Brief Answer:
Hypoglycemia most likely

Detailed Answer:
Dear sir, I have gone through your question and I understand your concerns.

These symptoms could be related to hypoglycemia.. if you experience these symptoms again I would recommend that you measure your blood glucose level and if you found its level below 70, then you are suffering from hypoglycemia which is reduced blood glucose level in response to your medications.

This should be managed by one teaspoon of sugar and wait for 15 minutes and measure your blood glucose level again. If still below 90 then take another teaspoon of sugar and measure again after 15 minutes.

If your blood glucose level was within normal level then there is no need to worry. Night chills alone are most likely nothing to worry about.

At night when we are sleeping, our body's metabolism slows down quite a bit. This causes the body to produce less heat than when it is awake. This can cause your body temperature to drop slightly and feel colder. This is not unusual.

But if you are having any sweats associated with these chills, it can be associated with some infection or any other pathologies. Chills alone without the sweats are not generally associated with any problem.

I hope I answered your question.
Let me know if I can assist you further.
Regards

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Brief Answer:
Underactive thyroid or anemia

Detailed Answer:
Dear sir,

I you are pretty sure that your blood glucose level does not get low as a cause of shivering then I would recommend that you check on your CBC test and thyroid hormonal profile. Anemia or under active thyroid gland can be a possible cause of intermittent shivering particularly at night. if all your tests came back normal then the reasonable explanation would be that slowed down metabolism at night while sleeping can lead to decreased body temperature and shivering to restore the body metabolism and temperature back to normal.

i hope you find this helpful.

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