The extent to which someone has chronic kidney disease (CKD) and the actual stage of the CKD is indicated by the estimated glomerular filtration rate (eGFR), a measure of how well the kidneys filter blood.
Someone with Stage 1 kidney disease has a GFR of over 90 mL/min and those with Stage 2 kidney disease have a GFR between 60-89 mL/min; there is little cause for concern here, however, and certainly, from a mortality modelling perspective, has little to no impact on life expectancy. Even someone with Stage 3a kidney disease – a GFR of between 45 and 59 mL/min – can lead a normal life, provided that they take medication and make the necessary lifestyle changes.
“The progression from Stage 1 to Stage 2 can take many years. The difficulty, however, is actually diagnosing the condition at such an early stage as there will likely be no tell-tale symptoms at that point,” said Fergus Bescoby, Head of Underwriting at CG Analysts.
“If someone is diagnosed as having Stage 1 or 2 CKD, making improvements to their lifestyle along with ensuring adequate control of any secondary conditions (hypertension, diabetes etc) can have a big impact and significantly slow the process of moving through the stages. Our research shows that Stages 1,2 and 3a have no real impact on life expectancy”.
It is when someone hits Stage 4 that the alarm bells begin to ring, as a eGFR of 15–29 mL/min means that they have a severe loss of kidney function, with toxins accumulating in the blood.
Fatigue, nausea, swelling, loss of appetite, itching, and bone disease are common here, and the individual concerned will be considering their options, which could include dialysis or a kidney transplant – or not.
“It is not uncommon for the elderly with Stage 5 CKD (eGFR <15) to refuse dialysis and opt for conservative treatment only. Dialysis can be a burdensome treatment and may reduce quality of life, particularly in patients with other conditions. Dialysis treatment doesn’t always prolong life in patients with other medical conditions and even if it does, much of it may be spent in hospital,” said Bescoby.
Dialysis and kidney transplants have been the primary life-sustaining treatments for advanced CKD for over 60 years. Dialysis was first successfully used in the 1940s but became widely available as a standard treatment in the 1970s. The first successful kidney transplant was performed in 1954, with the procedure becoming more common in the 1970s with improvements in immunosuppressive drugs and the establishment of the United Network for Organ Sharing.
Since then, however, there has been little change in how advanced kidney disease has been treated, but recent months have delivered two significant developments.
The first is in the field of xenotransplantation. In March last year, Richard Slayman, a 62-year-old American man living with kidney failure became the first person to receive a successful transplant of a pig kidney. Slayman sadly died in May 2024, but since then, others have also received kidney transplants, the most recent of whom is Tim Andrews, a 66-year-old who lives in Concord, New Hampshire.
In early February, United Therapeutics Corporation announced that the US FDA has approved it to initiate a clinical study of the company’s investigational UKidney, which is derived from a 10 gene-edited source pig. The study will enrol an initial cohort of six end-stage renal disease (ESRD) patients, expanding to up to 50 participants, and is intended to support a Biologics License Application (BLA) with the FDA. United Therapeutics expects the first xenotransplant in this trial to be performed around mid-year 2025.
The second is the approval of Ozempic to treat chronic kidney disease among people with type 2 diabetes.
These developments could be significant, and for mortality analysts, a rethink may be required.
“Treatment for kidney disease, and therefore our understanding of the impact of treatment on mortality has been similar for many years now. It’s imperative that, whenever significant developments like Ozempic come along, underwriters are aware of any potential improvements in life expectancy and revisit their pricing models accordingly”, said Bescoby.
The second Thursday in March marks World Kidney Day, which serves to raise awareness of kidney health globally; a wide range of organisations from all corners of the globe put on events designed to educate people about the impact of kidney disease and its associated health problems.
And it is exactly those associated problems that underwriters need to factor into their models. Kidney disease was the eighth biggest cause of death of Americans in 2023, but, unlike some of the other impairments on the list, such as cancer or heart disease, CKD is rarely the exclusive cause of death.
“CKD is usually caused by other conditions which put strain on the kidneys, for example heart disease, hypertension or diabetes. It is very common in the elderly and if you see an 80-year-old in the life settlement market, the chances of them not having some level of CKD are slim. The cause of death for someone with CKD will generally be one of the secondary conditions, the most common being some form of heart disease”. said Bescoby.
There are 92,000 Americans waiting for a kidney transplant, and not nearly enough kidneys. When a kidney does become available, there might be matching issues between donor and potential recipient. When you add to that the understanding of the effectiveness of Ozempic on kidney disease at the population level is still low and the fact that the growth stage of the field of xenotransplantation is embryonic at best adds up to something of a status quo for mortality modellers – for now.
“These new developments are hugely encouraging in theory, but much more data is needed to understand more precisely what the impact will be on both population and individual mortality. In life settlements, in particular, we are looking more at the overall picture of the individual than that of the population, and, in the short term, there will likely be little will change to how we view kidney disease,” said Bescoby.
“But, if these new treatments show progress in the next few years, then certainly, that could have a noticeable impact on the LE of many individuals.”