Carefully selected kidney donors can expect to live just as long as non-donors do and to experience no significant decline in kidney function, according to a report in The New England Journal of Medicine.
Prior research has supported the safety of kidney donation and that donation has no effect on survival or function of the remaining kidney, lead author Dr Hassan N. Ibrahim, from the University of Minnesota, Minneapolis, and colleagues explain. Still, most studies examining this topic have had relatively small sample sizes with only limited follow-up.
To examine long-term safety of kidney donation, Dr Ibrahim’s team analysed data for 3,698 individuals who donated kidneys from 1963 to 2007. In 255 donors whose surgery was performed in 2003 or later, the researchers assessed the glomerular filtration rate (GFR), albuminuria, hypertension, general health status, and quality of life.
GFR is a measure of kidney function as expressed as the amount of blood filtered through the kidneys per minute, sometimes referred to as creatinine clearance. The normal range is typically 90 to mL/min. Rates below 60 mL/min suggest kidney dysfunction and rates below 15 mL/min indicate kidney failure. Albuminuria, or albumin in the urine, is also an indication of kidney dysfunction.
No significant difference in survival was noted between donors and age-matched controls, the report indicates. Moreover, end-stage kidney disease was actually more common in controls than in donors: 268 vs 180 cases per million per year.
During an average follow-up period of 12.2 years, 85.5 per cent of the subjects in a subgroup analysis had a GFR of at least 60 mL/min/1.73 m² of body-surface area. Hypertension and albuminuria were seen in 32.1 per cent and 12.7 per cent of subjects, respectively.
Older age and higher body mass index were predictive of hypertension and a reduced GFR on long-term follow-up. By contrast, a longer time since donation did not correlate with reduced GFR or hypertension, although it was linked with a decrease in albuminuria.
Quality of life was not adversely affected by donation and, in fact, donors usually had scores that were better than those in the general population. Having more than one illness occurred with comparable frequency in the donor and general populations.
Noting that the donors studied were relatively young and mostly white, editorialists Dr Jane C. Tan and Dr Glenn M. Chertow from Stanford University School of Medicine, Palo Alto, comment that further studies are needed to determine if the findings are applicable to older and non-white donors. Still, data from the current study “could encourage the expansion of the donor pool, but cautious optimism is warranted”.
Reuters Health
Source: The New England Journal of Medicine for January 29, 2009