Diabetes Mellitus Definition
Diabetes Mellitus is chronic metabolic disease characterized by elevated level of blood glucose which leads over time to serious damage to the heart, kidney, lung, eyes, nerves etc.
It occurs either when the pancreas does not produce enough insulin or when the body cannot effectively use the insulin.
In 2014 the global prevalence of diabetes was estimated to be 9% among adult aged 18+ years.
About 347 million people worldwide have diabetes.
In 2012 an estimated 1.5 million deaths were caused by diabetes.
More than 80% of diabetes deaths occur in low & middle income countries.
WHO project that it will be the 7th leading cause of death in 2030.
The prevalence of diabetes is approximately twice in urban areas than in rural population.
In India, the prevalence of disease in adults was found to be 2.4% in rural & 4-11.6% in urban dwellers.
- Type 1 diabetes.
- Type 2 diabetes.
- Gestational diabetes mellitus.
- Impaired glucose tolerance.
i. Type 1 diabetes
Also known as insulin dependent diabetes mellitus or juvenile diabetes.
It is usually seen in individual less then 30 years of age .
This form of diabetes is immune mediated in over 90%.
Type 1 diabetes is usually associated with ketosis in its untreated cases.
In this insulin is absent. Pancreatic beta cell fail to respond to all insulinogenic stimuli. Exogenous insulin is
required to reverse the catabolic state.
ii. Type 2 diabetes.
Known as non insulin dependent diabetes mellitus.
It result from the body’s ineffectiveness to use insulin.
It occurs in middle aged & elderly.
Type 2diabetes comprises 90% of people with diabetes around the world.
It is largely result of excess of body weight and physical inactivity.
As a result disease may be diagnose several years after the onset,one complication already have come.
Obese person with diabetes leads to coronary artery disease and strock.
Excessive insulin level leads to high level of triglyceride and increase sodium retention by renal tubules thus inducing hypertension.
iii. Gestational diabetes
Gestational diabetes is hyperglycemic with blood glucose values above normal but below those diagnostic of diabetes occurring during pregnancy.
They have increase risk of type 2 diabetes in future.
iv. Impaired glucose tolerance.
It is intermediate condition in the transition between normality and diabetes.
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– weight loss
– vision change and fatigue
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a.) Pancreatic disorder: inflammatory, neoplastic, and other disease as fibrosis, cystic.
b.) defect in formation of insulin
c.) destruction of beta cell viral infection
d.) decrease insulin sensitivity due to decrease numbness of adipocyte and monocyte insulin receptor.
e.) genetic defect
a.) Age: prevalence rise steeply with age. type 2 usually comes in middle year of life.
b.) Genetic factor : twin studies showed that in identical twin who developed type 2 concordance was approximately 90%.
In type 1 concordance is 50%.
c.) Genetic marker: type 1 diabetes associated with HLA B8 & B15.more power fully with HLA DR3 & DR4.
Type 2 diabetes is not HLA associated.
d.) Obesity: central adiposity has long been accepted as risk factor for type 2 diabetes.
Obesity reduces the number of insulin receptor on target cells.
Voluntary weight loss improves insulin sensitivity.
e.) Immune mechanism: Some evidence of both cell mediated and of humeral activity against islet cells.
f.) Maternal diabetes: offsprings of diabetes pregnancies include gestational diabetes are often large and heavy at birth tends to develop obesity in childhood at high risk to develop obesity at early age.
Environmental risk factor
a.) Sedentary life style:it is risk factor for type 2 diabetes. Lack of exercise may alter the interaction between insulin and it is receptors.
b.) Diet : high saturated fat intake associated with lower insulin sensitivity.
c.) Malnutrition: malnutrition is early infancy and childhood may result in partial failure of beta cell function.
d.)Alcohol: excessive intake of alcohol may increase risk of diabetes by damage to pancreas and liver.
e.) Chemical agent: no. Of chemical agent are toxic to beta cells. Example: streptozotocin, rodenticide- VALCOR.
1. Urine examination
2. Blood sugar test
3. Glycated haemoglobin
1. Urine examination
Urine test for glucose 2 hours after a meal.
Most studies now confirm that although glucose is found in urine in most severe cases of diabetes .
It is often absent in milder form of disease.
Glycosuria may be present in normal people this gives rise to false positives.
For this reason urine testing is not considered on appropriate tool for case finding.
2. Blood sugar testing
Mass screening programme have used glucose measurement of fasting ,post prandial , random blood sample.
The measurement of glucose is RBC is consider unsatisfactory for epidemiological use. Therefore epidemiological purpose the 2 hour value after 75 g oral glucose may be used.
WHO criteria for diagnosis of diabetes.
– fasting plasma glucose:
> or = 126 mg/ dl
– 2 hour plasma glucose:
> or = 200 mg/ dl
3. Glycated haemoglobin
It provide an accurate and objective measure of glycemic control over a period of weeks to month.
HbA1c is now the preferred measurement.
> or= 48 mmol/ mol.
- Retinopathy ,cataract
- Peripheral Neuropathy
- Postural hypo tension
- Foot ulcer
- Myocardial infarction
- Ischemia in peripheral circulation.