A 52-year-old man presents with a 3-week history of increased thirst and urinary frequency and weight loss. He has hypertension and hyperlipidemia and a BMI in the obesity range. Which laboratory finding is most likely increased in this patient?

A 52-year-old man presents with a 3-week history of increased thirst and urinary frequency and weight loss. He has hypertension and hyperlipidemia and a BMI in the obesity range. Which laboratory finding is most likely increased in this patient?

• A. Fasting serum glucose
• B. Fasting triglycerides
• C. HbA1c
• D. Insulin level

Answer: (A)

In new-onset diabetes, hyperglycemia is the hallmark finding. The classic symptoms of increased thirst, urinary frequency, and weight loss reflect elevated blood glucose spilling into urine and driving osmotic diuresis. The fasting serum glucose directly measures the current level of glucose in the blood, so it is most likely to be elevated in this situation. HbA1c reflects average blood glucose over the past 2–3 months, so with a 3-week history, it may not yet be markedly elevated. Fasting triglycerides can be high in insulin resistance and metabolic syndrome, but they are not as specific or immediate as the glucose level to indicate current hyperglycemia. Insulin level can be variable in type 2 diabetes—often high early on due to insulin resistance, then potentially falling with beta-cell decline—but the single most likely elevated lab in this symptomatic scenario is fasting glucose.

In new-onset diabetes, hyperglycemia is the hallmark finding. The classic symptoms of increased thirst, urinary frequency, and weight loss reflect elevated blood glucose spilling into urine and driving osmotic diuresis. The fasting serum glucose directly measures the current level of glucose in the blood, so it is most likely to be elevated in this situation.

HbA1c reflects average blood glucose over the past 2–3 months, so with a 3-week history, it may not yet be markedly elevated. Fasting triglycerides can be high in insulin resistance and metabolic syndrome, but they are not as specific or immediate as the glucose level to indicate current hyperglycemia. Insulin level can be variable in type 2 diabetes—often high early on due to insulin resistance, then potentially falling with beta-cell decline—but the single most likely elevated lab in this symptomatic scenario is fasting glucose.