Association of environmental cadmium exposure with periodontal disease in U.S. adults

Healthy lifestyles ameliorate an increased risk of periodontitis associated with polycyclic aromatic hydrocarbons

The risk of chronic inflammatory diseases has been linked to exposure to polycyclic aromatic hydrocarbons (PAHs). However, limited data are available regarding their impact on periodontitis. This study aims to explore the association between PAHs and periodontitis while also evaluating the potential modifying effects of healthy lifestyles. We included 17,031 participants from the US National Health and Nutrition Examination Survey (NHANES, 2001-2004 and 2009-2014). A meta-analysis-based environment-wide association study (EWAS) was adopted to identify environmental chemicals for the mean probing pocket depth (PPD) and the mean attachment loss (AL). PAHs were further evaluated concerning the cross-sectional association with Mod/Sev periodontitis using multivariable logistic regression models. Moreover, healthy lifestyle scores were estimated to assess their modifying effect on the PAH-periodontitis association. EWAS analysis identified several urinary PAH metabolites as significant risk factors for the mean PPD and AL (false discovery rate <0.05, Q > 0.05). Periodontitis severity was positively associated with eight individual and total PAH concentrations. Stratifying the participants in terms of healthy lifestyle scores did not reveal any association in the healthy group. Moreover, the association weakened in never-smokers and individuals with sufficient physical activity and normal weight. PAH exposure was a risk factor for periodontitis. A healthier lifestyle was observed to offset the risk potentials of PAHs for periodontitis. Smoking cessation, physical activity, and weight loss might be recommended as a healthy lifestyle strategy for ameliorating PAH-related periodontitis.

Association of individual and combined exposures of 10 metals with periodontitis: Results from a large population-based study

AIMS

To systematically investigate the association between individual and combined metal exposure and periodontitis.

METHODS

Data encompassing complete periodontal examinations and metal detection in blood and urine samples were procured from the National Health and Nutrition Examination Survey (NHANES) 2011-2014. Three statistical methods, namely weighted logistic regression, Bayesian kernel machine regression (BKMR), and weighted quantile sum (WQS) regression, were used to evaluate the independent and combined associations between metals and periodontitis.

RESULTS

Elevated concentrations of blood cadmium (odds ratio [OR]: 1.73, 95% confidence interval [CI]: 1.15-2.61) and blood lead (OR: 1.17, 95 %CI: 1.02-1.34) exhibited a positive association with periodontitis, even after adjusting for potential confounding factors. The BKMR and WQS regression suggested that the co-exposure of metals was also positively associated with periodontitis. Moreover, estradiol and albumin were identified as potential mediators in the relationship between the WQS index of the 10 metals in blood and periodontitis explaining 25.36% and 2.02% of the relationship, respectively. Furthermore, generally consistent patterns of associations between metals and periodontitis and mediating roles of estrogen and albumin were observed after a series of sensitivity analyses.

CONCLUSION

This study provides evidence of positive associations between elevated levels of cadmium, lead or metal mixture and periodontitis, which may be partially mediated by sex hormones and oxidative stress indicators.

Mediating role of systemic inflammation in the association between heavy metals exposure and periodontitis risk

BACKGROUND

This study evaluated the mediating role of systemic inflammation in the association between exposure to heavy metals and periodontitis in a nationwide sample of adults.

METHODS

Pooled cross-sectional data from the National Health and Nutrition Examination Survey (NHANES 2009-2014) were used (n = 8993). Periodontitis was defined by a full-mouth examination and classified as no/mild and moderate/severe (mod/sev) groups. Blood and urinary heavy metal levels were investigated, including cadmium (Cd), lead (Pb), and mercury (Hg). In addition, systemic inflammation was assessed using circulatory leukocyte counts and C-reactive protein (CRP) levels.

RESULTS

Multivariable logistic regression analysis revealed the positive associations of blood and urinary levels of Cd and Pb with mod/sev periodontitis. In contrast,blood Hg levels did not show a significant association. The odds of having periodontitis were 1.233 and 1.311 times higher for each one-unit increment in Ln-transformed blood Cd (95% confidence interval [CI]: 1.109-1.371) and Pb (95% CI: 1.170-1.470), respectively. Mediation analysis suggested a 6.3% to 11.5% contribution of leucocyte counts in the association of blood Cd and Pb levels with periodontitis. Sensitivity analyses for urinary Cd levels yielded consistent mediating effects. However, no significant mediating effect of CRP was detected.

CONCLUSION

Higher exposures to Cd and Pb were positively associated with periodontitis risk. These associations might be partially mediated by the elevated levels of leukocytes rather than CRP. Further longitudinal studies are needed to elucidate the discordant results of the systemic inflammatory biomarkers.

Effect of blood lead levels on periodontitis in American adults: a cross-sectional analysis from the national health and nutrition examination survey

BACKGROUND

The primary objective of this study was to assess the impact of blood lead levels on the development and progression of periodontitis.

METHODS

This study included 8600 participants from the National Nutrition and Health Examination Survey conducted the United States between 2009 and 2014. The exposure variable was the blood lead level, while the outcome variable was periodontitis. To evaluate the relationship between the blood lead level and periodontitis, a multivariate logistic regression model was used.

