Concept and Etiology:
Diabetes Mellitus is an endocrine disorder characterized by
hyperglycaemia (high serum glucose levels) resulting from defects in
insulin production, insulin action, or both. DM can occur in three
forms—type 1, type 2, and gestational diabetes—each with its own
pathogenesis. Chronic diabetes conditions include type 1 diabetes
and type 2 diabetes. Potentially reversible diabetes conditions
include prediabetes and gestational diabetes. Prediabetes occurs
when your blood sugar levels are higher than normal, but not high
enough to be classified as diabetes. And prediabetes is often the
precursor of diabetes unless appropriate measures are taken to
prevent progression. Gestational diabetes occurs during pregnancy
but may resolve after the baby is delivered. (Story, L. 2018, pp. 312)
Classification:
The majority of diabetic patients are classified into one of two broad
categories: type 1 diabetes mellitus, or type 2 diabetes mellitus,
which is characterized by. In addition, women who develop diabetes
during their pregnancy are classified as having gestational diabetes.
• Type 1 diabetes (which is caused by an absolute or near absolute
deficiency of insulin)
• Type 2 diabetes (the presence of insulin resistance with an
inadequate compensatory increase in insulin secretion)
• Gestational diabetes mellitus (GDM) (diabetes diagnosed in the
second or third trimester of pregnancy that is not clearly overt
diabetes)
• Specific types of diabetes due to other causes, e.g., monogenic
diabetes syndromes (such as neonatal diabetes and maturity-onset
diabetes of the young [MODY]), diseases of the exocrine pancreas
(such as cystic fibrosis), and drug- or chemical-induced diabetes (such
as in the treatment of HIV/AIDS or after organ transplantation)
(Mayo Clinic, 2018)
Clinical Manifestations
• Hyperglycaemia
• Glucosuria (glucose is excreted in the urine in an attempt to lower
serum levels)
• Polyuria (increased urine output because of the osmotic effects
of the glucosuria)
• Polydipsia (increased thirst because of the dehydration caused by
the increased urine output)
• Polyphagia (increased appetite because of the energy loss as
glucose is excreted)
• Weight loss (from increased fat catabolism)
• Blurred vision (excessive glucose changes the shape and
flexibility of the lens of the eye, distorting the ability to focus and
causing blurred vision)
• Fatigue (because of a lack of an energy source)
• Nausea, vomiting, and abdominal pain (associated with sudden
onset of type 1 diabetes)
Included in the manifestations mentioned above are 3 classic signs of
diabetes mellitus. They are referred to as the three P’s:
• Polyuria
• Polydipsia
• Polyphagia
(Story, L. 2017) (NIH.GOV)
Diagnostic Tests:
Diagnostic procedures include a history, physical examination,
urinalysis (to detect the presence of glucose), fasting blood glucose
test, oral glucose tolerance test, random blood glucose test,
hemoglobin A1c (HgbA1c; an average of glucose control for the
previous 2–3 months), blood pressure measurement, and cholesterol
panel.
(American Diabetes Association, 2015)
REFERENCES:
Story, Lachel. Pathophysiology: A Practical Approach (pp. 312-315)
Available from: MBS Direct, (3rd Edition). Jones & Bartlett Learning,
2017.
Mayo Clinic (2018). Diabetes – Symptoms and Causes. Mayo Clinic.
Retrieved November 15, 2021, from
https://www.mayoclinic.org/diseases-conditions/diabetes/symptoms
-causes/syc-20371444
Classification of Diabetes Mellitus - NCBI Bookshelf (nih.gov).
Retrieved November 15, 2021, from
https://www.ncbi.nlm.nih.gov/books/NBK279119/
American Diabetes Association (2015). Diabetes Care. Retrieved
November 15, 2021, from
https://care.diabetesjournals.org/content/38/Supplement_1/S5
