title: Lower estimated glomerular filtration rates in patients on long term lithium: a comparative study and a meta-analysis of literature.
abstract: BACKGROUND
  Several studies have shown that long-term lithium use is associated with a subtle decline in estimated glomerular filtration rate. This study compared mean estimated glomerular filtration rates (eGFR) in patients on long term lithium, against matched controls.
  
  
  METHODS
  Patients with bipolar affective disorder, who are on lithium (for at least a year), were compared against controls that were matched (1:1) for age, gender and presence or absence of diabetes or hypertension. The eGFR was calculated from creatinine values according to the 'modification of diet in renal disease study' (MDRD) formula and was compared between cases and controls. A meta-analysis was performed to compare our findings with similar studies in literature.
  
  
  RESULTS
  Forty seven patients met the inclusion criteria. They were matched with 47 controls. The eGFR values of lithium users were significantly lower (p = 0.04) compared to controls. This difference persisted between the subgroup of lithium users without comorbidities (diabetes and hypertension) and their controls but disappeared for lithium users with comorbidities and their controls. Nonetheless, lithium users had lower eGFR values in both subgroups. A meta-analysis of 9 studies showed a significant lowering in the glomerular filtration rate in lithium users compared to controls [mean difference -10.3 ml/min (95% confidence interval: -15.13 to -5.55, p < 0.0001)].
  
  
  CONCLUSIONS
  Lithium causes a subtle decline in glomerular filtration rate; renal function needs to be monitored in patients on lithium treatment.
authors.affiliation: Department of Clinical Medicine, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka. chaturaka.rodrigo@gmail.com.
authors.forename: Chaturaka
authors.initials: C
authors.lastname: Rodrigo
authors.forename: Nipun Lakshitha
authors.initials: NL
authors.lastname: de Silva
authors.forename: Ravindi
authors.initials: R
authors.lastname: Gunaratne
authors.forename: Senaka
authors.initials: S
authors.lastname: Rajapakse
authors.forename: Varuni Asanka
authors.initials: VA
authors.lastname: De Silva
authors.forename: Raveen
authors.initials: R
authors.lastname: Hanwella
mesh_terms: D000328:Adult; D000928:Antidepressive Agents / Q000008:administration & dosage / Q000009:adverse effects*; D001714:Bipolar Disorder / Q000188:drug therapy* / Q000453:epidemiology / Q000652:urine; D015897:Comorbidity; D003404:Creatinine / Q000652:urine; D003920:Diabetes Mellitus / Q000453:epidemiology; D005260:Female; D005919:Glomerular Filtration Rate / Q000187:drug effects*; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D007668:Kidney / Q000187:drug effects / Q000503:physiopathology; D018020:Lithium Compounds / Q000008:administration & dosage / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D013997:Time Factors
chemical_list: D000928:Antidepressive Agents; D018020:Lithium Compounds; D003404:Creatinine