Diabetes I Flashcards
Diabetes Mellitus definition
+ A chronic multisystem disease related to
Abnormal insulin production
Impaired insulin utilization
Or both
+ Requires a multi-dimensional approach to successful management
How harmful is Diabetes mellitus
\+ Leading cause of End-stage renal disease Adult blindness Nontraumatic lower limb amputations \+ Major contributing factor Heart disease Stroke
Etiology and Pathophysiology of DM
\+ Theories link cause to single/ combination of these factors Genetic Autoimmune Viral Environmental
\+ Common types Type 1 Type 2 Prediabetes ** Other types Gestational Secondary diabetes
Altered Mechanisms in Type 1 and Type 2 Diabetes
Type 1 diabetes: Genetically susceptible individuals develop islet cell autoantibodies months to years before diagnosis of type 1 diabetes. Progressive autoimmune destruction of beta cells (80% -90% reduction) leads to hyperglycemia and diagnosis of type 1 diabetes.
+ Type 2 - Insulin resistance, caused by inherited defects in insulin receptors, is a universal finding in patients with type 2 diabetes. Precedes development of impaired glucose tolerance and type 2 diabetes by as much as 3 to 4 decades. Insulin resistance stimulates a compensatory increased insulin production by beta-cells in pancreas.
In pancreas: beta cell defects results in a decreased insulin secretory capacity below the amount needed for the degree of insulin resistance leading to hyperglycemia and the diagnosis of diabetes
In liver: excessive hepatic glucose production causes increased hyperglycemia in the fasting and postprandial state.
In adipose tissue: Adipokines from adipose tissue have a role in altered glucose and fat metabolism
Prediabetes
Individuals already at risk for diabetes Usually present with no symptoms Blood glucose high but not high enough to be diagnosed as having diabetes Long-term damage already occurring Heart, blood vessels \+ Must watch for diabetes symptoms - Polyuria - Polyphagia - Polydipsia
characteristics of Prediabtes
Characterized by
Impaired fasting glucose (IFG)
IFG: Fasting glucose levels are 100 to 125 mg/dL
Impaired glucose tolerance (IGT)
IGT: 2-Hour plasma glucose levels are between 140 and 199 mg/dL
AIC is in range of 5.7% to 6.4%.
Type 1 Diabetes Mellitus
Formerly known as “juvenile-onset” or “insulin-dependent” diabetes
Most often occurs in people younger than 40 years of age
Occurs more frequently in younger children
Type 2 Diabetes Mellitus
Most prevalent type of diabetes
Accounts for more than 90% of patients with diabetes
Usually occurs in people over 35 years of age
80% to 90% of patients are overweight.
Prevalence increases with age.
Genetic basis
Type 2 Diabetes MellitusEtiology and Pathophysiology
\+ Some endogenous insulin.
- Insulin produced is insufficient or is poorly utilized by tissues.
\+ Obesity (abdominal/visceral)
-Most powerful risk factor
\+ Genetic mutations
-Lead to insulin resistance
- Increased risk for obesity
- Insulin resistance
- Pancreas ↓ ability to produce insulin
- Inappropriate glucose production from liver
- Alteration in production of hormones and adipokines
Clinical ManifestationsType 2 Diabetes Mellitus
Nonspecific symptoms ( May have classic symptoms of type 1) Fatigue Recurrent infection Recurrent vaginal yeast or monilia infection Prolonged wound healing Visual changes
Diabetes MellitusDiagnostic Studies
AIC ≥ 6.5%
Ideal goal
ADA ≤7.0%
American College of Endocrinology 126 mg/dL
Random or casual plasma glucose measurement ≥200 mg/dL plus symptoms
Two-hour OGTT level ≥200 mg/dL when a glucose load of 75 g is used
Drug Therapy: Type 2Insulin
Exogenous insulin
Insulin from an outside source
Required for type 1 diabetes
Prescribed for patient with type 2 diabetes who cannot control blood glucose by other means
Often used for Type 2 patients in acute care who otherwise do not use insulin
Drug TherapyInsulin: storage and administration
++ Storage of insulin
Do not heat/freeze.
In-use vials may be left at room temperature up to 4 weeks.
Extra insulin should be refrigerated.
Avoid exposure to direct sunlight.
++Administration of insulin
Cannot be taken orally
Subcutaneous injection for self-administration
IV administration
Administration of insulin
Fastest absorption from abdomen, followed by arm, thigh, and buttock
Abdomen is the preferred site
Rotate injections within one particular site.
Do not inject in site to be exercised.
Drug Therapy: Insulin pump
Insulin pump Continuous subcutaneous infusion Battery-operated device Connected via plastic tubing to a catheter inserted into subcutaneous tissue in abdominal wall Potential for tight glucose control
Problem with insulin
++Problems with insulin therapy
Hypoglycemia
Allergic reaction
Lipodystrophy
Somogyi effect
Dawn phenomenon
++++Somogyi effect
- Rebound effect in which an overdose of insulin causes hypoglycemia in am
- Counterregulatory hormones released and cause rebound hyperglycemia and ketosis
+++++ Dawn phenomenon
- Characterized by hyperglycemia present on awakening in the morning
- Due to release of counterregulatory hormones in predawn hours
- Growth hormone/cortisol possible factors
Drug TherapyOral Agents
Focus on three defects of type 2 diabetes
+ Improve insulin resistance
Sulfonylureas, Biguanides, Thiazolidinediones
+ Improve insulin production
Sulfonylureas, Meglitinides, DPP-4 Inhibitors, Incretin Mimetic
+ Decrease hepatic glucose production
Sulfonylureas, Biguanides, Thiazolidinediones
Drug TherapyKnow these
\+ Sulfonylureas
Glipizide, glyburide
\+ Meglitinide
repaglinide
\+ Biguanides
Metformin
\+ Thiazolidinediones
Pioglitazone, rosiglitazone
