Diabetes Mellitus — MCQs

10 questions

Among the following, most reliable test for screening of diabetes mellitus?

In which of the following situations is intensive management of diabetes typically avoided?

Mr. Murali has 126 mg/dl of fasting plasma glucose. His venous plasma glucose 2h after ingestion of 75g oral glucose load is 149 mg/dl. This patient comes under which stage of WHO diagnostic criteria of diabetes & intermediate hyperglycemia?

In infants of diabetic mothers (IDM), when is ophthalmologic evaluation indicated?

Exenatide is a new drug used in diabetes mellitus. Mechanism of action of this drug is:-

An obese patient presented in casualty in an unconscious state, with a blood glucose level of 400 mg/dL and urine testing positive for sugar and ketones. Which drug is most useful in his management?

Which of the following is the MOST CHARACTERISTIC metabolic feature of type 1 diabetes mellitus?

Which of the following conditions is least likely to be associated with diabetes mellitus?

Polyuria in adults is commonly defined as urine output exceeding:

Q10

As per the etiological classification of diabetes mellitus, gestational diabetes mellitus is

Diabetes Mellitus Indian Medical PG Practice Questions and MCQs

Question 1: Among the following, most reliable test for screening of diabetes mellitus?

A. Urine sugar
B. Random sugar
C. Fasting sugar (Correct Answer)
D. Glucose tolerance test

Explanation: ***Fasting sugar*** - A **fasting plasma glucose** (FPG) test is the most common and reliable initial test for screening for **diabetes mellitus** because it measures blood glucose after an overnight fast (typically 8-12 hours), providing a baseline level unaffected by recent food intake [1]. - A fasting glucose level of **≥ 126 mg/dL** (7.0 mmol/L) on two separate occasions is diagnostic of diabetes, making it an excellent screening tool for identifying individuals with impaired glucose metabolism [1]. *Random sugar* - A random plasma glucose test can be used to diagnose diabetes if the level is **≥ 200 mg/dL** (11.1 mmol/L) in a symptomatic individual, but it is less reliable for screening asymptomatic individuals due to its variability depending on recent food intake [1]. - Because it can be measured at any time of day without regard to the last meal, it has a **lower sensitivity** for detecting early stages of diabetes compared to fasting glucose. *Glucose tolerance test* - An **oral glucose tolerance test** (OGTT) is highly sensitive and specific for diagnosing diabetes and impaired glucose tolerance, but it is more cumbersome and time-consuming, involving multiple blood draws over two hours after consuming a sugary drink. - While it is a definitive diagnostic test, its complexity makes it **less practical for routine screening** in large populations compared to simpler tests like fasting plasma glucose. *Urine sugar* - The presence of glucose in urine (glycosuria) indicates that blood glucose levels have exceeded the **renal threshold** (typically around 180 mg/dL), meaning the kidneys are unable to reabsorb all the glucose. - This is a **less sensitive and specific** method for screening, as it only becomes positive once blood glucose is significantly elevated, and it does not detect milder forms of impaired glucose metabolism or early diabetes.

Question 2: In which of the following situations is intensive management of diabetes typically avoided?

A. Stable diabetes with no complications
B. Diabetes in a well-controlled state
C. Diabetes with stable renal function post-transplant
D. Diabetes with acute myocardial infarction (Correct Answer)

Explanation: Diabetes with acute myocardial infarction - In the setting of **acute myocardial infarction (AMI)**, aggressive **glucose lowering** can increase the risk of **hypoglycemia** and is generally avoided due to potential for worse outcomes [1]. - The primary focus in AMI is on cardiovascular stabilization, and overly tight glycemic control can lead to **metabolic stress** and adverse events, particularly in patients with a high prevalence of cardiovascular disease [1]. *Stable diabetes with no complications* - Patients with **stable diabetes** and no complications are often candidates for **intensive management** to prevent long-term microvascular and macrovascular complications [1]. - The goal is to maintain near-normal glucose levels to reduce the risk of future disease progression [1]. *Diabetes in a well-controlled state* - **Well-controlled diabetes** usually indicates that current management is effective, but further **intensification** might be considered to achieve optimal glycemic targets and minimize long-term risks if there's room for improvement. - This scenario does not inherently contraindicate intensive management, as it could still benefit from fine-tuning to achieve even tighter control without undue risk. *Diabetes with stable renal function post-transplant* - Patients with **diabetes** and stable **renal function post-transplant** often require careful but often intensive diabetes management to preserve graft function and prevent cardiovascular complications. - While medication adjustments are necessary due to altered renal clearance, the goal remains to achieve good glycemic control, potentially through intensive strategies.

