Heart, feet, DKA and lost hypo warnings

Eyes, kidneys and nerves get most of the attention. This page covers four things that matter at least as much: the heart and blood vessels, the feet, diabetic ketoacidosis (DKA), and losing the warning signs of a low. Each one comes with good news about what can be done.

Heart and blood vessels: the one that matters most

Cardiovascular disease is what actually accounts for most of the difference in life expectancy for people with type 1. In Scottish national data, ischaemic heart disease alone explained about a third of that difference.

Heart events are rare in young adulthood, but risk builds quietly from diagnosis onward. That is the whole argument for paying attention to cholesterol and blood pressure in your twenties, when nothing hurts. And this risk has already been shown to move: in the long-term DCCT/EDIC follow-up, intensive glucose management was linked to 42% fewer cardiovascular events at about 17 years.

You may come across relative risk figures for heart disease in type 1 in research papers. They look alarming because they compare against a very low baseline in young people. They are real, but in everyday terms they can mislead badly, which is why none appear here.

Feet: the cheapest prevention in diabetes care

The chain is well understood and it runs in one direction: loss of sensation → an injury that goes unnoticed → an ulcer → infection. Almost every amputation is preceded by an ulcer, and almost every ulcer is preceded by a foot that stopped reporting pain.

Foot problems are less common in type 1 than in type 2, and the lifetime risks published online mostly lump both together.

In Canada, the recommendation is a foot examination at least once a year, more often if anything has already been found. No technology, no cost, no burden: just a look.

DKA: the one that matters most in young adults

Most patient material spends its time on complications that take decades and skips the one that can become an emergency this weekend. In Scotland's national type 1 data, the largest single share of years of life lost before age 50 (around a quarter) came from diabetic ketoacidosis (DKA) and diabetic coma, not from eyes, kidneys or nerves.

DKA is an acute, fast-moving and preventable emergency. Reported death rates range from under 1% to around 3%, and delay in treatment is what drives the higher end. That is why acting early matters so much.

What sets it off:

• illness and infection
• a pump failing (with no long-acting insulin in the body, DKA can develop quickly)
• insulin not taken: it ran out, it was unaffordable, the person was too unwell to dose, or they were avoiding it

In research, "insulin omission" covers all of those causes. It does not mean carelessness.

Losing the warning signs of a low, and getting them back

Repeated lows can train the body to stop reacting to them. The shaking and pounding heart that used to arrive at around 3.5 mmol/L stop appearing, and the first sign of a low becomes confusion, or nothing at all. This is called hypoglycemia unawareness.

It is a complication in its own right, and the one that most limits everything else. It makes tight targets unsafe, and it feeds the fear that shapes daily decisions.

The good news: it is reversible. Strictly avoiding lows for anywhere from a couple of days to three months has been shown to bring the warning symptoms back, at least partly. Diabetes Canada's advice is to deliberately loosen targets for up to three months to do it. Recovery is often partial rather than complete: sensors help restore some symptoms without fully restoring the body's hormone response.

So if someone is told by their team to run higher for a while, that is good medicine. It is not backsliding, and nobody should treat it as such. It is a useful reminder that lower is not always better.