%0 Journal Article
%T Undercarboxylated osteocalcin does not correlate with insulin resistance as assessed by euglycemic hyperinsulinemic clamp technique in patients with type 2 diabetes mellitus
%A Katsuhito Mori
%A Masanori Emoto
%A Koka Motoyama
%A Eiko Lee
%A Shinsuke Yamada
%A Tomoaki Morioka
%A Yasuo Imanishi
%A Tetsuo Shoji
%A Masaaki Inaba
%J Diabetology & Metabolic Syndrome
%D 2012
%I BioMed Central
%R 10.1186/1758-5996-4-53
%X We measured serum ucOC levels in 129 patients with type 2 diabetes. Insulin resistance was assessed using the euglycemic hyperinsulinemic clamp technique. The insulin resistance indices used were the M value, which is the total body glucose disposal rate, and the M/I value, which is the M value adjusted for the steady state plasma insulin level. ucOC levels were not correlated with the M value (¦Ñ = £¿0.013, p = 0.886) or the M/I value (¦Ñ = 0.001, p = 0.995).We found no association between ucOC levels and insulin resistance in patients with type 2 diabetes mellitus.Emerging evidence has shed light on the role of bone as an endocrine organ that regulates energy metabolism [1,2]. Among its intermediate factors, bone-derived osteocalcin (OC) has attracted much attention. Recent vigorous studies have demonstrated that OC regulates both insulin secretion and insulin sensitivity [3-5]. Clinically, serum OC level is utilized as a bone formation marker, because OC is synthesized by osteoblast [1]. Therefore, vitamin-K dependent gamma-carboxylated OC, which binds to hydroxyapatite in bone [1], has been considered to be active in bone metabolism. Intriguingly, in vitro and in vivo studies have clearly demonstrated that undercarboxylated form of OC (ucOC) is involved in glucose metabolism in rodents [3-5]. Most studies in humans have suggested that higher OC levels are associated with better metabolic profiles as assessed by cretain parameters, such as fasting plasma glucose (FPG), hemoglobin A1c (HbA1c), the homeostasis model assessment (HOMA)¨C¦Â, and the HOMA of insulin resistance (HOMA-IR) [1,2]. However, data that examines the correlation between ucOC kevels and glucose metabolism is limited. Kanazawa et al. reported that ucOC levels were negatively associated with FPG and HbA1c [6]. Focusing on insulin resistance, one report suggested that total OC and carboxylated OC levels, and not ucOC levels, were associated with the HOMA-IR [7]. In contrast, Iki et al. found an inverse
%K Osteocalcin
%K Undercarboxylated osteocalcin
%K Insulin resistance
%K Type 2 diabetes
%U http://www.dmsjournal.com/content/4/1/53