Independent effect of cardiometabolic syndromes and depression on dementia in Parkinson's disease: A 12-year longitudinal follow-up study of a nationwide cohort

Background: We aimed to investigate the incidence rate of Parkinson's disease dementia (PDD) according to age and disease duration by sex. Furthermore, we explored the effect of each cardiometabolic syndrome and depression on the incidence of PDD.Methods: Using data from the Korean National Health Insurance Service, 79,622 pa- tients with de novo Parkinson's disease (PD) aged >= 40 years between January 2002 and December 2010 were followed to December 2019. We analyzed the incidence of PDD according to age at PD diagnosis and disease duration. To determine cardiometabolic syn-dromes and depression that affected PDD, we used Fine and Gray competing regression after controlling for age and sex.Results: During the 12.5- year follow- up period, the incidence of PDD increased with age at PD diagnosis (0.81- 45.31 per 1000 person- years among those aged 40- 44 and over 80 years, respectively) and longer disease duration (22.68 per 1000 person- years in 1- 2 years to 34.16 per 1000 person- years in 15- 16 years). Hypertension (subdistri- bution hazard ratio [SHR] = 1.11; 95% confidence interval [CI] 1.07- 1.16), diabetes (SHR = 1.09; 95% CI 1.05- 1.14), dyslipidemia (SHR = 1.15; 95% CI 1.11- 1.20), and depres-sion (SHR = 1.36; 95% CI 1.30- 1.41) independently increased the risk for PDD.Conclusions: Our findings provide insights into cardiometabolic syndromes as modifiable risk factors for incident PDD. Furthermore, our results will help in designing public health policies with respect to controlling cardiometabolic syndromes and depression to prevent incident PDD in patients with PD.

Automated summary

This study aimed to investigate the incidence rate of Parkinson's disease dementia (PDD) according to age and disease duration by sex. The results showed that age and disease duration were associated with the incidence of PDD, and hypertension, diabetes, dyslipidemia, and depression independently increased the risk for PDD.