title: Subclinical hypothyroidism is related to lower heel QUS in postmenopausal women.
abstract: Recent findings suggest that thyroid stimulating hormone (TSH) is a negative regulator of skeletal remodeling by reducing both differentiation of osteoblasts and formation of osteoclasts. In addition, increased fracture risk in untreated hypothyroid patients has been reported to begin up to 8 years before diagnosis. The aim of the present study was to evaluate the effect of subclinical hypothyroidism on bone structure by using the heel QUS. Subjects were outpatients without any past or present history of thyroid disease. Among 210 postmenopausal women, 22 of 33 patients (Hypo), who had elevated serum TSH concentration (TSH>or=4 microU/ml) with normal serum free thyroxine (FT4) concentration, agreed to join to this study. We also randomly selected 24 control subjects (Cont) from 176 postmenopausal women with normal thyroid status. Calcaneus osteo sono assessment indices (OSI) of right feet were measured using the ultrasound bone densitometry AOS-100. Serum TSH concentrations in Hypo patients (5.31 +/- 1.3 microU/ml) were higher than those in Cont patients (2.05 +/- 1.1 microU/ml), and there was significant difference of FT(4) concentrations (Cont 1.33 +/- 0.15 ng/dl; Hypo 1.19 +/- 0.17 ng/dl). OSI and its Z-score in Hypo subjects (OSI, 2.138 +/- 0.152; Z-Score -0.322 +/- 0.504 SD, Mean SD) were significantly lower than those in Cont subjects (OSI, 2.347 +/- 0.243; Z-Score 0.322 +/- 0.91 SD, Mean +/- SD). Simple regression statistical analysis showed that OSI decreased according to the increase of serum TSH concentration (n = 47, P<0.037). In addition, multiple regression analysis showed that the elevation of serum TSH concentration was associated with the decrease of OSI. These results suggest that the elevation of serum TSH concentration in subclinical hypothyroidism affects not bone turnover but bone structure as assessed by QUS.
authors.affiliation: Division of Endocrinology and Metabolism, Department of Internal Medicine, Fujita Health University, Toyoake, Aichi 470-1192, Japan.
authors.forename: Mutsuko
authors.initials: M
authors.lastname: Nagata
authors.forename: Atsushi
authors.initials: A
authors.lastname: Suzuki
authors.forename: Sahoko
authors.initials: S
authors.lastname: Sekiguchi
authors.forename: Yasunaga
authors.initials: Y
authors.lastname: Ono
authors.forename: Keiko
authors.initials: K
authors.lastname: Nishiwaki-Yasuda
authors.forename: Tomoko
authors.initials: T
authors.lastname: Itoi
authors.forename: Sakura
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Shigeo
authors.initials: S
authors.lastname: Imamura
authors.forename: Taiya
authors.initials: T
authors.lastname: Katoh
authors.forename: Nobuki
authors.initials: N
authors.lastname: Hayakawa
authors.forename: Naohisa
authors.initials: N
authors.lastname: Oda
authors.forename: Shuji
authors.initials: S
authors.lastname: Hashimoto
authors.forename: Mitsuyasu
authors.initials: M
authors.lastname: Itoh
mesh_terms: D000368:Aged; D015519:Bone Density; D002111:Calcaneus / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000150:complications* / Q000000981:diagnostic imaging*; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000150:complications* / Q000000981:diagnostic imaging*; D017698:Postmenopause; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood; D014463:Ultrasonography
chemical_list: D013972:Thyrotropin; D013974:Thyroxine