Diabetes mellitus is a chronic metabolic disorder characterized by high blood glucose levels (hyperglycemia) resulting from defects in insulin secretion, insulin action, or both. It can lead to serious health complications if not properly managed.
Types of Diabetes
1. Type 1 Diabetes: An autoimmune condition where the body’s immune system attacks insulin-producing beta cells in the pancreas, leading to little or no insulin production. It typically develops in childhood or adolescence.
2. Type 2 Diabetes: A condition where the body becomes resistant to insulin or the pancreas fails to produce enough insulin. It is more common in adults, often associated with obesity and a sedentary lifestyle.
3. Gestational Diabetes: Develops during pregnancy and usually disappears after giving birth. However, it increases the risk of developing type 2 diabetes later in life.
4. Other Specific Types: These include monogenic diabetes syndromes, diseases of the exocrine pancreas (such as cystic fibrosis), and drug- or chemical-induced diabetes.
Cause of Diabetes
– Type 1 Diabetes: Autoimmune destruction of beta cells, possibly triggered by genetic and environmental factors.
– Type 2 Diabetes: Combination of genetic predisposition and lifestyle factors such as obesity, physical inactivity, poor diet, and aging.
– Gestational Diabetes: Hormonal changes during pregnancy that affect insulin action.
– Other Types: Genetic mutations, diseases, or certain medications can cause diabetes.
Pathophysiology of Diabetes
– Type 1 Diabetes:
– Immune-Mediated Destruction: The body’s immune system mistakenly targets and destroys the insulin-producing beta cells in the pancreatic islets of Langerhans. This autoimmune response involves T-cells and is often associated with the presence of autoantibodies such as islet cell antibodies (ICA) and glutamic acid decarboxylase antibodies (GAD).
– Insulin Deficiency: As beta cells are destroyed, insulin production decreases, leading to an absolute deficiency of insulin. Without insulin, glucose cannot be taken up by cells, resulting in hyperglycemia.
– Ketoacidosis: Due to lack of insulin, cells use fat as an alternative energy source, leading to the production of ketones. High levels of ketones can result in diabetic ketoacidosis (DKA), a life-threatening condition.
– Type 2 Diabetes:
– Insulin Resistance: Peripheral tissues (muscle, fat, liver) become less responsive to insulin. Insulin resistance is often linked to obesity, particularly visceral adiposity, which releases free fatty acids and pro-inflammatory cytokines that interfere with insulin signaling.
– Compensatory Hyperinsulinemia: In the early stages, the pancreas compensates for insulin resistance by producing more insulin. This compensatory hyperinsulinemia can maintain normal glucose levels initially.
– Beta Cell Dysfunction: Over time, the pancreatic beta cells become dysfunctional and are unable to sustain the increased insulin demand. This leads to relative insulin deficiency and hyperglycemia.
– Metabolic Syndrome: Many individuals with type 2 diabetes also have other components of metabolic syndrome, including hypertension, dyslipidemia, and central obesity, which further complicate glucose regulation and increase cardiovascular risk.
– Gestational Diabetes:
– Hormonal Changes: During pregnancy, the placenta produces hormones that can induce insulin resistance, including human placental lactogen, progesterone, and cortisol. These hormones help ensure adequate glucose supply to the fetus but can impair maternal glucose regulation.
– Increased Insulin Demand: The mother’s pancreas must produce more insulin to overcome this resistance. If the pancreas cannot meet this demand, hyperglycemia results.
– Postpartum Risk: Although gestational diabetes typically resolves after childbirth, it increases the risk of developing type 2 diabetes later in life for both the mother and the child.
– Other Types:
– Monogenic Diabetes: Caused by single gene mutations that affect insulin production or secretion, such as in maturity-onset diabetes of the young (MODY).
– Diseases of the Exocrine Pancreas: Conditions like cystic fibrosis or pancreatitis can damage the pancreas, impairing its ability to produce insulin.
– Drug- or Chemical-Induced Diabetes: Certain medications (e.g., glucocorticoids, some antipsychotics) and toxins can interfere with insulin production or action.
Symptoms of Diabetes
– Frequent urination (polyuria)
– Excessive thirst (polydipsia)
– Extreme hunger (polyphagia)
– Unexplained weight loss
– Fatigue
– Blurred vision
– Slow-healing sores or frequent infections
– Ketones in the urine (in type 1 diabetes)
– Numbness or tingling in the hands or feet (in type 2 diabetes)
Treatment of Diabetes
– Lifestyle Changes: Healthy diet, regular physical activity, maintaining a healthy weight, and monitoring blood sugar levels.
– Medications:
– Type 1 Diabetes: Insulin therapy (injections or insulin pump).
– Type 2 Diabetes: Oral hypoglycemic agents (e.g., metformin, sulfonylureas, DPP-4 inhibitors), non-insulin injectables (e.g., GLP-1 receptor agonists), and insulin in some cases.
– Monitoring: Regular blood glucose monitoring, HbA1c testing, and continuous glucose monitoring (CGM) for some patients.
– Education: Patient education on managing diabetes, recognizing symptoms of hypo- and hyperglycemia, and adjusting lifestyle and treatment plans.
– Other Treatments: Bariatric surgery for obese individuals with type 2 diabetes, as it can lead to significant weight loss and improvement in glucose control.
Proper management of diabetes involves a comprehensive approach that includes medical treatment, lifestyle changes, and regular monitoring to prevent complications and improve quality of life.
