Trigger finger most commonly affects patients with type 1 and type 2 diabetes

Trigger finger most commonly affects patients with type 1 and type 2 diabetes

Blocked fingers, also known as trigger fingers, are more common in diabetics than in the general population. A study from Lund University in Sweden shows that the risk of being affected increases with high blood sugar. The study was published in Diabetes Care.

Trigger finger means that one or more fingers, often the ring finger or thumb, come into a bent position that makes it difficult to straighten. This is due to the thickening of the tendons that flex the finger and their connective tissue sheath, which results in the finger being fixed in a bent position towards the palm. It is a painful condition that can often be treated with cortisone injections, but sometimes requires surgery.

In the hand surgery clinic, we have long noticed that people with diabetes, both type 1 and type 2, are more often affected by the index finger. Over 20 percent of those requiring surgery for this condition are patients who have or will develop diabetes.

Mattias Rydberg, doctoral student at Lund University, assistant doctor at Skåne University Hospital and first author of the study

To investigate whether high blood sugar (blood sugar dysregulation) increases the risk of index finger, the researchers examined two registries: the Skåne Region Health Database, which contains all diagnoses, and the Swedish National Diabetes Register. Between 1 and 1.5 percent of the population is affected by index finger, but the diagnosis is made in 10 to 15 percent of diabetics, and the phenomenon is most common in the group with type 1 diabetes.

The newly published study confirms that blood sugar levels are a decisive factor in an increased risk of index finger disease. High blood sugar increased the risk of developing index finger disease in both men and women in the type 1 diabetes and type 2 diabetes groups. Blood sugar is measured in HbA1C, also known as long-term blood sugar, and is below 48 when regulated. The group of men with the most poorly regulated blood sugar (HbA1C > 64) was up to five times more likely to be affected than men with well-regulated (HbA1 < 48) blood sugar.

“However, we cannot say with certainty whether one of the groups uses medical care more often than others, which could be a factor influencing the results,” says Mattias Rydberg.

The mechanism or mechanisms behind the increased risk are unknown, but there are theories that high blood sugar makes both the flexor tendons and their connective tissue sheaths thicker, causing them to lock more easily. It was previously known that people with unregulated blood sugar were more susceptible to pinched nerves in their hands.

"It is important to raise awareness of the complications of diabetes and their development in order to detect them early, which allows for faster treatment and therefore a better outcome. In addition to nerve compression and trigger finger, there may also be a connection with." Thickening of the connective tissue in the palm of the hand (Dupuytren's contracture), impairment of joint movement and risk of arthritis at the base of the thumb. The mechanisms behind these complications are likely to be different in diabetes. The results of this study are interesting, “We can show that blood sugar dysregulation is related to the development of the index finger,” says Lars B. Dahlin, professor at Lund University and consultant in hand surgery at Skåne University Hospital.

The next step in the research will be to find out how effective the surgery is in patients with diabetes affected by an index finger.

"In our experience in the clinic, the operation goes well and there are few complications, but it takes a little longer for patients with type 1 and type 2 diabetes to regain full movement and function. We want to investigate this hypothesis further. Another interesting idea." The aim is to find out whether the index finger could be a warning signal for type 2 diabetes. “It is far from all people affected by an index finger who suffer from diabetes, but it would be interesting to see if, using modern registries, we can identify those who are in the risk zone for developing diabetes,” concludes Mattias Rydberg.

Source:

Lund University

Reference:

Rydberg, M., et al. (2022) High HbA1c levels are associated with trigger finger development in type 1 and type 2 diabetes: An observational registry-based study from Sweden. Diabetes treatment. doi.org/10.2337/dc22-0829.

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