title: Investigation of vitamin D status and its correlation with insulin resistance in a Chinese population.
abstract: OBJECTIVE
  Although many studies worldwide have focused on the relationship between vitamin D and insulin resistance, results remain controversial. Furthermore, concentrations of serum 25-hydroxyvitamin D (25(OH)D) in the Chinese population are unclear. We aimed to investigate vitamin D status and its correlation with insulin resistance among a Chinese adult population.
  
  
  METHODS
  Serum 25(OH)D, fasting blood glucose, fasting insulin, glycated Hb (HbA1c) and other metabolic parameters were assessed. Neck circumference, waist circumference, hip circumference, weight and height were also measured. Lifestyle factors including smoking and drinking status were obtained. Diabetes mellitus was diagnosed by HbA1c according to the 2010 American Diabetes Association criteria.
  
  
  METHODS
  Eastern China.
  
  
  METHODS
  Of 7200 residents included, 6597 individuals were ultimately analysed.
  
  
  RESULTS
  We enrolled 2813 males (mean age 52·7 (sd 13·5) years) and 3784 females (52·3 (sd 13·5) years); mean serum 25(OH)D concentration was 43·1 (sd 11·6) and 39·6 (sd 9·8) nmol/l, respectively. Additionally, 83·3 % of participants were 25(OH)D deficient. A significant difference in 25(OH)D was observed between males and females in winter and spring (P<0·001). Furthermore, 25(OH)D concentrations were inversely associated with the homeostasis model assessment of insulin resistance (HOMA-IR) in the overweight and pre-diabetic populations. After adjusting for several variables, 25(OH)D was significantly associated with HOMA-IR in winter. When 25(OH)D values were categorized into quartiles, HOMA-IR was significantly associated with decreasing 25(OH)D.
  
  
  CONCLUSIONS
  The majority of the Chinese population was vitamin D deficient and this deficiency was negatively associated with insulin resistance, particularly in the overweight and pre-diabetic populations. Moreover, these associations might be more evident in the winter.
authors.affiliation: 1Institute and Department of Endocrinology and Metabolism,Shanghai Ninth People's Hospital Affiliated to Shanghai Jiaotong University School of Medicine,Shanghai 200011,People's Republic of China.
authors.forename: Bing
authors.initials: B
authors.lastname: Han
authors.affiliation: 2Department of Biostatistics,Shanghai Jiaotong University School of Medicine,Shanghai 200025,People's Republic of China.
authors.forename: Xiaojin
authors.initials: X
authors.lastname: Wang
authors.affiliation: 1Institute and Department of Endocrinology and Metabolism,Shanghai Ninth People's Hospital Affiliated to Shanghai Jiaotong University School of Medicine,Shanghai 200011,People's Republic of China.
authors.forename: Ningjian
authors.initials: N
authors.lastname: Wang
authors.affiliation: 1Institute and Department of Endocrinology and Metabolism,Shanghai Ninth People's Hospital Affiliated to Shanghai Jiaotong University School of Medicine,Shanghai 200011,People's Republic of China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Li
authors.affiliation: 1Institute and Department of Endocrinology and Metabolism,Shanghai Ninth People's Hospital Affiliated to Shanghai Jiaotong University School of Medicine,Shanghai 200011,People's Republic of China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Chen
authors.affiliation: 1Institute and Department of Endocrinology and Metabolism,Shanghai Ninth People's Hospital Affiliated to Shanghai Jiaotong University School of Medicine,Shanghai 200011,People's Republic of China.
authors.forename: Chunfang
authors.initials: C
authors.lastname: Zhu
authors.affiliation: 1Institute and Department of Endocrinology and Metabolism,Shanghai Ninth People's Hospital Affiliated to Shanghai Jiaotong University School of Medicine,Shanghai 200011,People's Republic of China.
authors.forename: Yingchao
authors.initials: Y
authors.lastname: Chen
authors.affiliation: 1Institute and Department of Endocrinology and Metabolism,Shanghai Ninth People's Hospital Affiliated to Shanghai Jiaotong University School of Medicine,Shanghai 200011,People's Republic of China.
authors.forename: Fangzhen
authors.initials: F
authors.lastname: Xia
authors.affiliation: 1Institute and Department of Endocrinology and Metabolism,Shanghai Ninth People's Hospital Affiliated to Shanghai Jiaotong University School of Medicine,Shanghai 200011,People's Republic of China.
authors.forename: Xiaoqi
authors.initials: X
authors.lastname: Pu
authors.affiliation: 1Institute and Department of Endocrinology and Metabolism,Shanghai Ninth People's Hospital Affiliated to Shanghai Jiaotong University School of Medicine,Shanghai 200011,People's Republic of China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Cang
authors.affiliation: 1Institute and Department of Endocrinology and Metabolism,Shanghai Ninth People's Hospital Affiliated to Shanghai Jiaotong University School of Medicine,Shanghai 200011,People's Republic of China.
authors.forename: Chaoxia
authors.initials: C
authors.lastname: Zhu
authors.affiliation: 1Institute and Department of Endocrinology and Metabolism,Shanghai Ninth People's Hospital Affiliated to Shanghai Jiaotong University School of Medicine,Shanghai 200011,People's Republic of China.
authors.forename: Meng
authors.initials: M
authors.lastname: Lu
authors.affiliation: 1Institute and Department of Endocrinology and Metabolism,Shanghai Ninth People's Hospital Affiliated to Shanghai Jiaotong University School of Medicine,Shanghai 200011,People's Republic of China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Meng
authors.affiliation: 1Institute and Department of Endocrinology and Metabolism,Shanghai Ninth People's Hospital Affiliated to Shanghai Jiaotong University School of Medicine,Shanghai 200011,People's Republic of China.
authors.forename: Hui
authors.initials: H
authors.lastname: Guo
authors.affiliation: 1Institute and Department of Endocrinology and Metabolism,Shanghai Ninth People's Hospital Affiliated to Shanghai Jiaotong University School of Medicine,Shanghai 200011,People's Republic of China.
authors.forename: Chi
authors.initials: C
authors.lastname: Chen
authors.affiliation: 3Department of Endocrinology and Metabolism,Shangyu People's Hospital,Zhejiang,People's Republic of China.
authors.forename: Weiping
authors.initials: W
authors.lastname: Tu
authors.affiliation: 4Department of Endocrinology and Metabolism,Fengcheng Hospital,Shanghai,People's Republic of China.
authors.forename: Bin
authors.initials: B
authors.lastname: Li
authors.affiliation: 5Department of Endocrinology and Metabolism,Third Hospital Affiliated to Nanchang University,Jiangxi,People's Republic of China.
authors.forename: Ling
authors.initials: L
authors.lastname: Hu
authors.affiliation: 2Department of Biostatistics,Shanghai Jiaotong University School of Medicine,Shanghai 200025,People's Republic of China.
authors.forename: Bingshun
authors.initials: B
authors.lastname: Wang
authors.affiliation: 1Institute and Department of Endocrinology and Metabolism,Shanghai Ninth People's Hospital Affiliated to Shanghai Jiaotong University School of Medicine,Shanghai 200011,People's Republic of China.
authors.forename: Yingli
authors.initials: Y
authors.lastname: Lu
mesh_terms: D000328:Adult; D000368:Aged; D044466:Asian People; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D001835:Body Weight; D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000453:epidemiology*; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D014807:Vitamin D / Q000008:administration & dosage / Q000097:blood*; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology*; D055105:Waist Circumference
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D006442:Glycated Hemoglobin; D007328:Insulin; D014807:Vitamin D
keywords: Insulin resistance; Overweight; Pre-diabetes; Season; Vitamin D