Hypothyroidism

ESIC – PGIMSR, MGM Hospital,

Mumbai

Presenter:

DR.UTKARSH DESHMUKHDNB General Medicine

Index:1.Case of Hypothyroidism2.Discussion of Hypothyroidism 3.Subclinical Hypothyroidism4.Myxedema Coma

History

• A 50 year female patient Mrs. Pramilabai Residing at Mumbai was working as maid came to our hospital with complaints of Generalized tiredness, cold intolerance, decrease

appetite since 18 months. Constipation & Somnolence since 12 months. Hoarseness of voice & forgetfulness, since 6

months. Difficulty in walking & getting up from squatting

position since 6 months. Since last 3 months swelling over face & feet.

CASE

History

• No H/o headache , vomiting or altered sensorium, seizures.

• With exception of H/O deafness no other H/S/O other cranial nerve involvement.

• No H/S/O sensory, autonomic or cerebellar involvement.

• No H/S/O cardiac, respiratory, renal involvement.

CASE

History• Past History:

• History of similar complaints 3 years back & taken treatment but she was noncompliant. ( Details of Treatment Not available)

• No H/O any other major illness.

• Personal History:• Mixed diet, constipation & somnolence was present.

• Obstetric & Gynecology• One son 25 year old

• Attained menopause 5 years back.

• Family History: • No history of similar complaints in family members

CASE

Examination

General Examination• Patient was conscious, oriented.• BMI 21 kg / m2 (No weight loss, Despite of loss of Appetite)

• Afebrile

• Pulse: 58/min regular (Sinus bradycardia)

• BP: 136/94 mm Hg (Diastolic Hypertension)

• RR: 16/min pallor:- present• Face:• Perorbital swelling with baggy eyelids.• Expressionless face with rough & dry skin of face.

CASE

Examination

General Examination cont….• Thyroid examination was normal• No Icterus, cyanosis, clubbing,

lymphadenopathy.• JVP not raised, Non- pitting pedal edema

present. • Skin all over body: thick & dry.• Examination of spine & skull normal.

CASE

ExaminationSystemic Examination [CNS]

• Higher function : -• Conscious, oriented.

• Speech slow, sluggish & hoarseness of voice.

• Memory impaired.

• Cranial Nerves : - Conductive deafness (VIII)• Motor examination:-

• Nutrition – Normal

• Tone – hypotonia• Power – Grade IV/V around hip joint bilaterally Rest WNL

• Co-ordination – Normal

• No abnormal movements

CASE

Examination

Systemic Examination [CNS]cont….

• Sensory examination : - Normal• Reflexes• Superficial reflexes:- Normal• Deep tendon Reflexes: -

Hung up reflexes-- specially ankle, bicep, triceps

• Cerebellar, autonomic examination normal• Gait : normal but slow

CASE

Examination

Systemic examination [CVS]• Sinus bradycardia and diastolic hypertension, rest

WNL

Systemic examination RS & Per-abdomen WNL

CASE

Patient

• Slow speech , expressionless face.• Here Watch for movements of the hand rather the

muscle

CASE

VID-20130813-WA0000.mp4

Investigations

• Hemogram• Hb – 10 gm/dl, WBC 8000/mm3, platelets 322,000

• Peripheral smear – Normocytic normochromic

• Thyroid function test• TSH – 110 µ U/ml (Normal 0.3-4.3)

• T4 – 0.5 µg/dl (Normal 5.5-11.5)

• T3 - 20 ng/dl (Normal 75-135)

• BUN – 15 mg/dl, Sr. creatinine 0.7 mg/dl• LFT – normal ECG – Sinus bradycardia Anterior

wall ischemia.• X-ray chest – WNL• Lipid profile Chole- 250 mg/dl, Tg – 200 mg/dl.

CASE

Treatment

Tab. Thyroxine 50 µ gm

TSH – 75 µ U/ml

Thyroxine increased to100 µg/dl

TSH – 35 µ U/ml

Thyroxin increased to 150 (OPD visit TSH 3 µ U/ml)

After 1 weeks

After 2 weeks

CASE

Treatment

Other Treatment StatinsAntinatianginal sos AntiplateletAntihypertensive

Discussion Hypothyroidism

DICUSSION

Introduction

• Definition: - “ It is a deficiency in thyroid hormone secretion by thyroid gland, resulting in state of circulating level of thyroid hormone and reduced action at the cellular level”.

• Etiology:Primary hypothyroidism ( 99 %)

Autoimmune Thyroiditis (Hashimoto`s Thyroiditis)Iodine deficiency.Iatrogenic : Surgery, I131 .Drugs : Iodine Excess, lithium, antithyroid drugs.Congenital hypothyroidism & Infiltrative disorders.

