Men live longer with ALS than women

You may know Stephen Hawking as the famous astrophysicist who described groundbreaking ideas about black holes and wrote a best-selling book, but you probably also know him for another achievement.

When he died in mid-March at 76 years old, he had lived for more than 50 years with Amyotrophic Lateral Sclerosis, or ALS. Scientists don’t know of anyone else who has lived that long with the incurable, crippling disease.

"This is exceptionally long," says Ola Nakken, a medical doctor and PhD candidate at the University of Oslo.

ALS affects the nervous system, causing paralysis and respiratory problems. It is always terminal.

A disease of late middle age

Nakken has examined various health records to determine the extent of the disease in Norway, and gave a talk about his findings in Oslo in mid March.

In Norway, the mean age of patients with the diagnosis is between 60 and 65 years old.

It is most common for people to get the disease in their late 50s or early 60s, and more men than women are affected.

Nakken found that the extent of the disease in Norway is significantly higher than previously estimated. Nevertheless, the risk of contracting the illness is low for most.

In Norway, eight people per 100,000 inhabitants live with ALS. Three new cases per 100,000 are diagnosed each year. This is about the same as in the rest of Europe.

Three years after diagnosis

There are big variations in how long a person may live after being diagnosed with ALS.

“The expected life after diagnosis is only three years on average,” says Nakken.

Women with ALS have slightly shorter survival times than men. Nakken does not know why, but has found some possible reasons as to why this might be the case.

It also takes roughly a year from the time the first symptoms occur until the disease is diagnosed.

A difficult diagnosis

Nakken says the disease can be difficult to diagnose. There is no blood test or imaging that can detect it, which means that physicians must rely on symptoms and a series of tests to rule out other possible diseases.

Almost nothing is known about the cause of the disease. Scientists know that genetics can play a role, and that environmental factors can also be a contributing factor.

About 10 per cent of patients live for 10 years or more, says Nakken. Scientists do not know, however, what allows some people with the disease to live longer than others.

"We see that some people basically get an easier version of the disease, where many of the motor neurons are spared for a long time," Nakken said.

A respirator can prolong life

Use of a respirator can prolong a person’s life for a few years, although this is a demanding treatment. Only 5 per cent of all ALS patients use a respirator.

"Relatively more men than women use respirators, but we don’t know why that is the case," says Nakken.

“More men than women may ask for this kind of treatment,” Nakken said. “And some versions of the disease respond better to a respirator, so that perhaps men are more likely to have this variant of the disease.”

Nevertheless, use of a respirator is a limited treatment option that is only suitable for a small proportion of patients.

More men than women take medicine for the disease

For his survey of ALS in Norway, Nakken relied on the Norwegian Patient Injury Registry, the Norwegian Prescription Database and the Norwegian Cause of Death Registry.

Only one medicine, Riluzolen, which is supposed to slow the progression of the disease, is approved for use for ALS in Norway. Nakken found that 70-80 per cent of patients use this medicine.

Roughly 5 per cent more men than women use this drug, he found.

“Does this mean that doctors are less likely to prescribe this medicine for women? Or that women don’t pick up the medicine when it is prescribed to them? We simply do not know,” he said.

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Read the Norwegian version of this article at forskning.no.