Hypertension causes kidney changes at an early stage

Hypertension causes kidney impairment at an early stage of the disease, according to a research team from the Medical University of Vienna who investigated structural changes in kidneys of patients with hypertension and type 2 diabetes.

The results show that high blood pressure can lead to abnormalities in the podocytes, specialised cells in the renal filter, even without other pre-existing conditions such as diabetes. The results, published in the journal Hypertension, underline the importance of early detection and consistent treatment of high blood pressure in order to prevent kidney damage.

To arrive at these results, the research team, led by Dr Christopher Paschen and Dr Rainer Oberbauer (Clinical Division of Nephrology and Dialysis, Department of Medicine III) and Prof Heinz Regele (Clinical Department of Pathology), analysed kidney tissue from a total of 99 patients who either suffered from arterial hypertension and type 2 diabetes or did not have either of the two conditions. The investigation was conducted on unaffected renal tissue samples from tumour nephrectomies (performed between 2013 and 2018), a surgical procedure in which a kidney is removed in whole or in part to treat a kidney tumour.

 Using modern imaging and computer-assisted methods, the size and density of the podocytes and the volume of the renal corpuscles (glomeruli) were determined in the tissue samples.

Artificial intelligence in the form of deep-learning-based image analysis was used for the analysis. With the help of a specially trained algorithm, digital tissue sections were automatically analysed to precisely capture the structure of podocytes and glomeruli.

“The results show that patients with hypertension have a reduced density of podocytes compared to healthy controls and that their cell nuclei are enlarged compared to those of healthy controls,” said Dr Paschen. These changes occurred independently of the additional diagnosis of type 2 diabetes and likely represent the first microscopically visible step towards impaired renal function. The study authors see this as an indication that high blood pressure can cause structural damage to the kidneys at an early stage and before clinical symptoms appear. “Early detection and treatment could help to slow the progression of kidney disease and prevent long-term damage,” said the authors.

Full study available at:
www.ahajournals.org/doi/10.1161/HYPERTENSIONAHA.124.24379