The value of loss of protective pain sensation in predicting afirst ulceration of the foot in people with diabetes.

Abstract

To determine both the risk of first ever ulcer (FEU) and its time to onset in a population which had loss of protective sensation (LOPS) in the foot either with or without loss of protective pain (LOPP). People with diabetes and LOPS without history of FEU presenting in a specialist clinic were included. LOPP was diagnosed by reduced vibration perception and pain perception by using a pinprick simulator. Participants were followed by routine foot checks, phone interview or by letter until the occurrence of a FEU, death or the end of observation period. Survival functions in LOPP strata were compared by log rank test. The hazard ratio (HR) of an FEU in people with compared to people without LOPP was estimated using Cox regression. Time to first ulcer was estimated using the framework of an accelerated failure time (AFT) model. One hundred and thirty participants were followed up for a median of 48.3 months. Pain perception was lost in 55.4%. Eighteen people with LOPP developed a FEU (25.0%) as opposed to six (10.3%) of those with no LOPP (p = 0.02). Age-sex-adjusted HR for FEU was 3.0 (p = 0.02) for people with compared to people without LOPP. Age-sex-adjusted time to FEU for people with LOPP was approximately half (p = 0.03) than people without LOPP. It is suggested that estimation of LOPP is included in routine practice because of its high predictive value for a FEU.