This is the first of a series of editions on complication screening in children and young adults with type 1 (T1D) and type 2 diabetes (T2D). All our education bulletins are available on our website here. Please share them with your colleagues.
Long-term diabetes complications include:
macro-vascular complications: cardiovascular disease, peripheral vascular disease and stroke.
Regular screening can help to prevent burdensome and costly diabetes complications.
Diabetes complications, including diabetic neuropathy can develop ‘silently’ and go unnoticed, as symptoms may develop in later stages when damage may not be reversable. Therefore, regular medical check-ups are essential to keep young people’s feet ‘happy’ and healthy.
In this bulletin we will discuss peripheral neuropathy and provide practical education and screening tools.
What is Diabetic Neuropathy
The somatic (voluntary) and autonomic (involuntary) peripheral nervous system can be affected in both T1D and T2D in youth and adults. The somatic peripheral nervous system allows the movement and control of our muscles. It is susceptible to shifts in glucose concentrations.
The somatic peripheral system involves small nerve fibres that carry pain and temperature perception which are frequently affected first in diabetes, followed by injury to nerve fibres which convey vibratory and position sense. These injuries occur mostly symmetrically (affecting both extremities)1.
The autonomic nervous system regulates involuntary processes including heart rate, blood pressure, respiration, digestion, sex organs and sweat glands. Damage to these nerves can also lead to hypoglycemia unawareness 1. Autonomic neuropathy will be discussed in a future bulletin.
The most common form of diabetic neuropathy is peripheral neuropathy which typically affects the feet and legs and sometimes the hands and arms1.
Prevalence of Diabetic Neuropathy in youth with type 1 and 2 diabetes
The reported prevalence of diabetic neuropathy in children and youth varies due to the following1:
level of blood glucose control in the population
use of different diagnostic tests
the frequent presence of subclinical neuropathy making the diagnosis challenging.
The ‘Pittsburgh Epidemiology of Diabetes Complications study’ reported the prevalence of diabetes neuropathy in youth with T1D as 3% (<18year olds), while the EURODIAB study reported 19% (in 15–29-year-olds)1. An Australian study reported 14% in T1D (11–17 years-olds) developing diabetic neuropathy 2–5 years after the diagnosis of diabetes1.
In T2D, rates of peripheral neuropathy can be even higher that in T1D. The SEARCH study reported 22%, and the TODAY study observed a cumulative incidence of 38.5% in males and 27.2% in females1.
Diabetic Neuropathy and foot problems can be prevented
Education is key - you as healthcare provider play a very important role
Access to a diabetes health care team is paramount in the prevention of diabetic neuropathy and serious foot problems2. The team can provide intensive education, psychosocial support, medical screening, appropriate care and treatment.
Young people and their families should be educated on the importance of appropriate footcare and regular medical screening, and on how to minimise risk factors. The diabetes team can explain about the possible signs and symptoms of diabetic neuropathy, and that it can be ‘silent’ at the early stage. The attached footcare education handout can be used to support the education session.
Managing risk factors to prevent peripheral neuropathy and other complications1:
Maintaining HbA1c <7.0% or as close to individual glycaemic targets as possible
BMI <95th percentile (use growth chart for children/BMI chart for adults)
No smoking
Regular physical activity
Achieving glycaemic targets is the most important determinant of vascular complications in youth with type 1 and 2 diabetes (ISPAD, 2022 guidelines) 1
Signs and symptoms of peripheral neuropathy may include:
Tingling
Burning feeling
Sharp pains
Numbness
Reduced ability to feel pain or temperature changes
Cramps
Muscle weakness
Extreme sensitivity to touch — for some people, even a bedsheet's weight can be painful
Serious foot problems, such as ulcers, infections, and bone and joint damage
Symptoms often get worse at night.
Screening recommendations for Diabetic Neuropathy (ISPAD 2022 guidelines)1
Screening in young people with T1D should start at puberty or from age 11 years with 2–5 years diabetes duration, and then repeated each year.
