BLOOD-PRESSURE AND LIFE-STYLE IN THE PEOPLES-REPUBLIC-OF-CHINA - 3 SAMPLES IN THE INTERSALT STUDY

In INTERSALT, the International Cooperative Study on Electrolytes and Blood Pressure, three centres located in the People's Republic of Chin a (PRC) had distinctive patterns of BP and of life style variables tha t, in INTERSALT overall, were found to relate to BP. The PRC centres h ad low body mass index (BMI) and alcohol consumption but high urinary sodium and sodium/potassium ratio (Na/K). Compared with 45 other INTER SALT centres, average BMI was 22.7 vs. 25.4 and alcohol consumption wa s 32% vs. 61%, with heavy drinking 3% vs. 14%. However, Na/K in the PR C was 6.7 vs. 3.2 in the other centres. This combination of factors ma y underlie the BP pattern observed. While mean BP in the PRC was lower than in the 45 centres (-7.0 mmHg SBP, -5.6 mmHg for DBP), this was c ounterbalanced by other findings. Upward slope of systolic pressure wi th age was 45% greater for the PRC than the other centres and 24% grea ter for diastolic pressure. As a result, although percentage hypertens ive for ages 20-49 years for the PRC was half that in the 45 centres ( 6% vs. 12%), by age 50-59 years the prevalence was 31% in the PRC and 38% in the other centres. Hypertension prevalence in Tianjin, with hig hest Na/K in INTERSALT (7.6) was 40% for ages 50-59 years. While sampl e size in individual centres does not provide power to demonstrate aet iological relationships, these findings permit formulation of the foll owing hypothesis: although lower body mass and lower alcohol intake ma y counteract to some degree impact of high salt intake, such intake ov er decades eventually takes its toll on BP.