title: The influence of lithium on calcium homeostasis in older patients in daily clinical practice.
abstract: BACKGROUND
  Lithium can influence calcium homeostasis resulting in changes in parathormone set point and renal calcium handling. The clinical significance of these changes in older patients is unknown. The objective of this study was to investigate the possible association between duration of lithium treatment and corrected calcium, parathormone and 24-h urinary calcium excretion in older psychiatric patients corrected for renal function and vitamin 25OH D and also to estimate the point prevalence of hypercalcemia and raised parathormone.
  
  
  METHODS
  A cross-sectional study of psychiatric outpatients visiting a specialized facility for older patients treated with lithium was performed. Patients underwent a comprehensive assessment and blood and urine testing. Potential confounders of calcium homeostasis were recorded. On the basis of the duration of lithium treatment, patients were divided into four groups.
  
  
  RESULTS
  One hundred eleven patients were included, mean age 75.2 years. There was no significant association between the duration of lithium treatment and corrected calcium, parathormone and 24-h urinary calcium excretion. The point prevalence of hypercalcemia was 2.7% and 47.8% for raised parathormone. There was an unexpected but significant negative association between the duration of lithium treatment and vitamin 25OH D, with 76.9% vitamin 25OH D deficiency (<50 nmol/L) in the group using lithium for more than 10 years.
  
  
  CONCLUSIONS
  No association was found between duration of lithium treatment and calcium parameters in older psychiatric outpatients, but there was a high prevalence of raised parathormone and an unexpected negative association between duration of lithium treatment and 25OH D.
authors: Department of Geriatrics, Reinier de Graaf Gasthuis, Delft, The Netherlands.
authors: Els Jacoba Maria
authors: EJ
authors: van Melick
authors: Ingeborg
authors: I
authors: Wilting
authors: Gijsbertus
authors: G
authors: Ziere
authors: Robert Martin
authors: RM
authors: Kok
authors: Toine Cornelis Gerardus
authors: TC
authors: Egberts
mesh_terms: D015652:25-Hydroxyvitamin D 2 / Q000097:blood; D000368:Aged; D000369:Aged, 80 and over; D014150:Antipsychotic Agents / Q000009:adverse effects* / Q000627:therapeutic use; D002118:Calcium / Q000378:metabolism* / Q000652:urine; D003430:Cross-Sectional Studies; D005260:Female; D006706:Homeostasis / Q000187:drug effects; D006801:Humans; D006934:Hypercalcemia / Q000139:chemically induced* / Q000453:epidemiology; D008094:Lithium / Q000009:adverse effects* / Q000627:therapeutic use; D008297:Male; D001523:Mental Disorders / Q000188:drug therapy*; D009426:Netherlands; D010281:Parathyroid Hormone / Q000097:blood
chemical_list: D014150:Antipsychotic Agents; D010281:Parathyroid Hormone; D015652:25-Hydroxyvitamin D 2; D008094:Lithium; D002118:Calcium
keywords: calcium homeostasis; elderly; hypercalcemia; lithium; parathormone; vitamin 25OH D