RESULTS

A positive association was observed between blood lead levels and the risk of periodontitis in Model 1 (OR = 7.04, 95% CI = 5.95-8.31). After adjusting for age (continuous), sex, ethnicity, and BMI (continuous) in Model 2, the significant association between blood lead levels and periodontitis risk remained evident (OR = 3.06, 95% CI: 2.54-3.70). Consequently, even after comprehensive adjustment for potential confounding factors in Model 3, the robust association between blood lead levels and periodontitis risk persisted (OR = 2.08, 95% CI = 1.67-2.60). When considering the serum lead concentration as a categorical variable and after adjusting for potential confounders in Model 3, we observed that the odds ratios (ORs) of periodontitis in the T2 (0.94 µg/dL-1.60 µg/dL) and T3 (lead ≥ 1.60 µg/dL) groups increased from 1.27 (OR = 1.27, 95% CI: 1.11-1.44) to 1.57 (OR = 1.57, 95% CI: 1.36-1.81) compared to T1 group. Subgroup analysis revealed no effect modifiers.

CONCLUSIONS

Our main findings suggest that there is no safe range of blood lead levels regarding periodontitis risk and that increasing blood lead levels can significantly increase the prevalence of periodontitis.

Association of urinary heavy metal combined exposure with periodontitis among US adults from NHANES 2011-2014

Some heavy metals are associated with periodontitis; whereas most of these associations have focused on individual metal, there are no specific studies on the effects of combined heavy metal exposure on periodontitis. We conducted an analysis on the association between urinary heavy metal exposure and periodontitis in participants aged 30 years and older using multiple logistic regression and Bayesian kernel machine regression (BKMR). This analysis was performed on data from the National Health and Nutrition Examination Survey from 2011 to 2014. The study found that using logistic regression, the 4th quartile of urinary lead and molybdenum and the 3rd quartile of urinary strontium were positively associated with periodontitis compared to the reference quartile after adjusting for covariates. Odds ratio (OR) with 95% confidence interval (CI) was 1.738 (1.069-2.826), 1.515 (1.025-2.239), and 1.498 (1.010-2.222), respectively. The 3rd and 4th quartiles of urinary cobalt were negatively associated with periodontitis, and their ORs and 95% CIs were 0.639 (0.438-0.934) and 0.571 (0.377-0.964), respectively. The BKMR model showed that urinary barium, lead, and molybdenum were positively associated with periodontitis in a range of concentrations and urinary cobalt, manganese, tin, and strontium were negatively correlated with periodontitis. Furthermore, the overall association between urinary heavy metals and periodontitis was positive. Our study provides evidence for an association between exposure to multiple urinary heavy metals and periodontitis. However, further longitudinal studies are needed to explore the specific mechanisms involved.

Association between levels of blood trace minerals and periodontitis among United States adults

Aim

Evidence linking trace minerals and periodontitis is limited. To investigate the relationship between trace minerals (selenium, manganese, lead, cadmium, and mercury) and periodontitis, data from the National Health and Nutrition Examination Survey (NHANES) were analyzed after accounting for potential confounding factors. No known studies have explored the relationship between these five trace minerals and periodontitis.

Materials and methods

A total of 4,964 participants who had undergone a full-mouth periodontal examination and laboratory tests for five trace minerals were studied in a cross-sectional study. Clinical attachment loss (CAL) and periodontitis grading were used to measure periodontitis severity. Linear and logistic regression models were used to evaluate the association between trace minerals and periodontitis. Further subgroup analyses were performed.

Results

Blood lead and cadmium levels were positively associated with mean CAL, and blood selenium was negatively associated with mean CAL; however, blood mercury, blood manganese, and mean CAL were not significantly associated. The association between trace minerals and mean CAL was more significant in males, the elderly, and patients with diabetes. There was a threshold effect between blood cadmium levels and mean CAL. Among the Black population, the relationship between blood cadmium levels and mean CAL followed an inverted U-shaped curve. There was a saturation effect in the study of blood lead in people aged 45–59 years old.

Conclusion

Our study highlighted that blood selenium, lead, and cadmium levels were significantly associated with periodontitis in a nationally representative sample of United States adults.

Prenatal and early childhood critical windows for the association of nephrotoxic metal and metalloid mixtures with kidney function

INTRODUCTION

As renal development and maturation processes begin in utero and continue through early childhood, sensitive developmental periods arise during which metal exposures can program subclinical nephrotoxicity that manifests later in life. We used novel dentine biomarkers of established nephrotoxicants including arsenic (As), cadmium (Cd), lead (Pb), chromium (Cr), and lithium (Li), and their mixtures, to identify critical windows of exposure-associated kidney function alterations in preadolescents.

METHODS

Participants included 353 children in the Programming Research in Obesity Growth, Environment and Social Stressors (PROGRESS) longitudinal birth cohort study based in Mexico City. Estimated glomerular filtration rate (eGFR) was assessed in 8-12 year old children using serum cystatin C measures. Pre- and postnatal metal(loid) concentrations were assessed in weekly increments by analyzing deciduous teeth with laser ablation-inductively coupled plasma-mass spectrometry. We used reverse distributed lag models (rDLMs) and lagged Weighted Quantile Sum (L-WQS) regression to examine time-varying associations between weekly perinatal metal(loid) exposure or metal(loid) mixtures and preadolescent eGFR while adjusting for age, sex, BMI z-score, SES and prenatal tobacco smoke exposure.

