Renal Function On and Off Lithium in Patients Treated with Lithium for 15 Years or More. A Controlled, Prospective Lithium-Withdrawal Study
| Title: | Renal Function On and Off Lithium in Patients Treated with Lithium for 15 Years or More. A Controlled, Prospective Lithium-Withdrawal Study |
|---|---|
| Authors: | Bendz, H.; Sjodin, I.; Aurell, Mattias |
| Publisher: | Nephrology, Dialysis, Transplantation |
| Date Published: | March 01, 1996 |
| Reference Number: | 31 |
BACKGROUND
Controversy remains over the magnitude and reversibility of reduced renal function in long-term lithium patients.
METHODS
Thirteen patients with 18 years (range 15-24) on lithium discontinued the treatment, and were re-examined twice after 5 and 9 weeks (4-16) off lithium. They were compared to a non-lithium psychiatric control group, matched for age and sex.
RESULTS
Glomerular filtration rate (GFR) tended to improve from 69 (39-96) to 74 (39-94) ml/min/1.73 m2 BSA, P = 0.057, which was not significantly different from 78 (61-106) ml/min per 1.73 m2 BSA in the controls. Reduced GFR was found in only two of the lithium patients off lithium, and in none of the controls. Maximal urinary concentrating capacity did not improve at all. It was 637 (130-875) mOsm/kg H2O in the lithium patients, which was lower than 856 (705-1035) mOsm/kg H2O (P is less than 0.01) in the controls. Two of the lithium patients had isosthenuria.
CONCLUSIONS
Lithium patients often have an irreversible, clinically important reduction of Umax, sometimes progressing to nephrogenic diabetes insipidus, while GFR is well preserved in most patients.
Controversy remains over the magnitude and reversibility of reduced renal function in long-term lithium patients.
METHODS
Thirteen patients with 18 years (range 15-24) on lithium discontinued the treatment, and were re-examined twice after 5 and 9 weeks (4-16) off lithium. They were compared to a non-lithium psychiatric control group, matched for age and sex.
RESULTS
Glomerular filtration rate (GFR) tended to improve from 69 (39-96) to 74 (39-94) ml/min/1.73 m2 BSA, P = 0.057, which was not significantly different from 78 (61-106) ml/min per 1.73 m2 BSA in the controls. Reduced GFR was found in only two of the lithium patients off lithium, and in none of the controls. Maximal urinary concentrating capacity did not improve at all. It was 637 (130-875) mOsm/kg H2O in the lithium patients, which was lower than 856 (705-1035) mOsm/kg H2O (P is less than 0.01) in the controls. Two of the lithium patients had isosthenuria.
CONCLUSIONS
Lithium patients often have an irreversible, clinically important reduction of Umax, sometimes progressing to nephrogenic diabetes insipidus, while GFR is well preserved in most patients.
This translation by the NDI Foundation is to assist the lay reader. To provide a clear, accessible interpretation of the original article, we eliminated or simplified some technical detail and complicated scientific language. We concentrated our translation on those aspects of the article dealing directly with NDI. The NDI Foundation thanks the researchers for their work toward understanding and more effectively treating this disorder.
© Copyright NDI Foundation 2007 (JC)
Bendz, et al., studied the magnitude and reversibility of reduced kidney function in 13 patients who had been treated with lithium for almost 20 years each. These patients were matched with controls who, with one minor exception, had never been prescribed lithium for their psychological disorder. The lithium group was tested once while on lithium and twice (at five and nine weeks) after they discontinued lithium use.
The researchers found that, for the most part, the lithium group's kidneys' ability to filter bodily fluids increased somewhat after the group discontinued lithium. However, their ability to concentrate urine, which was compromised while on lithium, did not improve at all after they discontinued lithium use. Several studies of short-term lithium use and its impact on kidney function showed a partly reversible reduction of urinary concentrating capacity. However, several other studies of long-term lithium users found results similar to the authors' study. The combined evidence of both short-term and long-term lithium use indicates irreversible damage to the functional capacity of the many little tubes within the kidney. This results in irreversible inability to concentrate urine. The extent of the damage increases with length of lithium use, and lithium now appears to be a common cause of NDI. In addition, lithium causes a partly reversible reduction of the kidneys' ability to filter bodily fluids. Hence, impairment of kidney function must be considered a serious side-effect of long term lithium use.