Calculating the estimated glucose disposal rate (eGDR) as a proxy for the level of insulin resistance may be useful way to determine if someone with type 2 diabetes (T2D) is at risk for having a first stroke, Swedish researchers have found.
In a large population-based study, the lower the eGDR score went, the higher the risk for having a first stroke became.
The eGDR score was also predictive of the chance of dying from any or a cardiovascular cause, Alexander Zabala, MD, reported at the annual meeting of the European Association for the Study of Diabetes (Abstract OP 01-4).
The link between insulin resistance and an increased risk for stroke has been known for some time, and not just in people with T2D. However, the current way of determining insulin resistance is not suitable for widespread practice.
“The goal standard technique for measuring insulin resistance is the euglycemic clamp method,” said Dr. Zabala, an internal medical resident at Södersjukhuset hospital and researcher at the Karolinska Institutet in Stockholm.
“For that reason, [the eGDR], a method based on readily available clinical factors – waist circumference, hypertension, and glycosylated hemoglobin was developed,” he explained. Body mass index can also be used in place of waist circumference, he qualified.
The eGDR has already been proven to be very precise in people with type 1 diabetes, said Dr. Zabala, and could be an “excellent tool to measure insulin resistance in a large patient population.”
Investigating the link between eGDR and first stroke risk
The aim of the study he presented was to see if changes in the eGDR were associated with changes in the risk of someone with T2D experiencing a first stroke, or dying from a cardiovascular or other cause.
An observational cohort was formed by first considering data on all adult patients with T2D who were logged in the Swedish National Diabetes Registry (NDR) during 2004-2016. Then anyone with a history of stroke, or with any missing data on the clinical variables needed to calculate the eGDR, were excluded.
This resulted in an overall population of 104,697 individuals, aged a mean of 63 years, who had developed T2D at around the age of 59 years. About 44% of the study population were women. The mean eGDR for the whole population was 5.6 mg/kg per min.
The study subjects were grouped according to four eGDR levels: 24,706 were in the lowest quartile of eGDR (less than 4 mg/kg per min), signifying the highest level of insulin resistance, and 18,762 were in the upper quartile of eGDR (greater than 8 mg/kg per min), signifying the lowest level of insulin resistance. The middle two groups had an eGDR between 4 and 6 mg/kg per min (40,187), and 6 and 8 mg/kg/min (21,042).
Data from the NDR were then combined with the Swedish Cause of Death register, the Swedish In-patient Care Diagnoses registry, and the Longitudinal Database for Health Insurance and Labour Market Studies (LISA) to determine the rates of stroke, ischemic stroke, hemorrhagic stroke, all-cause mortality, and cardiovascular mortality.