title: A higher serum gamma-glutamyl transferase level could be associated with an increased risk of incident osteoporotic fractures in Korean men aged 50 years or older.
abstract: Oxidative stress has detrimental effects on bone metabolism, and gamma-glutamyl transferase (GGT) is known to play an important role in the generation of free radical species through the extra-cellular hydrolysis of glutathione, the main cellular antioxidant. We performed a large longitudinal study with an average follow-up period of 3 years to investigate the association between baseline serum GGT levels and the development of future osteoporotic fractures (OFs) in men. A total of 16,036 Korean men aged 50 years or older who had undergone comprehensive routine health examinations were enrolled. Incident fractures at osteoporosis-related sites (e.g., hip, spine, distal radius, and proximal humerus) that occurred after baseline examinations were identified from the nationwide claims database of the Health Insurance Review and Assessment Service of Korea using selected ICD-10 codes. Among the study subjects, 156 cases (1.0%) developed incident OFs during the study period. The event rate was 32.7 (95% CI = 28.0-38.3) per 10,000 person-years. Multivariable adjusted Cox proportional hazard analyses adjusted for age, body mass index, lifestyle factors, and medical and drug histories revealed that the hazard ratio per standard deviation increase of the baseline GGT levels for the development of incident fractures was 1.115 (95% CI = 1.011-1.230). These data provide the first epidemiological evidence, in support of previous in vitro and animal studies, of the harmful effects of GGT on bone metabolism, and indicate that the serum GGT level may be a useful biomarker of poor bone health outcomes in men.
authors.affiliation: Division of Endocrinology and Metabolism, Asan Medical Center, University of Ulsan College of Medicine, 138-736 Seoul, Korea.
authors.forename: Beom-Jun
authors.initials: BJ
authors.lastname: Kim
authors.forename: Seunghee
authors.initials: S
authors.lastname: Baek
authors.forename: Seong Hee
authors.initials: SH
authors.lastname: Ahn
authors.forename: Seon Ha
authors.initials: SH
authors.lastname: Kim
authors.forename: Min-Woo
authors.initials: MW
authors.lastname: Jo
authors.forename: Sung Jin
authors.initials: SJ
authors.lastname: Bae
authors.forename: Hong-Kyu
authors.initials: HK
authors.lastname: Kim
authors.forename: Gyung-Min
authors.initials: GM
authors.lastname: Park
authors.forename: Young-Hak
authors.initials: YH
authors.lastname: Kim
authors.forename: Seung Hun
authors.initials: SH
authors.lastname: Lee
authors.forename: Ghi Su
authors.initials: GS
authors.lastname: Kim
authors.forename: Jaewon
authors.initials: J
authors.lastname: Choe
authors.forename: Jung-Min
authors.initials: JM
authors.lastname: Koh
mesh_terms: D044466:Asian People; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D058866:Osteoporotic Fractures / Q000453:epidemiology*; D016016:Proportional Hazards Models; D012306:Risk; D005723:gamma-Glutamyltransferase / Q000097:blood*
chemical_list: D005723:gamma-Glutamyltransferase