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Pathophysiology of Diabetes MellitusStudies conducted on the pathophysiology of diabetes mellitus suggested that abnormal metabolism of insulin hormone is the primary cause for the development of this complex syndrome. Even though the etiologies and triggering factors of the three types of diabetes mellitus are different, they cause nearly the same symptoms and complications.
What is Diabetes Mellitus Diabetes mellitus (DM) or simply diabetes, is a chronic health condition in which the body either fails to produce sufficient amounts of insulin or it responds abnormally to insulin. Commonly referred to as a syndrome, diabetes is classified into three types, namely, Type 1 diabetes, Type 2 diabetes, and Gestational diabetes. The ultimate outcome for all three types of diabetes is high blood glucose level. The pathophysiology of diabetes mellitus is very complex, as this ailment is characterized by different etiologies while sharing similar signs, symptoms, and complications. Diabetes Mellitus: Pathophysiology The pathophysiology of all types of diabetes is related to the hormone insulin, which is secreted by the beta cells of the pancreas. In a healthy person, insulin is produced in response to the increased level of glucose in the bloodstream, and its major role is to control glucose concentration in the blood. What insulin does is, allowing the body cells and tissues to use glucose as a main energy source. Also, this hormone is responsible for conversion of glucose to glycogen for storage in the muscles and liver cells. This way, sugar level is maintained at a near stable amount. In a diabetic person, there is an abnormal metabolism of insulin hormone. The actual reason for this malfunction differs according to the type of diabetes. Whatever the cause is, the body cells and tissues
do not make use of glucose from the blood, resulting in elevated blood glucose (a typical symptom of diabetes called hyperglycemia). This condition is also exacerbated by the conversion of stored glycogen to glucose, i.e., increased hepatic glucose production. Over a period of time, high glucose level in the bloodstream can lead to severe complications, such as eye disorders, cardiovascular diseases, kidney damage, and nerve problems. In Type 1 diabetes, the pancreas cannot synthesize enough amounts of insulin as required by the body. The pathophysiology of Type 1 diabetes mellitus suggests that it is an autoimmune disease, wherein the body's own immune system generates secretion of substances that attack the beta cells of the pancreas. Consequently, the pancreas secretes little or no insulin. Type 1 diabetes is more common among children and young adults (around 20 years). Since it is common among young individuals and insulin hormone is used for treatment, Type 1 diabetes is also referred to as Juvenile Diabetes or Insulin Dependent Diabetes Mellitus (IDDM). In case of Type 2 diabetes mellitus, the insulin hormone secreted by the beta cells is normal or slightly lower than the ideal amount. However, the body cells are not responding to insulin as they do in a healthy person. Since the body cells and tissues are resistant to insulin, they do not absorb glucose, instead it remains in the bloodstream. Thus, the Type 2 diabetes is also characterized by elevated blood sugar. It is commonly manifested by middle-aged adults (above 40 years). As insulin is not necessary for treatment of Type 2 diabetes, it is known as Non-insulin Dependent Diabetes Mellitus (NIIDM) or Adult Onset Diabetes. The third type of diabetes is called Gestational diabetes. As the term clearly suggests, it is exhibited by pregnant women. Over here, high level of blood glucose is caused by hormonal fluctuations during pregnancy. Usually, the sugar concentration returns to normal after the baby is born. However, there are also instances, in which it remains high even after childbirth. This is an indication for increased risks of developing diabetes in the near future. As already mentioned, the symptoms and effects of all the three forms of diabetes are similar. The noticeable symptoms include increased thirst (polydipsia), increased urination (polyuria), and increased appetite (polyphagia). Other diabetes signs and symptoms include excessive fatigue, presence of sugar in the urine (glycosuria), body irritation, unexplained weight loss, and dehydration. Elevated blood sugar and glycosuria are interrelated; when sugar amount in the blood is abnormally high, the reabsorption by proximal convoluted tubule is reduced, thereby retaining some glucose in the urine. Diabetes Mellitus: Diagnosis and Treatment Regarding the definition of diabetes mellitus, it is often described as a fasting blood glucose level of 126 milligrams per deciliter (mg/dL) or more. As per statistics, Type 2 diabetes is the most commonly occurring type, in comparison to the other two forms of diabetes mellitus. Early and correct detection of the diabetes is necessary to prevent severe health effects. After diagnosis, the physician prescribes appropriate medication for treatment of diabetes, which may include insulin injections or oral insulin
medicines, depending upon the type of diabetes mellitus. In addition to the therapeutic intervention, healthy lifestyle modifications, especially in terms of diet and exercises are recommended for effective management of diabetes symptoms and long-term effects. Since it is a global health issue, studies regarding the diabetes mellitus pathophysiology are currently in progress in order to minimize its associated health effects, and also, to treat it effectively. By Ningthoujam Sandhyarani Last Updated: 11/16/2011 http://www.buzzle.com/articles/pathophysiology-of-diabetes-mellitus.html
Gestational Diabetes- Carla Janzen, MD, Jeffrey S. Greenspoon, MD
Essentials of Diagnosis
Any degree of glucose intolerance with onset or first recognition during pregnancy. In the majority of cases of GDM, glucose regulation will return to normal after delivery.
