Thyroid physiology & Hypothyroidism
Upcoming SlideShare
Loading in...5
×
 

Thyroid physiology & Hypothyroidism

on

  • 2,179 views

An overview of the physiology of the thyroid and a discussion on management of hypothyroidism.

An overview of the physiology of the thyroid and a discussion on management of hypothyroidism.

Statistics

Views

Total Views
2,179
Views on SlideShare
2,061
Embed Views
118

Actions

Likes
0
Downloads
40
Comments
0

1 Embed 118

http://weight-loss-nutrition.net 118

Accessibility

Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

    Thyroid physiology & Hypothyroidism Thyroid physiology & Hypothyroidism Presentation Transcript

    • A C ASE PRO FIL E O F TH YRO ID D ISEASE - Dr.Mohammed Siraj - Dr.Parvez Khan - Dr.Mohammed Sadiq Azam - Dr.Praneetha Gayathri 1
    • TH YRO ID GL AN DH O RM O N O GEN ESIS 2
    • Thyroid Regulation HYPOTHALAMUS - TRH ANT. PITUITARY - TSH TSH -R THYROID T4 and T3 PLASMA T4 + FT4 PLASMA T3 + FT3 TISSUES FT4 to FT3, rT3 3
    • 4www.drsarma.in
    • In the Thyroid GlandThere the following 5 steps in the hormonogenesis Trapping of inorganic Iodine from dietary Iodides Activation of Iodine to high valance I2 Incorporation of I2 into Tyrosine of Thyroid Globulin Coupling of formed MIT and DIT to form T4 & T3 Proteolysis of Thyroglobulin to release T4 & T3 5
    • The Thyronines Mono Iodo Tyrosine – MIT Di Iodo Tyrosine – DIT Tri Iodo Thyronine – T3 – half life 6 hours Tetra Iodo Thyronine – T4 half life 7 days Reverse T3 - metabolically inactive T4 is 99.9% protein bound to TBG, TPA, TA T3 is 99.5% protein bound to TBG, TPA, TA Bound hormones are inactive – should not be measured 6 Only Free T4 and Free T3 are metabolically active
    • The ThyroxinesTri Iodo Thyronine – T3 - 10% is from thyroid gland - 90% derived from conversion of T4 to T3Tetra Iodo Thyronine – T4 - Is exclusively from thyroid glandFrom the thyroid gland - 80% of hormone secreted is T4 7 - 20% of hormone secreted is T3
    • Throid hormones in peripheral tissues• Plasma transport by thyroxine binding globulin TBG -75 -80%bound• Transthyretin 10-15%• Albumin 5-10% 8
    • 9
    • Thyroid Function Tests  TSH  Free T4  Free T3  Anti-Thyroid Antibodies  Nuclear Scintigraphy  FNAC of nodule 10
    • BASIC THYROID EVALUATIONFREE THYROXINE or FT4 HIGH NORMAL LOW LOW NORMAL HIGH THYROID STIMULATING HORMONE - TSH 11
    • BASIC THYROID EVALUATIONFREE THYROXINE or FT4 HIGH NORMAL EUTHYROID LOW LOW NORMAL HIGH THYROID STIMULATING HORMONE - TSH 12
    • BASIC THYROID EVALUATIONFREE THYROXINE or FT4 HIGH NORMAL PRIMARY LOW HYPOTHYROID LOW NORMAL HIGH THYROID STIMULATING HORMONE - TSH 13
    • BASIC THYROID EVALUATIONFREE THYROXINE or FT4 HIGH PRIMARY HYPERTHYROID NORMAL LOW LOW NORMAL HIGH THYROID STIMULATING HORMONE - TSH 14
    • BASIC THYROID EVALUATIONFREE THYROXINE or FT4 HIGH NORMAL SECONDARY LOW HYPOTHYROID LOW NORMAL HIGH THYROID STIMULATING HORMONE - TSH 15
    • BASIC THYROID EVALUATIONFREE THYROXINE or FT4 HIGH SECONDARY HYPERTHYROID NORMAL LOW LOW NORMAL HIGH THYROID STIMULATING HORMONE - TSH 16
    • BASIC THYROID EVALUATIONFREE THYROXINE or FT4 HIGH NORMAL SUB-CLINICAL HYPERTHYROID LOW LOW NORMAL HIGH THYROID STIMULATING HORMONE - TSH 17
    • BASIC THYROID EVALUATIONFREE THYROXINE or FT4 HIGH NORMAL SUB-CLINICAL HYPOTHYROID LOW LOW NORMAL HIGH THYROID STIMULATING HORMONE - TSH 18
    • BASIC THYROID EVALUATIONFREE THYROXINE or FT4 HIGH NORMAL LOW NON THYROID ILLNESS or NTI LOW NORMAL HIGH THYROID STIMULATING HORMONE - TSH 19
