Evolution of blood pressure from adolescents to youth in salt sensitivies: A 18-year follow-up study in Hanzhong children cohort

Background: Essential hypertension mostly originates from children. Salt Sensitivity (SS) is regarded as the intermediate phenotype of essential hypertension. The present study investigated the effects of salt-sensitivity on evolution of blood pressure (BP) and development to hypertension from adolescents to youth. Methods. A baseline survey was carried out in 4,623 adolescents aged 6-15years old in Hanzhong rural areas in 1987, 310 of whom(mean 9.2years) were randomly recruited for determination of salt sensitivity using the tests of oral saline load and furosemide sodium-volume depletion. SS was diagnosed in 101 subjects while 209 were determined as non-salt-sensitive (NSS). We made a 18-year followed-up of the cohort in 2005. Results: The response rate for surviving baseline adolescents was 71.9%. At follow up, BP in youth with baseline SS was higher than that in NSS (SBP:122.9±13.1 VS 117.3±12.4, P<0.01; DBP: 78.2±10.4 VS 74.7±10.8, P<0.05). Longitudinal analysis of 18-year BP evolution, subjects in SS had greater Systolic BP change than subjects in NSS(19.6±12.714.7±12. 2, P<0.01). The incidence of hypertension in salt sensitive group was higher than that in NSS group (15.5% VS 6.3%, RR=2.34, P<0.05). Conclusion: Our findings indicate that adolescents with higher BP salt-sensitivity have a higher rate of incident hypertension in youth. Salt sensitivity could be at high risk predisposing to development of hypertension from adolescents to youth.