[Limitations of joint mobility in patients with type 1 diabetes mellitus]. 
To assess limitation of joint mobility in patients with type I diabetes mellitus and to evaluate its relation with retinopathy, joint mobility was prospectively assessed in 96 diabetic patients and 68 healthy controls.  Joint mobility was explored with the praying maneuver and the measurement in mobility degrees of the third and fifth metacarpophalangeal joints, wrists and elbows.  The degree of metabolic control was assessed with the mean glycosylated hemoglobin in the last two years.  Retinopathy was investigated with direct funduscopy.  The results were statistically evaluated with chi-square and Student's t tests and the linear coefficient.  A reduced joint mobility was found in 41 diabetics and 5 controls (p less than 0.0001).  The reduction in joint mobility was related with the patients' age but not with the degree of metabolic control.  85% of diabetics with joint involvement had retinopathy of some degree.  A limited joint mobility is a common complication of type I diabetes mellitus.  The demonstration of this abnormality in diabetic patients might represent a first and simple marker of microangiopathy.