Does Poor Blood Sugar Control Affect Your Sense of Smell? New Research Suggests a Link

Most people know that Type 1 diabetes can affect the eyes, kidneys, and nervous system. But a new study published in the Journal of Diabetes Research reveals another potential complication: loss of smell.

Researchers have long recognized that people with diabetes sometimes experience olfactory dysfunction—a reduced ability to smell. What's less understood is how common this is in young people with Type 1 diabetes, and how strongly it connects to blood sugar control.

Scientists assessed smell function in adolescents with Type 1 diabetes using a validated test called the Sniffin' Sticks test. This test measures three aspects of smell: the lowest odor concentration someone can detect (threshold), the ability to tell different smells apart (discrimination), and the ability to recognize specific smells (identification).

The researchers combined these three measurements into a single score (called TDI) to diagnose hyposmia—medical term for reduced smell ability. They then looked at how diabetes duration and long-term blood sugar control (measured by mean HbA1c) affected these scores.

The findings showed a clear connection: adolescents with Type 1 diabetes who had higher average blood sugar levels had noticeably lower smell test scores.

The data was striking for one measure in particular. Adolescents with a mean HbA1c above 7.0%—indicating less stable long-term blood sugar control—had a 3.7 times greater risk of hyposmia compared to those with better control. This was the strongest independent predictor of smell loss in the study.

The researchers note that olfactory dysfunction can negatively affect eating behavior and quality of life. Loss of smell makes food less enjoyable and may influence what and how much someone eats.

While this is the first study of its kind to report these specific findings, the authors suggest that smell testing could someday become a useful early warning sign for diabetes complications. However, more research is needed before olfactory testing becomes a standard screening tool in diabetes care.

Source: Journal of diabetes research. Evidence type: PubMed indexed literature. Type1Cure is an information and intelligence hub, not a medical advice service. This article summarizes published research and does not provide diagnosis, treatment, or personal medical guidance. Always talk to your own care team before changing anything about your Type 1 diabetes management.