Living Donor Research Living Donor Risks Living Kidney Donor

Hyperfiltration: Adaptive or Maladaptive

Hyperfiltration is the term used to describe the changes in the remaining kidney after a nephrectomy (kidney removal).

As detailed here, it means that the vessels in the kidney widen under the increased pressure of filtering all the body’s blood, as well as a growth* in the actual cells that make up the glomeruli (small filter parts of the nephron). This increase’s the kidney’s re-absorption of sodium (salt) as well.

This process, or these changes, can be symptoms of diabetes or hypertension, or glomeruli damage. When it occurs in other parts of the body (eg. heart), it is seen as a significant health risk.

Yet the transplant industry has heralded the kidney’s adaptive capacity as more proof that living kidney donation is ‘safe’ for the donor, and does not leave him/her with any long-term ill renal effects.

The authors of this recently published study are not so sure. They conclude that “…alterations/adaptations in tubules and glomeruli in response to nephron deficiency may increase the risk of hypertension and renal disease in the long-term”.

Pass it on.

*Don’t confuse this with cell replication, which is how organisms normally grow. This is hypertrophy, an increase in cell size, not number.

For full abstract:

Living Donor Research Living Donor Risks Living Kidney Donor

Heart and Kidney Disease Risk for Living Kidney Donors

You might remember Mjoen from his prior paper wherein he concluded that after the age of 60, living kidney donors began dying off at a much faster rate than their well-matched, two-kidneyed cohorts.

This time his succinct conclusion is this:

Thus, kidney donors are at increased long-term risk for ESRD, cardiovascular, and all-cause mortality compared with a control group of non-donors who would have been eligible for donation.

Norway has a living donor registry, so they have info on *all* their living kidney donors, all the way back to 1963. The U.S., by comparison, has no identifying info on any kidney donor prior to 1994, and has no useful information over six-weeks past donation. Oops.

In Mjoen’s words:

Follow-up studies of living organ donors have not reported increased cardiovascular and all-cause mortality, but results may have been confounded by selection bias in the control groups… Most published studies have used unselected general populations as the control group, skewing results in favor of the donor cohorts as controls with coexisting medical conditions such as cardiovascular disease, malignancy, diabetes, hypertension, and chronic kidney disease were included that would have made them ineligible for kidney donation.

Median follow-up time was 15.1 years for LKDs and 24.9 years for the well-matched control group.

During the observation period, there were 224 deaths among 1901 kidney donors from the initial inclusion group, 68 (30.4%) of which were due to cardiovascular disease. There were 2425 deaths among the 32,621 controls, 688 (28.4%) of which were due to cardiovascular disease.

Median time from donation to end-stage renal disease was 18.7 years (10.3-24.3)

The crude incidence of ESRD in donors was 302 per million person-years. The overall incidence rate for development of ESRD in Norway is about 100 per million per person-year.

Three studies have included control groups selected to have comparable health status to the living donors, and each of these demonstrated no increase in cardiovascular disease or mortality over a follow-up time of approximately 6 years….Donation was not found to be associated with an increase in all-cause mortality. We also observed no increase in all-cause mortality during the initial 5–10 years after donation, but thereafter the survival curves began to deviate.

In our study, the donors had a substantially increased risk for developing ESRD compared with selected controls. The causes of ESRD were different in donors and controls. Seven out of the nine donors requiring renal replacement therapy had a primary renal disease. This was less common in controls.

Aw, but don’t worry:

We have, as one of the first transplant centers worldwide, strongly advocated this practice for more than four decades. Our findings will not change our opinion in promoting live-kidney donation.

Reinterpreted: As long as we off-handedly mention the risk during evaluation, it’s not really our problem.


Mjøen, G., Hallan, S., Hartmann, A., Foss, A., Midtvedt, K., Øyen, O., Reisæter, A., Pfeffer, P., Jenssen, T., Leivestad, T., Line, P., Øvrehus, M., Dale, D., Pihlstrøm, H., Holme, I., Dekker, F., & Holdaas, H. (2013). Long-term risks for kidney donors Kidney International, 86 (1), 162-167 DOI: 10.1038/ki.2013.460

Living Donor Research Living Donor Risks Living Kidney Donor

Kidney Donors Exhibit Biomarkers of Cardiovascular Risk

Six-months post-donation:


Among the panel of markers, the levels of symmetric dimethylarginine and fibroblast growth factor 23 increased significantly compared to baseline, suggesting that living kidney donation may result in changes in biomarkers that are associated with cardiovascular risk in other cohorts.

Take care of yourselves!
Huan Y. · Kapoor S. · DeLoach S. · Ommen E. · Meyers K. · Townsend R.R. (2013). Changes in Biomarkers Associated with Living Kidney Donation Am J Nephrol DOI: 10.1159/000354312

Living Donor Research Living Donor Risks Living Kidney Donor

Kidney Donors Exhibit Symptoms of Mild Chronic Kidney Disease

This is timely considering a commenter recenter asserted there is ‘no proof’ that living with one kidney is different than two.


A comparison of 203 kidney donors and 201 two-kidneyed individuals who would’ve been approved as living kidney donors showed LKDs experienced a 28% decrease in GFR (kidney function) six months post-donation, as well as a 23% increase in parathyroid levels, a ‘significant’ 8.2% increase in uric acid level, and a ‘significant’ 3.7% decrease in hemoglobin level.


Additionally, the authors noted that hyperuricemia has long been suggested to cause CKD, hypertension, diabetes, and cardiovascular disease (CVD), but this has been a source of ongoing controversy because it is possible that hypertension, diabetes, and CVD directly or indirectly cause hyperuricemia..


Keep in mind these measures were taken six months post-donation, and many symptoms, like hypertension, cardiovascular disease, etc. will not appear until many years later.


Take care of yourselves!



Living Donor Research Living Donor Risks Living Kidney Donor

Heart Risk in Folks Approved to be Living Kidney Donors

A 10% reduction in kidney function has been shown to significantly increase an individual’s risk for cardiovascular disease and deaths. Living kidney donors lose 20-40% of their pre-donation kidney function.


50 people approved as living kidney donors were assessed for heart risk prior to donation.


 In 72% of subjects, at least 1 of the risk factors was detected. Atherogenic index values considered to indicate high risk of atherosclerosis were found in 16% of subjects. More than 40% of subjects had more than 1 coronary risk factor, and most had 2.

In 26%, heart risk exceeded what would be expected by the individual’s age by 1-9%


Conclusion (emphasis mine):

The prevalence of coronary risk factors is high in potential kidney donors. HeartScore seems to be a useful method to evaluate the risk of cardiovascular mortality in these individuals, and is a simple tool to use in controlling the influence of the modification of risk factors on the global risk in follow-up. Comparison with the value of risk acceptable according to age and sex may oblige the physician to take action to reduce it.


Take care of yourselves…


Jankowski K, Gozdowska J, Lewandowska D, Kwiatkowski A, Chmura A, Durlik M, & Pruszczyk P (2013). Prevalence of the coronary artery disease risk factors and 10-year risk of cardiovascular mortality based on HeartScore in people qualified for kidney donation. Annals of transplantation : quarterly of the Polish Transplantation Society, 18, 393-8 PMID: 23912481