Salt intake reduction is effective in lowering the blood pressure and risk of long-term cardiovascular diseases, but it is also harmful due to sympathetic stimulation and insulin resistant. Compliance toward salt intake reduction is low. It is important to screen who will get more benefit for long term salt reduction diet and educational support. Epithelial sodium Channel (ENaC) protein plays an important role in maintaining plasma sodium level. The aim of this study is exploring the possibility of ENaC as a marker to screen salt-sensitivity.Design and Method:
This is an observational descriptive study. ENaC protein was detected by ELISA method using reagent from Cloud-Clone, catalog number SED337Hu. Morning urine were collected and centrifuged. For the first step of study, one male subject for each category, non-hypertensive, hypertensive with and without family history of hypertension, were recruited. For the second study 13 (6 male and 7 female) non-hypertensive subjects were recruited.Results:
ENaC proteins from plasma in non-hypertensive, hypertensive with, and without family history of hypertension are 1.12 ng/mL, 2.7 ng/mL and 4.0 ng/mL respectively. ENaC protein from centrifuged urine at upper part and lower part of supernatant are 0.4 ng/mL and 0.3 ng/mL in normal male; 2.8 ng/mL and 2.7 ng/mL; and 2.7 ng/mL and 3.7 ng/mL in hypertensive male with and without family history of hypertension. Mean ENaC protein level in non-hypertensive men and women are 1.4 (0.2-2) ng/mL and 2.1 (1.5-2.7)ng/mL. Mean ENaC protein level in those without and with family history of hypertension are 1.6 ng/mL and 1.1 ng/mL in male, and 2.6 ng/mL and 1.9 ng/mL in female.Conclusions
: ENaC protein is detectable in spot urine; the levels differ by hypertension status and also by gender. Further research on its use is needed.