hypothyroidism Thyroid Club亚临床甲状腺功能减退甲状腺俱乐部课件.pptVIP

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Formulation 2 Low TSH represents an effect of ageing and reduced turnover of pituitary-thyroid axis (biomarker for age) Decreased hepatic thyroid hormone clearance, ‘blunted’ diurnal TSH secretion flattened TSH response to TRH with ageing Adverse cardiac events AF (+ OP dementia) simply are consequences of “biological age” No need to treat for hyperthyroidism Formulation 1.5 Both the previous suggestions are true Adverse cardiac effects are due to excess thyroid hormones in some In others, low TSH is a biomarker for aging hence associated with poor outcome Need to distinguish between these two groups to treat some for hyperthyroidism Cardiovascular Health Study AF rate little different between grade I and grade II SH TSH mU/l N AF rate/1000 pt yrs Hazard ratio (5-95% CI) Euthyroid 2502 31 1.00 (ref) 0.44 47 67 1.98 (1.29-3.03) 0.1-0.44 40 59 1.85 (1.14-3.00) Cappola et al. 2006 Vadiveloo et al. JCEM 2011 ? 2004 patients with SH vs 10,111 controls ? 2 TSH measurements 4/12 apart ? Median follow up 5.6 yrs TEARS study What to do? ? Observe 3 to 6 months ? Look out for drug/ contrast effects -Thyroxine -Opiates -Glucocorticoid -Metformin -L-DOPA -Amiodarone -CT contrast (Iopaque) What to do? ? TSH 0.1 mU/l ? Age 75 ? Symptoms, goitre ? Above median FT3, FT4 ? +ve Antibodies, nuclide scan ? Complications, AF Intrinsic thyroid disease Ageing process TSH 0.1-0.4 mU/l ? Age 75 ? No symptoms ? Below median FT3, FT4 ? -ve Antibodies, scan ? No complications ? Algorithm Mitchell Pearce. Clin Endo 2010 * Rare causes ? Pituitary disease ? Tumour hCG ? Repeat testing ? May need investigations ? Maybe yearly re-testing ? Maybe never re-test “There is no reason to treat a patient with subclinical hyperthyroidism for thyrotoxicosis, provided they are in sinus rhythm” Vaidya B et al. Clin Endo 2008 27% agree 55% disagree Peer opinion: BTA Survey Summary Low serum TSH is common in adva