Poster Presentation Australian Diabetes Society and the Australian Diabetes Educators Association Annual Scientific Meeting 2017

No difference in Alkaline phosphatase or C-reactive protein levels in Diabetic Foot Infections with or without osteomyelitis (#283)

Jita Anil 1 , Wendy A Davis 2 , Lydia Lamb 3 , Dipen Sankhesara 1 , Tina Dilevska 4 , Erica Ryan 5 , Melissa Ting 5 , Ashley Makepeace 3 , P. Gerry Fegan 3 , Carsten Ritter 4 , Laurens Manning 6 , Emma J Hamilton 3 7
  1. General Medicine, Fiona Stanley Hospital, Perth, WA, Australia
  2. Medical School, University of Western Australia, Fremantle Hospital, Perth, WA, Australia
  3. Endocrinology Department, Fiona Stanley Hospital, Perth, WA, Australia
  4. Vascular Surgery Department, Fiona Stanley Hospital, Perth, WA, Australia
  5. Podiatry Department, Fiona Stanley Hospital, Perth, WA, Australia
  6. Infectious Diseases Department, Fiona Stanley Hospital, Perth, WA, Australia
  7. Fiona Stanley Hospital, Murdoch, WA, Australia

Background

Osteomyelitis frequently complicates diabetic foot ulceration and may precipitate lower limb amputation.  Early diagnosis and treatment of osteomyelitis may reduce morbidity, however diagnosis is often delayed as there is no single ideal, readily available diagnostic investigation.  Bone turnover markers, including alkaline phosphatase (ALP), are elevated in states of increased bone formation and/ or resorption and may be useful in the diagnosis of osteomyelitis.

Aims

To determine if there is a difference in ALP or C-reactive protein (CRP) levels in diabetic foot infections with and without osteomyelitis

Methods

A retrospective observational study was conducted of 128 patients admitted to Fiona Stanley Hospital Multidisciplinary Diabetic Foot Unit (FSH MDFU) from 1st February 2015 to January 31st 2016.  Osteomyelitis was diagnosed if one or more of the following were present- positive probe to bone test, bone visible in wound base, x-ray, MRI or radioisotope imaging findings of osteomyelitis and/ or positive culture of bone specimen.  ALP and CRP levels were recorded at admission.  Patients with chronic liver disease, Paget’s disease or bone metastases were excluded from analysis.

Results

124 of 128 FSH MDFU inpatients were included in the analysis- mean age was 60.4±15.0 years and 68.5% were male.  69 patients had osteomyelitis whilst 49 did not; in 5 patients bone involvement was uncertain and data was incomplete for 1 patient.  There was no difference in ALP levels in patients with no osteomyelitis versus those with osteomyelitis [geometric mean (SD range): [93(60-145) U/L vs 110(70-173) U/L; p=0.07].   There was also no difference in CRP levels in patients with no osteomyelitis versus those with osteomyelitis [30(6-154) mg/L vs 47(12-194) mg/L; p=0.10].

Conclusions

Neither ALP nor CRP differed in patients with diabetic foot infections with and without osteomyelitis.  The utility of other bone turnover markers for the diagnosis of osteomyelitis requires further investigation.