Evaluation of quality of life in patients with type 2 diabetes Mellitus with symptomatic distal symmetric polyneuropathy / Avaliação da qualidade de vida em doentes com diabetes Mellitus tipo 2 com polineuropatia simétrica distal sintomática

Abstract

INTRO/BACKGROUND The complications of Diabetes Mellitus (DM) are traditionally categorized as micro and macrovascular disorders. Among them, diabetic polyneuropathy (DPN) is one of the most common, presenting with or without associated neuropathic pain, and its morbidity exerts a significant impact on the quality of life (QOL) of these patients. About 50% of individuals with type 2 DM (T2DM) suffer from this condition and the distal symmetric polyneuropathy (DSPN) constitutes its most frequent clinical form. OBJECTIVE: To demonstrate the effect of symptomatic DSPN on the QOL of T2DM patients in a sample of the Brazilian population, correlating clinical and electrophysiological findings, besides comparing the results obtained by the Medical Outcomes Study Questionaire 36-Item Short Form Health Survey (SF-36) among patients with painful and non-painful diabetic DSPN. METHODS: This study comprised 25 outpatients with DSPN and T2DM submitted to a detailed anamnesis to identify clinical and demographic characteristics, besides comorbidities and complications of DM. Clinical evaluation was performed through neurological physical examination, in addition to specific scales for neuropathy as the Neuropathy Disability Score (NDS). In order to assess the health-related quality of life (HRQoL) of these patients, the SF-36 translated and adapted for the Brazilian population was applied. Nerve conduction study (NCS) was performed for the examined nerves (motor part of peroneal nerve and sensory part of the sural nerve). The following parameters were assessed: motor conduction velocity (MCV), amplitude of the compound muscle action potentials (CMAP) and amplitude of the sensory nerve action potentials (SNAP). RESULTS: Role Physical (RP) domain of SF-36 was significantly related to some of the clinical and electrophysiological factors measured. RP had an inverse and significant relationship with the NDS values (Rho: -0.44), showing the impact of neuropathy severity on these patients’ QOL. The sural nerve SNAP and peroneal nerve MCV showed a significant and positive relationship with RP (Rho: 0,52 and 0,36, respectively). The Mental Health (MH) domain showed a statistically significant difference between those patients with pain and without pain (p = 0.002), and patients without pain had higher mean values, as well as a higher minimum and maximum value. The Role Emotional (RE) domain also showed a significant difference between patients with and without pain, and patients with pain had a lower mean value (p = 0.04). For all other domains, patients with pain showed lower mean values than those without pain, however without statistical difference in the test performed. Between DM complications, only nephropathy presented statistically different RP scores from those without nephropathy (p = 0.02). CONCLUSION: There was a significant inverse relationship between the severity of DSPN and the QOL of the evaluated patients, as evidenced by lower values in the SF-36 specific RP domain, as polyneuropathy becomes more severe. This domain also presented significantly lower values in patients with associated nephropathy. The presence of pain negatively affected the QOL of patients with painful DPN, who presented significantly lower mean values in the MH and RE domains when compared to patients without pain.