Question 3: Mr. Murali has 126 mg/dl of fasting plasma glucose. His venous plasma glucose 2h after ingestion of 75g oral glucose load is 149 mg/dl. This patient comes under which stage of WHO diagnostic criteria of diabetes & intermediate hyperglycemia?

A. Decreased glucose resistance
B. IFG - Impaired fasting glucose
C. Diagnosis of diabetes (Correct Answer)
D. Impaired glucose tolerance

Explanation: **Diagnosis of diabetes** - The **fasting plasma glucose (FPG)** of 126 mg/dL meets the WHO criterion for **diabetes**, which is FPG ≥ 126 mg/dL [1]. - Although the 2-hour post-glucose load (149 mg/dL) falls within the **impaired glucose tolerance (IGT)** range (140-199 mg/dL), the elevated fasting glucose alone is sufficient for a diabetes diagnosis according to WHO guidelines. *Decreased glucose resistance* - This term is not a standard diagnostic category recognized by the WHO for glucose metabolism disorders. - Glucose resistance is more commonly associated with conditions like **insulin resistance** rather than a specific diagnostic stage [1]. *IFG - Impaired fasting glucose* - **Impaired fasting glucose (IFG)** is defined by a fasting plasma glucose level between 100 mg/dL and 125 mg/dL. - Mr. Murali's fasting glucose of 126 mg/dL is higher than the upper limit for IFG [1]. *Impaired glucose tolerance* - **Impaired glucose tolerance (IGT)** is defined by a 2-hour post-glucose load plasma glucose level between 140 mg/dL and 199 mg/dL. - While Mr. Murali's 2-hour reading of 149 mg/dL falls within this range, the elevated fasting glucose level takes precedence for the overall diagnosis [1].

Question 4: In infants of diabetic mothers (IDM), when is ophthalmologic evaluation indicated?

A. At the time of diagnosis
B. Only if visual symptoms develop (Correct Answer)
C. After 5 years routinely
D. After developing diabetes

Explanation: ***Only if visual symptoms develop*** - Unlike **retinopathy of prematurity**, infants of diabetic mothers (IDMs) do not have a higher incidence of **retinopathy** or other **ocular abnormalities** at birth or in early infancy. - **Ophthalmologic evaluation** is generally reserved for IDMs who develop specific **visual symptoms** or signs of ocular pathology. *At the time of diagnosis* - Routine ophthalmologic screening at the time of diagnosis of IDM is **not standard practice**, as the risk of **congenital ocular anomalies** is not substantially elevated to warrant universal screening. - Initial management focuses on metabolic stability, especially **glucose control**, and screening for other common IDM-related complications like **cardiac defects** or **respiratory distress**. *After 5 years routinely* - There is **no evidence or recommendation** for routine ophthalmologic screening of IDMs specifically at the age of 5 years. - Regular **well-child check-ups** include basic vision screening, which would identify significant refractive errors or strabismus, but not specifically for diabetes-related ocular issues. *After developing diabetes* - While it is true that individuals with **type 1 or type 2 diabetes** require regular **ophthalmologic evaluations** for **diabetic retinopathy**, this refers to the child developing diabetes later in life, not being an IDM. - Being an IDM is a **risk factor for developing diabetes** later in life, but it doesn't automatically mean they have diabetes-related ocular issues from birth.

