Urinary free cortisol: An intermediate phenotype and a potential genetic marker for a salt-resistant subset of essential hypertension - Chamarthi, B; Kolatkar, N S; Hunt, S C; Williams, J S; Seely, E W; Brown, N J; Murphey, L J; Jeunemaitre, X; Williams, G H (J Clin Endocrinol Metab, 2007)