Incidence and risk of dementia in people with Anxiety over 50 years old – an electronic health records study

Abstract

Background

Depression is a well-established risk factor for dementia, but we know far less about the links between Anxiety and future dementia risk in older people. The aim was therefore to investigate the incidence of dementia in people with and without Anxiety above the age of 50 years over a 10-year period.

Method

The Health Improvement Network (THIN) was used, a large UK primary care dataset, that includes approximately 15.6 million patients, which is representative of the UK population. All people between 1st January 2008 and 31 December 2018 who had new onset Anxiety over the age of 50 years were identified. At the time of the first record of Anxiety, each person was individually matched to 4 unexposed persons based on their sex and age and Exposure Density Sampling was used, creating a dynamic cohort. Weibull survival regression models were fitted and hazard ratios (HR) were estimated for modelling time-to-dementia in those with and without Anxiety; and when determining the risk of developing dementia in those with Anxiety. Hazard ratio estimates were adjusted for sociodemographic and lifestyle factors, and relevant physical and mental health conditions.

Result

In this cohort study, there were 37,824 men and 68,761 women diagnosed with a first episode of Anxiety. Of those who had Anxiety, 2,792 people developed dementia during the follow up period, compared to 19,000 people in the non-Anxiety group. The incidence of dementia in those with and without Anxiety was 7.21 (95% CI 6.94-7.48) and 3.22 (95% CI 3.18-3.28) respectively per 1,000 person-years. The risk of dementia was increased 2.47-fold [HR 2.47 (CI 2.37- 2.57)] in the Anxiety group when compared to the non-Anxiety group after adjustment for age, sex, social deprivation, alcohol, smoking, BMI, diabetes mellitus, cardiovascular diseases, learning disabilities, HIV, multiple sclerosis, brain injury and hearing impairment.

Conclusion

The incidence of dementia was greater in those with Anxiety and the risk of developing dementia was more than doubled in people with Anxiety compared to those without. This provides further evidence that Anxiety is a potential risk factor for dementia.