Association between History of Dental Amalgam Fillings and Risk of Parkinson’s Disease: A Population-Based Retrospective Cohort Study in Taiwan

Abstract

The impact of dental amalgam on the development of Parkinson’s disease (PD) is still uncertain, although a positive association between dental amalgam and PD has been found in a few case-control studies. The patients with amalgam fillings restored between 2000 and 2008 were identified by using the National Health Insurance Research Database (NHIRD) in Taiwan. The same number of patients who had no new amalgam filling restored was matched by sex, age, and treatment date. Both cohorts were followed up from the treatment date until the date of diagnosis of PD, death, or the end of the year 2008. The individuals who received amalgam fillings had a significantly higher risk of PD afterward (adjusted hazard ratio [HR]=1.583, 95% confidence interval [CI]=1.122–2.234, p=0.0089) than those who did not. In the individuals who received amalgam fillings, being diagnosed with diabetes or hyperlipidemia demonstrated a significantly lower HR of PD occurrence than in the patients without diabetes or hyperlipidemia (HR=0.449, 95% CI=0.254–0.794, p=0.0059; HR=0.445, 95% CI=0.260–0.763, p=0.0032) after adjusting for comorbidities and Charlson-Deyo Comorbidity Index (CCI) scores. Meanwhile, hypertension increased the hazard risk of PD (HR=1.645, 95% CI=1.098–2.464, p=0.0159). The patients exposed to dental amalgam fillings were 1.583 times more likely to have PD afterward compared to their non-exposed counterparts after adjusting for comorbidities and CCI scores.

Periodontal inflammatory disease is associated with the risk of Parkinson’s disease: a population-based retrospective matched-cohort study

“…The PD-related comorbidities include hypertension (ICD-9-CM codes: 401.1, 401.9, 402.10, 402.90, 404.10, 404.90, 405.1, and 405.9), hyperlipidemia (ICD-9-CM codes: 272.0–272.9), chronic kidney disease (ICD-9-CM codes: 580, 581–589, 753, 403, 404, 250.4, 274.1, 440.1, 442.1, 447.3, 572.4, 642.1, and 646.2), depression (ICD-9-CM code: 311), stroke (ICD-9-CM codes: 433, 434, and 436) and traumatic brain injury (ICD-9-CM codes: 800–804, 850–854, 905.0, 950.1, 950.3, 907.0, 959.01, 959.9, 310.2, and V15.52) ( Chang et al, 2016 ; Goodarzi et al, 2016 ; Hsu et al, 2016 ; Liu et al, 2013 ; Wu et al, 2016 ). We also recorded the Charlson Comorbidity Index (CCI), which contains 17 weighted comorbidities and was calculated for each participant ( Charlson et al, 1987 ).…”

Rethinking the Dental Amalgam Dilemma: An Integrated Toxicological Approach

“…A study performed in an Amazon community (Brazil) exposed to organomercury assessed how polymorphisms are associated with organomercury detoxification. Given that the biotransformation of organomercury uses mainly glutathione (GSH) in the bile, mediated by glutathione transferase [78], polymorphisms in the GSTM1 and GSTT1 genes alter the levels of this neurotoxin. Their study displayed individual variations of the mercury levels in blood and hair of 71 men and 73 women.…”

Metals and Parkinson's Disease: Mechanisms and Biochemical Processes

“…In one retrospective casecontrol study, PD patients had a significantly higher number of amalgam fillings before the onset of the disease compared to controls [61]. It has also been demonstrated that patients exposed to dental amalgam fillings were ~1.6 times more likely to have PD in comparison with their non-exposed counterparts after adjusting for comorbidities and Charlson-Deyo Comorbidity Index (CCI) scores [1].…”

“…Parkinson's disease (PD) is the most common muscular functioning disorder, and it is the second most common neurodegenerative disorder after Alzheimer's disease (AD). It is known as a neurodegenerative disease, characterized by neuronal cell loss in the substantia nigra and subsequently a reduction of dopamine secretion [1]. The prevalence of PD has increased in industrialized nations and will continue to increase alongside the longevity of the population [2,3].…”