed. Twenty-one healthy white male subjects completed the trial, and consumed an average of 3.6 cups of coffee a day. Data were evaluated by analysis of variance for repeated measures and t-test for paired means. RESULTS: No effect of coffee consumption on serum total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, or apolipoprotein B was found. Diet, creamer use, and cigarette use as well as group assignment and time factors were controlled for in the analysis. CONCLUSION: We found no effect of moderate consumption of filter-brewed coffee on serum levels of atherogenic lipids. This study supports previous work that filtered coffee has no adverse effect on serum lipids. This has far-reaching implications given the widespread use of coffee and the current concern over coronary risk factors.