Screening in T2D should start at diagnosis, and then repeat each year. Attention to risk factors should be escalated because of the increased risk of complications and mortality (see also the ISPAD 2022 guidelines chapter 3 on T2D).
Screening includes an assessment of sensation, vibration, temperature, and ankle reflexes.
Screening methods and tools for assessing Diabetic Neuropathy
Large fibre function
128 Hz tuning fork is used to assess the large nerve fibre function at the great toe for vibratory perception (high specificity but low sensitivity). Also, ankle reflex should be checked.
Touch/pressure sensation should be assessed:
a 10-gram monofilament is recommended to test for sensory loss in people with diabetes. Alternatively, a cotton wool can be used if a monofilament is not available.
Monofilament is nylon fishing line made from a single fibre of plastic material, attached to a base. It is commonly used to test for loss of sensation which can evaluate if a person with diabetes is at a high risk for developing wounds and ulcers. The test itself involves applying a monofilament wire (5.07 g) to the test site perpendicularly until it bends, then holding for one to two seconds (with a buckling force of 10 g). This non-invasive, low-cost, and easy-to-perform test can be done in a clinic setting with a relatively low user error3.
Instructions on how to use Monofilament 10 g to test for sensation in the feet (see the image below)
Image Source: Morning Report at the Toronto Western Hospital, Wednesday, June 27, 2012: https://morningreporttwh.blogspot.com/2012/06/we-discussed-diabetic-foot-ulcers-this.html
Show the monofilament to the person with diabetes.
Do a pretest: place the end of the monofilament tip on the person’s hand or arm. In this way, the person understands the testing procedure and knows how what it feels and that it doesn’t hurt.
Ask the person to respond ‘yes’ when they feel the touching of monofilament to the foot.
Ask the person to close their eyes.
Place the tip of the monofilament at 90 degrees to the skin surface.
Slowly and gently push the monofilament with pressure until it bends (approx. 1cm - don’t jab). Hold the monofilament in this position for 1-2 seconds, then slowly release the pressure until it is straight. Avoid areas of callus (thickened skin)!
Remove contact from the skin.
DO NOT ASK THE PATIENT ‘did you feel that’?
If the patient does not say ‘yes’ when you touch a given testing site, continue on to another site (see sites on above image).
Repeat the sequence randomly at each of the testing sites on each foot.
When you have completed the sequence, you may want to RETEST the area(s) where the person did not feel the monofilament.
Wipe the monofilament tip with Alco wipes or sanitising solution after each use.
Replace monofilament after around 100 tests or after 6-12 months, depending how often it is used3.
Scoring: Eight correct responses out of 10 applications is considered normal: one to seven correct responses indicate reduced sensation, and no correct answers indicate absent sensation4.
If the young person has reduced to absent sensation in their feet, it is VERY important to educate him/her on daily foot care (see attached footcare handout) and to explain that s/he should NEVER walk barefoot. Refer to a neurologist if available.
Monofilament video instructions are available here
Foot health assessment chart:
The Michigan Neuropathy Screening Instrument (MNSI)4 is a commonly used tool to assess and record diabetic neuropathy in youth1. It consists of a patient questionnaire and a physical examination (see pdf here) conducted by the healthcare professional. Here is the resource that explains how to score the questionnaire and how to conduct the physical examinations.
Other foot screening tools:
The International Diabetes Federation (IDF) has published Clinical Practice Recommendations on the Diabetic Foot5 – see link here.
An abbreviated version of these guidelines, the “Diabetes Foot Screening Pocket Chart”, has also been produced, available as pdf here: https://idf.org/europe/media/uploads/sites/2/2023/06/IDF_Diabetic_Foot_Z_Card_Final.pdf
References and further reading:
Bjornstad P, Dart A, Donaghue KC, Dost A, Feldman EL, Tan GS, Wadwa RP, Zabeen B, Marcovecchio ML. ISPAD Clinical Practice Consensus Guidelines 2022: Microvascular and macrovascular complications in children and adolescents with diabetes. Pediatr Diabetes. 2022;23: 1432–1450
