History of and factors associated with diabetic foot ulcers in Norway: The Nord-Trøndelag Health Study

Aims: To determine the proportion of people with diabetes mellitus reporting a history of foot ulcer and to investigate factors associated with this adverse outcome. Methods: All inhabitants aged 20 years and older residing in a large geographic region were invited to participate in the Nord-Trøndelag Health Study, 71% (n=65,604) attended. Those reporting diabetes (n=1,972) were invited to take part in an ancillary study on diabetes. Based on 1,494 responses to the question: "Have you had a foot ulcer that required more than three weeks to heal", the proportion with a history of foot ulcer was estimated. Results: The overall proportion with a history of foot ulcer was 10.4% (95% CI 8.8-11.9%). In the final multivariate logistic regression model, significant factors for a foot ulcer history included age ⩾75 years (OR 1.8, 95% CI 1.2-2.8), height (men>175 cm, women>161 cm) (1.9, 95% CI 1.3-2.8), gender (male) (1.5, 95% CI 1.03-2.2), using insulin (1.6, 95% CI 1.1-2.4), and macrovascular complications (1.8, 95% CI 1.2-2.6). Conclusions: The proportion of people reporting a history of foot ulcer in this population-based study exceeded the proportion of foot ulcer history reported previously. Height as a correlate has been occasionally reported in previous studies and needs further attention. Associated factors for a foot ulcer history help identify individuals who may be at particular risk of this adverse outcome.