RESULTS

We identified a critical window of susceptibility to Pb exposure, in the late 3rd trimester (5 weeks prior to birth) during which higher Pb exposure was associated with children's increased eGFR. When all elements were assessed as a mixture, we identified late 2nd/early 3rd trimester (weeks 8-17 of gestation) as a window of vulnerability associated with decreased eGFR, with Li and Cr contributing the greatest weights to the association. When stratified by sex, we observed stronger effects among boys than girls.

CONCLUSIONS

Using tooth-matrix biomarkers, we identified discrete developmental exposure windows wherein Pb and metal(loid) mixtures were associated with altered preadolescent kidney function.

Abnormal Micronutrient Intake Is Associated with the Risk of Periodontitis: A Dose-response Association Study Based on NHANES 2009-2014

The association between micronutrient intake and the risk of periodontitis has received much attention in recent years. However, most studies focused on the linear relationship between them. This study aimed to explore the dose-response association between micronutrient intake and periodontitis. A total of 8959 participants who underwent a periodontal examination, and reported their micronutrient intake levels were derived from the US National Health and Nutrition Examination Survey (NHANES, 2009-2014) database. Logistic regression was performed to evaluate associations between micronutrient intake and periodontitis after propensity score matching (PSM), and restricted cubic splines (RCS) analysis was conducted to explore the dose-response associations. Following PSM, 5530 participants were included in the RCS analysis. The risk of periodontitis was reduced with sufficient intake of the following micronutrients: vitamin A, vitamin B1, vitamin B2, and vitamin E. In addition, the risk of periodontitis was increased with excessive intake of the following micronutrients: vitamin B1 (1.8 mg/day, males; 1.3 mg/day, females), vitamin C (90 mg/day, males), and copper (1.1 mg/day, combined). In conclusion, a linear association was found between vitamin A, vitamin B2, vitamin C, and copper and periodontitis-namely, a sufficient intake of vitamin A and vitamin B2 might help reduce the prevalence of periodontitis; by contrast, a high intake of vitamin C and copper increased the risk. In addition, a nonlinear dose-response association was found for the incidence of periodontitis with vitamin B1 and vitamin E. When within reasonable limits, supplemental intake helped reduce the prevalence of periodontitis, while excessive intake did not help significantly and might even increase the risk. However, confounding factors, such as health awareness, should still be considered.

Urinary level of heavy metals in people working in smoking cafés

Previous researches have reported significant levels of heavy metals in indoor air of smoking cafés. The current research aimed to evaluate the potential exposure of smoking cafés workers to heavy metals through quantifying amounts of these pollutants in urine samples. To this end, 35 waterpipe/cigarette cafés workers were selected as the exposed population, 35 employees from non-smoking cafe' as the control group 1 (CG1) and 25 cases of the normal citizens as the control group 2 (CG2); and their urine samples were taken. Samples were then prepared by acid digestion approach and measured by the ICP in order to determine amount of heavy metals in them. The findings of the current work show the significant difference among urinary levels of metals in the exposed and both CG1 and CG2 (P value < 0.05). Furthermore, urinary metal levels in samples collected from smoking café workers after the exposure were considerably higher than those were collected before the exposure (P-value <0.05). According to the findings, "tobacco type" could be considered as a leading factor for heavy metal exposure in studied smokers. Additionally, a positive and significant association was found between urinary metals and urinary levels of 8-OHdG (a markers of DNA degradation through oxidative stress). Therefore, workers in waterpipe/cigarette café can be classified as high risk people in terms of DNA oxidative damage.

Ion release and surface roughness of silver soldered bands with two different polishing methods: An in-vitro study

OBJECTIVE:

To evaluate the surface roughness and ion release of silver-soldered joints by using two polishing methods.

METHODS:

174 orthodontic bands with and without silver-soldered joints were evaluated and divided into three groups: two experimental, with different polishing methods (SP1 and SP2), and one control (SS) composed of bands without silver solder. For ionic release, 50 bands of each group were immersed in saline solution and submitted to atomic absorption spectrophotometry to quantify the amount of Fe, Ni, Cr (in all the three groups), Ag, Cu, Cd, and Zn (in the two experimental groups). A rugosimeter was employed to verify the surface roughness.

RESULTS:

Ni and Cr were released in higher amounts after soldering. Cd, Ag, Zn, and Cu may be released from silver-soldered bands independently of the polishing method employed. Ag was released in higher amounts from the soldered bands that presented higher surface roughness.

CONCLUSIONS:

Differences exist in relation to the surface roughness of silver-soldered bands when distinct polishing methods are used. Toxic ions may be released from silver soldered joints and higher surface roughness may cause higher ionic release.

