Different diagnostic cut-off values of urinary fractionated metanephrines according to sex for the diagnosis of pheochromocytoma in Korean subjects.
The diagnosis of pheochromocytoma depends on the documentation of catecholamine overproduction.  The use of urinary fractionated metanephrines has recently become common for the diagnosis of pheochromocytoma.  In order to avoid false positive and false negative results, optimal cut-off levels are necessary; however, there have been few published reports on whether different cut-off levels are needed to diagnose pheochromocytoma according to sex.  We reviewed the medical records of 815 subjects (including 103 pheochromocytoma patients) whose of 24-h urinary fractionated metanephrine was measured using high-performance liquid chromatography methods and adrenal imaging at Samsung Medical Center.  Receiver operating characteristic (ROC) curves were used to determine cut-off values according to sex.  The upper limit values of fractionated metanephrine in healthy volunteers and the control group were significantly higher in male subjects compared with females.  When we applied cut-off values according to sex, the diagnostic efficacies (defining a positive test as either metanephrine or normetanephrine levels above the cut-off value) were a sensitivity of 96% in male subjects and 98.1% in female subjects and a specificity of 88.6% in male subjects and 94.1% in female subjects.  However, when we applied cut-off values without considering sex, the specificity decreased from 88.6% to 77.8% in male subjects.  In this study, urinary fractionated metanephrines had a high level of sensitivity and specificity for the diagnosis of pheochromocytoma.  However, diagnostic cut-off values were higher in male subjects than in female subjects.  Therefore, different cut-off values may be needed according to sex to diagnose pheochromocytoma in Koreans.
Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Seo Young
SY
Sohn
Hyung Doo
HD
Park
Soo Youn
SY
Lee
Jung Han
JH
Kim
Byong Chang
BC
Jung
Hye Jeong
HJ
Kim
Hye Won
HW
Jang
Kwang Won
KW
Kim
Moon Kyu
MK
Lee
Yong Ki
YK
Min
Jae Hyeon
JH
Kim
D000046:Academic Medical Centers; D000310:Adrenal Gland Neoplasms / Q000175:diagnosis* / Q000208:ethnology / Q000473:pathology / Q000652:urine; D000311:Adrenal Glands / Q000473:pathology; D000328:Adult; D000368:Aged; D002851:Chromatography, High Pressure Liquid; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008499:Medical Records; D008676:Metanephrine / Q000302:isolation & purification / Q000652:urine*; D008875:Middle Aged; D009647:Normetanephrine / Q000302:isolation & purification / Q000652:urine*; D010673:Pheochromocytoma / Q000175:diagnosis* / Q000208:ethnology / Q000473:pathology / Q000652:urine; D056910:Republic of Korea; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012727:Sex Characteristics; D047368:Tumor Burden
D009647:Normetanephrine; D008676:Metanephrine