BIOMARKERS OF GLOMERULAR FILTRATION, BUT NOT TUBULAR DYSFUNCTION, ARE ASSOCIATED WITH UNCONTROLLED HYPERTENSION IN THE GENERAL POPULATION. THE TROMSØ STUDY

• Published in: Journal of Hypertension
• Main Authors: Brobak, Karl Marius, Melsom, Toralf, Norvik, Jon Viljar, Andreassen, Runa Marie, Solbu, Marit Dahl
• Format: Article in Journal/Newspaper
• Language: English
• Published: Ovid Technologies (Wolters Kluwer Health) 2021
• Subjects: Tromsø
• Online Access: http://dx.doi.org/10.1097/01.hjh.0000745552.88409.99; https://journals.lww.com/10.1097/01.hjh.0000745552.88409.99

Objective: Uncontrolled hypertension (UHT) and chronic kidney disease (CKD) are common and frequently overlapping entities with considerable health consequences. Little is known about the relationship between low-grade kidney dysfunction and UHT. The importance of tubular in contrast to glomerular dysfunction in cardiovascular disease and hypertension has been recognised, but tubular biomarkers have not been examined in population-based studies of UHT. We assessed the associations between biomarkers of low-grade kidney dysfunction and UHT in treated hypertensive individuals from a general population. Design and method: In a cross-sectional design, we included all participants of the Tromsø Study 2007–08, second visit, who reported the use of two ore more blood pressure (BP) lowering drugs. The cohort was dichotomised into controlled hypertension or UHT; UHT was defined as systolic BP >=140 mmHg and/or diastolic BP >=90 mmHg. We used logistic regression to examine the associations between cardiovascular risk factors and UHT. In multivariable models we added estimated glomerular filtration rate (eGFR), urate, two urinary biomarkers of glomerular dysfunction (albumin-creatinine ratio [U-ACR] and orosomucoid-creatinine ratio [U-OCR]) and one biomarker of tubular dysfunction (N-acetyl-beta -D-glucosaminidase -creatinine ratio [U-NAG-Cr]). Results: Of the 7308 participants, 1189 persons (mean age 68.0 [8.9] years), fulfilled the inclusion criterion. Among these, 65% had UHT. Subjects with UHT were older and more frequently non-smokers than subjects with controlled hypertension. They had lower eGFR and higher U-ACR and U-OCR, whereas the level of U-NAG-Cr was similar between the groups. In multivariable analyses, higher U-OCR was associated with UHT (OR 1.17; 95% CI 1.02, 1.34 per log unit), whereas U-NAG-Cr was not. U-ACR was significantly associated UHT in models that did not include U-OCR (OR 1.14; 95% CI 1.03, 1.25 per log unit ACR). Conclusions: Although tubulointerstitial function is important in BP ...