Comparison between Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP) in Adult Persons Living with T2D and Without in Johannesburg, South Africa

Abstract

Background: Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP) is an immune-mediated demyelinating polyneuropathy. It is associated with various conditions. One significant condition studied is type 2 diabetes mellitus (T2D). Some CIDP patients have no identified cause. The global prevalence of CIDP reported ranges from 0.7 to 10.3 cases per 100,000 people. There were approximately 529 million people living with T2D worldwide in 2021. Distinguishing CIDP in patients with and without diabetes poses a clinical challenge. It is crucial to determine if the treatment of diabetes-associated CIDP and its clinical symptoms resemble those of non-diabetic CIDP, as there is limited data available. Objectives: To evaluate and compare clinical and electrophysiological characteristics of CIDP patients with T2D, compared to those without, to provide insight for diagnosis and treatment. Methods: This retrospective cohort study was conducted at the adult neurology clinics of Charlotte Maxeke Johannesburg Academic Hospital and Chris Hani Baragwanath Academic Hospital in Johannesburg, South Africa for patients with CIDP. Patient records were extracted from discharge summaries over a 6-year period (January 2016 to December 2022). Patients were grouped and analysed based on their T2D or non-T2D status. Demographics and Clinical features, electrophysiological features, and treatment regimen were evaluated and compared. Results: A total of 115 patient records with CIDP were retrieved, and a final number of 84 patient records with both clinical and electrophysiological findings were available and used in the study. There were 24 patients diagnosed with T2D and 60 patients without T2D. The T2D patients were poorly controlled with a median HbA1c of 8.22% (interquartile range (IQR) 5.6% to 15.4%). There were no clinical and electrophysiological differences for CIDP patients with T2D in comparison to patients without T2D; however, the diabetic group showed a prolonged mean duration of symptoms onset to diagnosis of 26 weeks (IQR 8-126 weeks) in comparison to a mean of 18 weeks (IQR 8-28 weeks) for the non-diabetic group (p=0.007). Conclusion: There are no distinct clinical and electrophysiological differences in CIDP among patients with and without T2D, other than individuals with CIDP and T2D have a prolonged period of symptoms before being diagnosed. This results in increased morbidity and poorer prognosis. Additional prospective research is urgently needed to better understand the reasons behind delayed diagnosis in order to improve clinical outcomes.