Knowledge is essential Applied, it is Wisdom Wisdom is Happiness

Knowledge is essential Applied, it is Wisdom Wisdom is Happiness www.drsarma.in

Charaka Samhita Sukham Samagram Vijnane Vimale cha Pratishthitam All happiness is rooted in the Good Science www.drsarma.in

www.drsarma.in Abnormal Thyroid Function A Practical Approach Dr.R.V.S.N.Sarma.,M.D., M.Sc., Consultant Physician and Chest Specialist www.drsarma.in

Some interesting cases • Govindammal – Persistant diarrhea • Sridhar – HM – Cachexia 70 kg to 40 kg • Kavitha – Weight loss – lung shadow • Sulochana – Severe anaemia – CHF • Lady doctor – listlessness – anaemia • Kamatchi – Infertility after 16 yrs of ML • Siva – Atrial fibrillation – cachexia • Begum - Our staff member – weight loss • John – 32 yrs. Premature IHD • Kadirvelu – severe diabetes • Annaji – dyspnea – tracheal compression www.drsarma.in

Have patient seated on a stool / chair Inspect neck – also while drinking water Examine with neck in relaxed position Palpate from behind the patient Remember the rule of finger tips Use the tips of fingers for palpation Palpate firmly down to trachea Pemberton’s sign for RSG Clinical Exam. of Thyroid www.drsarma.in

Where to look for Thyroid ? www.drsarma.in

Clinical Anatomy of Thyroid www.drsarma.in

Clinical Exam of Thyroid www.drsarma.in

Thyromegaly www.drsarma.in

Thyroid Gland Hormonogenesis www.drsarma.in

HYPOTHALAMUS - TRH ANT. PITUITARY - TSH THYROID T4 and T3 PLASMA T4 + FT4 PLASMA T3 + FT3 TISSUES FT4 to FT3, rT3 Thyroid Regulation TSH -R www.drsarma.in

There 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 In the Thyroid Gland www.drsarma.in

Metabolism of Thyroid Hormones Thyroid Gland 100 nm Thyroxine FT4 5 nm < 5 nm 45 nm 35 nm Reverse T3 (rT3) Triiodothyronine (FT3) 20 nm Tertrac etc., www.drsarma.in

Normal catabolism -Thyroxine FT4 FT3 rT3 will be LOW rT3 ÷ T3 ratio will be LOW Normal deiodination of T4 Abnormal catabolism -Thyroxine FT4 FT3 rT3 will be HIGH rT3 ÷ T3 ratio will be HIGH Fluoride affects the normal deiodination of T4 rT3 rT3 What happens in Fluorosis www.drsarma.in

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 Only Free T4 and Free T3 are metabolically active The Thyronines www.drsarma.in

The Thyroxines Tri Iodo Thyronine – T3 - 10% is from thyroid gland - 90% derived from conversion of T4 to T3 Tetra Iodo Thyronine – T4 - Is exclusively from thyroid gland From the thyroid gland - 80% of hormone secreted is T4 - 20% of hormone secreted is T3 www.drsarma.in

Thyroid Function Tests www.drsarma.in

TSH Free T4 Free T3 Anti-Thyroid Antibodies Nuclear Scintigraphy FNAC of nodule Thyroid Function Tests www.drsarma.in

What tests should I order ? • As per the Guidelines of the AACE and ATA, ITS • 1. TSH alone if Hypothyroidism is suspected • 2. TSH and Free T4only if Hyperthyroidism is suspected or for routine evaluation • 3. Free T3 if T3 toxicosis is suspected • 4. For follow-up of treatment only TSH • Don’t order for Total T4 or Total T3 • Never order RIU in pregnancy or lactation www.drsarma.in

Depends on the method of estimation of hormones EquilibriumDialysis is the gold Standard for TSH Radio-immuno assay - 3rd or 4th gen. RIA is the best Reliability of ELISA is not adequate Chemiluminescence immuno assay - CIA is the gold standard for FT4 but expensive and less widely available Choose a lab which offers 3rd or 4th generation RIA method Which Lab to choose ? www.drsarma.in

How to interpret results ? www.drsarma.in

The Nine Square Game To evaluate our Thyroid patient As per the AACE and ITS Guidelines www.drsarma.in

BASIC THYROID EVALUATION LOW NORMAL HIGH FREE THYROXINE or FT4 LOW NORMAL HIGH THYROID STIMULATING HORMONE - TSH www.drsarma.in

BASIC THYROID EVALUATION LOW NORMAL HIGH FREE THYROXINE or FT4 EUTHYROID LOW NORMAL HIGH THYROID STIMULATING HORMONE - TSH www.drsarma.in

BASIC THYROID EVALUATION LOW NORMAL HIGH FREE THYROXINE or FT4 PRIMARY HYPOTHYROID LOW NORMAL HIGH THYROID STIMULATING HORMONE - TSH www.drsarma.in

BASIC THYROID EVALUATION PRIMARY HYPERTHYROID LOW NORMAL HIGH FREE THYROXINE or FT4 LOW NORMAL HIGH THYROID STIMULATING HORMONE - TSH www.drsarma.in

BASIC THYROID EVALUATION LOW NORMAL HIGH FREE THYROXINE or FT4 SECONDARY HYPOTHYROID LOW NORMAL HIGH THYROID STIMULATING HORMONE - TSH www.drsarma.in

BASIC THYROID EVALUATION SECONDARY HYPERTHYROID LOW NORMAL HIGH FREE THYROXINE or FT4 LOW NORMAL HIGH THYROID STIMULATING HORMONE - TSH www.drsarma.in

BASIC THYROID EVALUATION SUB-CLINICAL HYPERTHYROID LOW NORMAL HIGH FREE THYROXINE or FT4 LOW NORMAL HIGH THYROID STIMULATING HORMONE - TSH www.drsarma.in

BASIC THYROID EVALUATION SUB-CLINICAL HYPOTHYROID LOW NORMAL HIGH FREE THYROXINE or FT4 LOW NORMAL HIGH THYROID STIMULATING HORMONE - TSH www.drsarma.in

BASIC THYROID EVALUATION LOW NORMAL HIGH FREE THYROXINE or FT4 NON THYROID ILLNESS or NTI LOW NORMAL HIGH THYROID STIMULATING HORMONE - TSH www.drsarma.in

BASIC THYROID EVALUATION NTI or Pt. on ELTROXIN LOW NORMAL HIGH FREE THYROXINE or FT4 LOW NORMAL HIGH THYROID STIMULATING HORMONE - TSH www.drsarma.in

BASIC THYROID EVALUATION PRIMARY HYPERTHYROID NTI or Pt. on ELTROXIN SECONDARY HYPERTHYROID SUB-CLINICAL HYPERTHYROID SUB-CLINICAL HYPOTHYROID LOW NORMAL HIGH FREE THYROXINE or FT4 EUTHYROID SECONDARY HYPOTHYROID PRIMARY HYPOTHYROID NON THYROID ILLNESS - NTI LOW NORMAL HIGH THYROID STIMULATING HORMONE - TSH www.drsarma.in