    • BASIC THYROID EVALUATIONFREE THYROXINE or FT4 HIGH NTI or Pt. on ELTROXIN NORMAL LOW LOW NORMAL HIGH THYROID STIMULATING HORMONE - TSH 20
    • BASIC THYROID EVALUATIONFREE THYROXINE or FT4 HIGH PRIMARY NTI or Pt. SECONDARY HYPERTHYROID on ELTROXIN HYPERTHYROID NORMAL SUB-CLINICAL SUB-CLINICAL HYPERTHYROID EUTHYROID HYPOTHYROID SECONDARY NON THYROID PRIMARY LOW HYPOTHYROID ILLNESS - NTI HYPOTHYROID LOW NORMAL HIGH THYROID STIMULATING HORMONE - TSH 21
    • THYROID HORMONES TEST REFERENCE RANGE TSH Normal Range 0.3 - 4.0 mU/L Free T4 Normal Range 0.7-2.1 ng/dLTSH upper limit will soon be revised to 2.5 mU/L 22
    • Thyroid Antibodies • Anti Microsomal (TM ) Antibodies • Anti Thyroglobulin (TG) Antibodies • Anti Thyroxine Per Oxidase (TPO) Ab. • Anti Thyroxine antibodies • Thyroid Stimulating (TSA) Antibodies High titres TPO Ab in Hashimotos & Reidle’s thyroiditis Anti thyroxine Ab in peripheral resistance to Thyroxine TSA (TSI) in Graves’ Hyperthyroidism 23
    • hypothyroidism 24
    • Hypothyroidism• Epidemiology • Most common endocrine disease • Females > Males – 8 : 1• Presentation • Often unsuspected and grossly under diagnosed • 90 % of the cases are Primary Hypothyroidism • Menstrual irregularities, miscarriages, growth retard. • Vague pains, anaemia, lethargy, gain in weight 25
    • Disease Burden 5% of the general population are Sub-clinically Hypothyroid 15 % of all women > 65 yrs. are hypothyroid Detecting sub-clinical hypothyroidism in pregnancy is highly essential – order for TSH and FT4 routinely in all pregnant women at the beginning of each trimester All persons aged above 60 years – Order for TSH26
    • • Primary hypothyroidism with Goitre Aquired Hashimotos thyroiditis Iodine deficiency Drugs blocking synthesis or release of T4 Goitrogens Cytokines Thyroid infiltration Causes of Congenital Iodide transport or utilization defect Hypothyroidism Iodotyrosine dehalogenase deficiency TPO deficiencyn nd dysfunction 27 Defects in thyroglobulin synthesis
    • • ATROPHIC HYPOTHYROIDISM Acquired HASHIMOTOS DISEASE Postablative due to 131 Iodine surgery Congenital Thyroid agenesis or dysplasia TSH receptor defects Thyroidal Gs protein abnormalities Idiopathic TSH unresponsiveness TRANSIENT HYPOTHYROIDISM 28 following subacute painless or postpartum thyroiditis
    • • CONSUMPTIVE HYPOTHYROIDISM• hemangiomas ,hemangioendoheliomas• CENTRAL HYPOTHYROIDISM• Acquired• pituatary origin• hypothalamic disorders• dopamine & or severe stress• Congenital• TSH deficiency/structural abnormality• TSH receptor defect• RESISTANCE TO THYROID HARMONE 29• generalised or pituatary dominant
    • Multi system effects - Hypothyroidism General Neuromuscular •Lethargy, Somnalence •Aches and pains •Weight gain, Goitre •Muscle stiffness •Cold Intolerence •Carpel tunnel syndrome Cardiovascular •Deafness, Hoarseness •Bradycardia, Angina •Cerebellar ataxia •CHF, Pericardial Effusion •Delayed DTR, Myotonia •HyperlipIdemia, Xanthelsma •Depression, Psychosis Haematological Gastro-intestinal Iron def. Anaemia, •Constipation, Ileus, Ascites Normo cytic /chromic Anaemia Dermatological Reproductive system •Dry flaky skin and hair •Infertility, Menorrhagia •Myxoedema, Malar flushes 30 •Impotence, Inc. Prolactin •Vitiligo, Carotenimia, Alopecia
