Health risk assessment of environmental selenium: Emerging evidence and challenges (Review)

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Published on Friday, 24 March 2017 12:00

Vinceti M, Filippini T, Cilloni S, Bargellini A, Vergoni AV, Tsatsakis A, Ferrante M

Mol Med Rep. 2017 Mar 24;15(5):3323-3335

Abstract

New data have been accumulated in the scientific literature in recent years which allow a more adequate risk assessment of selenium with reference to human health. This new evidence comes from environmental studies, carried out in populations characterized by abnormally high or low selenium intakes, and from high-quality and large randomized controlled trials with selenium recently carried out in the US and in other countries. These trials have consistently shown no beneficial effect on cancer and cardiovascular risk, and have yielded indications of unexpected toxic effects of selenium exposure. Overall, these studies indicate that the minimal amount of environmental selenium which is source of risk to human health is much lower than anticipated on the basis of older studies, since toxic effects were shown at levels of intake as low as around 260 µg/day for organic selenium and around 16 µg/day for inorganic selenium. Conversely, populations with average selenium intake of less than 13-19 µg/day appear to be at risk of a severe cardiomyopathy, Keshan disease. Overall, there is the need to reconsider the selenium standards for dietary intake, drinking water, outdoor and indoor air levels, taking into account the recently discovered adverse health effects of low-dose selenium overexposure, and carefully assessing the significance of selenium-induced proteomic changes.

Pesticides, polychlorinated biphenyls and polycyclic aromatic hydrocarbons in cerebrospinal fluid of amyotrophic lateral sclerosis patients: a case-control study

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Published on Saturday, 25 February 2017 12:00

Vinceti M, Violi F, Tzatzarakis M, Mandrioli J, Malagoli C, Hatch EE, Fini N, Fasano A, Rakitskii VN, Kalantzi OI, Tsatsakis A.

Environ Res. 2017 Feb 24;155:261-267.

Abstract

Neurotoxic chemicals including several pesticides have been suggested to play a role in the etiology of amyotrophic lateral sclerosis (ALS). We investigated the relation between organochlorine pesticides and their metabolites (OCPs), polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) in the etiology of sporadic ALS, determining for the first time their levels in cerebrospinal fluid as indicator of antecedent exposure. We recruited 38 ALS patients and 38 controls referred to an Italian clinical center for ALS care, who underwent a lumbar puncture for diagnostic purposes between 1994-2013, and had 1mL of cerebrospinal fluid available for the determination of OCPs, PCBs and PAHs. Many chemicals were undetectable in both case and control CSF samples, and we found little evidence of any increased disease risk according to higher levels of exposure. Among males >60 years, we found a slight but statistically very unstable increased ALS risk with higher levels of the congener PCB 28 and the OCP metabolite p,p'-DDE. Overall, these results do not suggest an involvement of the neurotoxic chemicals investigated in this study in disease etiology, although small numbers limited the precision of our results.

Glycaemic index, glycaemic load and risk of cutaneous melanoma in a population-based, case-control study

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Published on Wednesday, 15 February 2017 12:00

Malavolti M, Malagoli C, Crespi CM, Brighenti F, Agnoli C, Sieri S, Krogh V, Fiorentini C, Farnetani F, Longo C, Ricci C, Albertini G, Lanzoni A, Veneziano L, Virgili A, Pagliarello C, Feliciani C, Fanti PA, Dika E, Pellacani G, Vinceti M.

Br J Nutr. 2017 Feb 15:1-7. doi: 10.1017/S000711451700006X

Abstract

Glycaemic index (GI) and glycaemic load (GL) are indicators of dietary carbohydrate quantity and quality and have been associated with increased risk of certain cancers and type 2 diabetes. Insulin resistance has been associated with increased melanoma risk. However, GI and GL have not been investigated for melanoma. We present the first study to examine the possible association of GI and GL with melanoma risk. We carried out a population-based, case-control study involving 380 incident cases of cutaneous melanoma and 719 age- and sex-matched controls in a northern Italian region. Dietary GI and GL were computed for each subject using data from a self-administered, semi-quantitative food frequency questionnaire. We computed the odds ratio (OR) for melanoma according to quintiles of distribution of GL and GL among controls. A direct association between melanoma risk and GL emerged in females (OR 2·38; 95 % CI 1·25, 4·52 for the highest v. the lowest quintile of GL score, P for trend 0·070) but not in males. The association in females persisted in the multivariable analysis after adjusting for several potential confounders. There was no evidence of an association between GI and melanoma risk. GL might be associated with melanoma risk in females.

