(33) Incidence of Diabetes Mellitus Among Chronic Inflammatory Demyelinating Polyneuropathy Patients Compared to The General Population: A Real-World Study of US Commercially Insured Individuals

Publication Number: 364

Background: Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare, acquired autoimmune disorder characterized by progressive peripheral neuropathy. The association of CIDP with diabetes remains controversial, as both diseases have increased prevalence in older patients, underlying inflammatory pathogenesis, and can present with peripheral neuropathy. Some diabetes patients with diabetic neuropathy can be misdiagnosed with CIDP, but it may be less likely that CIDP patients will have misdiagnosis of incident diabetes.

Objectives: To evaluate the incidence of diabetes mellitus among CIDP patients compared to the general population.

Methods: Using the Optum Clinformatics US health insurance claims database, a cohort of individuals with and without CIDP were identified between 06/30/2010 and 02/28/2021 based on the following criteria: being continuously enrolled in medical and pharmacy coverage for a 6-month baseline period, not having any ICD-9 or ICD-10 diagnosis codes for CIDP (357.81, G61.81), multiple sclerosis (340, G35, respectively) or Guillain-Barré syndrome (357.0, G61.0) during the baseline period, be ≥ 18 years of age, and those with CIDP were identified as having at least 2 diagnosis codes for CIDP (357.81, G61.81) that were ≥ 30 days apart. The index date for CIDP patients were the date they satisfied the disease definition, a random index date was assigned to general population individuals. We followed all individuals in the cohort until the earliest of death, disenrollment from their insurance plan, or the end of available data (08/31/2021). CIDP patients and general population individuals were matched 1:5 based on age, sex, and index year. Incidence of diabetes in both groups were identified as having at least 2 diagnosis codes for diabetes (250.x, E10.x, E11.x) that were ≥ 30 days apart.

Results: A total of 2832 CIDP patients were matched to 14160 general population individuals in the database over the study period. The mean age was 65 years (SD 15) and 58% were male. There were 283 cases of diabetes among the CIDP patients and 559 cases among the general population, resulting in incidence rates of 35/1000 person-years (py) and 21/1000 py respectively. The incidence rate ratio was 1.63 (95% confidence interval 1.42, 1.89).

Conclusions: There was a significantly higher rate of diabetes among CIDP patients than in the general population.