Association of urinary C-megalin with albuminuria and renal function in diabetes: a cross-sectional study (Diabetes Distress and Care Registry at Tenri [DDCRT 21])

• Published in: Journal of nephrology Vol. 35; no. 1; pp. 201 - 210
• Main Authors: Kurita, Noriaki, Kinoshita, Maki, Fujimura, Maki, Kurosawa, Kentaro, Sakuramachi, Yui, Takano, Kiyoko, Okamura, Shintaro, Kitatani, Mako, Tsujii, Satoru, Norton, Edward C., Hayashino, Yasuaki
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 2022
• Subjects: Albuminuria - complications; Albuminuria - etiology; Creatinine - urine; Cross-Sectional Studies; Diabetes Mellitus, Type 2 - complications; Diabetes Mellitus, Type 2 - diagnosis; Diabetic Nephropathies - diagnosis; Diabetic Nephropathies - etiology; Glomerular Filtration Rate; Humans; Kidney - physiology; Low Density Lipoprotein Receptor-Related Protein-2; Medicine; Medicine & Public Health; Nephrology; Original Article; Registries; Urology; C-megalin; Biomarker; Renal function; Diabetes; Diabetic kidney disease
• ISSN: 1121-8428; 1724-6059
• DOI: 10.1007/s40620-021-00995-2

Background A urinary biomarker sensitive to glomerular functional or structural changes in diabetic kidney disease is required. This study examined whether urinary C-megalin reflects renal function or albuminuria in diabetes. Methods This was a cross-sectional study involving 1576 patients with type 1 or 2 diabetes. The exposure variables were estimated glomerular filtration rate (eGFR) and urinary albumin-to-creatinine ratio (UACR), and the outcomes were urinary C-megalin excretion and concentration. Two-part models were used to examine the associations between eGFR and UACR with urinary C-megalin excretion or concentration. Results The UACR was linearly associated with urinary C-megalin excretion (per 100 mg/gCr of UACR; 11.8 fM/gCr [95% CI 8.9–14.7]). There was no association between decreasing eGFR and increasing urinary C-megalin excretion. The UACR was also linearly associated with the urinary C-megalin concentration (per 100 mg/gCr of UACR, 7.7 fM/L [95% CI 5.8–9.6]). At eGFR values > 60 mL/min/1.73 m 2 , the eGFR and urinary C-megalin concentration were inversely linearly related (per 10 mL/min/1.73 m 2 decline, 7.7 fM/L [95% CI 0.2–15.1]). Conclusion Urinary C-megalin excretion as well as concentration levels are potentially useful biomarkers to detect early changes in diabetic kidney disease.