The Blood Pressure in a Representative Population Sample

A random sample of the population of Bergen, Norway, was examined in 1963/64 for blood pressure, weight and height in association with a chest X‐ray survey. The sample was made up of all individuals born on the 3rd, 13th and 23rd day of each month from 1864 to 1949, representing approximately 10% of the population 14 years of age and above, resident in Bergen on July 1, 1963. The study group comprised 8452 subjects, 3718 males and 4734 females. Of these, 8294 (98.1%) were actually examined, 7499 in survey centres and 795 in their private homes. The blood pressure measurements were carried out with a standardized technique by 19 specially trained and supervised nurses. The results have been analysed in detail with regard to observer variation. For each subject, two sphygmomanometers were used in alternating sequence; the cuff was 40 mm long and 14 cm wide. The results of the study are presented in seven figures and two tables; details are to be found in ten appendices. The systolic blood pressure was found to vary with sex and age, but very little with height, weight and pulse rate. In females, the mean values varied from 118 mm Hg in the age group 20–29 years to 171 mm at 70–79 years. In males, the mean values varied from 128 mm Hg at ages 20–29 years to 157 mm in the 40–49 year group. In the two diastolic pressures (phase 4 and phase 5) the same type of sex differences were present, but to a smaller degree. In females the mean values for the fifth phase increased from 66 to 82 mm Hg, and in males, from 69 to 82 mm. The systolic and diastolic blood pressures were well correlated in all age groups of both sexes. The subjects examined in their private homes showed slightly higher blood pressure values than those attending the survey centres. The reason for this difference was investigated, but no definite explanation was found.