DICUSSION

Introduction (cont….)

Secondary hypothyroidismHypopituitarism • Tumor • Surgery / irradiation• Infiltrative disorders• Sheehan`s syndrome

Hypothalamic diseases (Tertiary Hypothyroidism): - Tumor, trauma, infiltrative disorders

Isolated TSH deficiency

DICUSSION

Introduction (cont…)

Transient Hypothyroidism Silent Thyroiditis , including postpartum

thyroiditis Sub-acute thyroiditis Withdrawal of thyroxin therapy After surgery or I131

DICUSSION

Statistics

Epidemiology : - • Prevalence - 0.1 to 2%• 5 – 8 times more common in women.• More common in adult women with small

body size at birth & during childhood.• Prevalence is also increased in elderly patients.• The Framingham study: Above 65 yrs of age

hypothyroidism women 5.9% Men 2.4%

DICUSSION

Statistics (cont…) India• In population-based study in Cochin on 971

adult • Prevalence of hypothyroidism – 3.9%• Subclinical hypothyroidism – 9.4%

• Studies from Mumbai • Congenital hypothyroidism:- 1 out of 2640 neonate

compared to 1 out of 3800 world wide.• Population based study : 800 children with thyroid

diseases 79% had hypothyroidism.

DICUSSION

Clinical Features

GENERAL

• Lethargy, Somnolence

• Weight gain, Goiter• Cold Intolerance

CARDIOVASCULAR

• Bradycardia, Angina• CHF, Pericardial

Effusion Hyperlipidemia.

DICUSSION

NEUROMUSCULAR

• Aches and pains• Muscle stiffness• Carpel tunnel

syndrome• Deafness, Hoarseness• Cerebellar ataxia• Delayed DTR

Myotonia (pseudomytonia)

• Depression, Psychosis

Clinical Features

HAEMATOLOGICAL• Normocytic /

normchromic Anemia• Iron def. Anemia.

REPRODUCTIVE SYSTEM• Infertility, Amenorrhea

Menorrhagia• Impotence.

GASTRO-INTESTINAL• Constipation, Ileus, • Ascites.

Dermatological• Dry flaky skin and hair• Myxoedema, malar

flushes• Vitiligo Carotenimia

Alopecia

DICUSSION

Algorithm for Hypothyroidism

Measure TSH

Elevated TSH

Measure FT4

Normal Low

Sub-clinical hypo

TPO + TPO -

T4 repl Annual FU

Primary hypothyroid

TPO + TPO -

Hashimoto

Others

Normal TSH

TPO: Thyroid PeroxidiseFU: Follow Up

Next Slide

Algorithm for Hypothyroidism

Measure TSH

Elevated TSH Normal TSH

Considering Pituitary

No Yes

No tests Measure FT4

Low Normal

No testsEvaluate PituitarySick EuthyroidDrugs effect

Treatment

• Goal : Normalize TSH level (Generally in Lower Half of reference value)

• Treatment : Once daily dosing with Levothyroxine sodium (1.6µg/kg/day) this comes to 100 - 150 mcg per day

• Timing:- single dose empty stomach.

• Monitor TSH levels at 6 to 8 weeks, after initiation of therapy or dosage change

DICUSSION

How to Start ?

• Available Tab: – 25, 50 and 100 mcg tablets.

• Starting dose

Healthy patients at 1.6µg/kg/day. (Usually 100 – 150 µg/day)

Healthy patients Elderly

< 50 µg/day.

Dose ↑ by 25 µg, if needed, at 6 to 8 weeks intervals.

For patients with heart disease -

12.5 to 25 µg/day and

increase by 12.5 to 25 µg/day, if needed.

DICUSSION

SUBCLINICAL HYPOTHYROIDISM

DICUSSION

Subclinical Hypothyroidism

Definition: -

“Biochemical evidence of thyroid hormone deficiency in patients who have few or no apparent clinical features of hypothyroidism”.

Prevalence: - World wide 1- 10% Sex: - Highest rate in females > 75 yrs.

DICUSSION

Subclinical Hypothyroidism (cont…)

CausesInadequate treatment of overt

hypothyroidism.Transient elevation of TSH: Systemic illnessRare Causes

Heterophil antibody TSH producing pituitary tumor Thyroid hormone resistance

Laboratory errors.

DICUSSION

Subclinical Hypothyroidism (cont…) Risk Factors

Women, > 60 yrs. Autoimmune disease: • Diabetes Mellitus type I• Rheumatoid arthritis• Autoimmune thyroid disorder

Post-partum thyroiditis / Sub-acute thyroiditis. Prior H/O hyperthyroidism following:

surgery or RAI – 131 therapy. Head / neck Radiotherapy. Drugs: - Lithium, Amiodarone, Iodine.

