Clinical Endocrinology - Pituitary Disorders PDF

CLINICAL ENDOCRINOLOGY DORICE BERKOH DEPT. OF BASIC & APPLIED BIOLOGY UENR-SUNYANI. Hear the hormones Speak…. We are the chemical messengers of the body With diverse structure and function We act directly or through messengers Growth, health and welfare is our motto… ...

CLINICAL ENDOCRINOLOGY DORICE BERKOH DEPT. OF BASIC & APPLIED BIOLOGY UENR-SUNYANI. Hear the hormones Speak…. We are the chemical messengers of the body With diverse structure and function We act directly or through messengers Growth, health and welfare is our motto…  Hormones and the Endocrine System  Hormones are organic substances produced in small amounts by specific tissues (endocrine glands) secreted into the blood stream to control the metabolic and biological activities in target cells.  Hormones may be regarded as the chemical messengers involved in the transmission of information from one cell to another and from one tissue to another.  Endocrinology is the study of hormones and disorders associated with abnormalities of these hormones.  Hormones perform endocrine, paracrine, autocrine, juxtacrine, exocrine and neuroendocrine actions. Classification of Hormones  Steroids  Lipid in nature  Travel to target site and immediately diffuse into the cell membrane  Water insoluble and hence require carrier proteins (eg cortisol-binding globulin)  Long half-life; 4-120 mins Protein and Amine hormones  Protein hormones peptide or glycoprotein in nature. Mostly synthesized as prohormones, water soluble  They have a half life of 4-40 mins  Amine hormones are derived from amino acids. They circulate unbound to carrier molecules and have a short half-life  THE PITUITARY GLAND  Also known as hypophysis. Made up of two segments:  The adenohypophysis (or anterior pituitary) provides secondary level of control and stimulation. It produces and secretes stimulating hormones (tropins, usually glycoprotein hormones)  The neurohypophysis (posterior pituitary) primarily stores and releases certain hormones produced by the hypothalamus (oxytocin and antidiuretic hormone) HORMONES SECRETED BY THE PITUITARY GLANDS  Posterior Pituitary: antidiuretic hormone (ADH), Oxytocin  Anterior Pituitary: Adrenocorticotrophic hormone (ACTH), Thyroid-stimulating hormone (TSH), Luteinizing hormone (LH), Follicle-stimulating hormone (FSH), prolactin (PRL), Growth hormone (GH), Melanocyte –stimulating hormone (MSH)  PITUITARY DISORDERS  Pituitary disorders or disease affect primarily the pituitary gland  Main disorders affecting the pituitary are as follows:  Pituitary hormone - Hyperpituitarism (most commonly pituitary adenoma) overproduction  Hypopituitarism underproduction any pituitary hormone  Acromegaly overproduction growth hormone  Cushing's disease overproduction Adrenocorticotropic hormone  Growth hormone deficiency underproduction growth hormone  Syndrome of inappropriate antidiuretic hormone overproduction vasopressin Diabetes insipidus (can also be nephrogenic)  underproduction vasopressin Sheehan syndrome Hypothalamic-Pituitary-HORMONAL Axis Hypothalamus X + - Anterior Pituitary - Y + - A B THE HYPOTHALAMIC-PITUITARY-ADRENAL AXIS  PITUITARY DWARFISM IN CHILDHOOD  The lack of growth hormone in childhood results in dwarfism. It may be: 1. Idiopathic 2. Secondary to tumours in and around the pituitary e.g. craniopharyngioma  In the idiopathic type, shortness of stature first noticed at the age of 2 to 3 years. The body proportions are normal  There is usually delay in tooth eruption and bone show retarded growth. As years go by, height remains shorter even when compared to bone age, more so to chronological age  The facial features are immature. Muscle bulk is below normal  There is also sexual infantilism  PANHYPOPITUITARISM IN ADULT LIFE  The syndrome of panhypopituitarism is often due to atrophy or degeneration of the anterior pituitary and is also known as Simmond’s disease. In some instances the cause of the anterior pituitary involvement may be due to;  Granulomatous lesions  Invasion of tumour  Surgery or radiation The resulting lack of topic hormone e.g. gonadotropins, corticotropin etc. become manifest in due course CLINICAL MANIFESTATIONS 1. Gradual loss of 20 sex characteristics 2. Loss of pubic auxiliary hair 3. Genital hypoplasia 4. Secondary amenorrhoea 5. Sensitivity to cold 6. Absence of sweating, depigmentation with pallor of skin 7. Poor tolerance of infection, tendency to coma SUMMARY OF THE CAUSES OF PITUITARY HYPOFUNCTION  Tumour  Infarction  Trauma  Congenital malformation  Infection  Hypothalamic disorder PITUITARY HYPERFUNCTION  Pituitary Gigantism in Childhood  Gigantism results from excessive production of growth hormone in the prepubertal period and this is usually associated with eosinophilic adenoma of the pituitary, CAH, Hyperthyroidism or inherited disorders such as Klinefelter’s syndrome  Tallness can be to the extent of 7 to 9 feet usually with postural defects. Normal pubertal growth is absent. Hands and feet may be very large ACROMEGALY IN ADULT LIFE Acromegaly results from over-function of the pituitary especially in the production of somatotropin in adult life. The most likely cause is a pituitary adenoma The clinical manifestation are: Overgrowth of endochondral bone and skeletal changes become most marked in acral portions Skin is thickened, coarse and greasy. Increase in folds especially on the forehead gives a bull-dog like appearance Hands and feet become spatulate in appearance Body hair may increase and result in mild hirsutism Protruding jaw (prognathism) Larynx changes result in alteration which become deep and gruffly Sweating Impaired glucose tolerance  or DM, Goitre, hypertension, adrenal hyperfunction, gonadal hypofunction Headaches, visual defects due to pressure defects DIAGNOSIS OF ACROMEGALY 1. X-ray of the pituitary fossa 2. Assessment of heel-pad thickness and assay of GH(the basal serum are elevated) 3. GTT- A normal person will suppress GH in response to glucose load (expected metabolic response) The acromegallic patient’s GH levels do not suppress in response to a high glucose load 4. IGF1- Elevated levels of IGF1 in serum confirm the diagnosis of acromegally 5. The Triple function test THE COMBINED ANTERIOR PITUITARY FUNCTION TESTS (CAPFT)  This involves the simultaneous administration of insulin (stimulates ACTH, GH and Prolactin), TRH (stimulates TSH and Prolactin) and GnRH (stimulates FSH and LH).  Measure baseline and at time 30, 60, 90, and 120 of all hormones.  Results- Normal Response, Cortisol- x5 fold increase,  GHx50 Fold increase, LH x 20 fold, FSH x 5fold, TSH x20 fold.  Draw Graphs CASE STUDY 1 Kofi Taller a 21-year old mason and a native of Anomabo, recently became worried when his friends begun teasing him of his excessive height(1.85metres) and funny limbs. A doctor friend advised him to see an endocrinologist about his condition. He sweats often, has elevated but not extremely elevated high blood pressure. He also complains of intemittent headaches.  What is the possible differential diagnosis?  How would you investigate this case to arrive at a definitive diagnosis?  How would you manage such a patient and why? END OF PART 1