title: Increased serum calcium levels and risk of type 2 diabetes in individuals at high cardiovascular risk.
abstract: OBJECTIVE
  Insulin resistance and secretion depend on calcium homeostasis. Cross-sectional studies have associated elevated serum calcium levels with markers of impaired glucose metabolism. However, only one prospective cohort study has demonstrated an increased risk of diabetes in individuals with increased serum calcium concentrations. The aim of the current study was to prospectively investigate the association between albumin-adjusted serum calcium concentrations and type 2 diabetes in subjects at high cardiovascular risk.
  
  
  METHODS
  Prospective assessment of participants from two Spanish PREDIMED study centers where serum calcium levels were measured at baseline and yearly during follow-up. Multivariate-adjusted Cox regression models were fitted to assess associations between baseline and changes during follow-up in serum calcium levels and relative risk of diabetes incidence.
  
  
  RESULTS
  After a median follow-up of 4.78 years, 77 new cases of type 2 diabetes occurred. An increase in serum calcium levels during follow-up was related to an increased risk of diabetes. In comparison with individuals in the lowest tertile (-0.78 ± 0.29 mg/dL), the hazard ratio (HR) and 95% CI for diabetes incidence in individuals in the higher tertile of change (0.52 ± 0.13 mg/dL) during follow-up was 3.48 (95% CI 1.48-8.17; P for trend = 0.01). When albumin-adjusted serum calcium was analyzed as a continuous variable, per 1 mg/dL increase, the HR of diabetes incidence was 2.87 (95% CI 1.18-6.96; P value = 0.02). These associations remained significant after individuals taking calcium supplements or having calcium levels out of normal range had been excluded.
  
  
  CONCLUSIONS
  An increase in serum calcium concentrations is associated with an increased risk of type 2 diabetes in individuals at high cardiovascular risk.
authors.affiliation: Human Nutrition Unit, Faculty of Medicine and Health Sciences, Institut d'Investigació Sanitària Pere Virgili, Universitat Rovira i Virgili, Reus, Spain CIBERobn Physiopathology of Obesity and Nutrition, Institute of Health Carlos III, Madrid, Spain.
authors.forename: Nerea
authors.initials: N
authors.lastname: Becerra-Tomás
authors.affiliation: CIBERobn Physiopathology of Obesity and Nutrition, Institute of Health Carlos III, Madrid, Spain Department of Internal Medicine, August Pi i Sunyer Institute of Biomedical Research, Hospital Clinic, University of Barcelona, Barcelona, Spain.
authors.forename: Ramón
authors.initials: R
authors.lastname: Estruch
authors.affiliation: Human Nutrition Unit, Faculty of Medicine and Health Sciences, Institut d'Investigació Sanitària Pere Virgili, Universitat Rovira i Virgili, Reus, Spain CIBERobn Physiopathology of Obesity and Nutrition, Institute of Health Carlos III, Madrid, Spain.
authors.forename: Mònica
authors.initials: M
authors.lastname: Bulló
authors.affiliation: CIBERobn Physiopathology of Obesity and Nutrition, Institute of Health Carlos III, Madrid, Spain Department of Internal Medicine, August Pi i Sunyer Institute of Biomedical Research, Hospital Clinic, University of Barcelona, Barcelona, Spain.
authors.forename: Rosa
authors.initials: R
authors.lastname: Casas
authors.affiliation: Human Nutrition Unit, Faculty of Medicine and Health Sciences, Institut d'Investigació Sanitària Pere Virgili, Universitat Rovira i Virgili, Reus, Spain CIBERobn Physiopathology of Obesity and Nutrition, Institute of Health Carlos III, Madrid, Spain.
authors.forename: Andrés
authors.initials: A
authors.lastname: Díaz-López
authors.affiliation: Human Nutrition Unit, Faculty of Medicine and Health Sciences, Institut d'Investigació Sanitària Pere Virgili, Universitat Rovira i Virgili, Reus, Spain CIBERobn Physiopathology of Obesity and Nutrition, Institute of Health Carlos III, Madrid, Spain.
authors.forename: Josep
authors.initials: J
authors.lastname: Basora
authors.affiliation: CIBERobn Physiopathology of Obesity and Nutrition, Institute of Health Carlos III, Madrid, Spain Cardiovascular Risk and Nutrition (Regicor Study Group), Hospital del Mar Medical Research Institute, Barcelona Biomedical Research Park, Barcelona, Spain.
authors.forename: Montserrat
authors.initials: M
authors.lastname: Fitó
authors.affiliation: CIBERobn Physiopathology of Obesity and Nutrition, Institute of Health Carlos III, Madrid, Spain Department of Clinical Sciences, University of Las Palmas de Gran Canaria, Las Palmas, Spain.
authors.forename: Lluis
authors.initials: L
authors.lastname: Serra-Majem
authors.affiliation: Human Nutrition Unit, Faculty of Medicine and Health Sciences, Institut d'Investigació Sanitària Pere Virgili, Universitat Rovira i Virgili, Reus, Spain CIBERobn Physiopathology of Obesity and Nutrition, Institute of Health Carlos III, Madrid, Spain jordi.salas@urv.cat.
authors.forename: Jordi
authors.initials: J
authors.lastname: Salas-Salvadó
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D002118:Calcium / Q000097:blood*; D002318:Cardiovascular Diseases / Q000453:epidemiology* / Q000209:etiology; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000453:epidemiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012306:Risk; D012307:Risk Factors
chemical_list: D015415:Biomarkers; D002118:Calcium