It is confusing but from what I understand the range for someone without diabetes is narrower, 3.5mmol/l to 5.5mmol/l pre-meal is what you'd expect from someone without diabetes. On that basis the 5.8 fasting reading is marginally high, but given the accuracy of meter readings not necessarily anything to worry about. I think they'd be pretty keen to consider a verdict of prediabetic on that basis. When you go to the doctor they should test again, what they test depends on where you are and how up to date the doctor is 🙂rolleyes🙂. There could be a Hba1c which is an average and the results come in double figures, and I think anything above 47 is considered a "diabetic" reading, not entirely sure where the pre diabetes marker is but I imagine 46/47. That blood test shows you how well your body has been regulating blood sugar over a period of 12 weeks or so, and rules out the chances of a random high reading leading to a diagnosis. Some doctors still do glucose tolerance tests where you drink a delightful sugar solution and they test how your blood sugar responds, and some still do spot fasting glucose checks I understand. Spot reading aren't tremendously accurate for diagnosis is what I'm really saying, because anyone can have a blip, so they need more information. Best to get it checked though, opticians are great at spotting things 🙂. One other thing to keep in mind is the term prediabetes is a hotly contested one, it doesn't follow that someone who is considered in the prediabetic range will progress to diabetes (I think the current estimate is 50% go on to develop type 2), but since there's no way of knowing which 50% a person falls into its best to take action if you can.
If you do get a verdict of prediabetes, then lots of folk find they can "reverse" it with improved diet and exercise (not everyone can do that though because in some cases the root cause is genetic or linked to another medical condition), so if you are prediabetic and lucky enough to be able to make changes that impact it could be a really positive thing to get such an early indicator. Sorry I'm prattling on now, so I'll be quiet! Will you let us know how you go on?