Remnant cholesterol and the risk of diabetic nephropathy progression to end-stage kidney disease in patients with type 2 diabetes mellitus: A longitudinal cohort study

Aim Remnant cholesterol has been investigated as a predictor for the progression of DN in type 1 diabetes mellitus patients, as well as the incidence of DN in type 2 diabetes mellitus (T2DM) patients. This study aimed to evaluate the longitudinal relationship between baseline remnant cholesterol and kidney outcomes using a Chinese T2DM with biopsy-confirmed DN cohort. Methods We included 334 patients with T2DM and biopsy-confirmed DN during 2010–2019 West China Hospital T2DM-DN cohort. Remnant cholesterol was defined by Martin-Hopkins equation. Patients were divided into four groups based on the median (IQR) remnant cholesterol concentration at the time of renal biopsy. The kidney outcome was defined as ESKD. The relationship between remnant cholesterol and kidney outcome was analyzed using the Kaplan‒Meier method and Cox regression analysis. Results The mean age was 51.1 years, and 235 (70%) were men. During follow-up, a total of 121 (36.2%) patients reached ESKD. The Kaplan‒Meier analysis showed that patients in the highest quartile (quartile 4) group had lower cumulative renal survival (log-rank test, p = 0.033) and shorter median renal survival time [34.0 (26.4–41.6) vs 55.0 (29.8–80.2) months] than patients in the lowest quartile (quartile 1) group. By univariate analysis, the high remnant cholesterol group was associated with a higher risk of progression to ESKD. Moreover, the risk of progression to ESKD in the highest quartile was still 2.857-fold (95% CI 1.305–6.257, p = 0.009) higher than that in the lowest quartile, and one-SD increase of remnant cholesterol was associated with a higher risk (HR = 1.424, 95% CI 1.075–1.886, p = 0.014) of progression to ESKD, after adjusted for confounding factors. Conclusions High remnant cholesterol is independently associated with a higher risk of ESKD in patients with T2DM-DN, and it may be a new noninvasive marker of ESKD. Clinical relevance: Calculated remnant cholesterol has the advantages of being economical and clinically accessible. Moreover, to our knowledge, there are no longitudinal cohort studies for investigating the risk of progression of T2DM-DN to ESKD. In our study, higher remnant cholesterol was associated with a higher risk of ESKD in patients with T2DM-DN, and it may be a new noninvasive predictor of ESKD.