Cellular Ca²⁺ ATPase Activity in Diabetes Mellitus

Summary

Basal and maximal Ca²⁺ ATPase activity was studied in erythrocytes of 29 healthy controls, 15 patients with insulin-dependent diabetes mellitus (IDDM) and 22 patients with non-insulin-dependent diabetes mellitus (NIDDM). Basal and maximal Ca²⁺ ATPase activity was significantly decreased in insulin-dependent diabetes mellitus (8.4±0.5 and 22.5±1.1 pmol/10⁶ RBC/min) and non-insulin-dependent diabetes mellitus (7.3±1.0 and 18.6±1.8 pmol/10⁶ RBC/min) compared to healthy controls (9.3±1.0 and 24.6±1.1 pmol/10⁶ RBC/min). Maximal Ca²⁺ ATPase activity showed a significant correlation to systolic blood pressure in both insulin-dependent diabetes mellitus and non-insulin-dependent diabetes mellitus. There was no significant correlation of maximal Ca²⁺ ATPase activity to fasting serum glucose concentration and to HbA1 levels. Maximal Ca²⁺ ATPase activity was significantly correlated to creatinine clearance in non-insulin-dependent diabetes mellitus, but not in insulin-dependent diabetes mellitus. It is concluded that a decreased cellular Ca²⁺ ATPase activity may predispose to the development of hypertension in diabetes mellitus.

Key words

Diabetes Mellitus - Ca²⁺ ATPase - Erythrocytes - Hypertension