The pressure time integral: An underused, clinically significant parameter as a determinant of neuropathic ulceration in diabetes

Abstract

Background: The purpose of this study was to evaluate plantar pressure dynamics in the occurrence of active diabetic neuropathic ulceration (DNU) and any changes in loadings occurring in individuals with a history of diabetic neuropathic ulceration (DHNU). Since current gold standard offloading strategies are not producing desirable healing outcomes and optimum ulcer prevention, this study aimed to better understand the effect of diabetic peripheral neuropathy (DPN) and ulceration on mean peak plantar pressure (MPPP) and pressure-time integral (PTI) changes.

Research question: Is there a redistribution of plantar pressure during gait in the presence of active and history of diabetic neuropathic ulceration?

Methods: A prospective, cross-sectional study was conducted, in which, eighty adult participants were divided into four groups, namely, the DM, DPN, DNU and DHNU groups. Participants were instructed to walk barefoot over a Tekscan HR Mat™ at self-selected speed. MPPP and PTI data were analysed under five forefoot anatomical landmarks and compared between individuals with and without active neuropathic ulceration.

Results: Minimal MPPP significant changes were observed between ulcerated and non-ulcerated groups, however, PTI values were significantly increased in the ulcerated groups under all plantar ulceration regions. No significant plantar pressure differences were observed between the DNU and DHNU groups. Logistic regression tests demonstrated that as PTIs under the hallux increase, the likelihood of an individual living with DPN developing ulceration increases.

Significance: A significant increase in PTI values in the presence of ulceration highlights the importance of evaluating the duration of loads under forefoot regions during gait rather than just focusing on the magnitude of pressures during ulcer management and prevention. Moreover, results show that PTI values remain high in the presence of a history of neuropathic ulceration, possibly demonstrating the value of PTI as a clinical tool over MPPP in the assessment of the high-risk diabetic foot.

Keywords: Diabetic peripheral neuropathy; Mean peak plantar pressure; Neuropathic ulceration; Pressure-time integral.