Welcome to another Diabetes Digest commentary, and may I wish you all a very happy new year, wherever you are.
This commentary is on a paper is by Anna Trocha et al in Germany. It examined an overlooked and non-investigated important screening tool — pain/sharp sensation.
Considering that pain is our defensive alert mechanism for preventing tissue damage, this is an important piece of work for determining ulcer risk stratification and prevention interventions.
The study was a single-centre prospective study between 2017 and 2018 that recruited 130 subjects. The aim of the study was to determine both the risk of first-ever ulcer (FEU) and its time to onset in a population who had loss of protective sensation (LOPS) in the foot, either with or without loss of protective pain (LOPP). Subjects were included if they had no history of a diabetes-related foot ulcer. They were recruited in a diabetes specialist practice either as first attenders or as part of routine follow-up.
All had a LOPS determined by a 128 Hz tuning fork. LOPP was diagnosed at baseline by a handheld pinprick-pain simulator device. the Optistim Stimulator (Firma MRC-Systems, Heidelberg, Germany). This is an optical glass fibre exerting a force of 512 mN to the plantar proximal interphalangeal joint of the second toe three times, each lasting for 1 second. This device causes a sharp sting-like discomfort or pain. Pain sensation was deemed present if felt at least once, if unfelt LOPP was present.
Subjects were followed by routine annual foot checks, phone interview or by letter and follow-up was maintained until the occurrence of a first ulcer, death or the end of the observation period. The median follow-up period was 43.2 months (range 2.4–62.8 months). During the study period, 15 subjects died, but without developing an ulcer.
Stratified Kaplan–Meier curves, Cox proportional hazards regression and accelerated failure time regression were used to determine LOPP risk for FEU.
Overall, a FEU occurred in 24 subjects while 106 remained ulcer-free during the study period. LOPP was present in 55.4% of subjects. Significantly 25% (n=18) with LOPP compared to 10.3% (n=6) with LOPS only developed a FEU (P=0.02). The Age–sex-adjusted hazard ratio for FEU was 3.0 (P=0.02) for LOPP subjects versus LOPS. Age–sex-adjusted time to FEU for people with LOPP was approximately half (P=0.03) compared with LOPS only.
This study suggests that those with LOPP and LOPS are at significantly higher risk of FEU than those with LOPS alone. This data set is small and the follow-up could be longer, but these findings should not be left without a larger and longer-term study to determine risk stratification with LOPP.