Affecting about 60 to 70 percent of people struggling with diabetes, risk
of diabetic neuropathy rises due to a longer exposure to high blood sugar, abnormal blood fat levels, metabolic
factors, low insulin levels and other autoimmune factors (cause nerve inflammation), mechanical injury (carpel
tunnel syndrome), lifestyle factors (Smoking or alcohol), etc.
Signs & Symptoms
- Numbness, tingling or pain in the limbs (toes and feet)
- Muscle atrophy (wasting away of muscles) of feet and hands
- Urination problems
- Indigestion, nausea or vomiting
- Low blood pressure
- Weakness or dizziness
Diabetic Neuropathies: Major Types
Depending on the nerves and the body part as well as ensuing function affected, diabetes
associated neuropathy encompasses several types which mainly include:
Peripheral neuropathy
Most commonly observed in 75% of Diabetic Neuropathies affected, peripheral diabetic nerve pain or distal
polyneuropathy (DPN) is characterised by nerve damage in the limbs, viz. legs, feet and toes and
may also later affect the arms or hands. Affected individuals are asymptomatic at the start but
slowly begin to show symptoms like numbness, tingling or burning sensation, insensitivity to
pain or temperature, sharp cramps, extreme sensitivity to slight touch, loss of control and
coordination, which often worsen at night. Foot deformities and blisters result if injury or
pressure goes unnoticed and if not treated in time, can lead to amputations if the infection
spreads to the bones.
Autonomic Neuropathy (AN)
This affects the parasympathetic and sympathetic nerves of the peripheral nervous system which
control almost every organ in the body like heart, sex organs, etc. and regulate blood pressure,
blood glucose levels, etc. AN is daunting as it affects the internal organs creating complications
in vision, digestion, urination, respiratory function, etc., thus impairing the system's response
which restores the blood glucose levels to normal after an episode of hypoglycemia. According
to the specific nerve affected of the autonomic nervous system, frequently observed symptoms
include irregular heartbeats, difficulty in swallowing and eating, heat intolerance due to inability
to sweat normally, blood pressure drop on minor body movements due to dysregulation of blood
vessel contraction or expansion, gastrointestinal neuropathy symptoms like diarrhea, constipation,
etc.
Proximal Neuropathy (PN)
Most commonly observed in type 2 diabetics and older adults with diabetes, this condition is
characterised by a one-sided pain and weakness experienced in thighs,
legs, hips, etc. Depending on the type of nerve damage, duration of recovery period varies
and patients usually need help with basic activities like standing and sitting
Focal Neuropathy (FN)
As the name suggests, this condition being a mononeuropathy, affects a single nerve, usually
nerves of the head especially eyes, torso or legs causing different symptoms unlike the above
mentioned polyneuropathies (DPN, AN,PN). Symptoms are characterised by a sharp pain at
specific locations of lower back or legs, double vision, eye pain, paralysis on one side of face,
ete.
What causes Diabetic Neuropathies?
The exact causal factor of Diabetic Neuropathies or mechanism is still unknown, but researchers believe that there
is a connection between poor blood glucose control and development of Diabetic Neuropathies. Elevated blood
glucose levels or hyperglycemia damages the endothelial cell lining of small blood vessels like
arterioles, venules, capillaries, etc. These cells, upon being subjected to prolonged abnormally
high levels of glucose, form more glycoproteins leading to a thicker but weaker basement
membrane which further bleeds leaking proteins, eventually slowing blood flow throughout
the body. Hyperglycemia also hampers the normal functioning of various metabolic pathways
such as polyol pathway which results in accumulation of sorbitol and fructose, leading to reduced
myoinositol levels and decreased NAK-ATPase activity, thereby impairing axonal transport and
structural breakdown of nerves. Non-enzymatic glycation of proteins, lipids and nucleotides due
to excessive glucose levels leads to production of advanced glycation end products which disrupt
neuronal integrity and repair mechanisms. Increased free radical production in diabetes damages
the tiny blood vessels supplying to the nerves by creating oxidative stress. Along with prolonged
exposure to high blood glucose and low levels of insulin, progression to diabetic neuropathies is
a result of culmination of various other factors:
- Age
Individuals suffering from diabetes for over 25 years or more and older people are more prone to
develop Diabetic Neuropathies.
- Lifestyle factors
Excessive alcoholism and smoking, medication toxicity, exposure to industrial neurotoxic
agents like ethanol, arsenic, lead, ete, worsen the symptoms of Diabetic Neuropathies.
- Nerve injury
Prior nerve damage due to inflammation, autoimmune diseases like Sjogren's syndrome, lupus
and rheumatoid arthritis, or mechanical injury like nerve compression due to Carpal Tunnel
Syndrome: a sudden trauma from an accident, falls or surgical procedures may lead to partially
or completely crushed or stretched nerves. Broken or dislocated bones exert damaging pressure
on neighbouring nerves, thereby increasing the susceptibility to Diabetic Neuropathies. Infections due to Epstein-
Barr virus, cytomegalovirus, ete, severely damage sensory nerves causing peripheral neuropathy.
Various cancers that infiltrate nerve fibers by exerting damaging pressure, neuromas which cause
intense pain upon engulfing nearby nerves, as well as kidneys disorders are known to cause peripheral
neuro pathies
- Genetic factors
Mutations inherited or arising de novo in neuronal proteins are known to develop diabetic
neuropathies and a few candidate genes are: ACE, AKRIBI, APOE, MTHFR, NOS3, and VEGF
that play a significant role in development of DPN as well as CAN (Cardio-vascular Associated
Neuropathy)." Presence of HLA-DR3/4 phenotype in type 1 diabetes mellitus patients has also
been strongly associated with development of CAN.