Question 5: Exenatide is a new drug used in diabetes mellitus. Mechanism of action of this drug is:-

A. Inhibiting intestinal absorption of carbohydrates
B. Release of insulin acting as agonist of GLP-1 receptors (Correct Answer)
C. Stimulation of PPAR-gamma
D. Inhibition of DPP-4

Explanation: ***Release of insulin acting as agonist of GLP-1 receptors*** - **Exenatide** is a **glucagon-like peptide-1 (GLP-1) receptor agonist**, mimicking the action of endogenous GLP-1. - This leads to glucose-dependent **insulin release**, suppression of **glucagon secretion**, delayed **gastric emptying**, and increased **satiety**, all contributing to improved glycemic control. *Inhibition of DPP-4* - This mechanism describes the action of **DPP-4 inhibitors** (e.g., sitagliptin, saxagliptin), which prevent the breakdown of endogenous GLP-1 and other **incretin hormones**. - While both GLP-1 agonists and DPP-4 inhibitors target the incretin system, exenatide directly acts as an agonist, rather than preventing breakdown. *Inhibiting intestinal absorption of carbohydrates* - This mechanism describes drugs like **alpha-glucosidase inhibitors** (e.g., acarbose, miglitol), which delay carbohydrate absorption from the gut. - Exenatide's primary action is not on carbohydrate absorption but rather on pancreatic hormone secretion and gastric emptying. *Stimulation of PPAR-gamma* - This mechanism describes **thiazolidinediones** (TZDs) like pioglitazone and rosiglitazone, which enhance **insulin sensitivity** by acting on **peroxisome proliferator-activated receptor-gamma (PPAR-gamma)** in adipose tissue. - Exenatide belongs to a different class of antidiabetic drugs with a distinct mechanism of action.

Question 6: An obese patient presented in casualty in an unconscious state, with a blood glucose level of 400 mg/dL and urine testing positive for sugar and ketones. Which drug is most useful in his management?

A. Glibenclamide
B. Troglitazone
C. Insulin (Correct Answer)
D. Chlorpropamide

Explanation: Insulin - The patient presents with **hyperglycemia**, **ketonuria**, and an **unconscious state**, suggestive of **diabetic ketoacidosis (DKA)** or at least severe uncontrolled diabetes requiring urgent glucose management [1], [4]. - **Insulin therapy** is crucial for DKA management, as it lowers blood glucose, resolves ketosis, and helps correct electrolyte imbalances [3]. *Glibenclamide* - This is a **sulfonylurea** that stimulates insulin release from pancreatic beta cells. - It is **contraindicated in DKA** because the pancreas is often severely stressed or non-functional, and it can worsen hypoglycemia if given inappropriately [2]. *Troglitazone* - This is a **thiazolidinedione** (glitazone) which improves insulin sensitivity in peripheral tissues. - It is **not used for acute hyperglycemia or DKA** and was withdrawn from the market due to liver toxicity. *Chlorpropamide* - This is an older **first-generation sulfonylurea**, similar to glibenclamide, that stimulates insulin secretion. - It has a **long half-life** and a higher risk of **hypoglycemia**, making it unsuitable for acute, severe hyperglycemia like DKA [2].

Question 7: Which of the following is the MOST CHARACTERISTIC metabolic feature of type 1 diabetes mellitus?

A. Increased protein catabolism
B. Increased hepatic glucose output
C. Increased lipolysis (Correct Answer)
D. Decreased glucose uptake

Explanation: ***Increased lipolysis*** - Due to **absolute insulin deficiency** in type 1 diabetes, the body cannot properly utilize glucose, leading to a shift toward **fat metabolism** for energy. - This results in increased breakdown of **triglycerides** into **fatty acids** and **glycerol**, which are then converted to **ketone bodies** in the liver. - **Ketoacidosis** resulting from increased lipolysis is the most **characteristic and distinguishing** metabolic feature of type 1 diabetes, differentiating it from type 2 diabetes. *Decreased glucose uptake* - Decreased glucose uptake by insulin-sensitive tissues (muscle and adipose tissue) is the **primary metabolic defect** in type 1 diabetes due to the absolute lack of insulin. - While this is fundamental to the pathophysiology, it occurs in **both type 1 and type 2 diabetes**, making it less characteristic of type 1 specifically. *Increased hepatic glucose output* - Increased hepatic glucose output (via gluconeogenesis and glycogenolysis) is a prominent feature due to loss of insulin's suppressive effects on the liver. - However, this also occurs in **type 2 diabetes** and is not as distinctive as the dramatic shift to lipolysis and ketone production seen in type 1. *Increased protein catabolism* - While protein catabolism is increased in type 1 diabetes, contributing to **muscle wasting** and providing substrates for gluconeogenesis, it is a less immediate and less specific feature. - The metabolic shift to **lipolysis and ketogenesis** is more rapid, more clinically significant, and more characteristic of the type 1 diabetic state.