Incidence of amyotrophic lateral sclerosis in the province of Novara, Italy, and possible role of environmental pollution

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Published on Thursday, 02 February 2017 12:00

Tesauro M, Consonni M, Filippini T, Mazzini L, Pisano F, Chiò A, Esposito A, Vinceti M.

Amyotroph Lateral Scler Frontotemporal Degener. 2017 Feb 2:1-7

Abstract

OBJECTIVE AND METHODS: Based on nationwide death certificates, a cluster of amyotrophic lateral sclerosis (ALS) has been reported in the area of Briga (Novara province, northern Italy), known for its severe environmental contamination. We further investigated this finding, by following up with the collection of recent incidence ALS data in 2002-2012 of Novara province, also to assess the possible long-term effects of environmental pollution in that area.

RESULTS: In the whole Novara province we identified 106 ALS cases, of which 35 were from the Briga area. Incidence rates of Novara province were 3.98, 5.14 and 2.97 for the total population, males and females, respectively, compared with the Briga area where they were 4.65, 4.27 and 4.98, respectively. The ratio of observed-to-expected ALS cases in the Briga area, using incidence of the rest of Novara province as a reference, was 1.17 (95% CI 0.81-1.62), with a value of 0.83 (95% CI 0.47-1.37) in males and 1.68 (95% CI 1.03-2.60) in females.

CONCLUSIONS: Overall, our study did not confirm previous findings of an excess ALS incidence in an area characterised by severe environmental heavy metal pollution, and it suggests the need to interpret with caution clusters identified through mortality data.

Percutaneous endoscopic gastrostomy, body weight loss and survival in amyotrophic lateral sclerosis: a population-based registry study

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Published on Wednesday, 11 January 2017 12:00

Fasano A, Fini N, Ferraro D, Ferri L, Vinceti M, ERRALS, Mandrioli J.

Amyotroph Lateral Scler Frontotemporal Degener. 2017 Jan 11:1-10

Abstract

OBJECTIVE: To assess the role of percutaneous endoscopic gastrostomy (PEG) insertion, and its timing, on ALS survival, and to study prognostic factors of survival before and after PEG placement in a population-based setting.

METHODS: In this observational population-based, registry study, we enrolled patients with newly- diagnosed ALS, according to the El Escorial revised criteria, who were resident in the Emilia Romagna Region, and who developed severe dysphagia needing enteral nutritional support. The primary outcome measure was tracheostomy-free survival after PEG recommendation.

RESULTS: There were 210 patients needing PEG, out of an incident cohort of 545 patients from the Emilia Romagna Registry for ALS, who were diagnosed between 2009 and 2013. One hundred and ninety-three patients were included in the study, and 17 were excluded because they were already tracheostomized at the time of PEG placement. Of the 193 patients included in the study, 152 underwent PEG, whereas 41 did not undergo the procedure. Patients who did not undergo PEG, among the eligible ones, had the same tracheostomy-free survival from onset as patients who did (25 vs. 32 months, p = 0.21). Tracheostomy-free survival from PEG recommendation was greater in patients who underwent PEG placement than in patients who did not (6 vs. 2 months, p = 0.008). Median tracheostomy-free survival from PEG insertion was eight months (95% CI5-12); 30 days after PEG placement, survival was 89.60%. At Cox multivariable analysis, the hazard of death or tracheostomy after PEG insertion was significantly influenced by the difference between BMI at the time of the PEG procedure and BMI at diagnosis (HR 1.05, 95% CI 1.02-1.08; p = 0.002). The hazard of death or tracheostomy was not affected by the timing of PEG insertion.

CONCLUSIONS: The present study, although it has some limitations, suggests a gain of tracheostomy-free survival from the time of PEG recommendation for patients who undergo PEG placement, and, among patients who undergo PEG, a greater survival if PEG is inserted before a significant weight loss occurs, and if nutritional support avoids further weight loss. Should this association between prevention of weight loss and better clinical outcome be confirmed by further studies, it would have important implications for disease management.