The foot in type 2 diabetes: is there a link between vascular calcification and bone mineral density?

To examine the relationship between vascular calcification in the foot (FVC) and bone mineral density (BMD) in the heel of type 2 diabetes mellitus (DM) subjects.

65 subjects with type 2 DM and serum creatinine<125 μmol/l underwent CT scanning of the foot to assess FVC and dual energy X ray absorptiometry (DEXA) scan to assess heel BMD. Routine biochemistry including osteoprotegerin (OPG) and Receptor activator of nuclear factor kappa-B ligand (RANKL) was also carried out.

The proportion of subjects with FVC was 43%, whilst 40% had low BMD (T score<-1.0). Age, neuropathy and 25 hydroxyvitamin D were independent predictors of FVC. Body-weight, eGFR, 25 hydroxyvitamin D, OPG, and total cholesterol were independent predictors of low heel BMD. There was no correlation between albuminuria and BMD or FVC. There was no difference in heel BMD between those with FVC and those without, but those with frank osteoporosis were significantly more likely to have FVC than those with higher BMD.

There is no clear-cut association between FVC and low BMD in type 2 DM with relatively well-preserved renal function. Age, neuropathy, eGFR, hyperlipidemia, body-weight, 25 hydroxyvitamin D and OPG play a complex role in their pathogenesis.