title: Thyroid Function and its Implications in Oxidative Stress Influencing the Pathogenesis of Osteoporosis in Adults with Down Syndrome: A Cohort Study.
abstract: People with Down syndrome (DS) show lower bone mass density (BMD) and a higher prevalence of hypothyroidism compared to general population. Furthermore, DS is a well-known high oxidative stress (OS) condition because genes involved in OS map on chromosome 21. Thyroid function too is involved in OS. Since both thyroid function and OS lead to lower BMD and osteoporotic fractures, we have explored correlations among BMD, thyroid hormones, and parameters of OS in DS adults. A total of 105 DS patients (48 males; 21-71 years; mean BMI 28.88±7.12 kg/m(2)) were enrolled in a cohort study, 48 of them undergoing thyroid replacement therapy. We evaluated thyroid function, BMD, and total antioxidant capacity (TAC) in blood plasma. TAC was assayed by H2O2-metmyoglobin system, as source of radicals, and by the chromogenous ABTS, with a latency time (LAG) in the appearance of its cation ABTS+proportional to antioxidant concentration. BMD was evaluated with DEXA, using WHO criteria to classify osteoporosis. Low BMD was found in 83.78% of patients. TSH and LAG did not correlate with BMD. Nevertheless, LAG significantly correlates to Z-scores estimated at the lumbar spine (r(2)=0.558; p=0.03) in hypothyroid patients. Our data show that low TAC could be more associated with reduced BMD rather than TSH itself in DS patients and that the OS could have a role in the pathogenesis of osteoporosis regarding the hypothyroid subgroup.
authors.affiliation: Department of Geriatrics "Centro Medicina dell'Invecchiamento", Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: E R
authors.initials: ER
authors.lastname: Villani
authors.affiliation: Department of Geriatrics "Centro Medicina dell'Invecchiamento", Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Onder
authors.affiliation: Department of Geriatrics "Centro Medicina dell'Invecchiamento", Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Carfì
authors.affiliation: Division of Endocrinology, Department of Medical Sciences, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Di Segni
authors.affiliation: Division of Endocrinology, Department of Medical Sciences, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Raimondo
authors.affiliation: Institute of Biochemistry and Clinical Biochemistry, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Silvestrini
authors.affiliation: Institute of Biochemistry and Clinical Biochemistry, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Meucci
authors.affiliation: Division of Endocrinology, Department of Medical Sciences, Catholic University of the Sacred Heart, Rome, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Mancini
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000975:Antioxidants / Q000378:metabolism; D015519:Bone Density; D015331:Cohort Studies; D004314:Down Syndrome / Q000150:complications* / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000453:epidemiology / Q000209:etiology / Q000473:pathology*; D018384:Oxidative Stress; D015995:Prevalence; D011379:Prognosis; D013960:Thyroid Function Tests; D013961:Thyroid Gland / Q000503:physiopathology*; D013972:Thyrotropin / Q000378:metabolism; D013974:Thyroxine / Q000378:metabolism; D055815:Young Adult
chemical_list: D000975:Antioxidants; D013972:Thyrotropin; D013974:Thyroxine