Which of the following statements is true about diabetes mellitus?
A.
Type 2 diabetes is the result of the failure of the pancreas to produce insulin.
B.
The incidence of diabetes mellitus does not increase with age.
C.
Diabetes is diagnosed after two fasting plasma glucose readings over 125 mg/dL.
D.
Non-insulin-dependent diabetes mellitus is another name for type 1 diabetes.
The Correct Answer and Explanation is:
The correct answer is:
C. Diabetes is diagnosed after two fasting plasma glucose readings over 125 mg/dL.
Explanation:
Diabetes mellitus is a chronic condition characterized by elevated blood glucose levels. It encompasses two main types: Type 1 and Type 2 diabetes. Each type has distinct causes, diagnostic criteria, and management strategies.
- Type 1 Diabetes (T1D): This type is primarily an autoimmune condition where the body’s immune system attacks and destroys the insulin-producing beta cells in the pancreas. As a result, individuals with Type 1 diabetes have little to no insulin production. It is also known as insulin-dependent diabetes mellitus.
- Type 2 Diabetes (T2D): This type results from a combination of insulin resistance (where the body’s cells do not respond properly to insulin) and eventual insulin deficiency. Unlike Type 1, Type 2 diabetes is not due to a failure of the pancreas to produce insulin from the outset; rather, the pancreas initially produces insulin, but over time, it may not be sufficient to meet the body’s needs.
- Age and Incidence: The incidence of diabetes mellitus, particularly Type 2 diabetes, does increase with age. Older adults are at higher risk due to factors such as reduced insulin sensitivity and changes in glucose metabolism.
- Diagnostic Criteria: Diabetes mellitus is diagnosed based on several criteria. One of the standard methods is by measuring fasting plasma glucose levels. A diagnosis of diabetes is confirmed when two fasting plasma glucose readings are ≥ 126 mg/dL (not 125 mg/dL). Additionally, other criteria include a 2-hour plasma glucose ≥ 200 mg/dL during an oral glucose tolerance test (OGTT) or a hemoglobin A1c (HbA1c) level ≥ 6.5%.
- Non-Insulin-Dependent Diabetes Mellitus: This term is actually an outdated name for Type 2 diabetes. It is not used for Type 1 diabetes, which is termed insulin-dependent diabetes mellitus.
In summary, the correct diagnostic threshold for diabetes is two fasting plasma glucose readings of 126 mg/dL or higher, not 125 mg/dL. This measurement helps confirm the diagnosis and is critical for proper management and treatment planning.