Coronary heart disease risk factors in subjects whose brothers, sisters or husbands developed premature myocardial infarction during 12 years of follow-up. The Finnmark Study (1977-1989).

BACKGROUND

In individuals whose relatives have experienced heart disease, levels of classic risk factors may have been underestimated because of life style changes after serious family disease or inaccurate disease reports.

METHODS

To overcome pitfalls noted in previous research, risk factors were measured at a screening of the general population aged 20-52 years in four Norwegian municipalities. After 12 years of follow-up, a first myocardial infarction was evident in 51 of 753 sibships and in 68 of 1518 spouse pairs.

RESULTS

Multiple adjusted means were higher in men with than in men without a brother or sister who became affected: 7.17 versus 6.84 mmol/l (P=0.07) for serum total cholesterol, 140.8 versus 135.6 mmHg (P=0.02) and 85.7 versus 82.5 mmHg (P=0.04) for systolic and diastolic blood pressure. Total cholesterol readings were higher the younger (P < 0.01 ) the sibling who experienced heart disease. Elevations were less pronounced in women, but smoking was more frequent among wives of affected than wives of unaffected husbands (58.3% versus 41.2%, P<0.01).

CONCLUSIONS

The markedly adverse levels of modifiable risk factors found in individuals whose brothers or sisters developed heart disease offer a potential for prevention in families with heart disease.