CYP27A1 and type 2 diabetes mellitus: Based on a meta-analysis Hygum et al. found that both markers of bone formation (N-terminal propeptide of type I procollagen (PINP) and osteocalcin (OC)) and markers of bone resorption (C-terminal cross-linking telopeptide of type I collagen (CTX) and isoform 5b of tartrate resistant acid phosphatase (TRACP5b)) were decreased in T2DM [11].