    • Clinical Signs of Hypothyroidism Coarse Hair; Dry cool and pale skin Goitre (not in all cases), Hoarseness of voice Non-pitting oedema (myxoedema) Puffiness of eyes and face Delayed relaxation of DTR Slow hoarse speech and slow movements Thinning of lateral 1/3 of eye brows Bradycardia, pericardial effusion 31
    • Thyroid Failure - Organ SystemsCardiovascular• Decreased ventricular contractility• Increased diastolic blood pressure• Decreased heart rateCentral Nervous• Decreased concentration• General lack of interest• DepressionGastro-instestinal• Decreased GI motility• Constipation 32
    • Thyroid Failure - Organ SystemsMusculoskeletal Muscle stiffness, cramps, pain, weakness, myalgia Slow muscle-stretch reflexes, muscle enlargement, atrophyRenal Fluid retention and oedema Decreased glomerular filtration 33
    • Thyroid Failure - Organ SystemsReproductive• Arrest of pubertal development• Reduced growth velocity• Menorrhagia, Amenorrhea• Anovulation, InfertilityHepatic• Increased LDL / TC• Elevated LDL + triglycerides 34
    • Thyroid Failure - Organ SystemsSkin and Hair Thickening and dryness of skin Dry, coarse hair, Alopecia Loss of scalp hair and / or lateral eyebrow hair 35
    • HORMONAL EFFECTS ON THYROID FUNCTION• Glucocorticoid Excess-decreased TSH,TBG,TTR• Decreased serum T3/T4 and increase Rt3 production• Decreased T4 and increased T3 in graves disease• Deficiency-Increased TSH• Estrogen-Increased TBG sialylation and half life in serum• Increased TSH in post menopausal women• Increased T4 requirement in hypothyroid patients• Androgen-Decreased TBG• Decreased T4 requirment in hypothyroid patient 36• Growthhormone-Decreased D3 activity
    • 37www.drsarma.in
    • Cassava Plant Topiaco - Sago (Javva Arisi) 38
    • Tapioca Root - Sago Tapioca (tubers) Dried Tapioca - Sago 39
    • My xedema 40
    • My xedema 41
    • Co-morbidity• Hypercholosterolemia• Depression• Infertility – Menstrual Irregularities• Diabetes mellitus 42
    • Hypothyroidism andHypercholesterolemia • 14% of patients with elevated cholesterol have hypothyroidism • Approximately 90% of patients with overt hypothyroidism have increased cholesterol and / or triglycerides 43
    • Lipids in Patient with Hypothyroidism Hypercholesterolemia (>200 mg/dL) Hypertriglyceridemia (>150 mg/dL) Hypercholesterolemia and mild Hyper TG N= 268 Normal Lipids 44
    • Effect of Thyroxine therapyon Hypercholesterolemia inPatients with mild Thyroid failure “The decrease in total cholesterol achieved with [Thyroxine replacement] substitution therapy in patients with subclinical hypothyroidism [mild thyroid failure] may be considered as an important decrease in cardiovascular risk favouring treatment.” 45
    • Suspect Hypothyroidism 1. Amenorrhea 2. Oligomenorrhea 3. Menorrhogia 4. Galactorrhea 5. Premature ovarian failure 6. Infertility 7. Decreased libido 8. Precocious / delayed puberty 9. Chronic urticaria 46
    • 47
    • Algorithm for Hypothyroidism Measure TSH Elevated TSH Normal TSH Measure FT4 Considering Pituitary Normal Low No YesSub-clinical hypo Primary hypothyroid No tests Measure FT4TPO + TPO - TPO + TPO - Low NormalT4 repl Annual FU Hashimoto Evaluate Pituitary 48 No tests Sick Euthyroid Others Drugs effect
    • Hormonereplacement 49
    • Treatment • Goal : Normalize TSH level regardless of cause of hypothyroidism • Treatment : Once daily dosing with Levothyroxine sodium (1.6µg/kg/day-1.8ug/kg/day) • Monitor TSH levels at 6 to 8 weeks, after initiation of therapy or dosage change 50
