Urinary adiponectin as a new diagnostic index for chronic kidney disease due to diabetic nephropathy

• Published in: BMJ open diabetes research & care Vol. 7; no. 1; p. e000661
• Main Authors: Yamakado, Shinnosuke, Cho, Hiroki, Inada, Mikio, Morikawa, Mika, Jiang, Yong-Huang, Saito, Kenji, Nakaishi, Kazunari, Watabe, Satoshi, Takagi, Hitomi, Kaneda, Mugiho, Nakatsuma, Akira, Ninomiya, Masaki, Imachi, Hitomi, Arai, Takeshi, Yoshimoto, Takuo, Murao, Koji, Chang, Jyun-Hao, Chen, Shih-Min, Shih, Yi-Chen, Zeng, Min-Jing, Ke, Liang-Yin, Chen, Chu-Huang, Yoshimura, Teruki, Miura, Toshiaki, Ito, Etsuro
• Format: Journal Article
• Language: English
• Published: England American Diabetes Association 01.05.2019; BMJ Publishing Group LTD; BMJ Publishing Group
• Subjects: Adipocytes; adiponectin; Adiponectin - urine; Adult; Aged; Biomarkers - urine; Biophysics; Case-Control Studies; chronic kidney disease; Classification; Clinical medicine; Diabetes; diabetes mellitus; Diabetic Nephropathies - complications; Diabetic nephropathy; Disease Progression; Female; Follow-Up Studies; Glomerular Filtration Rate; Humans; Hypertension; Insulin; Kidney diseases; Male; Medical diagnosis; Metabolism; Middle Aged; Molecular weight; non-invasive test; Pathophysiology/Complications; Patients; Prognosis; Renal Insufficiency, Chronic - diagnosis; Renal Insufficiency, Chronic - etiology; Renal Insufficiency, Chronic - urine; Signal transduction; ultrasensitive ELISA; Urine; Young Adult; United States > US; Japan; adiponectin; non-invasive test; chronic kidney disease; diabetes mellitus; ultrasensitive ELISA
• ISSN: 2052-4897; 2052-4897
• DOI: 10.1136/bmjdrc-2019-000661

ObjectiveThe chronic kidney disease (CKD) is widely diagnosed on the basis of albuminuria and the glomerular filtration rate. A more precise diagnosis of CKD, however, requires the assessment of other factors. Urinary adiponectin recently attracted attention for CKD assessment, but evaluation is difficult due to the very low concentration of urinary adiponectin in normal subjects.Research design and methodsWe developed an ultrasensitive ELISA coupled with thionicotinamide-adenine dinucleotide cycling to detect trace amounts of proteins, which allows us to measure urinary adiponectin at the subattomole level. We measured urinary adiponectin levels in 59 patients with diabetes mellitus (DM) and 24 subjects without DM (normal) to test our hypothesis that urinary adiponectin levels increase with progression of CKD due to DM.ResultsThe urinary adiponectin levels were 14.88±3.16 (ng/mg creatinine, mean±SEM) for patients with DM, and 3.06±0.33 (ng/mg creatinine) for normal subjects. The threshold between them was 4.0 ng/mg creatinine. The urinary adiponectin levels increased with an increase in the CKD risk. Furthermore, urinary adiponectin mainly formed a medium-molecular weight multimer (a hexamer) in patients with DM, whereas it formed only a low-molecular weight multimer (a trimer) in normal subjects. That is, the increase in urinary adiponectin in patients with DM led to the emergence of a medium-molecular weight form in urine.ConclusionsOur new assay showed that urinary adiponectin could be a new diagnostic index for CKD. This assay is a non-invasive test using only urine, thus reducing the patient burden.