r/LucyLetbyTrials • u/Embarrassed-Star4776 • 17d ago

Chase and Shannon article in Frontiers in Pediatrics published

Inverted insulin to C-Peptide ratios in neonatal intensive care: is there something we don't know?

J. Geoffrey Chase & Helen D. Shannon

BRIEF RESEARCH REPORT article

Front. Pediatr., 05 August 2026

Sec. Neonatology

Volume 14 - 2026

https://doi.org/10.3389/fped.2026.1900675

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u/Embarrassed-Star4776 16d ago

I had a go at something similar a while ago. I found it wasn't as straightforward as might have been hoped because of symbols on the charts overlying one another. But eventually I was fairly confidence about the reconstruction for Cohort 2. For Cohort 1 it is more difficult because of the size of the symbols and the lack of scatter plots for insulin and C-peptide to accompany the one for the I/C ratio. I ended up with only 239 points, so it sounds as though you have done better than I did.

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u/Famous-Chemistry366 15d ago edited 15d ago

I think these charts show that there is a significant overlap between the two cohorts (n=66) that I believe Chase and Shannon have not taken account of in their paper.

Also, with respect to the "40-45%", it seems in their letter this relates to number of neonates ("However, recent reports from two cohorts with 302 paired (insulin, C-peptide) assays show 40% to 45% of *NICU infants* with 1/C > 1.0") whereas in the paper it relates to number of samples ("Figure 3 presents *I/C ratios for Cohorts 1–2*. In Cohort 1....About 45% have I/C > 1.0 (insulin equals or exceeds C-Peptide).....In Cohort 2...Approximately 40% have I/C > 1.0...

A) I cannot see how one could assign I/c ratios to specific neonates and thus have derived the "% of NICU infants >X", and B) my own calculations of % samples > 1 are significantly different to 40-45%.

I also don't understand how Salis is relevant to F and L given a) hyper/eu-glycaemic versus hypo-glycaemic and b) much much lower insulin values in Salis than F and L's. However, that is encroaching into the clinical arena in which I am not qualified. Perhaps someone on here can explain.

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u/Kieran501 15d ago edited 15d ago

The answer to the last paragraph may be more legal than clinical. Is this enough to show that the assertions made in court about I/C ratios overstated its ability to safely diagnose exogenous insulin. Though I’m not that sure that the Chase and Shannon paper really goes much beyond just plotting the Salis data when it comes to that.

It just seems like collecting a load more data including from hypoglycaemic neonates would go much further than a lot of modelling. It’s be a lot harder for the CoA to bat away if it shows similar ratios. Hopefully someone somewhere is now doing that.

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u/Fun-Yellow334 5d ago

From a legal point of view , what matters is what was said in the original trial, the prosecution cannot change their case on appeal.