PMID-sentid Pub_year Sent_text comp_official_name comp_offsetprotein_name organism prot_offset 1641867-4 1992 Fractional excretion of sodium showed a significant correlation with age in all the subjects, while that of potassium significantly correlated with serum beta 2-microglobulin. Potassium 108-117 beta-2-microglobulin Homo sapiens 154-174