A national Korean study finds a surprising link between varicose veins and dementia, and suggests that treating the veins can help prevent vascular brain damage.
Study: Association between varicose veins and the occurrence of dementia: a national population -based cohort research. Image Credit: New Africa / Shutterstock.com
A recent Plos One Study investigates the association between the development of dementia and the presence of varicose veins (VV).
Varicose veins and dementia
The global prevalence of VV currently varies from 2% to 73%, depending on the geographical location and study methods. VV is characterized by twisted, enlarged and superficial veins with a diameter of three millimeters (mm) or more.
Some factors that can contribute to the development of VV are aging, obesity, female gender and chronic constipation. Some of the vascular changes that are shared between VV and aging are also associated with neurodegenerative diseases and cognitive disorders.
Previous studies have reported that VV, venous hypertension and valvular reflux are correlated with changes in the white matter in the brain. Venous pathology can reduce cerebral venous drainage, aggravating known risk factors for dementia, such as the worsening of lesions of white matter and cerebral small vascular disease.
Dementia is defined as persistent and progressive cognitive decline, memory loss and behavioral changes, where Alzheimer’s disease or vascular dementia (VD) is responsible for most cases of dementia. Researchers predict that, due to the rapidly aging world population, the prevalence of dementia will rise considerably around the world.
Although the exact causes of dementia remain unclear, vascular damage and damage to target bodies as a result of venous problems contribute to the development of dementia. However, additional mechanistic studies must be carried out to further investigate this potential association.
About the study
The researchers of the current longitudinal study used population data to determine the relationship between VV and the risk of developing dementia, as well as the role of VV treatment in mitigating this association.
Data was obtained from the NHIS-COHORT database of National Health Insurance Service-Service-Service-Service-Service-Service-Service-Service (NHIS-Heals) between 2002 and 2019. This data is obtained from adults aged 40 years and older who underwent a free health screening twice every year.
The current analysis included 430,875 people who underwent health screening between 2005 and 2010. Persons with a history of dementia due to all causes and people with incomplete data were excluded. The final sample consisted of 396,767 people, of whom 1.3% had a history of VV.
Propensity Score Matching (PSM) was performed to guarantee a balanced comparison.
The primary research result was dementia for all causes, while secondary results include the occurrence of AD and VD. Diagnoses required two or more medical claims, along with medicines for antidement medicines, which improved diagnostic accuracy. Data on other covariates such as age, gender, income and physical activity levels were also taken into account for the analysis.
Study findings
The average age of the research cohort was 56 years, of which 46% were male. Compared to people with the diagnosis of VV, smoking, alcohol consumption and a history of diabetes mellitus, people without a history of VV were more common. However, the frequency of comorbidities was higher in the VV group.
During a median follow-up period of 13.3 years, 13.9%, 9.7%and 3.7%of individuals were diagnosed with dementia, AD and VD respectively. In the multivariate analysis, people with VV ran an increased risk of dementia for all causes.
VV did not correlate with AD or VD risk in multivariate models; However, the association between dementia for all causes and VV was consistently observed in the Post-PSM sensitivity analysis, regardless of Covariates. Men, current smokers and heavy drinkers in particular with VV had a considerably higher risk of developing dementia due to all causes.
The incidental risk of dementia for all causes was not significantly different between patients with the diagnosis VV who received or not treatments for their VV. The treatment/procedure of VV was associated with a lower risk of ad in front of PSM, but not after PSM. A significant link between Lager VD risk and the treatment/procedure of VV was observed before and after PSM.
Conclusions
The research results suggest that VV is associated with an increased risk of dementia due to all causes, whereby the treatment/procedure of VV may reduce the risk risk of VD. However, these associations do not imply causality due to the retrospective observational design.
An important limitation of the current study is the categorization and severity of VV, which cannot be derived from health data. Moreover, not -measured confusing factors such as a family history of dementia and different levels of urbanization may affect the results.
It is important that the data set used for the analysis was not representative of the entire South Korean population, because it contained a random sample of 10% of all South Koreans. Moreover, since the cohort only includes people aged 40 and older, the findings are not allowed to generalize to younger populations.