People with diabetes may feel better, day to day, when their blood sugar swings a bit more than conventional wisdom recommends — as long as it stays within a safe range — according to new research presented this week at the European Association for the Study of Diabetes's annual meeting in Milan.
The study tracked 400 adults with type 1 (72 percent) or type 2 (28 percent) diabetes for 14 days, pairing their continuous glucose monitor readings with daily well-being questionnaires based on the WHO-5 scale, a validated five-item measure of mood and vitality. Participants had an average HbA1c of 7.6 percent and a mean age of 47.
Researchers led by Dominic Ehrmann of the Research Institute Diabetes Academy Mergentheim, known as FIDAM, in Germany found that more time spent in a normal glucose range of 70 to 140 mg/dl predicted better quality of life the following day — expected, given the usual advice to avoid high and low blood sugar. The surprise was that higher glucose variability within that normal range was also linked to improved next-day well-being, while time spent dangerously high or low showed no clear link either way.
"Days with higher time in the normal, safe range for blood sugar were followed by days on which individuals with type 1 and type 2 diabetes reported better quality of life."
Dominic Ehrmann, FIDAM, Bad Mergentheim
The researchers, funded by Germany's national Center for Diabetes Research as part of the PRO-MENTAL study, suggest one explanation: chasing extremely tight, flat glucose control day after day may itself be exhausting, requiring constant vigilance, dose adjustments and dietary restriction that erode quality of life even when the numbers look good on paper.
Caveats Worth Noting
The findings come from a conference presentation, not yet a peer-reviewed journal publication, and the design is observational: it shows an association between next-day glucose patterns and mood, not proof that variability itself causes people to feel better. Self-reported well-being can be shaped by countless day-to-day factors a 14-day window can't fully account for, and the sample, while reasonably sized, was limited to people already using continuous glucose monitors, who may differ from the broader population of people with diabetes.
Still, the researchers frame the result as a reason to rethink messaging around glucose targets. Rather than treating any variability as failure, clinicians may need to weigh the psychological cost of rigid control against its physical benefits — a balance that, for now, remains an open question pending longer-term study.
