[Borderline hypertension. Survey of 8390 international officials]

The epidemiology of borderline hypertension (BHT) is studied on a population comprising 8390 international civil servants. The prevalence of BHT (systolic 141-159 mm Hg and/or diastolic 86-94 mm Hg) is noted to be 21,4%. It affects men and obese more frequently and increases with age. It differs according to national origin (p less than 0.001), being least frequent for Indians (9%) and most frequent in black Africans (38%). Professional status does not play a role. The occurrence of true hypertension is noted in 43% and 54% of those who were followed over a period of 15 resp. 20 years after discovery of BHT (as opposed to 22% for the entire population of the same age, p less than 0.01). The occurrence of sustained hypertension is more likely when there is both systolic and diastolic BHT, in certain predisposed national groups, in men and possibly also when there is obesity. Even when BHT does not change into sustained hypertension, the risk of cardio-vascular morbidity is increased 2.5 times. These findings give rise to series of practical considerations.