CAFFEINE INTAKE IN RELATION TO THE RISK OF PRIMARY CARDIAC-ARREST

We conducted a population-based case control study in King County, WA, to evaluate the association between usual caffeine intake and primary cardiac arrest. We identified primary cardiac arrest cases (N = 362) without a history of clinical heart disease or major comorbidity throu gh paramedic incident reports during the period 1988-1994. We identifi ed controls (N = 581), individually matched to cases on age (+/-7 year s) and gender and meeting the same general health criteria, through ra ndom digit dialing. We interviewed the spouses of cases and controls t o obtain information on usual caffeine intake from coffer, tea, and co la during the prior year. After adjusting for cigarette smoking and ot her risk factors, we observed little association between daily consump tion of the caffeine equivalent of fewer than 5 cups per day of drip c offee (<687 mg per day) and primary cardiac arrest. High usual caffein e consumption (greater than or equal to 687 mg per day) was associated with a modestly elevated risk of primary cardiac arrest [odds ratio = 1.44; 95% confidence interval (CI) = 0.82-2.53]. The elevated risk as sociated with high caffeine consumption appeared to be restricted to n ever-smokers (odds ratio for greater than or equal to 687 mg per day = 3.2; 95% CI = 1.3-8.1).