Screening for health risks. How useful is a questionnaire response showing positive family history of myocardial infarction, hypertension or cerebral stroke?

The participants in a community health survey in the Reykjavik area answered the question whether a first-degree relative had had myocardial infarction (MI), hypertension (HT) or cerebral stroke. The mean total serum cholesterol level was 5-10 mg/dl higher in the group with a positive history of MI than in the negative group. The frequency of hyperlipidaemia and the levels of other risk factors measured (blood pressure and body mass index) were similar in both groups. The group with a positive family history (FH) of HT had a mean systolic blood pressure 6-8 mmHg higher and diastolic hypertension (greater than 105 mmHg) on a single measurement twice as frequently as the negative group. The mean systolic blood pressure in the group with positive FH of stroke was 8-10 mmHg higher than in the negative group. The study thus suggests that positive FH of HT or stroke among first-degree relatives is a worthy indication for blood pressure measurements, at least after the age of 40.