Use of toenail-bounded heavy metals to characterize occupational exposure and oxidative stress in workers of waterpipe/cigarette cafés

Tobacco smoke is known for releasing metals in indoor air of waterpipe/cigarette cafés. However, the worker exposure to metals, and its association with oxidative stress in these cafés are still unclear. To this end, 54 workers and 38 customers from waterpipe/cigarette cafés (the exposed group), 30 workers from non-smoking cafés (the control group 1 (CG_1)) and 32 individuals from the general population (the control group 2 (CG_2)) were selected and toenails samples were then taken from them. Our findings revealed a significant difference in terms of toenail-bounded metal levels between the exposure and control groups (CG_1 and CG_2) (Mann-Whitney U test, Pvalue < 0.05). This study has also indicated that "type of tobacco" could be considered as a predictor for toenail-bounded heavy metals. Furthermore, our research's results suggest that toenail-bounded heavy metals are positively and significantly correlated with urinary levels of 8- hydroxy-2'-deoxyguanosine (8-OHdG, as a biomarker for the degradation of deoxyribonucleic acid (DNA) oxidative stress). Therefore, it can be concluded that workers of waterpipe/cigarette cafés are at high risks of adverse health of DNA oxidative degradation.

Analysis of the relationship between periodontitis and osteoporosis/fractures: a cross-sectional study

BACKGROUND

Chronic periodontitis is a multifactorial inflammatory disease resulting in patients exhibiting high levels of inflammatory factors causing systemic inflammatory bone destruction that may lead to osteoporosis development. The association between periodontitis and osteoporosis has been documented; however, the findings remain unclear. This study aimed to identify the association between periodontitis and osteoporosis using a cross-sectional study design and Korean Genome and Epidemiology Study (KoGES) health examinee data.

METHODS

This cross-sectional study used epidemiological data from the KoGES during 2004-2016. Of 125,324 participants (age, 40-79 years), 9969 with periodontitis and 115,332 controls (without periodontitis) were selected. We analyzed the history of osteoporosis and fractures of all participants. All participants were examined according to age, sex, income group, obesity, smoking habits, alcohol consumption, and food intake. To analyze the odds ratio (OR) of periodontitis for those with osteoporosis and fractures, a logistic regression model was used.

RESULTS

The adjusted odds ratio (aOR) of periodontitis for osteoporosis was 2.16 (95% confidence interval [CI], 2.01-2.31; P < 0.001). The aOR of periodontitis for any fracture was 1.54 (95% CI 1.46-1.62; P < 0.001).

CONCLUSION

Osteoporosis and fractures are associated with periodontitis. Performing regular oral hygiene and examinations of bone mineral density are recommended to prevent aggravation of osteoporosis and periodontitis.

Occurrence of neonicotinoid insecticides and their metabolites in tooth samples collected from south China: Associations with periodontitis

Neonicotinoid insecticides (NEOs) are widely used in agricultural production processes in China and worldwide. NEOs have been an increasing concern because of their potential toxicity to nontarget organisms. However, studies that focused on human exposure to NEOs in China are limited. In this study, levels of six parent NEOs (p-NEOs), namely imidacloprid (IMI), acetamiprid (ACE), clothianidin (CLO), dinotefuran (DIN), thiamethoxam (THIX), and thiacloprid (THI), and three metabolites (m-NEOs), such as 5-hydroxy-imidacloprid (5-OH-IMI), 1-methyl-3-(tetrahydro-3-furyl methyl) urea (UF), and N-desmethyl-acetamiprid (N-dm-ACE) were measured in 127 tooth samples collected from South China. P-NEOs and m-NEOs are frequently detected (76%-93%) in tooth samples, with median levels of 0.03-1.20 ng/g. UF is the most abundant NEOs in tooth samples (36%). Females have higher NEO levels than males, and gender-related differences in NEO levels are found. Associations among most p-NEOs are also found (p < 0.05), indicating the source of human exposure to p-NEOs is related. However, no significant relationships (p > 0.05) between levels of m-NEOs and their corresponding p-NEOs are found, suggesting that exogenous m-NEOs contribute to exposure. We have also examined the associations between human NEOs exposure and periodontitis, and associations between NEO exposure and periodontitis are observed (OR = 2.63-7.33; 95% CI = 1.01-21.1, p-trend < 0.05). Our results suggest that NEO levels are associated with increased odds of prevalent periodontitis. This study is the first to report about p-NEOs and m-NEOs in tooth samples collected from South China.

Exposure to multiple heavy metals associate with aberrant immune homeostasis and inflammatory activation in preschool children

