Death from MG peaks among teenage boys, older adults in China

Increase in mortality shows need to better manage myasthenia gravis, researchers advise

Margarida Maia, PhD avatar

by Margarida Maia, PhD |

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An illustration of a dead tree to symbolize mortality.

The rate of death from myasthenia gravis (MG) generally increases with age, but it peaks among teenage boys and older adults — in both men and women — according to a study from China.

Researchers also observed that the rate of death is showing an increasing trend over the years, particularly among adolescents and the elderly.

“The death burden due to MG [highlights] a pressing need to raise the profile of and improve the management of MG,” the researchers wrote.

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The study, “Mortality of myasthenia gravis: a national population-based study in China,” was published in the journal Annals of Clinical and Translational Neurology.

MG is a long-term disease that causes muscle weakness. It can occur at any age and the severity of symptoms varies from person to person, even though they tend to worsen with fatigue.

The disease often involves the muscles that control eye and eyelid movements, but it also can affect other parts of the body. When the muscles that control breathing are affected, MG can become life-threatening if not managed properly.

However, there haven’t been many studies assessing MG mortality. To gather more information on the subject, researchers in China looked at the number of deaths caused by MG in that country, and how this has changed over time.

To that end, they drew on data from the National Mortality Surveillance System, which covers nearly one-quarter of the total population of China. They looked for records of deaths occurring from 2013 to 2020 that were related to MG.

During that period, there were 4,224 deaths related to MG. From these, 2,501 (59.21%) were male patients and 1,723 (40.79%) were of female.

The median age at death for people with MG was 59.45 years, which was much younger compared with that of the general population (75.47 years). Male patients died at a median age of 56.02 years and female patients at a median age of 63.81 years.

Twice as high in male patients

In 2020, the age-adjusted rate of death from MG was 1.86 per million people, and it was almost twice as high in male patients (2.37 per million people) compared with female patients (1.31 per million people).

The number of deaths followed a pattern with two peaks. The first peak occurred at ages 10 to 19, and the second at ages 60 to 69. More than three-quarters (77.5%) of all deaths occurred among those older than 40.

The rate of death from MG also peaked among teenage boys, ages 10 to 19 (2.83 per million people), and then increased with age, reaching its highest level of 13.31 per million people for men, and 10.58 for women, 80 years and older. 

Across the country, the rate of death from MG was higher in rural areas than in urban areas. The highest rate, adjusted for age, was observed in the Southwest region (2.53 per million people).

From 2013 to 2020, the rate of death from MG showed an increasing trend. On average, it increased 3.5% per year. The most significant increases were seen in the age group of 10 to 19  and in those older than 70.

In male patients, the rate of death from MG increased by 31.67% — from 1.80 per million people in 2013 to 2.37 per million people in 2020. In female patients, the increase was much less accentuated (7.38%), rising from 1.22 per million people in 2013 to 1.31 per million people in 2020.

“Given [the] rapid aging in China, the increasing trends of mortality over time may exacerbate the disease burden associated with MG, which needs more public attention,” the researchers wrote.

“Unpacking the disparity between rural and urban areas, and among various regions, may inform healthcare providers and disease control priorities in China,” they wrote.