PMP22 and diabetes mellitus: CIDP+DM subjects had higher HbA1c values (7.7±2.0%) than CIDP-DM patients (5.6±0.4%, p<0.001) as expected, and a higher prevalence of retinopathy, nephropathy and hypertension (p = 0.001, p = 0.0007, p = 0.0005).