Association of kidney disease index with all‐cause and cardiovascular mortality among individuals with hypertension

Abstract

BackgroundThis study aimed to investigate the association between a novel kidney disease index (KDI), which combines information from both estimated glomerular filtration rate (eGFR) and urinary albumin‐to‐creatinine ratio (uACR), and all‐cause and cardiovascular disease (CVD) mortality among individuals with hypertension.MethodsWe analyzed data from 19 988 adults with hypertension who participated in the National Health and Nutrition Examination Survey from 1999 to 2018. Mortality outcomes were determined by linking to National Death Index records through December 31, 2019. Cox proportional hazards models were used to estimate hazard ratios and 95% confidence intervals for all‐cause and CVD mortality.ResultsBaseline KDI levels were positively associated with glucose, insulin resistance, hemoglobin A1c, triglycerides, and C‐reactive protein (p value for trend <.05). During a follow‐up period of 179 859 person‐years, a total of 5069 deaths were documented, including 1741 from cardiovascular causes. After multivariable adjustment, each standard deviation increment in KDI level was associated with a 27% increased risk of all‐cause mortality and a 31% increased risk of cardiovascular deaths (both p < .05). Further analysis showed a J‐shaped association between KDI and mortality, with the risk increasing dramatically when KDI exceeded 0.27.ConclusionElevated KDI levels were significantly associated with increased mortality from all causes and CVD among individuals with hypertension. We recommend routine testing of eGFR and uACR in hypertensive patients, and using KDI as a tool to identify individuals who are most likely to benefit from preventive therapies.

Comment on “Association of kidney disease index with all‐cause and cardiovascular mortality among individuals with hypertension”

“…3 Serum uric acid would interact with kidney function, and a mediation analysis may be one of the effective methods to evaluate the causal association between eGFR and mortality. 4 Fang et al 1 analyzed data in patients with hypertension, and cardio-renal effect on mortality would be a key point for the analysis.…”

“…To the Editor, I read the article by Fang et al 1 in "Clinical Cardiology," who investigated the association between a novel kidney disease index (KDI), which combined information from estimated glomerular filtration rate (eGFR) and urinary albumin-to-creatinine ratio (uACR), and all-cause and cardiovascular disease (CVD) mortality in patients with hypertension. The adjusted hazard ratios (95% confidence intervals) of each standard deviation increment in KDI level for all-cause mortality and cardiovascular deaths were 1.27 (1.23-1.30) and 1.31 (1.26-1.37), respectively.…”

“…They made an emphasis that the increased mortality risk by renal hyperfiltration was observed regardless of proteinuria. Fang et al 1 presented that the age of subjects became higher as KDI increased. Although the prevalence of renal hyperfiltration may not be frequent, KDI would mask the pathological increase of eGFR by aging.…”

“…Fang et al 1 analyzed data in patients with hypertension, and cardio‐renal effect on mortality would be a key point for the analysis. Taken together, I think that the advantages and masked risks of KDI may exist, which should be explored by further studies.…”