MORTALITY IN PARTICIPANTS AND NON-PARTICIPANTS OF A MULTIFACTORIAL PREVENTION STUDY OF CARDIOVASCULAR-DISEASES - A 28-YEAR FOLLOW-UP OF THEHELSINKI BUSINESSMEN STUDY

Objective-To investigate pretrial risk factors and long term mortality (1964-1992) in participants and nonparticipants of a multifactorial p rimary prevention trial. Design-A prospective study among 3313 initial ly healthy businessmen. During the 1960s (1964 onwards), 3490 healthy male business executives born between 1919 and 1934 participated in vo luntary health checks at the Institute of Occupational Health in Helsi nki. From that period cardiovascular disease (CVD) risk factors were a vailable in 3313 men. In the beginning of the 1970s these men were inv ited to join a multifactorial primary prevention trial of CVD. Six gro ups were formed: (I) healthy participants in a high risk intervention group (n = 612), and (II) their randomised control group (n = 610); (I II) a non-participant low risk group (n = 593); (IV) an excluded group with signs of CVD (n = 563); (V) a refused group (n = 867); and (VI) dead (n = 68). Groups I and II participated in the five year preventio n trial which started in 1974. Other groups were followed up through r egisters, with no personal contact. Measurements-Cardiovascular risk f actors during the 1960s. Mortality follow up using national registers up to 31 December, 1992. Main results-Baseline risk factors were lowes t in the low risk group, highest in the excluded group, intermediate a nd comparable in other groups. Eighteen-year (1974-1992) mortality (pe r 1000) was 79.3, 106.6, 155.2, 179.9, and 259.3 in the low risk, cont rol, intervention, refused, and excluded groups, respectively (P < 0.0 01). In the whole population of 3313 men, the 28-year (1964-1992) tota l (n = 577) and coronary deaths (n = 199) were significantly predicted by smoking, blood pressure, and cholesterol; cancer deaths (n = 163) by smoking only; and violent deaths (n = 83) by none of the risk facto rs. One-hour postload glucose was significantly associated with total mortality in the intervention group only. When the intervention and co ntrol groups were included in the same model, the effect of group an t otal mortality tended to be dependent on the 1 h blood glucose value ( P = 0.06 for the group by 1 h glucose interaction term). Conclusion-Th e traditional risk factors (smoking, blood pressure, and cholesterol) are significantly associated with 28-year mortality in this high socia l class population with previous health education. Conversely, a ''clu stering'' of low risk factors predicted low total, coronary, and cance r mortality. The findings on 1 h blood glucose suggest that factors re lated to glucose tolerance explain in part the excess mortality in the intervention group compared with the control group.