In the last installment, I discussed the context of blood glucose readings over 140 mg/dL in diabetics vs. non-diabetics. In this installment I'm going to discuss it in the context of an Oral Glucose Tolerance Test, OGTT. The crux of this post is that the results of this study do not justify the Ruhl/Jaminet/(and I'll add Kresser) takeaway message vis a vis diabetes complications and "spikes" in blood glucose. The fact that 50% of the neuropathy subjects to whom OGTT's were administered had 2 hr. glucose levels over 140 (e.g. diagnosed as Impaired Glucose Tolerance, IGT) simply does not support: Nerve Damage Occurs when Blood Sugars Rise Over 140 mg/dl (7.8 mmol/L) After Meals as stated on Ruhl's site and in Perfect Health Diet (Kindle Locations 712-716). (This seems to have been repeated by Chris Kresser as well).
What is an OGTT? The most common form is conducted in the fasted state, at least 8 hrs, studies seem to favor 10 or 12 hrs. It involves ingesting 75g of liquid glucose solution in a short period of time. Glucose (and often insulin) levels are sampled at 30 min (sometimes shorter at early time periods) intervals for 2 to 3 hours. There are two values that are assessed:
- 1 hour and/or peak BG: under 200 mg/dL = normal , 200 mg/dL or over = IGT or diabetic
- 2 hour BG: under 140 mg/dL = normal, 140-199 mg/dL = IGT, 200 mg/dL or over = diabetic
