Blood pressure, weight, height and cardiovascular risk factors were evaluated in 73 adults of Easter Island (mean age 49 +/- 12.9 (SD) years) in January 1989 and 1990. Their mean blood pressure (BP) was 129 +/- 24/81 +/- 14, significantly higher by 7/5 mm Hg than in 1979 (p < 0.05). Of the population studied 30% of subjects were hypertensives. Both systolic (S) and diastolic blood pressure (DBP) correlated with age (r = 0.40, p < 0.005 and r = 24, p < 0.05 respectively). In males body mass index correlated strongly with SBP and DBP (r = 0.55, p < 0.005 and r = 0.52, p < 0.01). Forty eight % of subjects were obese, 60% smoked (14 cigarettes/day), 38% drank alcohol and 70% lead sedentary lifes; their level of stress was considered average. In 23 nomotensives or undiagnosed hypertensives 24 hour urine was collected for sodium, potassium, creatinine and kallikrein; mean urinary sodium excretion was 121 +/- 39 mmol/day; potassium excretion 59 +/- 29 mmol/day, creatinine excretion 1383 +/- 489 mg/day and kallikrein excretion 682 +/- 355 mU/day; of these, only urinary sodium was significantly lower than values determined in a group of 29 continental volunteers. Eleven natives that had never left the island had similar BP and risk factors than a sex and age paired sample, who has spent 10.9 +/- 7.8 years in the continent. The present study demonstrates that Easter Island natives have increased their mean BP in 10 years, elevated their BP with age and have lost the protection previously associated to staying in the island. In this sample the prevalence of hypertension (30%) was high. We postulate that the 2 main factors determining the BP elevation are a sodium intake greater than 100 mmol/day and a high prevalence of obesity, which plays a stronger hypertensogenic role in males. It is highly probable that the contamination is due to returning migrants and to the massive entry of tourists.
