#2774 ASSOCIATION BETWEEN MODIFIED CREATININE INDEX AND MORTALITY IN PATIENTS UNDERGOING HEMODIALYSIS: A STRATIFIED ANALYSIS IN DIABETES MELLITUS
Authors: Fukuzaki Narumi , Suzuki Yuta , Nakajima Takuya , Matsuzawa Ryota , Uchida Juri , Yoshikoshi Shun , Harada Manae , Tobita Asumi , Nikkawa Sayaka , Matsunaga Atsuhiko 
Published: June 2023

Abstract

Background and Aims
Protein-energy wasting, including muscle atrophy, is one of the most frequently reported problems in patients undergoing hemodialysis. A decline in muscle mass leads to limitation and worsening of physical function and is associated with frailty, disability, and decreased survival. Modified creatinine index was used as a marker of lean body mass. Additionally, a longitudinal study revealed that a decrease in the modified creatinine index over time was independently associated with an increased risk of death in patients undergoing hemodialysis. Moreover, the prevalence of diabetes is high among patients undergoing hemodialysis. Diabetes not only leads to reduced skeletal muscle mass but is also a risk factor for cardiovascular events and death among patients undergoing hemodialysis. The relationship between modified creatinine index and mortality can be altered by the presence of diabetes; however, the effect of diabetes on this relationship among patients undergoing hemodialysis is unclear. This study aimed to examine the association between muscle mass and all-cause mortality in the presence or absence of diabetes, which is highly prevalent in hemodialysis patients.

Method
We included 361 outpatients undergoing maintenance hemodialysis treatment in 2013–2021 (mean age, 66.3±12.0 years; 61.0% males). Baseline was defined as the date of the first laboratory data and the modified creatinine index measurements, and participants were followed up from baseline to the date of the event (all-cause death, transfer, or end date of study follow-up [May 2021]). Modified creatinine index was calculated using age, sex, predialysis serum creatinine level, and single-pool Kt/V for urea. The primary outcome was death due to any cause. A Cox proportional hazards regression model was used to examine the association between the modified creatinine index and all-cause mortality. The dose–response association between the modified creatinine index and all-cause death was modeled using a restricted cubic spline model.

Results
A significant interaction was found between the presence of diabetes and modified creatinine index (p = 0.04). In the non-diabetic group, a lower modified creatinine index was associated with a higher risk of all-cause death (hazard ratio [HR], 1.33; 95% confidence interval [95% CI], 1.09–1.63), whereas no significant association between modified creatinine index and all-cause death was observed in the diabetic group (HR, 1.00; 95% CI, 0.83–1.20).

Conclusion
The modified creatinine index was more strongly associated with all-cause mortality in the nondiabetic group than in the diabetic group. The modified creatinine index is a useful tool for the nondiabetic group, and these results may provide useful information for examining the relationship between skeletal muscle mass and prognosis in patients undergoing hemodialysis.