| 51. |
- Krauskopf, Julian, et al.
(författare)
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Blood Transcriptome Response to Environmental Metal Exposure Reveals Potential Biological Processes Related to Alzheimer's Disease
- 2020
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Ingår i: Frontiers in Public Health. - : Frontiers Media S.A.. - 2296-2565. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Alzheimer's disease (AD) is a neurodegenerative disease which is manifested by a progressive and irreversible decline of cognition, memory loss, a shortened attention span, and changes in personality. Aging and genetic pre-dispositions, particularly the presence of a specific form of apolipoprotein E (APOE), are main risk factors of sporadic AD; however, a large body of evidence has shown that multiple environmental factors, including exposure to toxic metals, increase the risk for late onset AD. Lead (Pb) and cadmium (Cd) are ubiquitous toxic metals with a wide range of applications resulting in global distribution in the environment and exposure of all living organisms on earth. In addition to being classified as carcinogenic (Cd) and possibly carcinogenic (Pb) to humans by the International Agency for Research on Cancer, both compounds disrupt metal homeostasis and can cause toxic responses at the cellular and organismal levels. Pb toxicity targets the central nervous system and evidence for that has emerged also for Cd. Recent epidemiological studies show that both metals possibly are etiological factors of multiple neurodegenerative diseases, including Alzheimer's disease (AD). To further explore the association between metal exposure and AD risk we applied whole transcriptome gene expression analysis in peripheral blood leukocytes (PBLs) from 632 subjects of the general population, taken from the EnviroGenomarkers project. We used linear mixed effect models to associate metal exposure to gene expression after adjustment for gender, age, BMI, smoking, and alcohol consumption. For Pb exposure only few associations were identified, including a downregulation of the human eukaryotic translation initiation factor 5 (eIF5). In contrast, Cd exposure, particularly in males, revealed a much stronger transcriptomic response, featuring multiple pathways related to pathomolecular mechanisms of AD, such as endocytosis, neutrophil degranulation, and Interleukin-7 signaling. A gender stratified analysis revealed that the Cd responses were male-specific and included a downregulation of the APOE gene in men. This exploratory study revealed novel hypothetical findings which might contribute to the understanding of the neurotoxic effects of chronic Pb and Cd exposure and possibly improve our knowledge on the molecular mechanisms linking metal exposure to AD risk.
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| 52. |
- Lampa, Erik G., et al.
(författare)
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Optimizing occupational exposure measurement strategies when estimating the log-scale arithmetic mean value : An example from the reinforced plastics industry
- 2006
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Ingår i: Annals of Occupational Hygiene. - Oxford : Pergamon Press. - 0003-4878 .- 1475-3162. ; 50:4, s. 371-377
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Tidskriftsartikel (refereegranskat)abstract
- When assessing occupational exposures, repeated measurements are in most cases required. Repeated measurements are more resource intensive than a single measurement, so careful planning of the measurement strategy is necessary to assure that resources are spent wisely. The optimal strategy depends on the objectives of the measurements. Here, two different models of random effects analysis of variance (ANOVA) are proposed for the optimization of measurement strategies by the minimization of the variance of the estimated log-transformed arithmetic mean value of a worker group, i.e. the strategies are optimized for precise estimation of that value. The first model is a one-way random effects ANOVA model. For that model it is shown that the best precision in the estimated mean value is always obtained by including as many workers as possible in the sample while restricting the number of replicates to two or at most three regardless of the size of the variance components. The second model introduces the ‘shared temporal variation’ which accounts for those random temporal fluctuations of the exposure that the workers have in common. It is shown for that model that the optimal sample allocation depends on the relative sizes of the between-worker component and the shared temporal component, so that if the between-worker component is larger than the shared temporal component more workers should be included in the sample and vice versa. The results are illustrated graphically with an example from the reinforced plastics industry. If there exists a shared temporal variation at a workplace, that variability needs to be accounted for in the sampling design and the more complex model is recommended.
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| 53. |
- Liang, Yihuai, et al.
