All 4814 persons that were initially studied in the Heinz Nixdorf Recall Study were invited to participate in the follow-up examination after 5.1聽卤聽0.3 years. All traditional Framingham risk factors were quantified using standard techniques. Smokers were categorized in never, former and present smokers. The CAC scores were measured from EBCT using the Agatston method.
Overall, out of 342 men and 919 women with zero CAC at baseline, 107 (31.3%) men and 210 (22.9%) women had CAC>0 at second examination. In multivariable analysis, age (OR estimate per 5 years: 1.34 (95%CI: 1.21-1.47)), LDL cholesterol (per 10聽mg/dL: 1.05 (95%CI: 1.01-1.10)), systolic blood pressure (per 10聽mmHg: 1.19 (95%CI: 1.11-1.28)) and current smoking (1.49 (95%CI: 1.04-2.15)) were independent predictors of CAC onset. The probability of CAC onset steadily increased with age from 23.3% (men) and 15.3% (women) at age 45-49 years to 66.7% (men) and 42.9% (women) at age 70-74 years. The difference in age-dependent conversion rates was quantified by years between reaching a given level of CAC onset probability. We found a consistent pattern with respect to smoking status: presently (formerly) smoking middle-aged men convert to positive CAC 10 (5) years earlier than never smokers, for women (middle-aged to elderly) this time span is 8 (5) years.
Several traditional CVD risk factors are associated with CAC onset during 5 years follow-up. CAC onset is accelerated by approximately 10 (5) years for present (former) compared to never smokers.