title: Is environmental temperature related to renal symptoms, serum lithium levels, and other laboratory test results in current lithium users?
abstract: OBJECTIVE
  Lithium continues to be an important mood disorder treatment. Although patients exposed to higher environmental temperatures may have serum lithium level elevations due to dehydration, there is conflicting data in the literature. In addition, no study has assessed the association between temperature and other renal laboratory tests and symptoms in lithium users.
  
  
  METHODS
  This is a cross-sectional analysis of 63 current lithium users who participated in the McGill Geriatric Lithium-induced Diabetes Insipidus Clinical Study. The relationship between mean daily temperature with diabetes insipidus symptoms, glomerular filtration rate, urine osmolality, serum sodium, lithium level, and lithium dose-level ratio was assessed.
  
  
  RESULTS
  Although a higher temperature on the day of laboratory testing trended toward being independently associated with a lower lithium dose-level ratio (Beta = -0.17, p = 0.08), this was not found when using a dichotomous measure of temperature (T > 20°C). No association was observed between temperature and other renal parameters.
  
  
  CONCLUSIONS
  The association of temperature with lithium levels, renal symptoms, and laboratory tests appears to be of relatively little clinical importance in lithium users in temperate climates. However, future research should re-examine patients living in climates with extreme temperatures (e.g., >40°C), who may theoretically be at higher risk.
authors.affiliation: Department of Psychiatry, McGill University, Montreal, QC, Canada.
authors.forename: Soham
authors.initials: S
authors.lastname: Rej
authors.forename: Bandar
authors.initials: B
authors.lastname: AlAqeel
authors.forename: Marilyn
authors.initials: M
authors.lastname: Segal
authors.forename: Nancy C P
authors.initials: NC
authors.lastname: Low
authors.forename: Istvan
authors.initials: I
authors.lastname: Mucsi
authors.forename: Christina
authors.initials: C
authors.lastname: Holcroft
authors.forename: Karl
authors.initials: K
authors.lastname: Looper
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D003919:Diabetes Insipidus / Q000097:blood* / Q000139:chemically induced / Q000652:urine*; D004777:Environment; D005919:Glomerular Filtration Rate; D006801:Humans; D016014:Linear Models; D018020:Lithium Compounds / Q000009:adverse effects / Q000097:blood* / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D011619:Psychotropic Drugs / Q000009:adverse effects / Q000097:blood* / Q000627:therapeutic use; D012964:Sodium / Q000097:blood; D011795:Surveys and Questionnaires; D013696:Temperature; D055815:Young Adult
chemical_list: D018020:Lithium Compounds; D011619:Psychotropic Drugs; D012964:Sodium
keywords: lithium; renal; serum lithium levels; temperature