title: Differences in vitamin D concentration between metabolically healthy and unhealthy obese adults: associations with inflammatory and cardiometabolic markers in 4391 subjects.
abstract: OBJECTIVE
  This study aimed to compare concentrations of serum 25-hydroxy vitamin D and inflammatory markers in metabolically healthy obesity (MHO) and metabolically unhealthy obesity (MUO), and to determine whether the relationship between vitamin D levels and both cardiometabolic and inflammatory markers differs between MHO and MUO.
  
  
  METHODS
  This cross-sectional study comprised 4391 obese subjects aged>18 years. A panel of cardiometabolic and inflammatory markers, including anthropometric variables, glycaemic indices, lipid profiles, liver enzymes, homocysteine, C-reactive protein (CRP), fibrinogen and serum 25-hydroxy vitamin D levels, was investigated. All cardiometabolic and inflammatory markers in MHO and MUO as well as in vitamin D deficiency were compared.
  
  
  RESULTS
  Prevalence of MHO was 41.9% in our obese subjects using International Diabetes Federation criteria. Considering insulin resistance and inflammation, the prevalence of MHO was 38.4%. Individuals with MHO had significantly higher vitamin D concentrations compared with MUO, and this difference in vitamin D status persisted after accounting for BMI and waist circumference. Subjects with MHO had significantly better metabolic status, lower liver enzymes, lower inflammatory markers and higher serum 25-hydroxy vitamin D than those with MUO. Associations between vitamin D levels and inflammatory and cardiometabolic markers differed according to MHO/MUO status. Among MUO subjects, vitamin D deficiency was associated with higher liver marker and homocysteine levels. Serum vitamin D was negatively associated with fasting plasma glucose and HbA1c in MHO only.
  
  
  CONCLUSIONS
  Serum 25-hydroxy vitamin D levels were lower in MUO vs MHO, and reduced vitamin D concentrations were more strongly associated with cardiometabolic and inflammatory markers in MUO than in MHO subjects. These findings suggest that a deficiency in vitamin D could be a key component of MUO.
authors.affiliation: Endocrinology and Metabolism Research Center (EMRC), Vali-Asr Hospital, School of Medicine, Tehran University of Medical Sciences, P.O. Box 13145-784, Tehran, Iran. Electronic address: esteghamati@tums.ac.ir.
authors.forename: A
authors.initials: A
authors.lastname: Esteghamati
authors.affiliation: Endocrinology and Metabolism Research Center (EMRC), Vali-Asr Hospital, School of Medicine, Tehran University of Medical Sciences, P.O. Box 13145-784, Tehran, Iran; Department of Public Health, Tehran University of Medical Sciences, Iran. Electronic address: z-aryan@student.tums.ac.ir.
authors.forename: Z
authors.initials: Z
authors.lastname: Aryan
authors.affiliation: Endocrinology and Metabolism Research Center (EMRC), Vali-Asr Hospital, School of Medicine, Tehran University of Medical Sciences, P.O. Box 13145-784, Tehran, Iran. Electronic address: esteghamati@tums.ac.ir.
authors.forename: A
authors.initials: A
authors.lastname: Esteghamati
authors.affiliation: Endocrinology and Metabolism Research Center (EMRC), Vali-Asr Hospital, School of Medicine, Tehran University of Medical Sciences, P.O. Box 13145-784, Tehran, Iran. Electronic address: nakhjavanim@tums.ac.ir.
authors.forename: M
authors.initials: M
authors.lastname: Nakhjavani
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D001794:Blood Pressure; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000378:metabolism; D002318:Cardiovascular Diseases / Q000097:blood* / Q000503:physiopathology / Q000517:prevention & control; D003430:Cross-Sectional Studies; D005260:Female; D005340:Fibrinogen / Q000378:metabolism; D006442:Glycated Hemoglobin / Q000378:metabolism; D006710:Homocysteine / Q000097:blood; D006801:Humans; D007249:Inflammation / Q000097:blood* / Q000503:physiopathology; D007333:Insulin Resistance; D007492:Iran / Q000453:epidemiology; D008055:Lipids / Q000097:blood; D008099:Liver / Q000201:enzymology*; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood* / Q000503:physiopathology / Q000517:prevention & control; D008875:Middle Aged; D009765:Obesity / Q000097:blood* / Q000453:epidemiology / Q000503:physiopathology; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D055105:Waist Circumference
chemical_list: D015415:Biomarkers; D002097:C-Reactive Protein; D005340:Fibrinogen; D006442:Glycated Hemoglobin; D006710:Homocysteine; D008055:Lipids; D014807:Vitamin D; C517652:hemoglobin A1c protein, human; C104450:25-hydroxyvitamin D
keywords: Metabolic syndrome; Obesity; Vitamin D