Trigger finger, a condition where fingers get locked in a bent position, is more common in people with diabetes according to research from Lund University in Sweden.
The study has associated cases of trigger finger with high blood pressure, meaning people with diabetes are more susceptible to the condition than the general population.
When someone has trigger finger, the ring finger or thumb can get stuck in a bent position and can be difficult to straighten out. This is caused by the thickening of tendons which causes the connective tissue sheath in fingers to bend, meaning the finger becomes fixed in a bent position towards the palm. The condition can be painful and is usually treated with cortisone injections and can require surgery in some cases.
The study has been published in Diabetes Care.
Clear link between high blood pressure and trigger finger
“At the hand surgery clinic, we have noted for a long time that people with diabetes, both type 1 and type 2, are more often affected by trigger finger. Over 20% of those who require surgery for this condition are patients who have, or will develop, diabetes,” said Mattias Rydberg, a doctoral student at Lund University, and first author of the study.
To examine whether high blood pressure increased the risk of trigger finger, the researchers analysed data from two registers: Region Skåne’s healthcare database, which includes all diagnoses, and the Swedish national diabetes register.
The team found that 1-1.5% of the population was affected by trigger finger, the diagnosis rose to rates of 10-15% in people who have diabetes. Cases of trigger finger appeared most in people with type 1 diabetes.
The researchers found that the risk of trigger finger among men and women with both forms of diabetes was higher. Blood sugar is measured in HbA1C, a healthy person should have HbA1C levels below 48. Men with the worst-regulated blood sugar (HbA1C > 64) were five times more at risk than men with well-regulated blood sugar.
“However, we can’t know for certain if any of the groups seek healthcare more often than others which could be a factor that affects the results,” said Rydberg.
The exact mechanisms behind the increased risk are not known. It has been theorised that high blood sugar makes the flexor tendons and their connective tissue sheaths thicker, causing joints to lock more easily. It has already been established that unregulated blood sugar can lead to nerve entrapments in the hand.
Creating better treatment
“It is important to draw attention to the complications from diabetes and how they can arise in order to discover them early, which enables faster treatment and thus a better outcome,” said Lars B Dahlin, professor at Lund University and consultant in hand surgery at Skåne University Hospital.
“The mechanisms behind these complications probably differ in the case of diabetes. The results of this study are interesting, as we can show that blood sugar dysregulation has a connection with the development of trigger finger,” he added.
The researcher’s next steps will be to understand how trigger finger treatment can be improved. The team will chart how effective it is to operate on patients with diabetes who are affected by the condition.
“From our experience at the clinic, surgery 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,” concluded Rydberg.