Non-linear progression of chronic kidney disease and associated factors in hypertensive patients: a 4-year cohort study

Abstract

Background Recent studies suggest that the progression of chronic kidney disease (CKD) is not linear, but we do not have clear evidence on this issue, especially in hypertensive patients. We sought to evaluate the progression of CKD and associated factors over four years in a cohort of hypertensive patients. Methods We conducted a prospective cohort study during the years 2012 and 2016, with hypertensive patients diagnosed with CKD (n = 113). The progression of CKD was assessed through the evolution of the glomerular filtration rate (GFR) and the change in the stage of CKD between 2012 and 2016. Sociodemographic, economic, lifestyle, clinical, anthropometric, and biochemical variables were evaluated. The strength of the association between CKD progression and explanatory variables was assessed by odds ratio (OR) and their respective 95% confidence intervals using univariate and multivariate logistic regression. Results Regarding progression, 78.1% of the CKD patients did not progress over four years. When assessing the CKD trajectory (2012–2016) through the evolution of GFR, there was a mean reduction of 1.3 mL/min/1.73m² in four years. In the group that progressed, there was a reduction of 13 mL/min/1.73m², while in the group that did not progress, there was an increase of 2 mL/min/1.73m². In the multivariate analyses, age (p = 0.047), diabetes mellitus (DM) (p = 0.042), and urea (p = 0.050) were independently associated with CKD progression. Conclusions The findings of the present study showed a non-linear progression of CKD over the four years, contrary to what is traditionally expected. Age, DM and urea were independently associated with CKD progression.