Question 8: Which of the following conditions is least likely to be associated with diabetes mellitus?

A. Noonan syndrome
B. Ataxia telengiectasia
C. Fanconi syndrome (Correct Answer)
D. Myotonic dystrophy

Explanation: ***Fanconi syndrome*** - This syndrome primarily involves a generalized defect in **proximal renal tubular function**, leading to excessive excretion of glucose, amino acids, phosphate, and bicarbonate. - While it can be inherited or acquired, it is **not directly linked** to the pathogenesis or common complications of diabetes mellitus. *Noonan syndrome* - Individuals with Noonan syndrome are at an **increased risk of developing diabetes mellitus**, often due to insulin resistance and impaired glucose tolerance. - This genetic disorder, characterized by distinctive facial features, short stature, and cardiac defects, includes **endocrine abnormalities** that predispose to metabolic dysfunction. *Ataxia telangiectasia* - This rare, **autosomal recessive immune deficiency disorder** is associated with an increased incidence of diabetes mellitus [1]. - Patients often present with **insulin resistance** and impaired glucose homeostasis, making diabetes a recognized comorbidity [2]. *Myotonic dystrophy* - Myotonic dystrophy, particularly type 1, is frequently associated with **endocrine abnormalities**, including a high prevalence of **insulin resistance** and impaired glucose tolerance, often progressing to diabetes mellitus [2]. - This inherited neuromuscular disorder can manifest with a variety of systemic complications, with diabetes being a common one.

Question 9: Polyuria in adults is commonly defined as urine output exceeding:

A. 50 ml/ kg / day
B. 30 ml / Kg/ day
C. 60 ml/ kg / day
D. 40 ml / Kg/ day (Correct Answer)

Explanation: ***40 ml / Kg/ day*** - **Polyuria** is clinically defined as urine output exceeding 3 liters per 24 hours (L/day) in adults. - Converting this to a weight-based measurement for an average 75 kg adult, 3 L/day equates to approximately **40 ml/kg/day**. *50 ml/ kg / day* - This value represents a significantly higher urine output than the standard clinical definition of **polyuria**, making it an unlikely threshold. - While excessive, it would indicate a more severe and less common degree of diuresis, not the general definition. *30 ml / Kg/ day* - This value is below the typical threshold for **polyuria** and is closer to what might be considered normal or slightly elevated urine output. - Normal urine output is typically between **0.5-1 ml/kg/hour**, which translates to 12-24 ml/kg/day. *60 ml/ kg / day* - This is a substantially high urine output, indicating a profound level of **diuresis**, well beyond the standard definition of polyuria. - While possible in extreme cases, it is not the common cutoff used for defining polyuria.

Question 10: As per the etiological classification of diabetes mellitus, gestational diabetes mellitus is

A. Type IA
B. Type IB
C. Type II
D. Type IV (Correct Answer)

Explanation: ***Type IV*** - According to the **etiological classification of diabetes mellitus**, gestational diabetes mellitus (GDM) is classified as **Type IV** [1]. - GDM is specifically defined as **diabetes diagnosed during pregnancy** that is not clearly overt diabetes prior to gestation [2]. *Type IA* - Type IA diabetes refers to **autoimmune Type 1 Diabetes**, characterized by immune-mediated destruction of pancreatic beta cells [1]. - This form of diabetes typically presents in childhood or adolescence and is associated with **autoantibodies** against islet cells. *Type IB* - Type IB diabetes refers to **idiopathic Type 1 Diabetes**, which is a form of Type 1 diabetes where there is no evidence of autoimmunity [1]. - It is rare and primarily seen in individuals of African or Asian descent, distinguished by a lack of **autoimmune markers**. *Type II* - Type II diabetes is characterized by **insulin resistance** and a progressive loss of insulin secretion, typically diagnosed in adults. - While GDM shares some physiological characteristics with Type II diabetes, it is a distinct *classification* due to its onset specific to **pregnancy** [2].

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