This is how I have come to understand the workings of blood sugar. Please point out where I’m going wrong.
Glucose (sugar) comes from food. Insulin is a hormone that turns glucose into glycogen (fat) in the liver. The hormone glucagon turns glycogen back into glucose. Diabetics produce too little insulin, so their body can’t properly turn glucose into glycogen. So, if they don’t take their insulin with a meal, their blood sugar becomes too high. So far so good.
But how does this lead to low blood sugar? Their glucagon is working fine, so they should be able to turn glycogen into glucose when they need it. Right? Does this only occur when a diabetic accidentally takes too much insulin?
There are tons of different sources on this topic, but they’re either too confusing or they contradict each other. It doesn’t help that there are two types of diabetes. If anyone can explain, I’d appreciate it a lot!
In: Biology
Think of insulin as the key that opens the doors for glucose to get into your cells. In type 1 diabetes, your body isn’t making enough keys and you have to manually inject yourself with more. In type 2, your body malfunctions and the doors no longer accept the keys being made. All type 1 diabetics need to take insulin to help lower their blood glucose levels and only about 25% of people with type 2 need to take it. Generally speaking, the danger with diabetics is HYPERglycemia (too high blood sugar). HYPOglycemic emergencies are less common but can occur if a diabetic person accidentally takes too much insulin, in which case there are too many keys opening too many locks at once and their blood glucose levels can fall dangerously low
The biochemistry is complex, don’t get medical information from Reddit, that’s what doctors are for.
The problem with all these control systems is that they aren’t instantaneous. These are relatively slow biologic systems, and the delays are seconds to minutes.
Injecting insulin, on the other hand, is a discrete square-wave input. That excites the balance of the process, and can drive it to high or low extremes. That’s one advantage on insulin pumps that slowly release it in little bits.
You are on the right track! Keep it up! Let me know if there is anything you want more clarification on!
>Diabetics produce too little insulin
Type 1 diabetics produce little to no insulin so they take insulin shots. Often times, they become hypoglycemic because they took too much insulin causing the body to turn the glucose into glycogen. Sometimes, as a type 1 first starts showing symptoms, as the insulin producing cells in the pancreas gets destroyed, it will release the insulin it stored causing hypoglycemia too.
Type 2 diabetics are resistant to insulin so they need more insulin to have the same effect. Because of this, some need to take insulin and might overdose causing the same issue as in type 1. Sometimes, a type 2 diabetic’s pancreas will produce extra insulin like a last hurrah causing hypoglycemia. Sometimes a medicine they take to help can also cause hypoglycemia.
>But how does this lead to low blood sugar? Their glucagon is working fine, so they should be able to turn glycogen into glucose when they need it.
Insulin blocks glucagon, and vise versa. So even though we all make glucagon, it wont work if insulin is present in high levels. It makes sense if you think about it. Why make a storage product (glycogen) just to have it unstored right away. After we havent eaten for a while (aka now insulin levels are lower), glucagon can help maintain blood sugar levels by turning glycogen into glucose.
It’s almost always because of the diabetes medication, not the diabetes itself.
Insulin, and lots of (but not all) oral diabetes drugs will cause hypoglycaemia if one doesn’t eat enough carbohydrates.
Taking too much insulin is a common cause, but there are many things that can lower glucose levels. Exercise/physical activity lowers glucose levels, so when diabetics know they’re going to be active they often take less insulin. Heat can also lower glucose. Even prolonged rest (sleeping, when the body naturally slows down all basal metabolic processes so the body ends up requiring less insulin.) Sickness can impact glucose also. Those are a few of the most common examples, but there are many others. The difficult part for diabetics is timing, planning, and dosing their insulin requirements to account for this.
For example, some diabetics will have their glucose levels drop within 10 minutes of exercise, while others won’t see the impact until hours later. If you know you’re going hiking in hot weather in the afternoon, and so take less insulin that morning, but then someone offers a delicious chocolate trail mix while hiking, do you give a standard insulin dose for that chocolate, or less, given you’ve already reduced your dosage earlier in the day. Do you dose your insulin for the snack right away, or wait an hour? If the weather cools down 30 minutes into the hike, but you already dosed insulin assuming high heat all day, how does that change the plan? It’s a constant calibration and calculation balancing act – in my hiking example, the diabetic will probably bounce back and forth throughout the rest of the day between slightly high and slightly low glucose (hopefully avoiding any serious swings!)
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