Classification of chronic kidney disease biomarkers to predict coronary artery calcium

Area of Science:

• Nephrology
• Cardiology
• Biostatistics

Background:

• The association between chronic kidney disease (CKD) and coronary artery calcification (CAC) is well-documented, primarily in patients with advanced CKD or ESRD and hyperphosphatemia.
• Previous research often overlooks the role of serum phosphorus in individuals with normal kidney function.

Purpose of the Study:

• To investigate distinct serum phosphorus trajectory classes, adjusted for estimated glomerular filtration rate (eGFR), and their association with CAC in a general community sample.
• To determine if phosphorus levels, even within the typical range, predict CAC development and progression.

Main Methods:

• Utilized growth mixture modeling to classify serum phosphorus and eGFR into four distinct trajectory classes.
• Employed a two-part growth model to predict CAC as both a binary (onset) and continuous (accumulation) outcome based on these phosphorus trajectories.

Main Results:

• Each incremental class increase in phosphorus trajectory was associated with a significant 97.9 Agatston unit increase in CAC.
• This association is comparable in magnitude to established cardiovascular risk factors like age (55.3 AU increase) and inverse to female gender (-75.1 AU decrease).

Conclusions:

• Serum phosphorus trajectories offer refined prediction of CAC, even within conventionally normal ranges.
• Identifying specific phosphorus trajectory classes may establish clinically actionable thresholds for interventions targeting phosphorus reduction to mitigate cardiovascular risk.