However, irrespective of the cause, the end-result is failure of normal transport of oxygen and
nutrients to nerves by the tiny blood vessels, causing loss of function in the damaged ischemic
nerves. Exhaustion or dysfunction of endothelial progenitor cells is also speculated to accelerate
the course of diabetic neuropathies due to imbalances in neuronal metabolism and impairment
of nerve blood flow.
Diagnosis
Normally a physical examination based on existing symptoms and prior medical history is
performed to diagnose any type of Diabetic Neuropathies wherein blood pressure, muscle strength, heart,
sensitivity to position changes, touch, etc. are checked in the affected.
Pathology Test A blood test is carried out to measure the levels of hemoglobin Ale
(HbAle) and fasting plasma glucose to assess the glycemie status of the patient suffering
from any type of Diabetic Neuropathies, wherein the former is recommended to remain below 7% and the
latter should be below 110mg/dl.
- Quantitative Sensory Testing
A non-invasive procedure performed to assess
peripheral nervous system disorders by determining
the pain and sensation threshold for cold and warm
temperature. It is a pain-free technique and aids to
assess early detection as well as appropriate
therapy and monitoring progress.
- Foot exams
When doctors suspect DPN, comprehensive foot exams are performed frequently to
assess bone, muscles, circulation, skin and protective sensation of the feet using a
nylon monofilament or via pinprick.
- Nerve conduction studies and electromyography
Nerve conduction studies can aid in understanding the type and extent of nerve damage by
analysing the electric current transmission via a nerve whereas electromyography analyses
the muscle response to electrical signals transmitted by nearby nerves.
- Ultrasound
Sound waves are used in ultrasound which produces an image for structural assessment of
internal organs affected by particular ANs; for example: bladder and other parts of urinary pH
tract to analyse its function during urination.
- Invasive tests
Skin and nerve biopsies are performed by removing and examining a sample of skin or nerve
tissue, respectively, to evaluate the degree of nerve damage. Analysing skin sample is advantageous
over nerve biopsies as it facilitates examination of nerve fiber endings, thus revealing the extent
of damage present
- Other tests
Corneal confocal microscopy (CCM) is utilised for imaging corneal nerve fibers to define the
extent of nerve damage due to somatic Diabetic Neuropathies. Other causal factors of Diabetic Neuropathies like compressive lesions
and other pathological conditions in the spinal canal can be excluded upon performing plexus
magnetic resonance imaging (MRI) and computed tomography (CT) myelography
Treatment
The best way and the only way to slow down and treat this progressive nerve damage in any
type of Diabetic Neuropathies is to keep blood glucose levels under tight control i.e. as close to the normal ranges
as possible in order to protect nerves all over the body. Various medications for relieving diabetic
nerve pain include anti-depressants, nonsteroidal anti-inflammatory drugs (NSAIDs), opioids,
anticonvulsants, antibiotics; drugs for easing gastrointestinal complications (like indigestion,
vomiting, belching, etc.) and controlling high blood pressure are also prescribed by doctors for
smooth functioning of a patient's daily routine. Topical medications like Capsaicin cream and
Lidocaine patches are prescribed to heal any nerve pain in foot due to gradual lack of sensation.
However, the best modus operandi to deal with diabetes and the sugar surge is following a healthy diet, hearty
exercise and happy habits!
Sometimes it becomes too late to detect those tingling or numbing, sensations, thus
it is crucial to identify any kind of ulcer, corns, warts or callus development. In case of severe ulceration,
choosing appropriate therapeutic footwear, daily saline cleansing and dressing, debridement (damaged tissue removal
from wounds) when necessary and antibiotic therapies are essential.
Prevent it... Manage it... Fight it!
The only possible way to prevent diabetic foot is to control the dangerously high blood sugar levels, which is
possible only when people opt for timely monitoring with proper management of blood sugar levels. Self-monitoring
is the key to fight this tingling threat, as it leads to self assessment. Other preventive measures include,
- Regular feet washing (every day!)
- Adequately trimmed toenails
- Keeping dry and moisturised feet
- Changing socks frequently
- Regularly visiting a podiatrist for corns and callus removal
- Wearing comfy fitting shoes
Living with nerve damage
Though complete prevention of any extent of Diabetic Neuropathies may not be a possibility as diabetes mellitus is
a lifelong chronic disorder, managing this debilitating condition alone can become frustrating for
the patient. Along with a few strategies mentioned below, a strong support from family and friends
is a must as it helps to cope better with the persistent nerve pain experienced night and day
- Keep a tab on your blood glucose levels by taking
your medications on time, readjusting meals or
insulin shots.
- Eat right following a strict diabetic diet and be active by exercising regularly to keep your
metabolism in check, avoiding severe swings in blood sugar levels.
- Quit smoking and alcohol as they increase the risk of foot problems and amputations.
- Take special care of your foot by cleaning them regularly along with an essential regular inspection
for any injuries, corns, blisters, etc.
"Will you rather lose a leg to this so called
Diabetes? Or Fight the difficult yet manageable menace?", is the question that needs an answer from those 62 million
Indians' living with this diabetic calamity! Will you be those 44 lakh Indians who are still unaware of being a diabetic,
or else be the well-aware vehement individual who owns the strength to manage this malady? These are choices we ought to
make, to either let this condition make a healthy person or break a healthy person.
Therefore, controlling diet and nutrition is paramount in keeping diabetes in check as it pays
off by delaying or mitigating the imminent danger of further secondary complications, like
neuropathies. Till date, no cure is available for Diabetic Neuropathies; and although managing it can be enervating,
it is imperative for long-term survival.