    • Treatment• Treatment of choice is levothyroxin• Not recommended for use :  Desiccated thyroid extract  Combination of thyroid hormones  T3 replacement except in Myxedema coma 51
    • Dosage Adjustments• Age (in elderly start with half dose)• Severity and duration of hypothyroidism (↑ dose)• Weight (0.5µg/kg/day ↑ upto 3.0µg/kg/day)• Malabsorption (requires ↑ dose)• Concomitant drug therapy (only on empty stomach)• Pregnancy ( 25% -50%↑ in dose), safe in lactating mother• Presence of cardiac disease (start alt. day Rx) 52
    • Start Low and Go Slow• Goal : normalize TSH level – 25, 50 and 100 mcg tablets avail.• Starting dose for healthy patients < 50 years at 1.0 µg/kg/day• Starting dose for healthy patients > 50 years should be < 50 µg/day. Dose ↑ by 25 µg, if needed, at 6 to 8 weeks intervals.• Starting dose for patients with heart disease should be 12.5 to 25 µg/day and increase by 12.5 to 25 µg/day, if needed, at 6 to 8 weeks intervals 53
    • How the patient improves Feels better in 2 – 3 weeks Reduction in weight is the first improvement Facial puffiness then starts coming down Skin changes, hair changes take long time to regress TSH starts showing decrements from the high values TSH returns to normal eventually 54
    • Drug Interactions• Malabsorption Syndromes  Drugs that affect metabolism• Reduced Absorption  Rifampin  Cholestyramine resin  Carbamazepine  Sucralfate  Phenytoin  Ferrous sulfate  Phenobarbitol  Soybean formula  Aluminum hydroxide  Amiodarone  Colestipol hydrochloride 55
    • Inappropriate DosageOver-replacement risks• Reduced bone density / osteoporosis• Tachycardia, arrhythmia. atrial fibrillation• In elderly or patients with heart disease, angina, arrhythmia, or myocardial infarction2Under-replacement risks• Continued hypothyroid state• Long-term end-organ effects of hypothyroidism• Increased risk of hyperlipidemia 56
    • 20.2.98Massive Pericardial Effusion in Hypo 57
    • 26.7.98 58Clearing of Pericardial Effusion with Rx.
    • 14.9.99Reappearance of Pericardial Effusion 59 after treatment is discontinued
    • • CENTRAL HYPOTHROIDISM• AFTER SURGERYFT4 evaluation 60
    • Diet in Iodine deficiency • Iodized salt • Selenium supplementation • Avoid Cassava • Avoid cabbage (goitrogens) • Avoid formula milk • Fish, meat, milk & eggs 61
    • Specialsituations 62
    • My xedema Coma • Precipitating factors :  Infection, trauma, stroke, cardiovascular, hemorrhage drug overdose, diuretics • Signs and Symptoms :  Mental confusion, hypothermia, bradycardia, older age,  ↓ Na, ↓ glucose, ↑ CO2, ↓ WBC, ↓ Hct, ↑ CPK  ↓ EKG voltage, myxedema, b-carotnenemia • Treatment Initial IV THYROXINE 500-800 mcg/day ,followed by daily dose of I.V thyroxine 100 mcg thereafter ,alt I.V leothyronine 25mcg b.d 63
    • Sick Euthyroid Syndrome  Total T3 reduced  FT3 reduced  Total T4 reduced  FT4 Normal  TSH Normal  Clinically Euthyroid 64
    • • T3 -0.04nmo/l 0.93-2.33nmol/lit• T4-59.70nmol/l 60-120 nmol/lit• TSH-2.52IU/ml >7.0-hypothyroid <0.2 hyperthyroid Case-1 65
    • • T3 -1.42nmol/l• T4-106.96nmol/l• TSH-<0.05IU/mlCase 2 66
    • The Commandments Highly suspect hypothyroidism  All obese patients TSH a must Growth and pubertal delay  For all pregnant -test TSH, FT4 Unexplained depression  Postmenopausal 15% Hypothy TSH is the test in Hypothy.  Start low and go slow TSH, FT4 to confirm Dx.  Use Levothyroxine only Nine square magic  Always on empty stomach Test cord blood for TSH  Thyroxine - avoid empirical use 67
    • 68