Leg Bone Geometry in Human Diabetic Neuropathy

Abstract

Bone geometry is an important indicator of bone health and fracture risk, but has not been studied in individuals with diabetic neuropathy (DN). The objective was to investigate the effects of DN on tibial cortical and medullary cross‐sectional areas (CSA) using magnetic resonance imaging. Sequential images of 1mm thick slices were acquired of the right leg from the tibial plateau to the talus in 6 individuals diagnosed with DN and 8 age‐matched (32 to 79 y) controls. The CSA (cm2) was measured (average of 2 adjacent slices) at 3 sites, 20% (proximal), 50% (middle) and 80% (distal) of tibial length, by a blinded analyzer. At the proximal site only, medullary CSA in DN was significantly greater than controls (means + SD: 6.1±1.4 vs. 4.6±0.4). Also, as a percent of total CSA, DN compared with controls had significantly less cortical (~30% vs. ~38%) and greater medullary (~69% vs. ~62%) areas. At middle and distal sites there were no differences in any measures. These preliminary results indicate bone geometry is negatively affected by DN at the proximal tibia. This may be due to lower weight bearing or mechanical loading than at the middle or distal aspects. Presumed lower levels of physical activity in DN coupled with less muscle mass and strength, but heavier body weights, may be important factors influencing bone geometry to consider in future studies, including assessment of the lesser weight‐bearing fibula.Supported by NSERC.