DefinitionThe above definition applies regardless of whether insulin or only diet modification is used for treatment or whether the condition continues after pregnancy. It is possible that unrecognized glucose intolerance may have antedated or begun concomitantly with pregnancy. Gestational diabetes may be screened for by drawing a 1-hour glucose level following a 50-gram glucose load, but is definitively diagnosed only by an abnormal 3-hour GTT following a 100gram glucose load. Such persons are not within the norm (95%) for pregnancy.
SignificanceThe growth and maturation of the fetus are closely associated with the delivery of maternal nutrients, particularly glucose. This is most crucial in the third trimester and is directly related to the duration and degree of maternal glucose elevation. Thus the negative impact is as highly diverse as the variety of carbohydrate intolerance that women bring to pregnancy. In those with severe abnormalities, there is an increased rate of miscarriage, congenital malformations, prematurity, pyelonephritis, preeclampsia, in utero meconium, fetal distress, cesarean section deliveries, and stillbirth.
Incidence & Etiology
Inability to maintain glucose levels required by the body for proper functioning is a growing health problem in the United States; thus it is not surprising that more women are found during pregnancy to be unable to attain the low glucose levels required for proper fetal growth. The incidence of gestational diabetes varies from 12% in racially heterogeneous urban regions to 1% in rural areas with a predominantly white population.
PathophysiologyGestational diabetes is pathophysiologically similar to type 2 diabetes. Approximately 90% of the persons identified have a deficiency of insulin receptors (prior to pregnancy) or a marked increase in weight in the abdominal region. The other 10% have deficient insulin production and will proceed to develop mature-onset insulin-dependent diabetes. Similarly to women with type 2 diabetes, the women most likely to develop gestational diabetes are those who are overweight, with a body habitus often described as "apple shaped." HPL blocks insulin receptors and increases in direct linear relation to the length of pregnancy. Insulin release is enhanced in an attempt to maintain glucose homeostasis. The patient experiences increased hunger due to the excess insulin release as a result of elevated glucose levels. This insulin release further decreases insulin receptors due to elevated hormonal levels. Thus the vicious cycle of excess appetite with weight gain occurs. Few other symptoms mark this condition.
DiagnosisGlucosuria is a common Diabetes Mellitus & Pregnancy finding in pregnancy due to increased glomerular filtration and is therefore unreliable as a means of diagnosis. Glucose screening Introduction should be done in every Metabolism in Normal & Diabetic Pregnancy pregnant patient at or no Diagnostic Criteria for Diabetes Mellitus Prior to Pregnancy later than 28 weeks' Diagnostic Criteria for Gestational Diabetes Mellitus gestation, since risk factors Pregestational Diabetes are insufficient to identify all L Type 1 Diabetes (Insulin-Dependent) women with gestational L Type 2 Diabetes (Non-Insulin Dependent) diabetes. Ultrasound Gestational Diabetes findings of fetal weight Antepartum Care 70% for gestational age, Neonatal Complications polyhydramnios (AFI 20), Intrapartum & Postpartum Management midline congenital L Prognosis anomalies, or an abdominal References circumference measurement that exceeds the femur
growth by 2 weeks merit an immediate 3-hour GTT. Other clinical findings indicating possible diabetes are edema developing early in pregnancy and excessive weight gain. Initial screening is accomplished by ingestion of 50 grams of glucose (usually chilled glucola) at any time of the day