Increased osmotic fragility of erythrocytes in essential hypertension

The correlation between hypertension and the osmotic fragility of erythrocytes was examined. High osmotic fragility of erythrocytes was observed in patients with essential hypertension and normotensive subjects with family history of hypertension, compared with normotensive controls without family history of hypertension. In patients with secondary hypertension, the osmotic fragility of erythrocytes was not significantly different from that of normotensive controls without family history of hypertension. The membrane fragility had no correlation with the level of blood pressure or dietary salt intake. Thus, the osmotic fragility of erythrocytes might reflect functional or structural abnormalities of cell membranes, and could be one of the genetic markers of the hypertensive predisposition.