Trigger finger, also known as stenosing tenosynovitis, is a common condition that affects the hand, causing a finger to catch or lock when bent. This ailment is observed more frequently in individuals living with diabetes. Understanding the mechanisms behind this increased prevalence is important for both prevention and management.
What is Trigger Finger
Trigger finger is a condition where a finger becomes stuck in a bent position, or “triggers,” when straightened. This can cause pain and stiffness, often worse in the morning. A tender lump may be felt at the base of the affected finger or thumb in the palm, and the finger may click when straightening.
This condition occurs when the flexor tendons, responsible for bending the fingers, become inflamed or develop a nodule. These tendons glide through a protective sheath. If the sheath narrows or the tendon thickens, its movement is restricted, causing the catching or locking sensation as the tendon struggles to pass through.
How Diabetes Contributes
Diabetes significantly increases the risk of developing trigger finger through several physiological mechanisms. One primary factor is the formation of advanced glycation end products (AGEs). High blood glucose levels, a hallmark of diabetes, lead to glycation, where sugar molecules attach to proteins and lipids.
This glycation process causes collagen, a major component of tendons and their sheaths, to form abnormal cross-links. These cross-links make collagen less flexible and prone to thickening in both tendons and their sheaths. This structural change narrows the sheath and thickens the tendon, impeding smooth movement.
Chronic low-grade inflammation, common in diabetes, also plays a role. This persistent inflammation can thicken and irritate the tendon and its sheath, exacerbating mechanical issues. Impaired blood flow to tendons and their sheaths, a consequence of diabetic microvascular changes, also affects tissue health and repair. This reduced blood supply hinders natural healing and makes tissues more susceptible to damage and inflammation.
Studies show a direct relationship between higher HbA1c levels, indicating average blood sugar control, and trigger finger development in both type 1 and type 2 diabetes. For instance, men with type 1 diabetes and HbA1c levels above 8% had a higher risk of trigger finger compared to those with well-regulated blood sugar. This suggests prolonged hyperglycemia drives the connective tissue changes seen in trigger finger.
Addressing Trigger Finger with Diabetes
Managing trigger finger in individuals with diabetes often requires a comprehensive approach that considers their underlying metabolic condition. Controlling blood glucose levels is a foundational step, as good glycemic management can help prevent condition progression and improve treatment outcomes. Maintaining a lower HbA1c is associated with a reduced risk of developing trigger finger.
Non-surgical treatments are typically the first line of defense. These include resting the affected hand, splinting the finger to keep it straight, and taking nonsteroidal anti-inflammatory drugs (NSAIDs) to reduce pain and inflammation. Corticosteroid injections into the tendon sheath can also be effective in reducing inflammation and allowing the tendon to glide more freely, though their effectiveness may be lower in people with diabetes. Corticosteroid injections can temporarily affect blood sugar levels, so patients with diabetes should monitor their glucose closely after such procedures.
If conservative measures do not provide sufficient relief, surgical intervention, known as trigger finger release, may be considered. This procedure involves making a small incision to widen the tendon sheath, allowing the tendon to move without obstruction. While surgery is generally effective, individuals with diabetes may experience a slightly slower recovery and potentially more initial pain and stiffness. Patients should inform their healthcare providers about their diabetic status to ensure appropriate management and monitoring.