Find out about the problems and insights for safe driving for people with diabetes

Noriyuki Miyatani, a 65 year old man with diabetes, turned right into Midosuji Street in Osaska on June 30, 2014. He drove the wrong way, hitting a woman on her bicycle, fracturing her ribs.

He then backed up and went in the other direction, hitting a truck, before smashing into the wall of a store. Police waited until Miyatani recovered from his injuries and then questioned him.

He had taken his insulin injections on the morning of the accident and that while he was driving, he felt hungry and ate some sweets. However, he could not remember causing the accident. Miyatani was charged for dangerous driving in Japan.

Driving in India is risky; at least 400 people are killed in road accidents every day. There are 18 cars per thousand people in India. India is also home to about 67 million people with diabetes. Therefore, the likelihood of the occurrence of such an accident is high.

This does not mean that people with diabetes should not drive. Driving is one of the basic skills that most people need for their daily life. It enables them to go to their workplace, meet friends and family, go shopping etc. It gives a person the independence to travel as per his or her own convenience.

Appropriate situational judgment and quick reaction time are essential for safe driving which might be affected by changes in physical, mental, or emotional condition.

Diabetes is one such condition that may affect a person’s ability to drive.

In the UK, people with diabetes are subject to a number of licensing requirements and restrictions. These licensing decisions involve regular reviews at various levels, depending upon the type of driving and the category of vehicle they want to drive.

Drivers have to declare their diabetic condition to the 'Driver and Vehicle Licensing Agency' (DVLA) once they are diagnosed or their treatment is changed. DVLA asks drivers with diabetes various questions about their condition, including their management regimen and whether they have experienced any diabetes-related problems that could affect their ability to drive safely.

Restrictions are imposed to make sure that drivers with diabetes are as safe as other drivers when they drive particular groups of motor vehicle. The factors that can affect the driving ability of people with diabetes are hypoglycemia, retinopathy or neuropathy.

The intensity of the effect of these conditions on an individual results in restrictions being placed by DVLA on a person's license, including restriction on the type of vehicle they may drive. Preventive restrictions on driving for people with diabetes can keep both the driver and the society safe.

Even then many countries, including India, do not demand any special compliance for people living with diabetes.

Hypoglycemia (low blood sugar level): Our brain needs sugar to function properly. Hypoglycemia or low blood sugar level can reduce the cognitive ability such as basic reasoning and increase reaction time. When hypoglycemia is severe, a person can lose consciousness.

Hypoglycemia is mostly the effect of insulin or diabetes management drugs and is induced due to a mismatch in the food, activity, and medication. Most of the time people are aware of their blood sugar being low as they start experiencing symptoms like hunger, tingling, sweating (even in cold weather), and increase in heart rate.

This can be easily managed by taking any fast acting glucose in the form of sugary drinks, glucose tablets or sweet candy. However, hypoglycemia can occur without warning symptoms which in turn poses a serious problem.

In the absence of low sugar warning symptoms (usually is due to recurrent and prolonged hypoglycemia, uncontrolled diabetes, delayed food intake, or other medical conditions), the person will exhibit direct neurological symptoms like impaired cognitive abilities which can push even the best of drivers into making dangerous decisions or mistakes on the road.

Many of the accidents caused by hypoglycemia occur because drivers ignore their hypoglycemia warning signs like hunger, sweating, feeling faint, etc. and continue driving.

Diabetic Retinopathy (Vision problem): Another concern with diabetes and driving is the condition called as Diabetic Retinopathy. It is a long term complication of poorly controlled diabetes which causes damage to the tiny blood vessels inside the eye.

This leads to problem with vision and eventually, can lead to blindness. In early stages diabetic retinopathy cannot be self-diagnosed unless people with diabetes get their eyes regularly checked by a qualified professional for retinal changes. In advanced stage, diabetic retinopathy must be treated with laser photocoagulation.

Diabetic retinopathy itself and /or its treatment with laser can produce a loss of visual field. In the UK drivers need to have corrected vision of 6/10 on a Snellen chart and visual field of 120-degree to be eligible to drive.

Drivers with treated retinopathy may experience difficulty in driving at night as well. Loss of vision in one eye completely does not affect ability to drive safely if the other eye is normal.

Diabetic Neuropathy (Loss of sensation in feet): People with long-term poorly-controlled diabetes develop neuropathy where there is either reduced or complete loss of sensation from their feet. With reduced sensation, people may find it more difficult to gauge pressure on the accelerator, brake or clutch pedals.

Sometime people with diabetic neuropathy develop severe pain. And to relieve the pain there are few medications that are available. These drugs such as gabapentin or amitriptyline used for neuropathic pain, can have a sedative effect which can impact the drivers’ alertness.

Other associated conditions: Sleep Apnea is associated with obesity and Type 2 diabetes. In people affected by Sleep Apnea, poor sleep quality at night leads to daytime drowsiness and an increased risk of road accidents. Similarly, heart attacks are common in people with diabetes.

People with diabetes have increased risk of heart rhythm disturbances, which can lead to sudden unconsciousness during driving. There is higher risk of stroke in people with diabetes, which can also severely impair a person’s ability to drive.

How to be a safe driver if you have diabetes:
Having diabetes does not mean that people having this condition need to give up driving, but it does mean that they need to be aware and often plan in advance before they get behind the wheels. In India, there are no fixed/set driving laws for people with diabetes. So you need to follow these 10 rules for safe driving if you have diabetes.

• You should understand that hypoglycemia can affect your judgment and reaction time even if you are a good driver at other times
• If you take insulin or sulfonylurea group of diabetes medication, it can induce hypoglycemia. So you should check your blood sugar level one-two hours before getting behind the wheel.
• If your blood sugar is below 70 mg /dl, you should treat it with a fast-acting sugar source such as juice, non-diet soda, hard candy, or glucose tablet. This should be followed by a carbohydrate snack such as fruit, sandwich or toast. You should still wait for 45 minutes before you drive as your blood sugar level can drop again. Recheck it to make sure it is above 90 mg / dl before you start driving.
• If your blood sugar is below 90 mg/dl, but above 70 mg/dl, you should take a carbohydrate meal before driving to prevent your blood sugar from dropping while you drive.
• For longer distances, stop every 2 hours and check your blood sugar level. It is better to travel with a companion who can take over driving or help you in-case you are not feeling well.
• Always keep hypoglycemia treatments (juice box, glucose tablets or hard candy) and a complex carbohydrate snack (sandwich or toast) handy in the car and preferably within reach of your driving seat.
• Always carry your blood glucose meter with you when driving. As soon as you feel any signs of low blood sugar (hypoglycemia), stop the vehicle at a safe place, and check your blood sugar level. Correct or stabilize it as needed.
• It goes without saying that you should not drive after consuming alcohol. If you have diabetes you should not drink alcohol even the night before as it can cause hypoglycemia in the morning.
• Always take regular meals and snacks.
• You should have your eyes and feet checked at least once a year to make sure that there are no complications that can affect your’ driving.

The author of the article is Dr. Satyan Rajbhandari, Group Medical Director, Diabetacare.