Chronic kidney disease (CKD) affects 13 percent of adults globally and less than 10 percent are aware that they have it, according to nephrologist Dr. Adrian Sawyer. He said CKD limits life expectancy and appropriate clinical management is costly, but that timely identification can lead to preventive strategic treatments, although it has enormous financial costs for all forms of healthcare systems.
According to Sawyer, new cases of end-stage kidney disease (ESKD) in African Americans in 2019 was 936 per million population, compared to 280 per million population for whites – translated to The Bahamas with an approximate population of 400,000 – new cases per year would be around 320 people, as such, he said there is no way that a middle-income country like The Bahamas could realistically fund kidney replacement for the number of ESKD patients at current costs.
The doctor said in 2019, the average cost per person annually for ESKD treatment by modality in the United States (US) was pegged at $95,000 for haemodialysis – $81,000 for peritoneal dialysis and $38,000 for a kidney transplant. Higher utility costs in The Bahamas he said would make the numbers comparable, but that it is only for dialysis treatments alone and for maintenance of transplants with medications, respectively.
“At the end of December 2020, there were approximately 475 prevalent ESKD patients in the public sector receiving haemodialysis, with the majority (111 persons) in Grand Bahama, supported by the Public Hospitals Authority (PHA), 14 in Abaco, and 135 persons in Nassau; the hospital population was approximately 160 persons. The total population of patients on dialysis treatments funded by the Public Hospitals Authority was 500-plus.”
Sawyer said private patient numbers were unavailable.
“Diabetes and hypertension together account for approximately 70 percent of the causes of end stage kidney disease. In the United States, African Americans have a three-to-four times greater burden of chronic kidney disease than whites and are more than three times as likely to progress to ESKD. They account for 13 percent of the US population, but account for 31 percent of the ESKD population, 34 percent of the kidney transplant waiting list and 28 percent of kidney transplants. They have more advanced CKD and are more likely to have severe hypertension and diabetes. Recent genetic studies have implicated some unique genetic markers for worse kidney disease in this group.”
Sawyer said there is an out-of-pocket burden of medications related to dialysis treatments amounting to approximately $1,800 per month (without insurance); blood tests are required every two months at an average cost of $500 to $700, making a total of at least $2,400 in expenses.
Sawyer said, realistically, costs of kidney transplantation range from $125,000 to $400,000 – figures that he said indicate the extent of the financial burden imposed by chronic kidney disease/ESKD management on healthcare systems.
With Kidney Awareness Month during March, the focus is on bringing awareness to kidney health and encouraging people to support kidney disease research, and for people to take steps to keep their own kidneys safe and healthy.
Impact of chronic kidney disease on health outcomes
The nephrologist said CKD is common, and affects approximately one in 10 adults, globally, with some regional variations.
“It has steadily been moving up the table of causes of death worldwide since 1990, when it ranked number 17 in causes of annual mortality (death). In 2017, it had risen to the 12th leading cause of global mortality. Current estimates indicate that, by 2040, it will be ranked as the fifth leading cause of death,” said Sawyer.
“The most recent global burden of disease study related to chronic kidney disease published in the Lancet, in February 2020, revealed that the global incidence and prevalence is increasing; the study included 195 countries. There were 697.5 million cases of chronic kidney disease in 2017, with 90 countries having more than 1,000,000 cases; China and India accounted for nearly one third of the total.”
Sawyer said 1.23 million deaths directly caused by CKD occurred in 2017, with a further 1.36 million deaths related to cardiovascular diseases – heart failure, myocardial infarctions and strokes – were caused by impaired kidney function. The study also revealed significant variations in prevalence with Central America and Andean Latin America having the highest figures.
Causes of CKD
Causes of CKD include diabetes, hypertension (high blood pressure), inflammatory disease of the kidneys and cystic kidney disease.
“Diabetic kidney disease accounts for the largest single category of CKD/ESKD worldwide. In the USA, approximately 46 percent of the patients on dialysis, or transplant, have diabetes as the primary cause of kidney failure. In Europe, the figure averages to 20 percent. The last time data was analyzed for The Bahamas, the figure was 38 percent.
“Hypertension accounts for approximately 20 to 25 percent of causes of CKD/ESRD. One in four adults have hypertension and increases to two in four with aging. Hypertension damages kidneys via damage to the small blood vessels in the kidney. At the commencement of stage 5 CKD, of whatever cause, approximately 85 to 90 percent of patients have hypertension.
“Inflammatory disease of the kidneys – damage related to inflammation in anatomical compartments of the kidney – are the next leading cause of CKD/ESKD. Relevant to populations of African ancestry is the high incidence of systemic lupus kidney disease in females which is more aggressive than in Caucasians. Approximately 70 percent of lupus patients will develop kidney involvement within 10 years of diagnosis.
“Cystic kidney disease – familial types – autosomal dominant polycystic kidney disease – accounts for approximately five to seven percent of ESKD; it affects 50 percent of offspring in a family.”
Other causes Sawyer said account for approximately 10 percent of the total causes include people born with anatomical abnormalities of the kidneys and others with genetic/metabolic abnormalities.
The PAHO Burden of Kidney Disease in the Americas 2000-2019 survey report of deaths for 2019 shows 30.9 deaths per 100,000 for The Bahamas.
The figures range from a high of 73.9 deaths per 100,000 population for Nicaragua, 55.8 deaths per 100,000 population for Bolivia, 35.0 deaths per 100,000 for Haiti, 24.0 deaths per 100,000 for Jamaica, 16.3 per 100,000 for Barbados, 13.1 for the US and 5.0 per 100,000 for Canada.
“The economic costs of kidney replacement treatments, dialysis, or kidney transplantation are disproportionately high in relation to the numbers affected, and present challenges for national health systems.”
There are five stages of kidney disease – Stage 1 (mild kidney damage, kidneys work as well as normal); Stage 2 (mild kidney damage, kidneys still work well), Stage 3a (mild to moderate kidney damage, kidneys don’t work as well as they should); Stage 3b (moderate to severe damage, kidneys don’t work as well as they should); Stage 4 (severe kidney damage, kidneys are close to not working at all); and Stage 5 (most severe kidney damage, kidneys are very close to not working or have stopped working – failed).
“Chronic kidney disease is a virtual death sentence, as, once established, only 10 to 15 percent of those with CKD will survive to start dialysis or undergo transplantation,” said the doctor. “The major cause of death is cardiovascular – strokes, heart attacks, heart failure, with a rate of up to 20 times that of non-CKD, age-matched controls.”
Sawyer said two new classes of medications initially targeted for the treatment of diabetes have been found to also reduce the risks of cardiovascular events such as strokes, heart attacks, and heart failure, which are responsible for the majority of deaths before ESKD.
“Further clinical trials indicate that they also retard the progression to dialysis, by one to three years. In the last year, major diabetes and kidney professional organizations have recommended these agents as almost first-line agents in the management of diabetes as well as for non-diabetic kidney diseases. Unfortunately, the trade-off is the costs of these new agents,” said the doctor.
The second Thursday in March was observed as World Kidney Day, with the month designated as Kidney Month. The theme for 2022 is “Kidney Health for All”.