Foot bone mass and analysis of calcium metabolism in diabetic patients affected by severe neuropathy

Charcot neuro osteoarthropathy (NAC) is a devastating foot complication which is associated to peripheral neuropathy. The aim of this study was to investigate the changes in foot bone mass in patients with peripheral neuropathy and to correlate this with calcium metabolism in diabetes.

The study included three groups of patients enrolled consecutively: group 1 consisted of 28 diabetic patients, affected by both peripheral neuropathy and autonomic neuropathy as well as monolateral foot ulcer; group 2 consisted of 10 diabetic patients without neuropathy and without foot ulcerations; group 3 consisted of 10 healthy people. In all patients we studied calcium and bone metabolism and quantitative ultrasonography (QUS) of calcaneal bone was performed in both feet in each subject. Calcium and bone metabolism were assessed by the assay of serum parathyroid hormone (PTH), serum calcium, serum phosphorus, serum magnesium, serum bone alkaline phosphatase isoenzyme and urinary excretion of deoxypyridinoline DPD.

In patients with neuropathic ulceration, QUS showed a decrease in bone density in the affected foot: mean T score in the normal foot was -0.54+/-0,26 (mean+/-ESM) while mean T score in the foot with the ulcer was -1.23+/-0.31 (mean+/-ESM) (P=0.004). In diabetic patients without neuropathy the authors did not find any difference in T score between the two feet. Moreover, the T score in the feet in these patients didn't show any differences in comparison to the T score of the healthy foot in neuropathic patients. The T-score in the feet of normal subjects didn't show any difference in respect to the healthy feet in diabetic patients. No difference of serum parameters of calcium metabolism was seen among the groups, while, among the parameters of bone metabolism, B-ALP was elevated in patients with foot ulcer.

These data suggest that bone demineralization is associated to peripheral neuropathy with foot ulceration. MOC can represent a way to personalized therapy of patients who are prone to fractures and to the development of NAC.