“Keep track of” is perfect. A few small modifications: “…by asking a lot of questions and checking their grades.”

“The score” in the US would be “grades”. In other places, it might be “marks.” But “score” is more for competitions and not for education.

Ah, okay. It’s common to “keep track of” a number and observe the changes. So you can keep track of your weight, but observe if you’re gaining or losing weight. So with diabetics and insulin, maybe you keep track of your insulin levels, and then make adjustments based on the levels.

You can say something like, “Diabetics adjust their daily dose of insulin according to their current fasting blood sugar levels.”

Diabetics keep close track of their fasting blood sugar so they know how much insulin to take.
If they lose track of these levels, it could be dangerous and life threatening.

Diabetics adjust daily insulin injection according to their fasting blood sugar .these are dependent to each other . So i chose “these changes”. If you have another suggestion instead of it , i’ll be glad to know .

These are fantastic examples. Just a few small edits: You can say, “diabetics” so “Diabetics keep close track…”
In the second, you can say, “If they lose track of their insulin levels, it can be dangerous and life threatening.”

Correction :Diabetic patients