A cross-sectional study investigating frequency and features of definitely diagnosed diabetic painful polyneuropathy

Abstract

This cross-sectional multicentre study aimed at investigating frequency and features of painful diabetic polyneuropathy. We consecutively enrolled 816 patients attending hospital diabetic outpatient clinics. We first definitely diagnosed diabetic polyneuropathy and pure small-fibre polyneuropathy using clinical examination, nerve conduction study, and skin biopsy or quantitative sensory testing. Adhering to widely agreed criteria, we then identified neuropathic pain and diagnosed painful polyneuropathy using a combined approach of clinical examination and diagnostic tests. Of the 816 patients, 36% had a diabetic polyneuropathy associated with male sex, age, and diabetes severity; 2.5% of patients had a pure small-fibre polyneuropathy, unrelated to demographic variables and diabetes severity. Of the 816 patients, 115 (13%) suffered from a painful polyneuropathy, with female sex as the only risk factor for suffering from painful polyneuropathy. In this large study, providing a definite diagnosis of diabetic polyneuropathy and pure small-fibre polyneuropathy, we show the frequency of painful polyneuropathy and demonstrate that this difficult-to-treat complication is more common in women than in men.

Painful and non‐painful diabetic polyneuropathy: Clinical characteristics and diagnostic issues

“…This has been stressed in several previous reviews. However, the detection of DN is challenging in clinical practice due to the lack of a clear consensus for the definition and optimal clinical assessments to diagnose DN. Similar differences have been encountered for pain, where the criteria for neuropathic pain have also varied considerably.…”

“…In addition, they found pain being correlated with more severe DPN. In contrast, the Italian multicenter study of 816 type 1 and type 2 diabetes patients found female sex to be a risk factor for PDPN using the same definition of PDPN and DPN as the PiNS study. They showed that patients with type 2 diabetes had a higher risk of neuropathy compared with patients with type 1 diabetes.…”

“…They showed that patients with type 2 diabetes had a higher risk of neuropathy compared with patients with type 1 diabetes. In addition, higher body mass index, longer diabetes duration, and higher HbA1c levels were risk factors for both PDPN and DPN.…”

“…Also, inconsistent findings for an association between pain and neuropathy severity exists. Recently, three large cross‐sectional studies – a British, a German–Czech and an Italian study have been carried out using comprehensive clinical evaluations of DPN including quantitative sensory testing (QST), skin biopsies (small nerve fiber quantitation), nerve conduction studies and a general neurological evaluation. The definitions of DPN and PDPN as well as the study design were fairly similar in the three studies, and the population consisted mostly of patients with type 2 diabetes.…”

“…The study by Raputova et al . and the PiNS study compared patients with DPN, mild PDPN and moderate‐to‐severe PDPN, whereas the Italian study compared patients without DPN and patients with DPN or PDPN.…”