EXPLORATION OF ENDOCRINE SYSTEM EXPLORATION OF ENDOCRINE PANCREAS HORMONAL EXPLORATION IN PREGNANCY
Transcription
EXPLORATION OF ENDOCRINE SYSTEM EXPLORATION OF ENDOCRINE PANCREAS HORMONAL EXPLORATION IN PREGNANCY
EXPLORATION OF ENDOCRINE SYSTEM - EXPLORATION OF ENDOCRINE PANCREAS - HORMONAL EXPLORATION IN PREGNANCY - EVALUATION OF NUTRITION STATUS EXPLORATION OF ENDOCRINE PANCREAS The pancreas has both endocrine and exocrine functions. The endocrine tissue is grouped together in the islets of Langerhans and consists of four different cell types each with its own function. - Alpha cells produce glucagon. - Beta cells produce proinsulin. Proinsulin is the inactive form of insulin that is converted to insulin in the circulation. - Delta cells produce somatostatin. - F or PP cells produce pancreatic polypeptide. Glucagon metabolism Insulin metabolism Exploration of endocrine pancreas is connected with the diagnosis and treatment of diabetes mellitus. This is a complex disease characterized primarily by relative or absolute insufficiency of insulin secretion and concomitant insensitivity or resistance to the metabolic action of insulin on target tissues. Pathophysiology of Diabetes Mellitus Laboratory tests Laboratory tests used in order to explore the pancreas endocrine function are : Fasting blood glucose Oral Glucose Tolerance Test (OGTT) HBA1c level (also called glycosylated haemoglobin level) Urine glucose concentrations Urinary ketone bodies Insulin blood level – measured by RIA ( n. value :10-20 uU/ml ; 21U = 40ug insulin) Glucagon secretion – measured by RIA (n. value: 50-85pg/ml - fasting level) Islet Cell Antibody tests Fructosamine level Fasting blood glucose Normal value : 70 -110 mg/dl ( venous blood ) Variations : >110 mg/dl – hyperglycaemia 50-60 mg/dl - hypoglycaemia Oral Glucose Tolerance Test (OGTT) During the oral glucose tolerance test your blood glucose is tested two hours after drinking 75 grams of glucose (1 g glucose/kg body weight ) solved in 200-300 ml water Normal values : fasting value < 110 mg/dl 2 hours < 140 mg/dl Diabetes mellitus fasting glucose -2 hours - - > 110 mg/dl > 200 mg/dl Impaired glucose tolerance (IGT) fasting glucose -2 hours - - > 110 mg/dl 140 - 200 mg/dl Impaired fasting glycaemia ( IFG) fasting glucose -2 hours - - > 110 mg/dl < 140 mg/dl Glycosylated hemoglobin or hemoglobin A1c This test is a measurement of how high blood sugar levels have been over about the last 120 days (the average life-span of the red blood cells on which the test is based). Excess blood glucose hooks on to the hemoglobin in red blood cells and stays there for the life of the red blood cell. The percentage of hemoglobin that has had excess blood sugar attached to it can be measured in the blood. The test involves having a small amount of blood drawn. %HbA1c Blood glucose level ( mg/dl) Normal value 4-6 110 Good control 6-8 160 Medium control 8-10 200 Poor control >10 >200 Urine glucose concentrations - Normal value : undetectable amounts of glucose in the urine. ( Benedict method) - Variations : Diabetic patients lose glucose in small to large amounts ( glycosuria), in proportion to the severity of disease and the intake of carbohydrates. The renal threshold for glucose ( the arterial blood level at which glycosuria appears) is reached when the glucose concentration in plasma is above 180 mg/dl). Urinary ketone bodies - Normal value : normal individuals do not lose ketone bodies in the urine (Legal - Imbert method) - Variations : the identification ( violet ring ) and the quantity of urinary ketone bodies is important in the diagnosis of the severity of the diabetes. Diabetes mellitus is characterized by recurrent or persistent hyperglycemia, and is diagnosed by demonstrating any one of the following: Fasting plasma glucose level at or above 7.0 mmol /L (126 mg/dL). Plasma glucose at or above 11.1 mmol /L (200 mg/dL) two hours after a 75 g oral glucose load as in a glucose tolerance test. Symptoms of hyperglycemia and casual plasma glucose at or above 11.1 mmol/L (200 mg/dL). Glycated hemoglobin (hemoglobin A1C) at or above 6.5. (This criterion was recommended by the American Diabetes Association in 2010). HORMONAL EXPLORATION IN PREGNANCY Pregnancy tests All pregnancy tests work by detecting a certain hormone in the urine or blood that is only there