The long game: the evidence, the targets and the screening
What the daily work is actually buying, what success looks like in numbers, which appointments to book, and the five levers of long-term risk.
The daily work of type 1 is not arbitrary. This page covers what it is actually buying, what the targets are (and why they are not 100%), which screening appointments to book, and the other four levers that matter as much as glucose over a lifetime.
What all this daily work actually buys
From 1983, a trial called the DCCT followed 1,441 people with type 1 in two groups. The only real difference between them was an average A1C of about 7% against about 9%. Here is what those two percentage points were worth:
- 76% less eye disease
- 60% less nerve damage
- 54% less kidney protein leakage
- 57% fewer heart attacks and strokes, decades later
- 33% lower risk of dying, over 27 years
And the effect outlasted the effort: those benefits kept showing up years after both groups' numbers had converged. Researchers call it metabolic memory — and it fades, so a rough stretch is not a life sentence either.
This is the most hopeful evidence in all of diabetes medicine, and the reason the daily work matters.
What success looks like — and it is not 100%
These are the time-in-range targets from the 2019 international consensus, for most non-pregnant adults, plus Diabetes Canada's A1C target. Children, older adults and pregnancy have their own targets.
- >70% time in range, 3.9 to 10.0 — about 17 hours a day
- <4% below 3.9 — about an hour, and under 1% below 3.0
- <25% above 10.0 — roughly six hours a day
- ≤7.0% A1C, for most adults — Diabetes Canada's target
Read the first two together: guideline-level success includes about seven hours a day outside range, and roughly an hour low. If every high reading feels like a failure, the target itself disagrees with you. Perfectionism is what drives burnout, and the guideline is the best available argument against it. Your own targets are set with your diabetes team.
The appointments to actually book
| What | When it starts | How often | What it involves |
|---|---|---|---|
| Eyes | 5 years after diagnosis, age 15+ | Annually | An optometrist looks at the retina |
| Kidneys | After 5 years' duration | Annually | A urine sample and a blood test |
| Nerves | 5 years after puberty ends | Annually | A nylon filament and a tuning fork on the feet |
| Feet | From diagnosis | At least annually | Someone looks properly, shoes and socks off |
| Cholesterol | At diagnosis | Annually if untreated | A blood test, fasting or not |
| Blood pressure | From diagnosis | Every visit | Target below 130 over 80 |
Notice that every one of the microvascular screens starts at five years. Canadian guidelines do not expect a newly diagnosed person to have anything to find.
If you take one action from this page, book whichever of these appointments is overdue.
Glucose is the biggest lever. It is one of five.
Registry work models long-term risk by how many of five factors are on target, and the risk rises step by step for each one that is not. Only the first asks anything of you hour to hour.
- Glucose. A1C at or under 7.0%, time in range over 70%. The one that never stops.
- Blood pressure. Under 130 over 80. Usually one tablet.
- Cholesterol. LDL under 2.0, or halved. A statin from 40, or from 30 with 15 years' duration.
- Kidney protection. An ACE inhibitor or ARB where indicated — the strongest kidney intervention there is.
- Not smoking — and moving regularly. Both sit in the same model as the other four.
Four of these are settled at an appointment rather than at every meal. That is genuinely good news, and chronically undersold. Most people with type 1 have never been walked through the other four, so asking your team about them is a concrete next step.
The full DCCT and EDIC evidence, each complication explained plainly, and how far the rates have fallen are in the Complications section.