Structural alterations in subcutaneous small resistance arteries predict changes in the renal function of hypertensive patients

Abstract

Background: We have previously demonstrated that structural alterations in subcutaneous small resistance arteries of hypertensive patients, as indicated by an increased media to lumen ratio (M/L), are a potent predictor of cardiovascular events, and that a close correlation exists between serum creatinine and M/L. The aim of the present study was to assess whether M/L of subcutaneous small resistance arteries may predict subsequent changes in renal function in hypertensive patients.

Method: Sixty participants (13 normotensive participants and 47 hypertensive patients) underwent a biopsy of subcutaneous fat. Resistance-sized arteries were dissected and mounted on a wire myograph, and M/L was measured. Patients were re-evaluated after a mean follow-up period of 8.6 years. Serum creatinine, blood urea nitrogen, and uric acid were measured; glomerular filtration rate (eGFR) was estimated according to Modification of Diet in Renal Disease formula.

Results: At baseline, we observed significant correlations between M/L and serum creatinine, eGFR, blood urea nitrogen, systolic, diastolic, mean, and pulse pressure. In addition, we observed significant correlations between M/L and serum creatinine at follow-up (r = 0.57; P < 0.001), percentage changes in serum creatinine (r = 0.46; P < 0.001), eGFR at follow-up (r = -0.43; P < 0.001); percentage changes in eGFR, yearly changes in eGFR, blood urea nitrogen at follow-up, and uric acid at follow-up. A multivariate analysis in which all common cardiovascular risk factors were included showed that M/L ratio is the most potent predictor of changes in renal function.

Conclusion: Our data suggest that structural alterations in subcutaneous small arteries may predict the time course of changes in renal function during a follow-up period of about 9 years.