Epidemiological Study of Hypertension in Okinawan People.

We examined the mean blood preasure levels (MBPL) and prevalence rates of hypertension by sex and age in the people of Okinawa. The number of subjects studies was 16.759. Of which 6.352 were male and 10.407 were female over 10 years old. We estimated the volume of salt intake per person per day. We found that MBPL and pevalence rates of hypertension were significantly lower in Okinawan people than in mainland Japanese people. The main cause of a lower MBPL and lower prevalence rates of hypertension in Okinawan people results from the warm climate of the subtropical zone and a low salt intake (9.6 g). This may influence the low prevalence rates of ischemic heart disease and cerebrovascular disease in Okinawa, diseases which are number two and three respectively among the three main causes of death in Japan.