[Autoantibodies against beta1 and M2 receptor in diabetic patients with refractory hypertension]

To explore the role of the autoantibodies against M(2)-muscarinic receptor (M(2)-receptor), beta(1)-adrenergic receptor (beta(1)-receptor) in the development of diabetic with refractory hypertension.

Serum autoantibodies against M(2) and beta(1) were detected by ELISA using synthesized epitopes of the second extracellular loop of M(2) receptor (169 - 193) and beta(1) receptor (197 - 222) in healthy controls (n = 40), diabetic patients (n = 62), diabetic patients with non-refractory hypertension (n = 55) and diabetic patients with refractory hypertension (n = 81).

The positive rates of the autoantibodies against M(2) receptor and beta(1) receptor were similar among healthy controls (15.0% and 17. 5%), diabetes mellitus patients (17.7% and 14.5%) and diabetic patients with non-refractory hypertension (16.4% and 12.7%) but are significantly higher in diabetic patients with refractory hypertension (64.2% and 55.6%, P < 0.01 vs. other 3 groups).

This finding suggests that autoimmune mechanisms might play a role in the pathogenesis of diabetic patients with refractory hypertension.