Periodontitis is commonly viewed as a disease confined to the mouth, characterised by bleeding gums, progressive tissue damage and eventual tooth loss. However, growing evidence suggests its effects may extend throughout the body. The chronic inflammation associated with periodontal disease has been linked to cardiovascular disease and diabetes, raising questions about its possible connection to chronic kidney disease (CKD). While earlier studies have associated periodontitis with advanced CKD, its relationship with early kidney dysfunction has remained less clear.
Researchers at the University Medical Center Hamburg-Eppendorf, led by Dr Christian Schmidt-Lauber and Prof Dr Ghazal Aarabi, investigated whether periodontal disease is associated with early signs of impaired kidney health. “We aimed to evaluate the relationship between periodontitis and markers of early kidney dysfunction, including reduced renal function and albuminuria, and to explore the potential mediating role of systemic inflammatory markers,” Dr Schmidt-Lauber explained. The findings were published in Volume 18 of the International Journal of Oral Science on April 6, 2026.
The study analysed 6,179 participants from the Hamburg City Health Study, a population-based cohort in Germany. Participants underwent detailed periodontal examinations, with disease severity classified using the 2017 American Academy of Periodontology/European Federation of Periodontology staging system. Kidney health was assessed through estimated glomerular filtration rate (eGFR) and urinary albumin-to-creatinine ratio (uACR). Researchers also measured high-sensitivity C-reactive protein (hsCRP) and interleukin-6 (IL-6) to examine whether systemic inflammation could help explain the relationship.
The results showed a consistent association between worsening periodontal health and poorer kidney function. Severe periodontitis affected 14% of participants with normal kidney function, compared with 36% of those with moderately reduced kidney function. Advanced periodontal disease also became increasingly common as urinary albumin levels rose. Measures of cumulative oral damage, including clinical attachment loss and tooth loss, similarly worsened across stages of kidney dysfunction. Importantly, the associations remained after researchers adjusted for major factors including age, sex, diabetes and smoking.
Systemic inflammation appeared to explain only part of the connection. Levels of hsCRP and IL-6 rose alongside both periodontal disease severity and declining kidney health. However, hsCRP accounted for about 35% of the association between severe periodontitis and reduced eGFR, and only around 10% of the link with albuminuria. The researchers suggest other mechanisms may be involved, potentially including the spread of microbes from periodontal tissues, endothelial dysfunction, oxidative stress and metabolic changes.
Because CKD can progress without noticeable symptoms until significant kidney damage has occurred, recognising early indicators of risk remains a major clinical challenge. “By demonstrating an association between periodontitis and markers of early kidney dysfunction, this study highlights oral health as a potential window into kidney health,” Prof Dr Aarabi said. The findings suggest periodontal health could potentially contribute to future kidney risk assessment and support further studies examining whether treating gum disease can help preserve kidney function. Overall, the research strengthens evidence that oral and kidney health are closely interconnected and that periodontitis should be considered within the broader context of systemic health.
More information: Christian Schmidt-Lauber et al, Association of periodontitis with reduced kidney function and albuminuria in early chronic kidney disease: a population-based study, International Journal of Oral Science. DOI: 10.1038/s41368-026-00435-6
Journal information: International Journal of Oral Science Provided by Editorial Office of West China School of Stomatology, Sichuan University
