application) The overall goal of this research project grant (R01) is to develop a comprehensive understanding of the biophysical factors determining diabetic foot ulcer healing. Approximately 16 million Americans are known to have diabetes. Foot ulcers and their sequelae are a major source of morbidity, cause for hospitalization, and pathway to lower extremity amputation for these patients. An understanding of the biophysical determinants to heal diabetic foot ulcers is needed to improve treatment and reduce the enormous associated morbidity and suffering. The purpose of this study is to evaluate the impact of extrinsic physical and intrinsic biological factors in healing of diabetic foot ulcers. Specifically, the following hypotheses will be tested: 1) Repetitive daily loading is a more sensitive determinant of the rate of ulcer healing than peak normal pressure with total contact cast treatment (TCC); 2) Diabetic patients with slower rates of ulcer healing will have a) less sympathetic nerve activity and b) less sympathetically-controlled blood flow than patients with faster rates of ulcer healing, c) decreased sympathetic nerve activity and sympathetically-controlled blood flow are associated with decreased local tissue oxygenation; and 3) In the absence of severe hyperglycemia or clinical infection, rates of ulcer closure will be slower for patients with impaired local tissue oxygenation. 80 subjects with diabetic foot ulcers will be treated with TCC's and followed until ulcer healing or for 13 weeks. Extrinsic physical factors assessed include spatially averaged peak pressures measured with an array of capacitive sensors and repetitive loading measured with a step counter. Intrinsic biological factors measured will include sympathetic nerve activity and sympathetically-controlled blood flow, as determined by microneurography and doppler techniques, local tissue oxygenation (TCO2), glycemic control (HbA1c), and bacterial burden (quantitative bacteriology). Three-dimensional rate of ulcer healing will be measured with stereophotography and computerized image analysis techniques.

Agency
National Institute of Health (NIH)
Institute
National Institute of Nursing Research (NINR)
Type
Research Project (R01)
Project #
5R01NR007721-03
Application #
6539466
Study Section
Special Emphasis Panel (ZDK1-GRB-3 (O2))
Program Officer
Armstrong, Nell
Project Start
2000-09-30
Project End
2004-06-30
Budget Start
2002-07-01
Budget End
2003-06-30
Support Year
3
Fiscal Year
2002
Total Cost
$339,822
Indirect Cost
Name
University of Iowa
Department
Orthopedics
Type
Schools of Medicine
DUNS #
041294109
City
Iowa City
State
IA
Country
United States
Zip Code
52242
Gardner, Sue E; Hillis, Stephen L; Frantz, Rita A (2011) A prospective study of the PUSH tool in diabetic foot ulcers. J Wound Ostomy Continence Nurs 38:385-93
Rao, Smita; Saltzman, Charles L; Yack, H John (2010) Relationships between segmental foot mobility and plantar loading in individuals with and without diabetes and neuropathy. Gait Posture 31:251-5
Gardner, Sue E; Hillis, Stephen L; Frantz, Rita A (2009) Clinical signs of infection in diabetic foot ulcers with high microbial load. Biol Res Nurs 11:119-28
Rao, Smita; Saltzman, Charles; Yack, H John (2007) Segmental foot mobility in individuals with and without diabetes and neuropathy. Clin Biomech (Bristol, Avon) 22:464-71
Rao, Smita; Saltzman, Charles; Yack, H John (2006) Ankle ROM and stiffness measured at rest and during gait in individuals with and without diabetic sensory neuropathy. Gait Posture 24:295-301
Gardner, Sue E; Frantz, Rita A; Saltzman, Charles L et al. (2006) Diagnostic validity of three swab techniques for identifying chronic wound infection. Wound Repair Regen 14:548-57
Saltzman, Charles L; Hagy, Mark L; Zimmerman, Bridget et al. (2005) How effective is intensive nonoperative initial treatment of patients with diabetes and Charcot arthropathy of the feet? Clin Orthop Relat Res :185-90
Herbst, S A; Jones, K B; Saltzman, C L (2004) Pattern of diabetic neuropathic arthropathy associated with the peripheral bone mineral density. J Bone Joint Surg Br 86:378-83
Saltzman, Charles L; Zimmerman, M Bridget; Holdsworth, Ryan L et al. (2004) Effect of initial weight-bearing in a total contact cast on healing of diabetic foot ulcers. J Bone Joint Surg Am 86-A:2714-9
Hartsell, Heather D; Brand, Richard A; Frantz, Rita A et al. (2004) The effects of total contact casting materials on plantar pressures. Foot Ankle Int 25:73-8

Showing the most recent 10 out of 12 publications