Investigations of Vitamin D Receptor Polymorphism Affecting Workers’ Susceptibility to Lead

Abstract

exposure status, smoking and alcohol drinking, were significantly associated with ICL and time-weighted ICL. Regression analyses suggested that exposure status and personal habits (smoking and alcohol drinking) are still the major effects on blood lead parameters for lead workers rather than genotypes. In conclusion, VDR genotypes did not significantly affect the long term blood lead parameters after adjustment for all factors, but industrial hygiene improvement, including engineering control and health education, are the most important ways to protect workers' health. Blood lead levels or even bone lead levels would not always explain workers' health status, because individual susceptibility to lead toxicity may play an important role in lead toxicology and physiology. For example, lead inhibition of zinc metalloenzyme, delta-aminolevulinate dehydratase (ALAD), is one of the most sensitive indicators of blood lead levels. Previous studies have suggested that polymorphism in delta-ALAD, a heme synthetic enzyme, may be associated with differences in blood lead levels, perhaps due to different binding of lead in erythrocytes 1, 2) . Moreover, the toxicological relationship in which lead affects calcium and vitamin D metabolism had not been well understood. The biological interactions between lead and calcium are complex 3) . Some studies suggested that variant VDR alleles modify lead concentrations in bone, either by influencing lead content or calcium content or both 4) . We have been following up a group of lead workers for 12 yr. Although some studies had been done on personal hygiene habits 5) and health effects 6) , we cannot

Effects of Vitamin D Receptor, Metallothionein 1A, and 2A Gene Polymorphisms on Toxicity of the Peripheral Nervous System in Chronically Lead-Exposed Workers

“…Very few studies have discussed the influence of VDR-Apa (rs7975232) SNP. A previous study mentioned that higher TWICL was noted for the CC genotype than CA type than AA type in Apa (rs7975232) [27]. A similar trend was also observed in this study, although the difference was not significant.…”

“…Chuang et al found that chronically lead-exposed workers had higher blood lead levels and index of cumulative blood lead (ICL) in the Apa AA genotypes. [27] Metallothioneins (MTs) are cysteine-rich, metal-binding, low-molecular-weight proteins [28,29]. MT proteins have multiple functions, such as free radical scavenging and the detoxification of metal(loid)s including cadmium, arsenic, mercury, and lead [30][31][32][33][34].…”

Vitamin D Receptor FokI, ApaI, and TaqI Polymorphisms in Lead Exposed Subjects From Saudi Arabia

“…While a study reported that VDR genotypes do not affect long term BLLs (Chuang et al, 2004); our study shows a relation between various genotypes. This could be either due to sample sizes or because the study was conducted over a short term.…”

Ecogenetics of lead toxicity and its influence on risk assessment

“…: NC_000009.12), 22 –25 VDR (Vitamin D receptor; Gene ID: 7421; Accession no. : NC_000012.12), 26 –29 G6PD (Glucose-6-phosphate dehydrogenase; Gene ID: 2539; Accession no. : NC_000023.11), HFE (Hemochromatosis; Gene ID: 3077; Accession no.…”