What could be the reason behind the sudden increase in heart rate, blood pressure, and plummeting sugar levels after a meal?

Question

Hello doctor,

I am a 46-years-old person with borderline hypothyroidism (TSH value 4.2 mlU/mL). When I take a nap and wake up in the afternoon, my heart races for 2 to 3 minutes, and after that point onwards, I cannot do any physical activity. If I do any exercise, such as lifting small weights or any exertion and try to eat my meal afterward in the next 20 to 30 minutes, my sugar levels plummet immediately. It starts with my body feeling cold; my heart rate suddenly increases, and my blood pressure shoots off to 200/110 mm Hg. This happens over 2 to 3 times before things get to normal. This happened the first time around two years back, after a late lunch, afternoon nap, late evening exercise, and while eating dinner within 30 minutes after exercise. This pattern repeated over the next two years; the episodes happened thrice. I went to the emergency room suspecting a stroke, took tests, and everything came out normal. These episodes usually occur when my work stress is slightly intense, and I sit at my work desk for prolonged hours. Can you please recommend what tests I need to take to find the cause? I suspect reactive hypoglycemia or worse case hypoglycemia associated with some tumor. I did intermittent fasting for two years, skipped breakfast before quitting, and started eating regular breakfast. My fasting sugar levels are between 70-75 mg/dL every morning. I take Vitamin D and B12 tablets and started Synthroid 75 mg this month. I have undergone a CT scan of the abdomen, and blood work for vitamin B, D, B12, and cortisol levels.

Answer 1

Hello,

Welcome to icliniq.com.

I just read your query and the reports that you have attached (the attachments have been removed to protect the patient's privacy). I have some differential diagnoses from your symptoms, and I feel you should be investigated further for this.

1) Insulinoma. Since your CT (computed tomography) scan of the abdomen was normal, you can still detect it on prolonged supervised fasting for upto 72 hours when admitted in a hospital setup and then measure the insulin and C -peptide levels, then the fast is terminated.

2) MEN type 1, which is multiple endocrine neoplasia associated with carcinoid, insulinoma, and gastrinoma. An MRI (magnetic resonance imaging) scan of the pituitary is recommended, and prolactin levels are required.

3) Pheochromocytoma. An abdominal MRI (magnetic resonance imaging) is indicated, along with MIBG scanning and 24 hours urinary collection of metanephrines.

You have to discuss these with your endocrinologist before getting them done.

Answer 2

Hello,

Welcome back to icliniq.com.

1) Pheochromocytoma- You had sudden episodic very high blood pressure with palpitations.

2) Insulinoma- You eat a meal, and your sugar levels plummet immediately in 20 to 30 minutes. It starts with your body feeling cold, and your heart rate suddenly increases.

3) MEN 1- It is the condition where both the above symptoms can happen.

I have listed my differential diagnosis in the order of suspicion of most likely possibility.