Pathophysiology - Diabetes

Diabetes Insipidus

• not to be confused with diabetes mellitus
• is a condition caused by a deficiency or total absence of vasopressin (ADH)
• maybe a result of congenital deficiency
• maybe induced by damage to posterior lobe due to surgery, tumor, trauma
• major symptom is inability to concentrate urine (low specific gravity)
• polyuria - production of large volumes of urine
• polydipdis - excessive thirst
• development of dehydration and hypernatremia
• diagnostic test 
• water deprivation test
• the client is instructed not to drink water to concentrate urine. If urine remains dilute, the patient is positive for diabetes insipidus

Diabetes Mellitus

• is a metabolic disorder characterized by a relative or absolute lack of the hormone insulin resulting in impaired fat, carbohydrate and protein metabolism
• can also result from
• pancreatic and endocrine diseases
• certain forms of drug therapy
• autoimmune response
• secreted by the beta cells of the islets of langerhans
• untreated DM may increase clients susceptibility to cardiovascular disease, cause kidney and nerve damage and vision loss as in diabetic retinopathy
• Pathophysiology
• when CHO is ingested blood glucose begin to rise
• triggers to release the insulin from the pancreas
• insulin transport glucose to cells, converts glycogen into glucose, utilization of fatty acids by cells and at the same time inhibits breakdown of fats to fatty acids
• continued release of insulin causes a reduction in blood glucose concentration (hypoglycemic state)
• this results in the inhibition of further insulin release
• blood sugar levels range between 115-125mg/dl
• when blood glucose exceeds 180mg/dl excess glucose can spill in urine
• this may draw water in the urinary tract increasing frequency of urination