Reevaluation of Validity of Percent Creatinuria for Diagnosing Steroid Myopathy

Accession number;06A0103395
Title;Reevaluation of Validity of Percent Creatinuria for Diagnosing Steroid Myopathy
Author; SHIMOHATA TAKAYOSHI (Niigatadai Noken Shinkeinaika) UMEDA MAIKO (Niigatadai Noken Shinkeinaika) TANAKA KEIKO (Niigatadai Noken Shinkeinaika) NISHIZAWA MASATOYO (Niigatadai Noken Shinkeinaika)
Journal Title;Brain Nerve
Journal Code:Z0685A
ISSN:0006-8969
VOL.58;NO.1;PAGE.39-42(2006)
Figure&Table&Reference;FIG.1, REF.7
Pub. Country;Japan
Language;Japanese
Abstract;Steroid myopathy is usually a slowly progressive disease, which causes weakness primarily to the proximal muscles of the upper and lower extremities. The monitoring of this problem is difficult in situations in which the primary disease itself produces muscle weakness. The distinguishing feature in steroid myopathy is the occurrence of creatinuria in the presence of normal muscle enzymes including creatine kinase and aldolase. To evaluate the usefulness of percent creatinuria {urinary excretion of creatine/(urinary excretion of creatine + urinary excretion of creatinine)} in the diagnosis of steroid myopathy, we measured percent creatinuria in 26 patients (14 male and 12 female) without muscle diseases before the initiation of steroid treatment. We found that the median values of percent creatinuria of the male and female patients were 2.5% and 17.1%, and that the ratios of the male and female patients presenting with an elevated percent creatinuria (more than 10%) were 3 out of 14 patients (21.4%) and 8 out of 12 patients (66.7%), respectively. We also found one patient with mild renal dysfunction presenting with an elevated percent creatinuria but without muscle weakness or myalgia. These findings suggest that the measurement of percent creatinuria is of little value in the diagnosis of steroid myopathy with a cutoff value of 10%. Furthermore, it is important to measure percent creatinuria before the steroid treatment, while paying close attention to the measurement method, sex, renal function and protein level of the diet. (author abst.)
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