February 15, 2010 by akhilendra
Diabetes Mellitus
Diabetes mellitus is a metabolic syndrome which is caused due to either lack of insulin or due to decreased responsiveness of insulin of peripheral tissues to secreted insulin. It is a disorder which comprises of abnormal metabolism, which results in high blood sugar level (hyperglycemia). Blood glucose levels are controlled by insulin, which is secreted by beta cells of langerhans of pancreas. It is characterized by,
- Excessive urine Production
- Increased thirst
- Blurred vision
- Increased weight loss
- Lethargy
It is classified into,
1) Type 1 Diabetes mellitus – It is characterized by reduced secretion of insulin by beta cells resulting in lack of insulin. It can be immune-mediated or idiopathic. Most of the type 1 diabetes mellitus is immune mediated, where beta cells are destroyed due autoimmune reactions. It can affect young adults or children. It is also termed as “Juvenile diabetes”.
2) Type 2 Diabetes mellitus – It is characterized by resistance to secreted insulin or reduced insulin sensitivity, combined with either reduced or no insulin secretion. It involves responsiveness of insulin receptor in cell membrane. It may go unnoticed in initials stage as symptoms are mild, non-existent or sporadic.
3) Gestational diabetes– It resembles type 2 diabetes mellitus. It involves relatively low insulin secretion and responsiveness. It occurs in 2-5 percent of all pregnancies and may improve or disappear with delivery. Gestational diabetes is treatable. About 20-50 percent of affected women develop type 2 diabetes in later stages of life.
Pathophysiology
Insulin is the main hormone which regulate the glucose consumption by most of the cells. Lack of insulin or resistance to secreted insulin by cells will result in a metabolic syndrome resulting in elevated blood glucose level. Insulin is secreted by beta cells, of the islet of Langerhans in pancreas. Insulin regulates the procedure of conversion of glucose to glycogen, which is stored in liver.
Methods of diagnosis
The diagnosis is generally prompted by increased thirst(Polydipsia), increased urination(Polyuria) and weight loss. About 25 percent of people with Type 1 diabetes develop Ketoacidosis.
It is demonstrated by any one of the following,
l Fasting Plasma glucose level at or above 126 mg/dl
l Plasma Glucose level or above 200 mg/dl two hours after a 75 g oral glucose load as in GTT (Glucose Tolerance test)
l Symptoms of Hyperglycemia and casual Plasma glucose at or above 200 mg/dl
Hba1c ( Glycosylated haemoglobin) – Though it is mainly used for tracking the treatment, but sometimes it is used by physicians to track the blood glucose level of last 90 days. Its value differs with labs but for most of the labs, a value of 6.0 percent or higher is considered as abnormal. Recommended level for diabetic patient is upto 7 percent.
For screening purpose, various methods are/can be chosen,
– Fasting Blood glucose
– Post-Prandial blood glucose level
– Random glucose levels
Complications
Diabetic Ketoacidosis– It is a acute and dangerous complication. It is characterized by elevated level of ketone bodies in blood. Low insulin levels causes liver to turn fat to glucose. Ketones are byproduct of the reaction. Ketoacidosis generally led to coma. Elevated level of ketone in blood causes decrease in its pH value. Ketoacidosis can easily cause hypotension, shock and death.
Hyperglycemia hyperosmolar state
HNS is an acute complication. When blood glucose level is very high (300mg/dl),water is osmotically drawn out of the cells into the blood and the kidney eventually excrete glucose in urine. This results in loss of water and an increase in blood osmolarity. If fluid is not replaced then it result in dehydration. Electrolyte imbalance is very common.
Hypoglycaemia
hypoglycaemia or abnormally low blood glucose level, is a diabetes treatment. The patient may get sweaty, agitated and symptoms of sympathetic activation of the autonomic nervous system. In extreme cases, consciousness may be lost leading to coma, seizures or brain damage and death. This condition occur due to anti-hyperglycaemic effect of the drugs, which are used for the treatment of diabetes.
Vascular disease
Chronic elevation of blood glucose level leads to damage of blood vessel(angiopathy). The endothelial cell lining the blood vessel takes in more glucose than usual and form more glycoproteins and cause basement membrane to grow thicker and weaker. Damage to small blood vessels is known an mirovascular disease and damage to big vessels is called macrovascluar disease.
Diabetic retinopathy- diabetes result in growth of poor-quality blood vessels in retina and macula edema ( swelling of the macula). This can lead to severe vision loss or blindness.
Diabetic neuropathy- it causes abnormal and decreased sensation starting from feet and later in hands and fingers. When it co-exist with damaged blood vessels it result in diabetic foot.
Diabetic nephropathy- diabetes can cause damage to kidney resulting in chronic renal failure. Diabetes is the most common cause of adult kidney failure.
Diabetic cardiomyopathy- it damages to the heart causing diastolic dysfunction and eventually heart failure. It can accelerate atheroscloresis. It worsen the situation in cases of heart patients.
Leave a Reply