title: Vitamin D levels and bone turnover markers are not related to non-alcoholic fatty liver disease in severely obese patients.
abstract: BACKGROUND
  Morbidly obese patients usually present vitamin D deficiency or secondary hyperparathyroidism. Low vitamin D levels have been recently related to non-alcoholic fatty liver disease (NAFLD). The aim of this study was to analyse the relationship between vitamin D, bone turnover markers and non-alcoholic fatty liver disease and metabolic syndrome in severely obese patients.
  
  
  METHODS
  One hundred and ten patients who underwent bariatric surgery were included. Liver biopsy was taken during surgery. Two univariate analyses were carried out in order to i) analyse the relationship between liver histology and vitamin D-bone turnover markers (intact parathyroid hormone (PTH), osteocalcin and Carboxy-terminal collagen crosslinks) and ii) establish the association between metabolic syndrome components-insulin resistance (HOMA) and vitamin D-bone turnover markers.
  
  
  RESULTS
  70% of the patients had lower levels of vitamin D or secondary hyperparathyroidism. None of the components of liver histology were associated with levels of vitamin D or with bone turnover parameters. Patients with metabolic syndrome showed lower levels of PTH and osteocalcin (72,42 (29,47) vs 61.25(19.59) p-Value: 0.022; 19.79 (10.43) vs 16.87(10.25) p-Value: 0,028, respectively). HOMA was not related to Vitamin D or bone turnover markers.
  
  
  CONCLUSIONS
  Low levels of vitamin D or hyperparathyroidism are common in severely obese patients. Vitamin D and bone metabolism markers were associated neither to NAFLD nor with metabolic syndrome in our series of obese morbid patients.
authors.affiliation: High Risk Obesity Unit, Complejo Asistencial Universitario de León. Endocrinology and Nutrition Department, Complejo Asistencial Universitario de León.. rudiro81@gmail.com.
authors.forename: Rubén
authors.initials: R
authors.lastname: Díez Rodríguez
authors.affiliation: High Risk Obesity Unit, Complejo Asistencial Universitario de León.Digestive Disease Department, Complejo Asistencial Universitario de León.. rudiro81@gmail.com.
authors.forename: María D
authors.initials: MD
authors.lastname: Ballesteros Pomar
authors.affiliation: High Risk Obesity Unit, Complejo Asistencial Universitario de León. Endocrinology and Nutrition Department, Complejo Asistencial Universitario de León.. rudiro81@gmail.com.
authors.forename: Alicia
authors.initials: A
authors.lastname: Calleja Fernández
authors.affiliation: High Risk Obesity Unit, Complejo Asistencial Universitario de León. Immunology Department, Complejo Asistencial Universitario de León. León, Spain.. rudiro81@gmail.com.
authors.forename: Sara
authors.initials: S
authors.lastname: Calleja Antolin
authors.affiliation: High Risk Obesity Unit, Complejo Asistencial Universitario de León. Endocrinology and Nutrition Department, Complejo Asistencial Universitario de León.. rudiro81@gmail.com.
authors.forename: Isidoro
authors.initials: I
authors.lastname: Cano Rodríguez
authors.affiliation: Digestive Disease Department, Complejo Asistencial Universitario de León.. rudiro81@gmail.com.
authors.forename: Pedro
authors.initials: P
authors.lastname: Linares Torres
authors.affiliation: Digestive Disease Department, Complejo Asistencial Universitario de León.. rudiro81@gmail.com.
authors.forename: Francisco
authors.initials: F
authors.lastname: Jorquera Plaza
authors.affiliation: High Risk Obesity Unit, Complejo Asistencial Universitario de León.Digestive Disease Department, Complejo Asistencial Universitario de León.. rudiro81@gmail.com.
authors.forename: José Luis
authors.initials: JL
authors.lastname: Olcoz Goñi
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D015519:Bone Density; D016723:Bone Remodeling; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease / Q000378:metabolism*; D009767:Obesity, Morbid / Q000378:metabolism*; D015675:Osteocalcin / Q000378:metabolism; D010281:Parathyroid Hormone / Q000378:metabolism; D014807:Vitamin D / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D010281:Parathyroid Hormone; D015675:Osteocalcin; D014807:Vitamin D