Diabetes Mellitus
There is an increased risk of developing diabetes mellitus
DIABETES MELLITUS
- Type 1: Autoimmune destruction of pancreatic β-cells, leading to absolute insulin deficiency. Typically affects young, thin individuals and is prone to Diabetic Ketoacidosis (DKA). Associated with anti-GAD and anti-islet antibodies, and HLA
- Type 2: Characterised by insulin resistance and a relative deficiency in insulin secretion. Usually affects older, obese individuals with an insidious onset. Ketoacidosis is uncommon. Strong family history is common.
- Diagnosis: - Fasting plasma glucose ≥7.0 mmol/L - Random plasma glucose ≥11.1 mmol/L - HbA1c ≥48 mmol/mol (6.5%) - Oral Glucose Tolerance Test (OGTT) 2-hour plasma glucose ≥11.1 mmol/L
- DKA (Type 1): Caused by severe insulin deficiency leading to hyperglycaemia, lipolysis, ketone production, and metabolic acidosis. Common triggers include infection and missed insulin doses. Features include Kussmaul breathing, acetone brea
- HHS (Type 2): Characterised by very high glucose levels ( 30 mmol/L), markedly elevated serum osmolality, absence of significant ketosis, and no significant acidosis. It has a high mortality rate. Management prioritises fluid resuscitation,
Read this in Endocrine & Renal Pathology — Must Know Notes
DIABETES MELLITUS
- Diagnosis: Fasting glucose ≥7.0 / Random ≥11.1 / HbA1c ≥48 mmol/mol / OGTT 2h ≥11.1 mmol/L.
- HbA1c: Reflects 2–3 month average glucose. Falsely low in haemolytic anaemia, haemoglobinopathies. Unreliable in pregnancy.
Read this in Endocrine & Renal Pathology
Diabetes Mellitus
- Diabetes mellitus is characterized by elevated blood glucose levels due to defects in insulin secretion, action, or both. It is classified into two primary types:
Read this in LECTURE 6: Pancreatic and Adrenal Hormones
What our notes say
- There is an increased risk of developing diabetes mellitus (Paediatrics Year 6 MBChB end of semester CAT: clinical case MCQs, 29 of 30 quest)
- Maternal diabetes mellitus (the baby has larger shoulders and trunk). (Junior Clerkship in Reproductive Health (MBOG 4200): end of year examination, 4 )
- All children develop diabetes mellitus and need insulin by 5 years of age (Paediatrics end of 2nd semester exam (MBPE 4300): 5 October 2021, 50 MCQs)
- Untreated diabetes mellitus results in all of the following, except: (Internal Medicine (MBIM 4100) main exam, Paper One: 3 July 2019)
- A 58-year-old man with a history of diabetes mellitus has noted the presence of bone pain, especially of his hands, for the past 6 months. (Chemical pathology and Endocrine pathology — Past Paper Questions & Answers)
- Obesity with insulin resistance and diabetes mellitus often accompany PCOS. (Female system — Past Paper Questions & Answers)
Study material on Diabetes Mellitus
- Pancreatic Disorders: A Comprehensive Review
- Chemical Pathology Practice Examination
- Chemical Pathology MCQs
- renal pathology
- ENDOCRINE PATHOLOGY
- Chemical pathology and Endocrine pathology
- Chemical Pathology MCQs: Clinical Chemistry, Endocrine & Renal
- Internal Medicine (MBIM 4100) main exam, Paper One: 3 July 2019
- Gastrointestinal and liver
- Chemical path 2021
- MCQ: Gastrointestinal Pathology
- Pancreatic Disorders: A Comprehensive Review
- Pancreatic Disorders: A Comprehensive Review
- Pathology by Dr. Irungu
- Weekly Year 2: Molecular Genetics and Cytogenetics Exam - July 17, 2026 (Section A: MCQs)
Practice questions on Diabetes Mellitus
Which of the following lab tests is most sensitive for detecting early renal damage from diabetes mellitus?
- Urinary albumin-to-creatinine ratio (UACR)
- Serum creatinine
- Blood urea nitrogen (BUN)
- Estimated Glomerular Filtration Rate (eGFR)
Answer: A. Microalbuminuria, detected by the urinary albumin-to-creatinine ratio (UACR), is the earliest clinical sign of diabetic nephropathy. Serum creatinine and BUN may not be elevated until significant renal function has been lost, and eGFR is also less sensitive than UACR in the early stages.
A patient with uncontrolled diabetes mellitus presents with a rapidly progressing facial swelling, black eschar on the palate, and signs of rhinocerebral infection. Microscopic examination of tissue biopsy reveals broad, non-septate hyphae branching at wide angles. This presentation is highly suggestive of infection by members of the order:
- Mucorales
- Aspergillales
- Candidales
- Cryptococcales
Answer: A. The clinical presentation (diabetic patient, rapid progression, facial swelling, black eschar) combined with the characteristic broad, aseptate (non-septate) hyphae branching at wide angles (typically 90 degrees) is pathognomonic for mucormycosis, caused by fungi in the order Mucorales (e.g., Mucor, Rhizopus, Lichtheimia).
Which environmental factor is most commonly associated with unmasking the genetic trait in type 2 diabetes mellitus?
- Smoking
- Obesity
- Alcohol consumption
- Stress
- Mostly unchanged in early disease
Answer: B. Type 2 diabetes often first manifests clinically after weight gain, demonstrating how obesity as an environmental factor unmasks the diabetic genetic trait. ---
A 44-year-old man has a history of poorly controlled diabetes mellitus leading to coronary artery disease. He now has decreasing cardiac output. An increase in which of the following substances in his blood is most indicative of reversible cell injury from decreased perfusion of multiple organs and tissues?
- Carbon dioxide
- Creatinine
- Glucose
- Lactic acid
- Troponin I ANSWER: D
Answer: D. Decreased tissue perfusion leads to hypoxemia and depletion of ATP when cell metabolism shifts from aerobic to anaerobic glycolysis, resulting in depletion of glycogen stores and increased production and accumulation of lactic acid, reducing intracellular pH. ---
Which environmental factor commonly unmasks the genetic trait in type 2 diabetes mellitus?
- Cold exposure
- Obesity and weight gain
- High altitude
- Vitamin deficiency
- Mostly unchanged in early disease
Answer: B. Type 2 diabetes has features of a complex multigenic disorder where obesity and weight gain often unmask the diabetic genetic trait, demonstrating gene-environment interaction. ---
Diagnostic criterion for diabetes mellitus using fasting plasma glucose is
- ≥ 6.1 mmol/L
- ≥ 7.8 mmol/L
- ≥ 6.5 mmol/L
- ≥ 7.0 mmol/L
Answer: D. ≥ 7.0 mmol/L (126 mg/dL) on two occasions confirms diabetes; 6.1–6.9 mmol/L is impaired fasting glucose. ---