Dialysis Linked to Foot Ulceration in Diabetic Patients

Laurie Barclay, MD

June 01, 2010

June 1, 2010 — Dialysis treatment is independently associated with foot ulceration in patients with diabetes and stage IV or V chronic kidney disease (CKD), according to the results of a cross-sectional study reported online May 18 in Diabetes Care.

"Foot ulceration is a serious problem for people with diabetes which additionally results in huge economic costs," write Agbor Ndip, MD, from Central Manchester University Hospitals NHS Foundation Trust in Manchester, United Kingdom, and colleagues. "Causal pathways to foot ulceration are multifactorial and involve combinations of physiologic and mechanical factors, self-care and treatment factors. Diabetic nephropathy has been identified to be an important risk factor for foot ulceration and amputation."

The goal of the study was to examine whether dialysis is an independent risk factor for foot ulceration in 326 consecutive patients with diabetes and stage IV or V CKD who were attending clinics in Manchester. Mean age was 64 years, 61% were men, 78% had type 2 diabetes, and 11% had prevalent foot ulceration.

Patients receiving dialysis treatment and those not receiving dialysis were evaluated for diabetic peripheral neuropathy (DPN), peripheral arterial disease (PAD), prior foot ulceration and amputation, and foot self-care. Logistic regression identified risk factors for prevalent foot ulceration.

Patients receiving dialysis had a higher prevalence of DPN vs patients not receiving dialysis (79% vs 65 %), PAD (64% vs 43%), prior amputations (15% vs 6.4%), prior foot ulceration (32% vs 20%), and prevalent foot ulceration (21% vs 5%; all P < .05). Factors associated with foot ulceration in univariate analyses were use of custom-made footwear (odds ratio [OR], 5.6; 95% confidence interval [CI] 2.5 - 13), dialysis (OR, 5.1; 95% CI, 2.3 - 11), prior foot ulceration (OR, 4.8; 95% CI, 2.3 - 9.8), PAD (OR, 2.8; 95% CI 1.3 - 6.0), and years of diabetes (OR, 1.0; 95% CI, 1.0 - 1.1; P < .01 for all).

However, the only factors associated with prevalent foot ulceration in multivariate logistic regression were dialysis treatment (OR, 4.2; 95% CI, 1.7 - 10; P = .002) and prior foot ulceration (OR, 3.1; 95% CI, 1.3 - 7.1; P = .008).

"Dialysis treatment was independently associated with foot ulceration," the study authors write. "Guidelines should highlight dialysis as an important risk factor for foot ulceration requiring intensive foot care."

Limitations of this study include cross-sectional design, precluding inference about causal relationships; lack of generalizability to nonwhite ethnic groups; insufficient power to compare the site of foot ulceration in dialysis and no-dialysis groups. In addition, the site and severity of peripheral edema and the severity of PAD were not systematically evaluated.

"Our findings have important clinical implications as they alert health care practitioners that dialysis is an independent risk factor for foot ulceration thus requiring extra vigilance and foot care," the study authors conclude. "Current diabetes guidelines and recommendations fail to recognise the strength of the link between dialysis-treatment and foot ulceration. Our findings suggest that in terms of foot ulcer risk, dialysis treatment should be ranked equivalent to a history of previous foot ulceration (i.e. risk category 3, IWGDF [International Working Group on the Diabetic Foot] classification [risk 0 (no risk factors), risk 1 (neuropathy and no other risk factors), risk 2 (PAD with/without neuropathy), risk 3 (current foot ulcer, history of foot ulcer or amputation), and risk 4 (current foot ulcer, history of foot ulcer, or prior amputation)])."

Diabetes UK supported this study, as well as the Manchester NIHR Biomedical Research Centre and the Manchester Academic Health Science Centre. Some of the study authors have disclosed various financial relationships with Higher Education Funding Council for England; National Institutes of Health; KCI; Diabetica Solutions; LaseCure; National Healing; Advanced Biohealing; Pfizer; Cytomedix, Inc; and/or Diabetic Solutions.

Diabetes Care. Published online May 18, 2010.