Dementia is a global epidemic; the number of people with dementia worldwide was estimated at 47.47 million in 2015 and expected to reach 135.46 million in 2050. In a recent study, researchers have found that younger age at diabetes onset was associated with a higher risk of subsequent dementia. The research has been published in the JAMA on April 27, 2021.
In several studies and meta-analyses, diabetes was estimated to increase the risk of dementia by approximately 50%. In recent years the prevalence of type 2 diabetes mellitus (T2DM) increased considerably with younger age. Studies have shown the vascular complications of early-onset type 2 diabetes. However, the associations with dementia remain unclear. Therefore, Dr Archana Singh-Manoux, PhD, and her team conducted a study to determine whether younger age at diabetes onset is more strongly associated with the incidence of dementia.
It was a longitudinal cohort study. The researchers analyzed data from 10,095 residents in the United Kingdom who had six clinical exams between 1991 and 2016 and electronic health records data spanning through at least March 2019. The major outcome assessed was Incident dementia ascertained through linkage to electronic health records.
Key findings of the study were:
Among 10 095 participants, the researchers identified a total of 1710 cases of diabetes and 639 cases of dementia over a median follow-up of 31.7 years.
They noted that dementia rates per 1,000 person-years were
◊ 8.9 among those who did not have diabetes at age 70 years,
◊ 10 among those with diabetes onset up to 5 years earlier,
◊ 13 among those with diabetes onset 6 to 10 years earlier and
◊ 18.3 among those with diabetes onset more than 10 years earlier.
Upon multivariable-adjusted analysis, they found that compared with participants who did not have diabetes at age 70 years, the Hazard's ratio of dementia among participants with
◊ Diabetes onset more than 10 years earlier was 2.12,
◊ 1.49 for those with diabetes onset 6 to 10 years earlier and
◊ 1.11 (95% CI, 0.7-1.76) for those with diabetes onset 5 years earlier or less.
Upon linear trend test, they found a graded association between age at onset of type 2 diabetes and dementia.
In an analysis adjusted for sociodemographic and health factors, they found that at every 5-year younger age at the onset of type 2 diabetes had an association with an HR of dementia of 1.24 (95% CI, 1.06-1.46) at age 70.
The authors concluded, "In this longitudinal cohort study with a median follow-up of 31.7 years, younger age at onset of diabetes was significantly associated with higher risk of subsequent dementia."
For further information:
https://jamanetwork.com/journals/jama/article-abstract/2779197