Alzheimer’s Disease Association with Metals and Metalloids Concentration in Blood and Urine

Abstract

As there is some evidence that the risk for Alzheimer’s disease (AD) is partially attributable to environmental exposure to some metals and metalloids, we examined an association between AD and arsenic, chromium, and selenium in 53 AD patients and 217 controls. Urinary arsenic, blood chromium, and selenium were determined by inductively coupled plasma mass spectrometry. Logistic regression models calculating odds ratios (ORs) and 95% confidence intervals (CI) were used to estimate AD association with arsenic, chromium, and selenium. In AD patients, urinary arsenic and blood chromium were significantly higher, while blood selenium was significantly lower compared to controls. Increased blood selenium was related to a significant decrease in the odds of AD after adjustment for risk factors. Blood selenium per 1 kg × 10−9/m3 × 10−4 increment was associated with 1.4 times lower risk of AD (OR = 0.71; 95% CI 0.58–0.87). A significant increase in the odds of AD associated with increased blood chromium was also seen in the adjusted model: the OR per 1 kg × 10−9/m3 × 10−3 chromium increment was 2.39 (95% CI 1.32–4.31). The association of urinary arsenic with the risk of AD was not significant. The data obtained provide evidence that selenium reduces the risk of Alzheimer’s disease, while chromium increases it.

Exposure to World Trade Center Dust Exacerbates Cognitive Impairment and Evokes a Central and Peripheral Pro-Inflammatory Transcriptional Profile in an Animal Model of Alzheimer’s Disease

“…nection with AD neurotoxicity include the essential metals iron, copper, zinc, manganese, selenium, and chromium, and the non-essential metals lead, mercury, and aluminum [26,27]. Among the 32 chemical elements analyzed we found that the concentration of chromium shows a statistically significant 20% increase in the whole brain of 5XFAD mice exposed to a high level of WTCPM compared to vehicleexposed 5XFAD controls ( * p = 0.02) (Table 1).…”

Role of the Exposome in Neurodegenerative Disease: Recent Insights and Future Directions

“…130 However, reports of associations of AD risk with arsenic are inconsistent. [137][138][139] A number of metals are also associated with cerebrospinal fluid p-tau and other pathological AD biomarkers. 136 Meta-analyses support the aforementioned findings, and a compilation of trace element data from AD participants and controls may help interrogate relevant associations as more data become available.…”

“…Lead, in particular, is considered neurotoxic and aggravates pathology 130 . However, reports of associations of AD risk with arsenic are inconsistent 137–139 . A number of metals are also associated with cerebrospinal fluid p‐tau and other pathological AD biomarkers 136 .…”

Metals in Alzheimer’s Disease

“…As exposure also increases Aβ levels [ 67 ], promotes tau hyperphosphorylation [ 32 , 68 , 69 ], tau aggregation [ 32 ], oxidative stress caused mainly by mitochondrial dysfunction [ 70 ], vascular damage [ 71 ], neuroinflammation [ 34 ], and apoptosis and the necrosis of neurons [ 37 , 38 ] ( Figure 1 ). In the majority of human studies, there were no significant differences in As levels between AD patients and the controls, although some studies observed a significant increase in As levels in AD patients [ 72 , 73 ] and a positive association with CSF AD biomarkers [ 74 ].…”