Heavy metals generate adverse health effects by interfering with immune homeostasis and promoting inflammation in individuals. Our objective was to explore the induction of immune and inflammatory responses by multiple heavy metals in children living in the e-waste contaminated area. A total of 147 preschool children were recruited, including 73 children from Guiyu, a typical e-waste recycling area, and 74 from a reference group. Blood levels of heavy metals, including lead (Pb), cadmium (Cd), mercury (Hg) and arsenic (As), were detected using an inductively coupled plasma mass spectrometry (ICP-MS). Immune cell counts (neutrophils, monocytes, lymphocytes) were determined by an automatic blood cell analyzer, pro-inflammatory cytokines (IL-1β, IL-6, IL-8, TNF-α) and anti-inflammatory cytokines (IL-1RA, IL-4, IL-10, IL-13) were analyzed by a Luminex 200 multiplex immunoassay instrument. Multiple correspondences and linear regression analyses were applied to investigate the relationships between heavy metal exposure and relevant parameters. Results shows Guiyu children had higher levels of Pb, Cd, Hg, As, IL-1β and IL-6, but decreased lymphocyte, IL-1RA and IL-13. Neutrophil count was positively correlated with Pb, Cd and Hg exposure. Anti-inflammatory IL-1RA concentration was negatively related with Pb, Cd, Hg and As, while pro-inflammatory IL-1β and IL-6 were positively correlated with Pb. Guiyu children may have dysregulated immune response and high inflammation risk. Exposure to Pb, Cd, Hg and As could be harmful for immune response and inflammatory regulation. Our finding of decreased IL-RA production in children exposed to Pb, Cd, Hg, and As is novel and could be an opportunity for future research.

Elevated levels of lead exposure and impact on the anti-inflammatory ability of oral sialic acids among preschool children in e-waste areas

The oral health of preschool children in an electronic waste (e-waste) area is susceptible to lead (Pb) exposure increasing the risk of dental caries and causing periodontitis and other oral diseases. The aim of the present study is to investigate the relationship between chronic exposure to Pb and oral anti-inflammatory potential of preschool children. For this analysis, 574 preschool children from 2.5 to 6 years of age were recruited between November and December 2017, in which 357 preschool children were from Guiyu (n = 357), an e-waste-contaminated town, and 217 from Haojiang Shantou. We measured the levels of child blood Pb, salivary sialic acid, serum interleukin-6 (IL-6) and serum tumor necrosis factor-α (TNF-α), and investigated the prevalence of dental caries in deciduous teeth. The medians of blood Pb levels, serum IL-6 and TNF-α were significantly higher in the Guiyu children than in Haojiang children. Concomitantly, salivary sialic acids were lower in the Guiyu children [9.58 (3.97, 18.42) mg/dL] than in Haojiang [17.57 (5.95, 24.23) mg/dL]. Additionally, the prevalence of dental caries in deciduous teeth was significantly higher in the Guiyu children than in Haojiang (62.5% vs. 53.9%). Blood Pb levels were negatively correlated with salivary sialic acids, in which IL-6 played as a mediator of the association between blood Pb levels and saliva sialic acid concentrations according to the mediation model. To our knowledge, this is the first report on the potential association between chronic Pb exposure and the anti-inflammatory ability of oral sialic acids among preschool children. These results suggest that the chronic Pb exposure can reduce salivary sialic acid levels, attenuate oral anti-inflammatory potential and increase the potential risk of dental caries in deciduous teeth among preschool children in an e-waste site.

Risk assessment of heavy metal contamination of paddy soil and rice (Oryza sativa) from Abakaliki, Nigeria

The study assessed the concentration and bioavailability of Pb, Cd, Zn, Cr and Fe metals in soil from rice fields in Abakaliki, Nigeria. The concentrations of these heavy metals in rice grains were also determined, with a view to assessing their human health risk on consumers. Heavy metal concentrations in soil and rice were determined using FAAS after digestion with 5:1 HNO₃:HClO₄ while Tessier's sequential extraction method was used to obtain the fractionated soil digests. The mean concentrations (μg/g) of the total heavy metal ranged from 1.036 ± 1.86 (Cd) to 6900.537 ± 734.82 (Fe) in soil while that of rice grains ranged from 0.024 ± 0.07 (Cd) to 101.446 ± 75.26 (Fe).The concentrations of Fe and Cd in most of the soil samples and Pb in rice grains exceeded some Nigerian and International standards. The heavy metal sequential extractions of soil samples showed that lead and zinc were less mobile in the soil and are bioavailable for plant uptake. The estimated daily intake of the metals was below the tolerable daily intake. The hazard quotient and the total hazard index were less than one showing that at present, there is no possible adverse health effect on rice consumers.

Health Effects of Trace Metals in Electronic Cigarette Aerosols-a Systematic Review

Electronic cigarettes (ECs) are essentially nicotine delivery devices that mimic the appearance of a conventional cigarette (CC). Lately, they have been marketed as tools for quitting smoking. Even though they are promoted as safe alternatives to CC, they are not devoid of hazardous components. Literature reveals that the EC aerosols and e-liquids are a potential source of elements that induce and promote development of chronic conditions. These include trace metals which are leached from their core assembly. Some of these metals like nickel, chromium, cadmium, tin, aluminum, and lead are potential carcinogens. They have been associated with fatal conditions like lung and sinonasal cancer. Besides, they may have adverse effects on oral tissues like periodontal ligament and mucosa where they may trigger chronic periodontitis and oral cancer. However, there is only trivial evidence related to health hazards of metals released from ECs. With this background, the present review first focuses on the structure of the ECs followed by an appraisal of the data from experimental studies about the metals released in EC aerosols and their associated health hazards.

