Abstract
Objective
To evaluate cognitive impairment and risk factors of elders in high fluoride drinking water areas and investigate whether DKK1 is involved in this disorder.
Methods
MoCA-B and AD-8 were used to measure the cognitive functions of 272 and 172 subjects over the age of 60 came from the high and normal fluoride drinking water areas respectively, general information and peripheral blood were collected, the level of SOD, GSH and MDA were measured, mRNA level of DKK1, the concentration of blood fluoride and the polymorphism of APOE were tested.
Results
The blood fluoride concentration, mRNA level of DKK1 and ratio of abnormal cognitive function of subjects in high fluorine drinking water areas were higher than those in normal areas. The level of SOD of subjects in high fluorine drinking water was low compared with those in normal areas. The level of MDA and GSH had no difference between the two crowds in different fluorine drinking water areas. There were differences in cigarette smoking, education, dental status, hypertension, hyperlipidaemia and APOE results between the two crowds in different fluorine drinking water areas. The mRNA level of DKK1 and the level of cognitive function showed a positive correlation and DKK1 was one of five risk factors involved in cognitive impairment of older people living in high fluorosis areas.
Conclusions
The cognitive functions could be impaired in the older people living in high fluoride drinking water areas, and DKK1 may as a potential intervention point of this brain damage process need attention.
*Full-text study online at https://bmcpublichealth.biomedcentral.com/articles/10.1186/s12889-021-12310-6
Excerpt:
Study of subjects
The fluoride concentration of drinking water was high in the Feng County, Xuzhou City, Jiangsu Province, China, where dental fluorosis was very common. However, there was no data available regarding the cognitive function of the individuals who lived in this area. In this study, a total of 272 subjects from the high fluoride drinking water community (water fluoride concentration > 2 mg/L) of Feng County, Xuzhou City, Jiangsu Province, China, were randomly enrolled in this study. And a total of 172 subjects, from the normal fluoride drinking water community (water fluoride concentration < 0.8 mg/L) of Suining County, Xuzhou City, Jiangsu Province, China, were randomly chosen as the control group. These two counties have a similar culture, lifestyle and economic development level. Individuals with cerebral ischaemia, brain tumours and psychiatric disorders were excluded. This study was approved by the Ethics Committee of Affiliated Xuzhou Oriental Hospital of Xuzhou Medical University, China.
General information
Socio-demographic and personal information was collected from each subject. These data included gender, age, education, alcohol drinking, smoking, dental status, hypertension, hyperlipidaemia, diabetes and family history (psychiatric diseases or dementia). Age was categorized into 3 groups as follows: 60–69 years of age, 70–80 years of age and older than 80 years of age. Education was categorized into the following groups: illiterate, primary school, middle school, and high school or higher. Dental status was categorized as follows: dental fluorosis, normal and dentures.
Cognitive function tests
The Montreal Cognitive Assessment-Basic (MoCA-B) and AD-8 were used to investigate the cognitive functions of the subjects. The MoCA-B had excellent validity in screening for mild cognitive impairment in poorly educated older adults regardless of literacy [25]. The AD-8 is an 8-item informant-based questionnaire, which was designed to detect changes in the fields of memory, orientation, judgement and executive function [26].
*Full-text study online at https://bmcpublichealth.biomedcentral.com/articles/10.1186/s12889-021-12310-6
Print 
PDF