(författare)
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Renal function after reduction in cadmium exposure : an eight-year follow-up of residents in cadmium-polluted areas
- 2012
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Ingår i: Journal of Environmental Health Perspectives. - : National Institute of Environmental Health Sciences. - 0091-6765 .- 1552-9924. ; 120:2, s. 223-228
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Tidskriftsartikel (refereegranskat)abstract
- Background and objective: Long-term exposure to cadmium (Cd) causes renal dysfunction, but its change with exposure is unknown. We aimed at assessing the evolution of Cd-induced renal effects after a reduction in dietary exposure to Cd in rice.Methods: 412 residents in previously Cd-polluted and non-polluted areas were examined twice: in 1998 and 2006. Changes in blood Cd, urinary Cd, and kidney function (N-acetyl-β-D-glucosaminidase = NAG, β2-microglobulin, and albumin in urine) were measured. Results: In the most polluted area, mean blood Cd was 8.9 μg/L in 1998 and 3.3 μg/L in 2006, and urinary Cd was 11.6 and 9.0 μg/g creatinine in 1998 and 2006, respectively. Urinary albumin in 1998 increased with urinary Cd but no such exposure-response appeared for 2006 albumin versus urinary Cd 1998, indicating recovery. Other biomarkers of kidney function were also elevated in 1998. Partial recovery was observed for NAG, among women, and suggested for β2-microglobulin, among young individuals. The probability of having a β2-microglobulin above the 95th percentile in 2006 was high in those with an elevated β2-microglobulin in 1998 (odds ratio: 24.8, 95% CI: 11.2-55.3), whereas corresponding estimates for albumin and NAG were 3.0 (1.2-7.5) and 2.6 (1.6-4.4), respectively.Conclusions: Results suggest that a Cd-mediated increase in urinary albumin excretion is reversible upon substantial reduction of exposure. For the markers of tubular effects, a tendency towards improvement, but not complete recovery, was observed. Data from repeated observations suggests that β2-microglobulin may be more informative than NAG as an indicator for the individual's future tubular function.
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| 54. |
- Ljungberg, Johan, et al.
(författare)
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Arterial hypertension and diastolic blood pressure associate with aortic stenosis
- 2019
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Ingår i: Scandinavian Cardiovascular Journal. - : Taylor & Francis Group. - 1401-7431 .- 1651-2006. ; 53:2, s. 91-97
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: Due to age-related differences in aortic valve structure, it is likely that the pathophysiology of aortic stenosis (AS) and associated risk factors differ between age groups. Here we prospectively studied the influence of traditional cardiovascular risk factors on AS development requiring surgery among patients without concomitant coronary artery disease (CAD) and stratified for age.DESIGN: This study included 322 patients, who had prior to surgery for AS participated in population-based surveys, and 131 of them had no visible CAD upon preoperative coronary angiogram. For each case, we selected four referents matched for age, gender, and geographic area. To identify predictors for surgery, we used multivariable conditional logistic regression with a model including arterial hypertension (or measured blood pressure and antihypertensive medication), cholesterol levels, diabetes, body mass index (BMI), and smoking.RESULTS: In patients without CAD, future surgery for AS was associated with arterial hypertension and elevated levels of diastolic blood pressure in patients younger than 60 years at surgery (odds ratio [95% confidence interval]), (3.40 [1.45-7.93] and 1.60 [1.09-2.37], respectively), and with only impaired fasting glucose tolerance in patients 60 years or older at surgery (3.22 [1.19-8.76]).CONCLUSION: Arterial hypertension and elevated diastolic blood pressure are associated with a risk for AS requiring surgery in subjects below 60 years of age. Strict blood pressure control in this group is strongly advocated to avoid other cardiovascular diseases correlated to hypertension. If hypertension and elevated diastolic blood pressure are risk factors for developing AS requiring surgery need further investigations. Notably, elevated fasting glucose levels were related to AS requiring surgery in older adults without concomitant CAD.
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| 55. |
- Ljungberg, Johan, et al.
(författare)
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Arterial hypertension and elevated diastolic blood pressure is associated with developing aortic stenosis requiring surgery in persons less than 60 years of age
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Background: Due to age-related differences in aortic valve structure, it is likely that the pathophysiology of aortic stenosis and associated risk factors differ between age groups. Here we prospectively studied the influence of traditional cardiovascular risk factors on aortic stenosis development among patients without concomitant coronary artery disease, and stratified for age. Methods: This study included 131 patients from previous population-based surveys, who underwent surgery for aortic stenosis and had no visible coronary arteriosclerosis upon preoperative coronary angiogram. The younger group included 49 patients of <60 years old at surgery: median age, 54.4 years; median follow-up, 8.7 years. The older group included 82 patients of ≥60 years old at surgery: median age, 71.3 years; median follow-up, 11.0 years. For each case, we selected four referents matched for age, gender, and geographic area. To identify predictors for surgery, we used multivariable conditional logistic regression with a model including arterial hypertension, cholesterol levels, diabetes, BMI, and smoking. Results: Future surgery for aortic stenosis was associated with arterial hypertension and elevated levels of diastolic blood pressure in the younger group (odds ratio, 3.40; 95% confidence interval, 1.45–7.93, and odds ratio 1,60; 95% confidence interval, 1.09–2.37, respectively), and with only impaired fasting glucose tolerance in the older group (odds ratio, 3.22; 95% confidence interval, 1.19–8.76). Conclusion: Arterial hypertension and elevated diastolic blood pressure are associated with a risk for aortic stenosis development in subjects below 60 years of age. Strict blood pressure control in this group are strongly advocated to avoid other cardiovascular diseases correlated to hypertension. If hypertension and elevated diastolic blood pressure are risk for developing aortic stenosis need further investigations. Notably, elevated fasting glucose levels were related to aortic stenosis in older adults without concomitant coronary artery disease.