Evaluating the possible association between systemic osteoporosis and periodontal disease progression in postmenopausal women

To evaluate the association between systemic osteoporosis and periodontal diseases in postmenopausal women. A total of 300 women aged (50-70 years) were divided into an osteoporotic (OP) group (n = 150) and non-osteoporotic (NOP) group (n = 150) depending on BMD measured using (DXA) at the femoral neck and lumbar spine. Periodontal examination including PI, GI, PPD, and CAL was measured. A standard digital dental panoramic radiograph was taken for each patient and analyzed using specially developed software graphic program to assess the alveolar bone level and BMD. Elemental analysis of root surfaces of extracted teeth was done for detecting Ca, P, F, Mg, and K using (LIBS). Results showed the differences between both groups were not statistically significant in PI, GI, and PPD. A statistically significant difference was found between both groups in CAL, the distance between CEJ-AC and alveolar bone density. Elemental analysis of the root surfaces revealed that Ca was statistically significantly less in the OP group while the differences between both groups regarding F and P were not statistically significant. Mg and K found to be significantly more in the OP group than in the NOP group. To conclude osteoporosis is certainly a risk factor for periodontal disease and seems to plays a vital role in disease progression.

Cadmium Exposure Disrupts Periodontal Bone in Experimental Animals: Implications for Periodontal Disease in Humans

Cadmium (Cd) is an environmental contaminant that damages the kidney, the liver, and bones. Some epidemiological studies showed associations between Cd exposure and periodontal disease. The purpose of this study was to examine the relationship between Cd exposure and periodontal disease in experimental animals. Male Sprague/Dawley rats were given daily subcutaneous injections of Cd (0.6 mg/kg/day) for up to 12 weeks. The animals were euthanized, and their mandibles and maxillae were evaluated for levels of periodontal bone by measuring the distance from the cementoenamel junction (CEJ) to the alveolar bone crest (ABC) of the molar roots. After 12 weeks of Cd exposure in animals, there was a significantly greater distance between the CEJ and ABC in the palatal aspect of the maxillary molars and the lingual aspect of the mandibular molars when compared with controls (p < 0.0001). This study shows that Cd has significant, time-dependent effects on periodontal bone in an animal model of Cd exposure. These findings support the possibility of Cd being a contributing factor to the development of periodontal disease in humans.

Oral mycobiome in community-dwelling elderly and its relation to oral and general health conditions

OBJECTIVE

Oral fungal infection is generally associated with dysbiosis related to antibiotic use, immunodeficiency, or frailty. However, fungal colonization in a typical population without apparent symptoms and its associated conditions are poorly understood. In this study, oral fungal colonization in community-dwelling and independently living elderly populations was evaluated and factors affecting fungal colonization were analyzed.

SUBJECTS AND METHODS

The subjects (410; 181 males and 229 females) were 75-99 years of age; those under prior antibiotic use were excluded. Fungal populations in the saliva were evaluated by PCR-based molecular techniques. Body mass index (BMI), smoking habits, and oral health conditions were examined.

RESULTS

Salivary fungal amounts exceeded 10⁴  CFU/ml in 63 (15.4%) of 410 subjects. Candida albicans was most frequently detected (98.4%), followed by Candida glabrata (54.0%), and Candida dubliniensis (38.1%) in those subjects with fungi at 10⁴  CFU/ml or over. Fungi at 10⁴  CFU/ml or over in the presence of C. glabrata or C. dubliniensis was significantly associated with low BMI.

CONCLUSIONS

Candida albicans, C. glabrata, and C. dubliniensis dominated the oral mycobiome in Japanese community-dwelling elderly. Lower BMI might signify compromised health status and thus could result in susceptibility to specific candidiasis by C. glabrata and C. dubliniensis.

Factors affecting the variability in the observed levels of cadmium in blood and urine among former and current smokers aged 20-64 and ≥ 65years

Data from National Health and Nutrition Examination Survey for 1999-2012 were used to evaluate factors that affect observed levels of blood cadmium (BCd) and urine cadmium (UCd) among former and current smokers aged 20-64 and ≥65 years. Adjusted levels (AGM) for BCd and UCd were higher among females as compared to males. The order of AGM for BCd by race/ethnicity for 20-64 years old was non-Hispanic white (NHW) < non-Hispanic black (NHB) and NHW > NHB for ≥65 years old. The order of AGMs for UCd for 20-64-year-old current smokers was NHW > NHB and NHW > NHB for former smokers. For 20-64-year-old current smokers, exposure to environmental tobacco smoke at home was associated with higher levels of BCd. Levels of both UCd and BCd increased with age, but the rate of increase was as much as seven times higher among ≥65 years old than 20-64 years old. For current smokers, the number of cigarettes smoked inside home was positively associated with the levels of BCd. For current smokers aged 20-64 years, the number of cigarettes smoked inside home was positively associated with the levels of UCd (p < 0.01), and the number of cigarettes smoked every day on the days they were smoked was also positively associated with the levels of UCd (p < 0.01). Among former smokers, levels of both UCd and BCd were positively associated (p < 0.1) with the number of cigarettes smoked per day at the time of quitting smoking and negatively associated with the time since smoking was quitted (p < 0.01).

