Freestyle Libre - Data Interpretation


(Ian) #1

I just started to use a CGM and the the following image shows yesterdays readings.

At around 6 pm I had a small meal with approximately 36 g of carbs. I normally don’t eat that much carbs in one meal, but wanted to see what it did to my BG levels. As you can see my glucose spiked to approximately 7.8 from 4 mmol/L (i.e. an increase of approximately 3.8 mmol/L) one hour later and by 2 hours had dropped to what appears to be approximately 3.5 mmol/L and then bounced back to the mid 5’s.

Does an increase of 3.8 mmol/L in response to 36 g or carbs still indicate a degree of metabolic dysfunction?

Does the quick fall in BG within 2 hours of the meal suggest that my insulin sensitivity has improved and appears to be more normal? than previous?

Any idea what would cause my BG to bounce back to up to 5.4 after the apparent hypo (no additional food was eaten)?

Does anyone using this meter know how to get it to record peaks and lows, numerically in addition to the graph?


(Michael - When reality fails to meet expectations, the problem is not reality.) #2

You may find the following of interest.


(Bacon enough and time) #3

Blood sugar is variable. It makes sense that it would rise after a meal high in carbohydrate. Thirty-six grams may not seem all that much, but it is nearly twice the recommend daily limit, and you ate it all in one meal, so it’s not surprising that you saw a noticeable rise in serum glucose. The drop in the first hour is a sign of insulin activity. It would appear that the pancreas over-responded, given how low your glucose dropped before it rose again.

The goal is to have minimal, smooth fluctuations in your serum glucose. It is best to avoid sharp rises and steep falls. The more you restrict your carbohydrate intake, the less you will cause large fluctuations in your serum glucose. In the absence of dietary carbohydrate, the pancreas secretes a hormone called glucagon, which in some ways is an antagonist to insulin, and vice versa. A low ratio of insulin to glucagon (i.e., they are being secreted in close to equal amounts) occurs when there is a low amount of dietary carbohydrate, and the glucagon stimulates the processes of gluconeogenesis and ketogenesis in the liver. A high ratio of insulin to glucagon occurs in the presence of high amounts of dietary carbohydrate, resulting in elevated serum glucose, which needs to be brought down as expeditiously as possible (hyperglycaemia causes damage to the body if left unchecked). The elevated serum insulin, unchecked by glucagon, shuts down gluconeogenesis and ketogenesis in the liver, forces the muscles to metabolise glucose instead of ketone bodies, forces excess glucose into the adipose tissue in the form of fatty acids, and so forth. Left to its own devices (and not flooded with exogenous glucose), the body maintains a steady level of serum glucose, the liver manufacturing just enough to replace what is consumed by the red blood cells, brain, etc.


(Bunny) #4

This is interesting when it comes to weight and size. Adiposity vs. Lean body mass (esp. muscle volume)?


image link

”…For example, if your target is 100 mg/dl, your current BG is 60 mg/dl and each gram of carbohydrate raises you 4 mg/dl, then you need (100-60)/4, or 10g of carbohydrate. …” …See Chart

See also: Conversion of Glucose Values from mg/dl to mmol/l


(Stephen Judd) #5

I connect Libre to computer via USB and export the data file. I then import it and transform it in Excel to get the individual measurements, which are every fifteen minutes.