We have read the article by Moulik, Mtonga, and Gill (1) with much interest. Their findings are that increased mortality associated with foot ulceration is not influenced by underlying risk factors, namely peripheral neuropathy and peripheral vascular disease, and that it is only influenced by the age of the patient at presentation. There are points in this study regarding the method, the presentation of outcomes data, and the conclusion that we would like to highlight, and we would be grateful for a response from the authors.
A patient presenting with a new ulcer may have a history of ulceration. The period from first ulceration could therefore be potentially much longer than that measured in this group of patients presenting with new foot ulcers. Does the term “new onset” refer, therefore, to those patients with no history of ulceration or to those with current ulceration of short duration? The identification of significant vascular disease in patients with diabetic foot ulceration cannot be based solely on the detection of foot pulses because this is unreliable (2). More accurate evaluation requires a second method of assessment, such as the calculation of the ankle-brachial or toe-brachial pressure index and color duplex imaging (3). In the conclusion, it is noted that the high rates of morbidity and mortality in those patients with no identifiable ischemia or neuropathy were likely due to failure to detect underlying disease. Indeed, the amputation rates in this group were much higher than those of the neuropathic group and approached those of the ischemic group. Was further information obtained on the vascular status of the nonischemic patients who subsequently required amputation?
The data on the 5-year mortality rates in the groups appear inconsistent. In the article, Table 1 shows the number and percentage of deaths as 21 (25%) vs. 20 (46%) for the neuropathic and ischemic groups, respectively. The 5-year mortality figures in Table 3, however, show values of 21 (45%) and 20 (56%), respectively. It is unclear why these figures are different. If the Table 3 figures are incorrect, then the age-related adjustment may be invalid and ischemic disease would remain a significantly greater risk factor for subsequent mortality than neuropathy. This is further reinforced by the high number of deaths associated with vascular disease and would then be consistent with the significantly higher amputation rates seen in patients with ischemia versus neuropathy alone.