Factors affecting the variability in the observed levels of urinary cadmium among children and nonsmoker adolescents

Data from the National Health and Nutrition Examination Survey for 1999-2012 were used to evaluate factors that affect observed levels of urine cadmium (UCd) among children aged 6-11 years and nonsmoker adolescents aged 12-19 years. Adjusted UCd levels were found to be statistically significantly higher for female nonsmoker adolescents than male nonsmoker adolescents (p < 0.01). Non-Hispanic white (NHW) participants had statistically significantly lower adjusted levels of UCd (<0.01) than non-Hispanic black (NHB) participants for both children (p < 0.01) and adolescents (p < 0.01). Dietary intake of cadmium was not found to affect the levels of UCd. While unadjusted levels of UCd for nonsmoker adolescents declined (p < 0.01) over 1999-2012 by 28.3%, no statistically significant trend was observed for adjusted levels.

Is Urinary Cadmium a Biomarker of Long-term Exposure in Humans? A Review

Cadmium is a naturally-occurring element, and humans are exposed from cigarettes, food, and industrial sources. Following exposure, cadmium accumulates in the kidney and is slowly released into the urine, usually proportionally to the levels found in the kidneys. Cadmium levels in a single spot urine sample have been considered indicative of long-term exposure to cadmium; however, such a potentially exceptional biomarker requires careful scrutiny. In this review, we report good to excellent temporal stability of urinary cadmium (intraclass correlation coefficient 0.66-0.81) regardless of spot urine or first morning void sampling. Factors such as changes in smoking habits and diseases characterized by increased excretion of proteins may produce short-term changes in urinary cadmium levels. We recommend that epidemiologists use this powerful biomarker in prospective studies stratified by smoking status, along with thoughtful consideration of additional factors that can influence renal physiology and cadmium excretion.

Environmentally Realistic Doses of Cadmium as a Possible Etiologic Agent for Idiopathic Pathologies

Cadmium is a heavy metal of increasing environmental concern that has long been associated to several human pathological processes. Recent population surveys have correlated cadmium non-occupational exposure to widespread idiopathic pathologies. Food and tobacco are reported to be the main exposure sources of cadmium to the general population, as phosphate fertilizers are rich in such a metal, thus contaminating the crops. Although its mechanisms of toxicity are not a consensus in the literature, it is well established that reactive oxygen species play a key role in this process, leading to the oxidation of several biological molecules. We have therefore assessed whether three environmentally realistic doses of cadmium alter the oxidative status of Wistar rat testis and eventually result in histological damages. Our results show that even the lowest environmental dose of cadmium was able to disturb the endogenous antioxidant system in Wistar testis, although an increase in lipid peroxidation was observed only within the group exposed to the highest environmental dose. Despite that no remarkable morphological changes were observed in any group, significant alterations in blood vessel lumen were reported for some cadmium-exposed animals, suggesting that endothelium is one of the primary targets involved in cadmium toxicity.

Association of internal exposure of cadmium and lead with periodontal disease: a study of the Fourth Korean National Health and Nutrition Examination Survey

AIMS

This study was performed to examine the association of the internal exposure of cadmium and lead with periodontitis in a representative sample of adults, who were involved in the Fourth Korea National Health and Nutrition Examination Survey (KNHANES).

MATERIALS AND METHODS

One thousand nine hundred and sixty-six subjects over the age of 19 who participated in KNHANES were examined. Cadmium (Cd) and lead (Pb) exposure were grouped into three categories: low (<25th percentile), middle (25th-75th percentile) and high (≥75th percentile). The periodontal status was assessed by the Community Periodontal Index. The multivariate logistic regression analysis was performed to get the adjusted odds ratio (OR), and subgroup analysis was also performed. All analyses considered a complex sampling design.

RESULTS

The multivariate logistic regression analysis revealed associations of Cd with periodontitis. Subjects with a high Cd had a 1.57 (95% CI: 1.03-2.38) times higher OR for periodontitis than those with a low Cd. In the subgroup analysis, the association of Pb and Cd with periodontitis was different according to the strata of gender and smoking.

CONCLUSIONS

High Cd could be associated with periodontitis in females and current smokers, and middle Pb showed associations in females and non-smokers among a representative sample of adults in Korea.

Blood cadmium concentration and lipid profile in Korean adults

Although animal experiments have shown that cadmium exposure induces alterations in lipid profiles, no epidemiological study of this relationship has been performed. The objective of this study was to evaluate the association between blood cadmium concentration and blood lipid levels in Korean adults. A cross-sectional study comprising participants (n=3903) aged 20 years or older from the 2005, 2008, and 2009 Korea National Health and Nutrition Examination Surveys was conducted. Demographic characteristics and dietary intake were obtained from the participants by questionnaire, and cadmium and lipid levels were determined by analysis of blood samples. After adjusting for demographic and dietary factors, blood concentration of cadmium was positively associated with the risk of low high-density lipoprotein cholesterol (HDL-C) in a dose-dependent manner (p for trend <0.001). In addition, the odds ratios (ORs) of a high triglyceride to HDL-C ratio was significantly increased in the high blood cadmium groups [OR=1.36; 95% confidence interval (CI), 1.03-1.79 for fourth quintile and OR=1.41; 95% CI, 1.07-1.86 for fifth quintile] compared with the lowest quintile group. However, high blood cadmium was not associated with a risk of high total cholesterol, high low-density lipoprotein cholesterol, or high triglycerides. These data suggest that an increased cadmium body burden increases the risk of dyslipidemia, mainly due to the increased risk of low HDL-C and the high ratio of triglycerides to HDL-C.

