Association of haptoglobin with sodium sensitivity and resistance of blood pressure.
Sodium sensitivity and resistance of blood pressure were examined in 117 normotensive and 85 hypertensive subjects by means of a protocol using rapid extracellular fluid volume expansion with intravenously administered saline (2 L over 4 hours) followed by a day of low dietary sodium intake (10 mEq) and volume contraction induced by a diuretic (furosemide, 120 mg orally). Genetic markers were also examined. Both hypertensive and normotensive subjects with haptoglobin 1-1 phenotype were significantly more (p less than 0.05) likely to be sodium-sensitive than were those with 2-1 or 2-2 phenotypes, and subjects with 2-2 phenotypes were more apt to be sodium-resistant. A second population was examined in which both adults and children with haptoglobin 1-1 phenotype were found to have significantly (p less than 0.05) higher casual systolic and diastolic blood pressures. These two studies independently confirm a relationship between haptoglobin phenotypes and blood pressure and suggest an environmental factor (sodium) as well.
D000293:Adolescent; D001794:Blood Pressure; D002648:Child; D002675:Child, Preschool; D005260:Female; D006242:Haptoglobins / Q000235:genetics*; D006801:Humans; D006973:Hypertension / Q000235:genetics* / Q000503:physiopathology; D008297:Male; D010641:Phenotype; D012964:Sodium / Q000502:physiology*
D006242:Haptoglobins; D012964:Sodium