Chronic kidney disease mortality has risen faster in U.S.–Mexico border counties than in nonborder counties, according to new county-level research that also finds a persistent link between lower access to nephrologists and higher death rates.
The analysis, scheduled for presentation at ASN Kidney Week 2026, does not establish that a shortage of kidney specialists causes deaths. But it documents a widening geographic health disparity and identifies specialist availability as a factor that remains associated with mortality even after accounting for several clinical, economic and health-care-access conditions.
A faster increase along the border
Investigators analyzed U.S. Centers for Disease Control and Prevention data from 1999 through 2022. In U.S.–Mexico border counties, chronic kidney disease-related mortality increased from 48.2 deaths per 100,000 people to 81.4 per 100,000 over that period. The researchers calculated an approximate annual rise of 2.7%.
For the comparison group of nonborder counties, mortality rose from 35.1 to 54.4 deaths per 100,000 people, an annual increase of about 1.3%. Both groups saw worsening mortality, but the pace reported for border counties was roughly twice as high.
Those numbers do not explain why the trend differs. They do, however, put a measurable scale on a disparity that researchers say is developing in communities that are often predominantly Hispanic and medically underserved.
Where specialist access is lowest
The study also examined the local nephrology workforce. Counties with the lowest density of nephrologists had substantially higher chronic kidney disease mortality than counties with the greatest availability: 91.4 deaths per 100,000 people compared with 52.8 per 100,000.
After adjusting for diabetes, obesity, poverty, uninsured status, rurality, hospital access and demographic factors, each reduction of one nephrologist per 100,000 people was associated with approximately 7% higher chronic kidney disease mortality.
That association is important but should not be mistaken for proof of causation. County-level analyses describe patterns across places, not treatment histories for individual patients. Areas with fewer specialists may also face other barriers that are difficult to fully capture in available data, such as travel distances, the availability of primary care, continuity of insurance, language access or delayed diagnosis.
Why access may matter
Nephrologists specialize in kidney disease, including the management of declining kidney function and complications associated with conditions such as diabetes and high blood pressure. The research does not show exactly how workforce availability affects outcomes in individual counties, but it raises a concrete question for health-system planners: whether the communities with the heaviest kidney-disease burden also have sufficient access to specialized care.
Corresponding author Sofia Yamada of the University of Texas Rio Grande Valley School of Medicine described the results as evidence of a growing kidney-health disparity at the border. The analysis found that the workforce-mortality relationship persisted after adjusting for multiple health, socioeconomic and access-related factors.
That persistence strengthens the case for closer investigation, while leaving open the possibility that several overlapping conditions are driving the pattern. Chronic kidney disease is shaped by medical risk, diagnosis and treatment access, affordability, geography and the broader capacity of local health systems.
Findings presented before peer-reviewed publication
The work will be presented at ASN Kidney Week 2026, making it preliminary conference research rather than a completed peer-reviewed journal report. Conference presentations can provide an early view of findings, but methods and conclusions may change as researchers complete full analyses and seek publication.
The reported results are still useful as a warning signal. They show that mortality has increased in both border and nonborder counties, with the sharper rise occurring along the border, and that low nephrologist density tracks with a substantially higher mortality burden.
What comes next
The immediate policy question is not simply how many nephrologists a county has. It is whether people at risk of kidney disease can obtain timely screening, diagnosis, specialist input and ongoing treatment. The study cannot prescribe a single intervention, but it provides data for testing whether workforce investments and other access measures can change outcomes in high-burden areas.
Further work should examine patient-level records, referral patterns, travel burdens and the availability of kidney care across the border region. That could help distinguish the role of specialist shortages from the effects of poverty, insurance coverage, rural access and other structural barriers.
Key points
- Border-county chronic kidney disease mortality rose from 48.2 to 81.4 deaths per 100,000 between 1999 and 2022.
- The annual increase was about 2.7% in border counties versus 1.3% in nonborder counties.
- Counties with the lowest nephrologist density had higher mortality than those with the greatest availability.
- The study reports an association, not proof that specialist shortages directly cause mortality.
This article is based on reporting by Medical Xpress. Read the original article.
Originally published on medicalxpress.com
