Oxidative stress links periodontal and chronic kidney disease
BIRMINGHAM, UK: Previous studies have confirmed a connection between periodontitis and chronic kidney disease (CKD), as they showed that patients with severe inflammation of the gingivae also had poorer kidney function. A new study led by researchers from the University of Birmingham has found, for the first time, that a biological imbalance causes the correlation between these two diseases.
Prior research has also demonstrated that periodontitis has been associated with increased mortality in patients with CKD. As inflammation and oxidative stress play a role in the pathogenesis of periodontitis and CKD, the researchers assumed that these diseases may increase negative consequences when occurring in combination.
In the recent study, data was collected from 613 patients with CKD, using detailed oral and full-body examinations including blood samples. Using structural equation modelling, it was investigated whether periodontal inflammation and kidney function affect each other and what the underlying mechanism is that may facilitate this.
The results confirmed the assumption that periodontitis and CKD are linked. A 10% increase in periodontal inflammation corresponded to a 3% decrease in renal function. For this particular cohort, a 3% deterioration in kidney function would translate to an increased risk of kidney failure from 32% to 34% over a five-year period. In addition, a 10% reduction in renal function increased periodontal inflammation by 25%.
It was also determined that oxidative stress causes this bidirectional relationship, contrary to the common belief that the inflammatory load is the link between periodontitis and other systemic diseases. Oxidative stress is an imbalance between the body’s oxygen-producing free radicals and its antioxidant capacity, which damages tissue on a cellular level.
“This is the first paper to quantify the causal effect of periodontitis on kidney function and vice-versa as well as the first to elucidate the pathways involved,” said lead author Dr Praveen Sharma, from the Periodontal Research Group at the University of Birmingham’s School of Dentistry, in a university press release.
“It showed that even a modest reduction in gum inflammation can benefit renal function. Given the relative ease of achieving a 10% reduction in gum inflammation, through simple measures like correct brushing techniques and cleaning between the teeth, these results are very interesting,” he added.
The study results highlighted the role of periodontal inflammation as a hidden source of increased systematic oxidative stress in CKD. However, the study authors stated that it is not yet known whether periodontal treatment “will improve the oxidative stress burden in patients with CKD and, ultimately, impact morbidity and mortality associated with CKD”.
“We hope that this research paves the way for further studies to see if improvements in kidney function, following periodontal care, translate to longer, healthier life for patients with chronic kidney disease. We would also hope that the hypothesis we have identified could be tested in other groups,” commented Sharma.
The study, titled “Oxidative stress links periodontal inflammation and renal function”, was published online on 27 December 2020 in the Journal of Clinical Periodontology, ahead of inclusion in an issue.