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| 56. |
- Ljungberg, Johan, et al.
(författare)
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Lipoprotein(a) and the Apolipoprotein B/A1 Ratio Independently Associate With Surgery for Aortic Stenosis Only in Patients With Concomitant Coronary Artery Disease
- 2017
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Ingår i: Journal of the American Heart Association. - : John Wiley & Sons. - 2047-9980. ; 6:12
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Aortic stenosis (AS) has different clinical phenotypes, including AS with or without concomitant coronary artery disease (CAD). It is unknown whether these phenotypes share the same risk factors. In particular, lipoprotein(a) [Lp(a)] and apolipoproteins (Apo) are associated with AS, but it is unknown whether these associations differ among phenotypes. In this prospective analysis we examined the impact of Lp(a) and Apo in subgroups of patients with AS.METHODS AND RESULTS: We identified 336 patients (mean age at survey 56.7 years, 48% female) who underwent surgery for AS after a median 10.9 years (interquartile range 9.3 years), participants in 1 of 3 large population surveys. For each patient, 2 matched referents were allocated. Lp(a) and Apo were analyzed in the baseline samples. Uni- and multivariable logistic regression analyses were used to estimate risks related to a 1 (ln) standard deviation increase in Lp(a) and the ratio of Apo B to Apo A1 (Apo B/A1 ratio). High levels of Lp(a) predicted surgery for AS in 203 patients with concomitant CAD (odds ratio [95% confidence intervals]) (1.29 [1.07-1.55]), but not in 132 patients without CAD (1.04 [0.83-1.29]) in the fully adjusted model. Similarly, a high Apo B/A1 ratio predicted surgery in patients with concomitant CAD (1.43 [1.16-1.76]) but not in those without CAD (0.87 [0.69-1.10]).CONCLUSIONS: High levels of Lp(a) and a high Apo B/A1 ratio were associated with surgery for AS in patients with concomitant CAD but not in those with isolated AS. This finding may lead to a new avenue of research for targeted risk factor interventions in this population.
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| 57. |
- Ljungberg, Johan, et al.
(författare)
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Traditional Cardiovascular Risk Factors and Their Relation to Future Surgery for Valvular Heart Disease or Ascending Aortic Disease : A Case-Referent Study
- 2017
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Ingår i: Journal of the American Heart Association. - : John Wiley & Sons. - 2047-9980. ; 6:5
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Tidskriftsartikel (refereegranskat)abstract
- Background: Risk factors for developing heart valve and ascending aortic disease are based mainly on retrospective data. To elucidate these factors in a prospective manner, we have performed a nested case-referent study using data from large, population-based surveys. Methods and Results: A total of 777 patients operated for heart valve disease or disease of the ascending aorta had previously participated in population-based health surveys in Northern Sweden. Median time (interquartile range) from survey to surgery was 10.5 (9.0) years. Primary indications for surgery were aortic stenosis (41%), aortic regurgitation (12%), mitral regurgitation (23%), and dilatation/dissection of the ascending aorta (17%). For each case, referents were allocated, matched for age, sex, and geographical area. In multivariable models, surgery for aortic stenosis was predicted by hypertension, high cholesterol levels, diabetes mellitus, and active smoking. Surgery for aortic regurgitation was associated with a low cholesterol level, whereas a high cholesterol level predicted surgery for mitral regurgitation. Hypertension, blood pressure, and previous smoking predicted surgery for disease of the ascending aorta whereas diabetes mellitus was associated with reduced risk. After exclusion of cases with coronary atherosclerosis, only the inverse associations between cholesterol and aortic regurgitation and between diabetes mellitus and disease of the ascending aorta remained. Conclusions: This is the first truly prospective study of traditional cardiovascular risk factors and their association with valvular heart disease and disease of the ascending aorta. We confirm the strong association between traditional risk factors and aortic stenosis, but only in patients with concomitant coronary artery disease. In isolated valvular heart disease, the impact of traditional risk factors is varying.