Toxic elements in tobacco and in cigarette smoke: inflammation and sensitization

Biochemically and pathologically, there is strong evidence for both atopic and nonatopic airway sensitization, hyperresponsiveness, and inflammation as a consequence of exposure to tobacco mainstream or sidestream smoke particulate. There is growing evidence for the relation between exposure to mainstream and sidestream smoke and diseases resulting from reactive oxidant challenge and inflammation directly as a consequence of the combined activity of neutrophils, macrophages, dendritic cells, eosinophils, basophils, as a humoral immunological consequence of sensitization, and that the metal components of the particulate play a role in adjuvant effects. As an end consequence, carcinogenicity is a known outcome of chronic inflammation. Smokeless tobacco has been evaluated by the IARC as a group 1 carcinogen. Of the many harmful constituents in smokeless tobacco, oral tissue metallothionein gradients suggest that metals contribute to the toxicity from smokeless tobacco use and possibly sensitization. This work reviews and examines work on probable contributions of toxic metals from tobacco and smoke to pathology observed as a consequence of smoking and the use of smokeless tobacco.

Cadmium, environmental exposure, and health outcomes

We provide an update of the issues surrounding health risk assessment of exposure to cadmium in food. Bioavailability of ingested cadmium has been confirmed in studies of persons with elevated dietary exposure, and the findings have been strengthened by the substantial amounts of cadmium accumulated in kidneys, eyes, and other tissues and organs of environmentally exposed individuals. We hypothesized that such accumulation results from the efficient absorption and systemic transport of cadmium, employing multiple transporters that are used for the body's acquisition of calcium, iron, zinc, and manganese. Adverse effects of cadmium on kidney and bone have been observed in environmentally exposed populations at frequencies higher than those predicted from models of exposure. Population data raise concerns about the validity of the current safe intake level that uses the kidney as the sole target in assessing the health risk from ingested cadmium. The data also question the validity of incorporating the default 5% absorption rate in the threshold-type risk assessment model, known as the provisional tolerable weekly intake (PTWI), to derive a safe intake level for cadmium.

Elemental bio-imaging of trace elements in teeth using laser ablation-inductively coupled plasma-mass spectrometry

OBJECTIVES

In this study we present the application of a novel laboratory method that employs laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) to construct two-dimensional maps of trace elements in teeth.

METHODS

Teeth were sectioned longitudinally, embedded in resin and polished to a smooth surface. Data were generated by laser ablating the entire sectioned tooth surface. Elemental images were constructed using custom-built software.

RESULTS

Quantified images of (66)Zn, (88)Sr, (111)Cd and (208)Pb, with a spatial resolution of 30 μm(2), were generated from three teeth. Concentrations were determined by single-point calibration against NIST SRM 1486 (bone meal). Zn and Sr concentrations were determined in the μg g(-1) range and Cd and Pb in the ng g(-1) range. Concentrations of Pb, Zn and Cd were higher in dentine particularly in regions adjacent the pulp.

CONCLUSIONS

Elemental bio-imaging employing LA-ICP-MS is a novel method for constructing μm-scale maps of trace elements in teeth. This simple imaging method displays the heterogeneity of trace elements throughout the tooth structure that correspond to specific structural and developmental features of teeth. As a preliminary study, this work demonstrates the capabilities of LA-ICP-MS imaging in dental research.

Cadmium, environmental exposure, and health outcomes

OBJECTIVES

We provide an update of the issues surrounding health risk assessment of exposure to cadmium in food.

DATA SOURCES

We reviewed epidemiologic studies published between 2004 and 2009 concerning the bioavailability of cadmium in food, assessment of exposure, and body burden estimate, along with exposure-related effects in nonoccupationally exposed populations.

DATA EXTRACTION AND SYNTHESIS

Bioavailability of ingested cadmium has been confirmed in studies of persons with elevated dietary exposure, and the findings have been strengthened by the substantial amounts of cadmium accumulated in kidneys, eyes, and other tissues and organs of environmentally exposed individuals. We hypothesized that such accumulation results from the efficient absorption and systemic transport of cadmium, employing multiple transporters that are used for the body's acquisition of calcium, iron, zinc, and manganese. Adverse effects of cadmium on kidney and bone have been observed in environmentally exposed populations at frequencies higher than those predicted from models of exposure. Increasing evidence implicates cadmium in the risk of diseases that involve other tissues and organ systems at cadmium concentrations that do not produce effects on bone or renal function.

CONCLUSIONS

Population data raise concerns about the validity of the current safe intake level that uses the kidney as the sole target in assessing the health risk from ingested cadmium. The data also question the validity of incorporating the default 5% absorption rate in the threshold-type risk assessment model, known as the provisional tolerable weekly intake (PTWI), to derive a safe intake level for cadmium.