Impact of pain severity on functioning domains, sleep, and cognition in painful diabetic peripheral polyneuropathy patients

Abstract

Abstract Background Several studies have observed that painful diabetic peripheral polyneuropathy (PDPN) had an impact on the level of functioning domains and quality of sleep as well as cognitive functions. This study is aimed to explore the relationship between severity of pain and level of functioning, sleep quality, and cognitive functions among these patients. We recruited 100 diabetics with a mean HbA1C% of 7.3±0.9, diagnosed with PDPN, and included in the study with a mean age of 51±12.8 years and disease duration of 10.2±7.4 years. The following assessment was done for each patient; clinical and neurophysiology assessment, routine laboratory assessment, measuring pain severity, and average pain severity interference scores using pain visual analog scale (VAS) and brief pain inventory (BPI) short form, respectively, sleep quality assessment using Pittsburgh Sleep Quality Index (PSQI) and Montreal cognitive function assessment (MOCA) scales. Results Moderate to severe pain was recorded in 71% of patients according to the VAS pain score. The severe pain group recorded the significant highest average pain severity and interference scores in BPI and domains compared to other less pain groups with average pain intensity scores of 7.5±0.6 vs 5.3±0.8 in the moderate and 3.3±0.4 in mild pain groups. Poor sleep quality and pattern were observed in these patients with a mean PSQI score of 6.8±3.1, and the severe pain group had a significant highest score of 9.4±2.3 compared to other less group scores of 7±2.3 and 3.7±1.8. Their mean MOCA score was low 24.2±2.2. Out of them 48/100 patients had mild cognitive impairment and recorded high frequency in the severe pain group (28/32) followed by the moderate pain (15/39) group. There is a significant correlation between the score of VAS and PSQI as well as MOCA. Conclusions Painful DPN patients had a poor level of functioning and sleep quality as well as cognitive impairment based on pain intensity. Trial registration This study was registered on a clinical trial with registration number NCT03275233 on 7 September 2017.