Haptoglobin 1-1 phenotype: A risk factor for 24-hours polyuria.

The Hp1 allele was more frequent in subjects with polyuria, and participants with the Hp 1-1 phenotype were at greater risk for polyuria. Hp 1-1 subjects demonstrated an altered ability to concentrate urine with a slower continuous excretion of sodium throughout the day. Plasma Hp concentration of Hp 1-1 was positively correlated with 24-hours sodium clearance in subjects without polyuria.