Secular trends in longevity among people with Down syndrome in Japan, 1995–2016

Abstract

Background Life expectancy in Japan has increased dramatically and is one of the longest in the world. However, the changes in lifespan in Japanese individuals with congenital diseases remain unknown. We investigated secular changes in the lifespan of people with Down syndrome over the last 20 years. Methods We observed secular trends in the number of stillbirths, deaths and the mortality rates at ages 20, 40, and 60 among all deaths registered with Down syndrome as the cause of death (ICD10 code: Q90) in the Japan national death registry database between 1995 and 2016. Changes in the median age at death between 1995–2005 and 2006–2016 were investigated based on sex and history of surgery. Results We identified 240 stillbirths and 1,099 deaths in this period. The annual number of stillbirths and deaths above the age of 1 year increased, whereas the number of deaths below 1 year did not change. The proportional mortality indicator at ages 20, 40, and 60 increased from 21.7%, 11.7%, and 1.7% in 1995 to 69.9%, 66.7%, and 36.6% in 2016, respectively. The median age at death was higher in females, individuals without a surgical history, and deaths occurring in 2006–2016. The median age at death increased over the period in those without a surgical history. Conclusions The age at death among people with Down syndrome has increased over the last 20 years, with currently 1 in 3 persons living over 60 years, necessitating adequate social welfare services in this aging population.

Causes of death in patients with Down syndrome in 2014–2016: A population study in Japan

“…The increased SMOR for early‐onset Alzheimer's disease was observed at a higher age range (ages 60–69) compared to the studies from the United States (ages 41–59 (Yang et al, 2002 ) and Sweden (ages 41–59) (Englund et al, 2013 ), which might be explained by several factors. First, even if patients with Down syndrome in Japan and other countries develop Alzheimer's disease at a similar age, patients with Down syndrome in Japan may live longer (Motegi et al, 2020 ). Second, patients with Down syndrome in Japan may develop Alzheimer's disease at a higher age due to genetic or environmental factors.…”

“…In the general Japanese population of Japan, the proportionate mortality of natural death in 2018 was 8.0% (Summary of Vital Statistics, 2018 ), which is higher than that in Australia (0.2%) and the United States (0.0%). This discrepancy may be due to two factors, long life expectancy of patients with Down syndrome in Japan (Motegi et al, 2020 ) and ambiguity of the medical definition of natural death. The expected life span of patients with Down syndrome is 50–60 years.…”

“…These findings suggest that susceptibility to dementia may be has increasing over the years. Given the continuing increase in deaths due to dementia and longer life expectancy in patients with Down syndrome (Englund et al, 2013;Motegi et al, 2020), it is equally probable that the proportionate mortality for Alzheimer's disease associated with advanced age will increase in patients with Down syndrome in future. (Perluigi & Butterfield, 2012) underlie the increased risk.…”

“…(Englund et al, 2013 ; Hasle et al, 2016 ; O'Leary et al, 2018 ; Santoro et al, 2021 ; Yang et al, 2002 ). However, several studies suggest that the life expectancy of patients with Down syndrome might have increased in many countries including Japan (Motegi et al, 2020 ; Presson et al, 2013 ; Yang et al, 2002 ), in parallel with advances in medical care and welfare. Despite this, the impact of changing demographics of this patient population including racial and ethnic differences (Santoro et al, 2016 ) on specific medical issues has not been extensively investigated.…”

Medical Needs of Adults with Down Syndrome Presenting at a Regional Medical and Rehabilitation Center in Japan

“…In Japan, the recent live birth of DS was estimated at around 1 in 500, a higher rate than in Western countries, owing to advanced maternal age 5 . In addition, among the total number of Japanese people with DS, the proportion of older people over 60 is increasing, with the most senior age reported in Japan being 102 years old 6 . Therefore, lifelong continuous support for people with DS is essential because of a longer lifetime in adulthood.…”