What my research means for you
I’m an anaesthesiologist and researcher at Amsterdam UMC. Below are the main things my research has found so far, explained without medical jargon, and — if you’re taking part in one of my studies — what that study was about, how it worked, and what it found.
Not personal medical advice. This page explains research findings in general terms. If you have a question about your own care or a study you’re taking part in, please speak to your own doctor or the study’s research nurse or coordinator.
Key findings, in plain language
A short summary of what my research has found so far. Each finding is based on published, peer-reviewed studies — see Publications for the full papers.
A diabetes medicine may help protect the kidneys during heart surgery
A group of diabetes medicines called SGLT2 inhibitors seem to help protect the kidneys during heart surgery. In a small first study, patients who took the medicine before their operation were much less likely to develop kidney injury afterwards (20% vs 67%). Larger trials are now under way to confirm this.
It’s often safe to keep taking SGLT2 inhibitors before surgery
Doctors used to routinely stop these medicines several days before any operation, as a precaution against a rare side effect. Newer research, including work I’ve contributed to, suggests that for many patients it’s actually safer to keep taking them, once the small risk of that side effect is weighed against the benefits of staying on the medicine.
GLP-1 medicines (semaglutide, liraglutide and similar) and surgery
These widely used diabetes and weight-loss medicines slow down digestion, which raised concern about anaesthesia and the stomach not being empty. Our research found the added risk mainly applies to people who started the medicine very recently — for most long-term users, there’s little evidence it needs to be stopped before surgery.
Metformin is safe to continue before surgery
Metformin, the most commonly used diabetes tablet, was once feared to cause a dangerous build-up of acid in the blood around surgery. A trial I led found continuing it made no meaningful difference to blood levels and gave no extra benefit from stopping — so for most patients, it’s fine to keep taking it.
Not everyone needs a diabetes blood test before surgery
Checking blood sugar (HbA1c) before an operation is useful for people already known or suspected to have diabetes. Our research found it isn’t a good way to screen everybody, though — it rarely turns up an undiagnosed case, and it doesn’t predict how well someone recovers.
Kidney injury after heart surgery is common — and we’re working on it
Somewhere between 1 in 20 and 2 in 5 people who have heart surgery develop some degree of kidney injury afterwards. It usually recovers, but not always, and it raises the long-term risk of kidney problems. Most of my research is aimed at understanding and preventing this.
Clinical trials — information for participants
If you or a family member took part in one of my randomised trials, here’s what each one set out to do, how it worked, and what it found (or where it currently stands).
GLOBE trial
Metformin perioperative trial
MERCURI-1
MERCURI-2
PRINCESS
For the full scientific detail behind any of these, see Research or Publications.
Patient organisations
I work with, and learn from, the following Dutch patient organisations. They’re independent of my research, and a good place to go for support and information as a patient.
Nierpatiënten Vereniging Nederland
The Dutch association for kidney patients, transplant recipients, and their families — information, peer support, and advocacy.
Visit nvn.nl → Heart & vascular diseaseHarteraad
The Dutch patient association for people living with heart or vascular disease and their loved ones.
Visit harteraad.nl → DiabetesDiabetesvereniging Nederland
The largest Dutch patient association for people with diabetes — information, courses, and community.
Visit dvn.nl →