Awano Hiroyuki, Nambu Yoshinori, Osawa Kayo, Shirakawa Taku, Matsumura Tsuyoshi, Wakisaka Akiko, Kuru Satoshi, Funato Michinori, Takeshima Yasuhiro, Ishigaki Keiko, Kobayashi Michio, Sato Tatsuharu, Fujii Tatsuya, Sugie Kazuma, Kimura Koichi, Komaki Hirofumi, Nakamura Akinori, Matsuo Masafumi
Research Initiative Center, Organization for Research Initiative and Promotion, Tottori University, Yonago, Japan.
Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan.
Clin Chim Acta. 2025 Jan 30;566:120053. doi: 10.1016/j.cca.2024.120053. Epub 2024 Nov 17.
Becker muscular dystrophy (BMD) is a dystrophinopathy caused by a pathological variant of the DMD gene. Urinary titin, a degradation product of the giant protein titin present in muscle sarcomeres, has been used as a biomarker to reflect muscle degradation in Duchenne muscular dystrophy, a more severe dystrophinopathy. However, the clinical significance of urinary titin levels in BMD remains unclear. This study aimed to investigate the relationship between urinary titin levels and the clinical data in patients with BMD.
Urine samples were collected from 123 patients with BMD, and urinary titin levels were measured. The association of urinary titin with clinical data, including age, physical measurements, physical activity, blood tests, and cardiopulmonary test results, was examined.
A total of 257 urine samples were obtained from patients of 5-79 years of age. The median urinary titin level was 72.6 pmol/mg Cr (range 0.2-4325.0 pmol/mg Cr). No strong correlation was found between urinary titin levels and age, physical measurements, physical function, blood test results, or cardiopulmonary function. However, on comparing clinical data between the age-matched high urinary titin (N = 94) and normal (N = 29) groups, the high urinary titin group had a significantly greater number of non-ambulatory cases (23.9 % vs. 3.6 %), weaker grip strength (16.3 vs. 32.0 kg), and higher serum creatine kinase (1072 vs. 398 U/L) and cardiac troponin I (10.6 vs. 2.5 pg/mL) levels.
Urinary titin was identified as a biomarker reflecting walking ability, muscle strength, and skeletal and cardiac damage in patients with BMD.
贝克尔肌营养不良症（BMD）是一种由DMD基因的病理性变异引起的肌营养不良症。尿肌联蛋白是肌肉肌节中存在的巨大蛋白质肌联蛋白的降解产物，已被用作反映杜氏肌营养不良症（一种更严重的肌营养不良症）中肌肉降解的生物标志物。然而，尿肌联蛋白水平在BMD中的临床意义仍不清楚。本研究旨在探讨BMD患者尿肌联蛋白水平与临床数据之间的关系。
收集123例BMD患者的尿液样本，并测量尿肌联蛋白水平。研究了尿肌联蛋白与临床数据的相关性，包括年龄、体格测量、身体活动、血液检查和心肺检查结果。
共获得了年龄在5至79岁患者的257份尿液样本。尿肌联蛋白水平的中位数为72.6 pmol/mg Cr（范围为0.2至4325.0 pmol/mg Cr）。未发现尿肌联蛋白水平与年龄、体格测量、身体功能、血液检查结果或心肺功能之间存在强相关性。然而，在比较年龄匹配的高尿肌联蛋白组（N = 94）和正常组（N = 29）的临床数据时，高尿肌联蛋白组的非行走病例数明显更多（23.9%对3.6%），握力较弱（16.3对32.0 kg），血清肌酸激酶（1072对398 U/L）和心肌肌钙蛋白I（10.6对2.5 pg/mL）水平更高。
尿肌联蛋白被确定为反映BMD患者行走能力、肌肉力量以及骨骼和心脏损伤的生物标志物。
