Instructor Notes — Chapter 11
Teaching notes
What this chapter is actually for
Three things, and the third is the one students will still be using in Part III:
- The evidence-scaling principle. Insulin needed no randomized trial because no alternative explanation was available. This is a rare exception, not a precedent, and the chapter says so twice for a reason.
- Hypoglycemia as a structural consequence, not a dosing failure — the two-lever argument.
- The override/replace rule in its cleanest form. Type 1 diabetes is the purest replacement case in medicine, and insulin's fifty-year durability is the control condition against which Chapter 8's weight regain becomes legible.
The chapter also does something the rest of Part II cannot: it shows what a century of accumulated evidence looks like, so students have a calibration point for how thin most evidence bases actually are.
Common misconceptions
"Insulin proves we over-rely on randomized trials." This will be said, and it is the most dangerous takeaway available from this chapter. The correction is the scaling principle: randomization excludes natural history, expectation, and chance. Untreated type 1 diabetes offered none of those. Ask students to name a modern condition where the same reasoning would apply — the list is very short, and building it is the lesson.
"Hypoglycemia means the dose was wrong." Sometimes. But the two-lever argument shows it is structural: a hormone whose correct dose changes hourly, delivered in a form that cannot be withdrawn, will produce excursions regardless of technique. Students who get this understand why the entire device industry exists.
"Type 2 diabetes is just milder type 1." Different diseases. The replacement/override distinction is the useful frame and it predicts the dosing differences.
"They gave away the patent for a dollar and then charged hundreds." Universally believed, partly true, and causally wrong. The 1923 patent covered the 1923 product. Students find the correction genuinely surprising, and it is a good opportunity to model correcting a story you are sympathetic to.
"Insulin analogs are obviously better." In type 1, for nocturnal hypoglycemia, yes. In type 2 the incremental benefit is contested and the cost difference is large. The split rating is the point.
The hardest point to teach
That confirming an assumption is not a wasted trial.
Students reliably say the DCCT was unnecessary — everyone already believed glucose caused complications. Two moves fix this.
First: pair it with CAST (Chapter 5). Both tested a confident belief. One confirmed, one refuted and found harm. Ask what would have predicted which in advance. Nothing would have. That is the argument.
Second: point out that DCCT measured the price — more severe hypoglycemia — which nobody had quantified. A trial reporting only the benefit would have supported worse decisions. Both halves of a result are the result.
Demonstrations that work
Three labels, side by side. Project a rapid-acting analog, NPH, and a long-acting analog from DailyMed and compare onset, peak, and duration. The whole engineering problem in §11.6 is visible in three rows of numbers, and students grasp it faster from the labels than from the prose.
The two-lever diagram, built live. Draw normal regulation with both levers. Then erase the first lever and ask what happens. Students reach "it can't be taken back" themselves, and the structural nature of hypoglycemia lands without being asserted.
The Toronto notebooks. Five minutes on the University of Toronto digitized collection. Dog numbers, extract preparations, glucose readings, in handwriting. It humanizes the origin of the entire field and students remember it.
The replacement/override sort. Give students six therapies — insulin in type 1, insulin in type 2, a GLP-1 agonist for weight, thyroid hormone replacement, a statin, testosterone replacement — and have them sort into replacement and override, then predict discontinuation behavior for each. This is the single best preparation for Part III available anywhere in the book.
Timing
For a 75-minute session:
| Minutes | Content |
|---|---|
| 0–12 | §11.1 and Figure 11.1 — the discovery and the scaling principle. Notebooks. |
| 12–20 | §11.2–11.3 — structure and receptor. Briskly; contrast with GPCRs. |
| 20–35 | §11.4 — hypoglycemia. The two-lever diagram, built live. |
| 35–45 | §11.5 and §11.8 — replacement vs override. The sorting exercise. |
| 45–55 | §11.6 — analogs. Three labels side by side. |
| 55–63 | §11.7 — devices, briefly. Note that the ✅ is for a system, not a molecule. |
| 63–75 | §11.9 and Case Study 2 — pricing. |
If short, compress §11.6 and §11.7. Do not cut §11.4 or the sorting exercise.
Assessment notes
Discriminating items: 11.9, 11.19, 11.21, 11.25, 11.27.
11.19 (one rule, two opposite outcomes) is the best single item in the chapter, and its final part — what the rule predicts for a compound you have not yet met — is the transferable skill.
11.27 (state the pricing situation accurately with three complications) is worth grading strictly on the complications. A student who reproduces the simple outrage version has not done the reading, and a student who reproduces the industry-defense version has not either.
11.25 (does a device rating belong in a peptide book?) rewards students who can argue against the book's own choice. Full credit requires both sides.