[Serum levels of retinol-binding protein-4 and its association with metabolic syndrome in first-degree relatives of type 2 diabetes mellitus].
OBJECTIVE
To evaluate serum levels of retinol-binding protein-4 (RBP-4) in first-degree relatives (FDR) of type 2 diabetes mellitus (T2DM) with different glucose tolerance status and to observe its correlation to metabolic syndrome (MS).


METHODS
Subjects from FDR of T2DM, including 174 with NGT, 55 with IGT/IFG, and 71 patients with newly diagnosed of T2DM and 114 subjects without diabetic family history as control group [(18 +/- 7) microg/ml vs (22 +/- 8) microg/ml, (NC) [(18 +/- 7) microg/ml vs (22 +/- 8) microg/ml, were recruited. Serum RBP-4 level was measured by radioimmunoassay. Insulin resistance was evaluated by the homeostasis model assessment (HOMA-IR). MS was diagnosed according to 2005 IDF consensus.


RESULTS
(1) Serum RBP-4 levels in NC, NGT, IFG/IGT and T2DM groups were (18 +/- 7), (22 +/- 8), (24 +/- 9) and (26 +/- 9) microg/ml respectively. Serum RBP-4 was significantly elevated in NGT group of diabetic FDR as compared with NC group [(26 +/- 9) microg/ml vs (24 +/- 9) microg/ml], and increased with the severity of glucose intolerance. However, no difference was found between serum RBP-4 in the IFG/IGT and T2DM groups. (2) When the distribution of RBP-4 was stratified into quartiles (Q1-Q4), subjects in the top quartile (Q4) was not only associated with greater risk for impaired glucose regulation as compared with Q1 OR = 5.26) , but also significantly with risk for hypertension (OR = 1.96), dyslipidemia (OR = 4.14), obesity (OR = 2.18) and MS (OR = 4.30).


CONCLUSIONS
(1) Serum RBP-4 levels in FDR of T2DM were elevated significantly even before the development of impaired glucose regulation and were further increased with severity of glucose tolerance, suggesting a possible role of RBP-4 in the early pathogenesis of T2DM. (2) Serum RBP-4 level was closely related to MS.
Gao
Shan
S
Department of Endocrinology, Jingxi Branch, Chaoyang Hospital, Capital University of Medical Sciences, Beijing 100043, China.
Li
Ming
M
Wang
Zhi
Z
Zhang
Xiu-Juan
XJ
Li
Hai-Hui
HH
Zhang
Kui
K
Wu
Cong-Yuan
CY
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000473:pathology; D005260:Female; D006801:Humans; D007333:Insulin Resistance; D008297:Male; D024821:Metabolic Syndrome / Q000209:etiology / Q000378:metabolism*; D008875:Middle Aged; D054839:Retinol-Binding Proteins, Plasma / Q000378:metabolism*; D011795:Surveys and Questionnaires
D001786:Blood Glucose; C101326:RBP4 protein, human; D054839:Retinol-Binding Proteins, Plasma