when a woman is pregnant. This hormone is called human chorionic gonadotropin or hCG. It is also called the pregnancy hormone. HCG is being produced by the placenta and enters the blood stream as soon as implantation happens, about one week after fertilization and ovulation, when the embryo implants and the placenta attaches to the uterine lining. Quantitative tests ( blood tests) : - hCG < 5 mIU/ml : Negative. Not pregnant - hCG : 5-25 mIU/ml : "Equivocal". Maybe pregnant maybe not. Repeat test in a couple of days - hCG > 25 mIU/ml : You are pregnant! hCG Information hCG is measured in milli-international units per milliliter (mIU/ml) There is a wide range of normal hCG levels and values and the values are different in blood serum or urine. Urine hCG levels are usually lower than serum (blood) hCG levels. Blood hCG testing is much more sensitive than a urine HPT. This means that the blood test can detect pregnancy several days earlier than the urine test, as early as 2-3 days after implantation or 8-9 days after fertilization. Urine tests measure the urine HCG qualitatively, which means that the HPT results are either "positive" or "negative." Around the time of the first missed period (14+ days after ovulation), over 95% of HPTs are usually positive. About 85% of normal pregnancies will have the hCG level double every 48 72 hours. As you get further along into pregnancy and the hCG level gets higher, the time it takes to double can increase to about every 96 hours hCG Information 1. Greater than normal levels of human chorionic gonadotropin (hCG) may indicate: a tumor of the placenta with death of the fetus multiple pregnancy, such as twins or triplets ovarian cancer and other types of cancer in some cases a normal pregnancy blood or protein in the urine, which can interfere with the result use of medications to prevent seizures, drugs to treat Parkinson’s syndrome, or phenothiazine drugs, such as chlorpromazine, by the mother 2. Lower-than-normal human chorionic gonadotropin (hCG) levels may indicate: ectopic pregnancy a miscarriage, or abortion. Home Pregnancy Tests ( HPT) - qualitative tests Home Pregnancy Tests ( HPT) SPECIMEN COLLECTION AND PREPARATION : For optimal detection of early pregnancy, a "first morning" urine specimen is preferred, since it contains the highest concentration of ß hCG. However, randomly collected urine specimens may be used. Collect the urine specimen in a clean container. If testing is not immediate, the specimen should be refrigerated (4 degrees C )or kept cool (below 25 degrees C )for up to twenty-four hours. In any case, bring the specimen to room temperature prior to testing. atc anti-hCG + hCG Positive test : = coloured reaction ( coloured line) (on the stick) (urine) READING TEST RESULTS: 1. Negative: One (1) colored band appears in the control region (C). No apparent band is detectable in the test region (B). 2. Positive: In addition to the control band, a clearly distinguishable band also appears in the test region (B), indicating the presence of ß hCG in the sample. 3. Inconclusive: The test is inconclusive in the absence of distinct color bands in both the control (C) and test window (B). In this case, it is recommended that the test be repeated, or a fresh specimen be obtained and tested forty-eight hours later. EVALUATION OF NUTRITION STATUS ( somatic measurements) Body weight ( kg): IBW - Estimated ideal body weight in (kg) Males: IBW = 50 kg + 2.3 kg for each inch over 5 feet. Females: IBW = 45.5 kg + 2.3 kg for each inch over 5 feet. ABW - Estimated adjusted body weight (kg) If the actual body weight is greater than 30% of the calculated IBW, calculate the adjusted body weight (ABW) ABW = IBW + 0.4(actual weight - IBW) Body Mass Index (BMI) The body mass index (BMI) is a statistical measure which compares a person's weight and height. Though it does not actually measure the percentage of body fat, it is used to estimate a healthy body weight based on a person's height. Due to its ease of measurement and calculation, it is the most widely used diagnostic tool to identify weight problems within a population, usually whether individuals are underweight, overweight or obese . BMI Categories: Underweight = <18.5 Normal weight = 18.5-24.9 Overweight = 25-29.9 Obesity = BMI of 30 or greater Body Mass Index (BMI) Body Mass Index (BMI)