Spokane doctor leads study finding high rates of chronic kidney disease with diabetes, disparities

Research led by a Spokane physician found that “concerningly” high rates of chronic kidney disease occur in people with diabetes, particularly among members of racial and ethnic minority groups .

The five-year study published last week in the New England Journal of Medicine with more than 654,000 diabetes patients is a call for action among health providers to check on early intervention and treatments for kidney disease if someone has diabetes, including regular testing and awareness about high-risk populations, said Dr. Katherine Tuttle, the study’s lead author and Providence’s executive director for research in its Inland Northwest region.

The paper found new-onset chronic kidney disease rates were higher by about 60% among Native Hawaiian-Pacific Islanders, 40% among Blacks, 33% among American Indians and Alaska Natives and 25% higher among Hispanic-Latino groups, compared with white people who have diabetes.

The work involved researchers from Providence, the University of California Los Angeles Health, the Centers for Disease Control and Prevention and the University of Washington School of Medicine in tracing the large number of adults with diabetes from 2015-20 using electronic health records from Providence and UCLA.

“What’s unique about this study is we had over 654,000 people with diabetes who didn’t have any kidney disease at baseline, so from the standpoint of their kidneys, they were normal when they started,” Tuttle said.

Researchers looked at laboratory tests conducted over time.

“What we were able to do is track them over a five-year period to see how many people developed kidney disease based on these laboratory markers. What we showed is that during this time period, there are some marked disparities in who develops this disease. That’s important because we need to know where it starts in order to identify interventions.”

Prior to this study, health care providers knew about prevalence, or the total number of people with kidney disease “and/or” diabetes, but understanding the rate each year of new-onset chronic kidney disease in people with diabetes was previously unknown, Tuttle said.

“It allows us to estimate what the projections are going to be for the total number of people who will need care and the types of care,” Tuttle said.

It helps identify high-risk populations, determine the effectiveness of interventions and assess the effects on health care delivery and public health responses, she said.

Chronic kidney disease involves a gradual loss of kidney function. In early stages, most people don’t know they have the condition because symptoms aren’t apparent. It can progress to end-stage kidney failure, which is fatal without dialysis or a transplant.

Worldwide, about 537 million people have diabetes, a number projected to reach about 780 million by 2045, Tuttle said. Among those with Type 2 diabetes, the most prevalent in which the pancreas makes insufficient amounts of the hormone insulin and results in poorly controlled blood sugar levels, about 40% will get kidney disease. For those with Type 1 diabetes, about a third will.

“Those people will either die largely of cardiovascular disease or progress to kidney failure, so it’s very serious and it’s been underrecognized and undertreated.”

The prevalence of kidney failure requiring dialysis or transplant more than doubled to nearly 800,000 people in the U.S. between 2000 and 2019, with diabetes as the leading cause.

“The reason kidney disease is important is certainly because it leads to kidney failure but it’s also the strongest predictor of deaths and cardiovascular events in people with diabetes,” Tuttle said. “The people who should be identified are people who have kidney dysfunction, because they really drive the cardiovascular deaths.”

Tuttle added while the rate of chronic kidney disease incidence in diabetes showed a slight decline in the study population between 2015-16 and 2019-20, that isn’t enough to offset a “diabetes epidemic” overall.

While there was a slight improvement, the chronic kidney disease rates are still high – somewhere between 7% and 8% per year, she said. “If you do math, it doesn’t take very long for a huge chunk of the population to have kidney disease.”

The racial and ethnic disparities are key, she added. While it’s known diabetes is more prevalent in racial and ethnic groups, the paper assesses the first “quantification of what the rate actually is,” she said, because of the study’s large numbers among these groups.

“We had enough people that we could report at each census category of race and ethnicity. We had enough people to reliably estimate the rates of kidney disease onset.”

She said her interpretation of why some groups have higher rates, which is not part of the paper’s data, include social-economic determinants of health, access to health care and type of care received, versus any biological reasons.

“I really think that seeing this data is a call to action to become really serious about seeking these screenings and when we detect it, taking action to prevent progression,” Tuttle said.

“It’s important to prevent kidney failure but also important to save lives and prevent the cardiovascular events that go along with it. We now have the tools on hand to do that. I personally feel that it’s a moral and ethical obligation to identify people by tests that are very simple.”

When kidney dysfunction is detected, providers have treatments that are more effective earlier in its progression, she said.

“These people are being treated for diabetes, and now they need treatment to prevent their kidney disease from progressing and causing other complications such as cardiovascular disease or death,” she said. “Some therapies we’ve had for many years, and there are some new therapies that are transformative in terms of saving lives, kidneys and hearts.”