Prevalence of symptomatic polyneuropathy in patients with type 2 diabetes mellitus attending the diabetes clinic at Helen Joseph Tertiary Hospital, South Africa

Abstract

Background: Diabetic neuropathy has an estimated prevalence of 50% among individuals with longstanding diabetes, with distal symmetric polyneuropathy (DSPN) being the most common manifestation. Poor glycaemic control is a recognised risk factor for DSPN. This study aimed to determine the prevalence of symptomatic DSPN in patients with type 2 diabetes mellitus (T2D) using a validated symptom-screening questionnaire – the diabetic neuropathy symptom (DNS) score. In addition, the association between haemoglobin A1c (HbA1c) and DSPN was investigated.
Methods: A cross-sectional study was performed at the diabetes clinic at Helen Joseph Tertiary Hospital, Johannesburg, South Africa. A total of 206 consecutive patients with T2D were included. Underlying comorbidities and HbA1c values were obtained from patient records. The DNS score was used to assess for the presence of symptomatic DSPN.
Results: The prevalence of symptomatic DSPN was 61.2%. Among those who screened positive for DSPN, 58% were not receiving pharmacological treatment for DSPN. Patients with HbA1c values of 7% – 10% and > 10% were 2.9 and 3.7 times, respectively, likely to have DSPN (prevalence ratio [PR] = 2.9; 95% confidence interval [CI] 1.5–5.4, p = 0.001; PR = 3.7; 95% CI 2.0–7.0, p < 0.001, respectively), compared with those with an HbA1c value < 7%.
Conclusion: A higher than expected prevalence of symptomatic DSPN was observed in this study population, indicating the need for enhanced screening. Furthermore, a significant proportion of symptomatic patients were not receiving treatment. Poor glycaemic control with HbA1c values > 7% significantly increases the risk of DSPN.
Contribution: The DNS score can easily be implemented at a primary care level to detect symptomatic neuropathy and facilitate prompt treatment.