Decline in Diabetic Foot Ulcers Observed in Patients with Type 2 Diabetes

Frank de Vries, PharmD

Although diabetic foot ulcers (DFU) are considered both a major cause of patient suffering and high healthcare costs in the treatment of diabetes, low predictive power of DFUs makes primary prevention practices extremely limited for clinicians and patients.

Stemming from this challenge, a recent study examined incidence rates (IR) and changes over time for the first DFU in patients with diabetes seen in primary care in the United Kingdom.

Led by Frank de Vries, PharmD, PhD, Division of Pharmacoepidemiology & Clinical Pharmacology, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, investigators observed a decline in diabetic foot ulcers (DFU) in patients with type 2 diabetes (T2D), but no changes were observed in patients with type 1 diabetes (T1D).

Methods

Investigators used data from the Clinical Practice Research Datalink (CPRD) GOLD, which contains medical records of 674 primary care practices in the United Kingdom.

Criteria for inclusion consisted of a diagnosis of either T1D or T2D with a prescription of either insulin or a non-insulin anti-diabetic drug (NIAD) from the start of the database (1987) until the end of the study period (2017).

The primary outcomes consisting of the average yearly IR of first registered DFU in people with T1D and T2D and changes over time were analyzed from 2007 and onwards. Additionally, secondary outcomes included hospitalization-risk in relation to the first registered DFU.

At inclusion, data on sex, age, body mass index (BMI), smoking status, and history of diabetes related complications (neuropathy, retinopathy, nephropathy, and Charcot neuroarthropathy) were collected.

In terms of statistical analysis, changes over time in the IRs were described through Poisson regression expressed as incidence rate ratio per year (IRR) and logistic regression expressed as odds ratios (OR).

Findings

A total of 129,624 people with diabetes were identified through a prescription for insulin or an NIAD.

During the study period, the yearly IR of first registered DFU varied from 1.0 (95% CI, 0.4 - 2.6) to 2.4 (95% CI, 1.3 - 4.7) per 1000 person-years in patients with T1D. In patients with T2D, it varied from 1.4 (95% CI, 1.2 - 1.7) to 3.6 (95% CI, 3.2 - 4.1) per 1000 person-years.

de Vries and colleagues noted that the mean IR of first registered DFU was 2.5 (95% CI, 2.1 - 2.9) per 1000 person-years for patients with T2D and 1.6 (1.3 - 1.9) per 1000 person-years for patients with T1D.

Over time, no change in IR was observed in patients with T1D (IRR: 0.96; 95% CI, 0.89 - 1.04), but IRs declined for patients with T2D (IRR: 0.97; 95% CI, 0.96 - 0.99).

Additionally, the average proportion of patients with T2D hospitalized with first registered DFU was 8.2% (SD: 4.8) out of the total population with first DFU. The average 1-year mortality-risk for people with T2D and first registered DFU was 11.7%.

Over time, both average hospitalizations (OR: 0.89; 95% CI, 0.84 - 0.94) and mortality (OR: 0.94; 95% CI, 0.89 - 0.99) declined.

Takeaways

“The decline in DFUs, hospitalizations and mortality, suggests that prevention and care of the first ulcer has improved for this group in primary care in the UK,” investigators wrote.

The study, “Incidence, hospitalization and mortality and their changes over time in people with a first ever diabetic foot ulcer,” was published in Diabetic Medicine.