DICUSSION

Subclinical Hypothyroidism (cont…)

EFFECTS OF SH ON BODY

Associated with elevated cholesterol.Altered endothelial function & carotid

intimal thickness.Associated with increased risk of CHD.Impaired mood & cognition.

DICUSSION

Subclinical Hypothyroidism (cont…)

DiagnosisAsymptomatic.Diagnosed during routine thyroid function test.Subclinical Hypothyroidism• Mild: - TSH < 10 mU/L Common• More severe: - 10 – 20 mU/L.

DICUSSION

High TSH

TSH > 10 mU/L TSH 5-10 mU/LFor > 3 months

L levothyroxine TPO Antibody & Other

Positive Negative

No Treatment &Follow up Yearly

High TSH

TSH > 10 mU/L TSH 5-10 mU/LFor > 3 months

L levothyroxine TPO Antibody & Other

Positive Negative

No Treatment &Follow up Yearly

Other: -Increased lipids, young age, pregnancy, anovulation.

Subclinical Hypothyroidism (cont…)

MANAGEMENT Target of the treatment

TSH: - 0.5 – 3.0 mU/L.

Levothyroxine: - 25 – 50 µg / Day.

Subclinical Hypothyroidism (cont…)

BENEFITS OF TREATMENT Improve cardiac function. Improve mood and cognition. Improve symptoms. Prophylaxis against progression. Help to decrease size of goiter. Improve lipid status. Improve quality of life.

MYXEDEMA COMA

DICUSSION

Myxedema Coma

Definition: - “It is serious form of thyroid hormone deficiency associated with altered mental status, hypothermia, Bradycardia high mortality rate around 50%.

Precipitating factors :

• Infection (Pneumonia), Sepsis.

• CVS: - Congestive Cardiac Failure, MI

• CNS: - Cerebrovascular Accidents

• GIT : - GIT bleeding

• Cessation of thyroxin therapy

• Drug : - Sedatives, Antidepressants, diuretics.

DICUSSION

Exposure to cold

Hypoventilation

Hypoxia Hypercapnia

Myxedema

HypoglycemiaDilutional Hyponatremia

Infection

Pathogenesis

Myxedema Coma (cont…)

Clinical Features & Investigations

• Mental confusion, hypothermia, bradycardia.

• ↓ Na, ↓ glucose, ↑ CO2,

• ↓ WBC, ↓ Hematocrit, ↑ CPK

• ↓ EKG voltage, myxedema.

DICUSSION

Treatment

Hormone replacementSupportive TreatmentTreatment of precipitating Factors

DICUSSION

Myxedema Coma (cont…)

Treatment :-

Admission in ICU

Hormone replacement

Inj. Levothyroxine (T4 ) 500 µgm IV Follwed by 50-100 µgm for several days

Can also be given nasogastric tube in same dose

Inj. Levothyronine (T3 ) 10 -20 µgm ( Excess dose Provoke arrhythmia)

Treatment ICU transfer, T3 100 µg IV sixth hourly, 500 µg of T4 ,

antibiotics, ventilation, hydrocortisone IV, passive warming, careful volume management

DICUSSION

Myxedema Coma (cont…)

Supportive Treatment Oxygen (Ventilation, if necessary) External warming (If Temperature < 30º C)oSpace blankets

Inj. Hydrocortisone 50 mg IV 6 hrly.

Treatment of precipitating Factors Broad spectrum antibiotics Hypertonic saline Glucose

Avoid sedatives

DICUSSION

References

1. Desai PM. Disorders of the Thyroid Gland in India. Indian J Pediatr. 1997;64:11–20. [PubMed]

2. Jameson AL, Weetman AP. Disorders of Thyroid gland. In: Fauci, Braunwald, Kasper, Hauser, Longo, Jameson, Loscalzo, editors.Harrison`s Principles of Internal Medicine.18th ed.USA.The McGraw-Hill Companies, Inc;2009.

DICUSSION

References

3. Sawin C, Castelli W, et al. The aging thyroid. Thyroid deficiency in the Framingham Study. Arch Intern Med. 1985;145(8): 1386-8.

4. Bajaj S, Singh SK.Hypothyroidism.In:Bajaj S, et al,editors Manual of Clinical Endocrinology 1st ed. India.Endocrine Society Of India Osmania General Hospital,Inc.2012

DICUSSION

Take Home Massage

Hypothyroidism is common disease which is more common in women

It is one of the condition which can be very well controlled with single dose tablet

So patient must be screened by doing TSH & FT4 to rule out Hypothyroidism & Subclinical Hypothyroidism

Compliance is very importantTreatment for lifelong in case of

hypothyroidism.

DICUSSION