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| 58. |
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| 59. |
- Nilsson Sommar, Johan, et al.
(författare)
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Hip Fracture Risk and Cadmium in Erythrocytes : A Nested Case-Control Study with Prospectively Collected Samples
- 2014
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Ingår i: Calcified Tissue International. - : Springer. - 0171-967X .- 1432-0827. ; 94:2, s. 183-190
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Tidskriftsartikel (refereegranskat)abstract
- Several studies have investigated the relation between bone mass density and cadmium exposure, but only few studies have been performed on fractures and biomarkers of cadmium. This study analyzed the association between hip fracture risk and cadmium in erythrocytes (Ery-Cd). Prospective samples from the Northern Sweden Health and Disease Study's biobank were used for 109 individuals who later in life had sustained a low-trauma hip fracture, matched with two controls of the same age and gender. The mean concentration of Ery-Cd (±SD) in case samples was 1.3 ± 1.4 versus 0.9 ± 1.0 μg/L in controls. The odds ratio (OR) was 1.63 [95 % confidence interval (CI) 1.10-2.42] for suffering a hip fracture for each microgram per liter increase in Ery-Cd. However, when taking smoking into consideration (never, former, or current), neither Ery-Cd nor smoking showed a statistically significant increase in fracture risk. Using multiple conditional logistic regression with BMI, height, and smoking, the estimated OR for a 1-μg/L increase in Ery-Cd was 1.52 (95 % CI 0.77-2.97). Subgroup analysis showed an increased fracture risk among women (OR = 1.94, 95 % CI 1.18-3.20, for a 1 μg/L increase), which also remained in the multiple analysis (OR = 3.33, 95 % CI 1.29-8.56). This study shows that fracture risk is associated with Ery-Cd. It is, however, not possible to draw firm conclusions on whether cadmium is the causal factor or whether other smoking-related factors cause this association. Subgroup analysis shows that cadmium is a risk factor for hip fracture among women.
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| 60. |
- Nilsson Sommar, Johan, 1983-
(författare)
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Prospective and longitudinal human studies of lead and cadmium exposure and the kidney
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Cadmium and lead accumulate in humans and can have toxic effects. Exposure to cadmium is well known to cause kidney damage. Cadmium binds to metallothioneins, proteins that play a role in cadmium transport. Lead exposure’s main effect is on the central nervous system, but associations with kidney disease have also been found, although it is unknown if the latter is a causal association. The main source of both metals within the non-smoking population is from the diet.This thesis aims to 1) compare the biomarkers lead and cadmium concentration in whole-blood, plasma and urine with regard to their ability to discriminate between individuals with different mean concentrations, and to describe the effect of urinary dilution, 2) estimate the association between end-stage renal disease and blood concentrations of cadmium, lead and mercury, using prospectively collected samples for exposure evaluation, 3) use longitudinal data on kidney function makers to evaluate kidney recovery after a substantial decrease in cadmium exposure, and 4) assess the influence of metallothionein polymorphisms (MT1A rs11076161, MT2A rs10636 and MT2A rs28366003) on cadmium-associated kidney toxicity and recovery due to a reduction in Cd exposure.Repeated sampling of whole-blood, plasma and urine was conducted on 48 occupationally lead-exposed men and 20 individuals under normal environmental lead exposure, for estimation of the day-to-day and between individual-variation. Prospective samples were obtained for 118 cases that later in life developed end-stage renal disease, and 378 matched controls. Erythrocyte cadmium, lead, and mercury concentrations were determined and the risk of developing end-stage renal disease associated with metal concentrations was estimated. For evaluation of kidney recovery after a reduction in cadmium exposure and to test for gene-environment interactions, follow-up data on N-acetyl-β‑d-glucosaminidase, β2‑microglobulin, albumin, and gene polymorphisms were obtained for 412 individuals within the Chinese population and the relation to blood and urinary cadmium was assessed.The concentration of lead in blood was found to be the biomarker with the largest fraction of the total variance attributable to between-individual variation, and was therefore the biomarker with the best ability to discriminate between individuals with different mean concentrations, both for individuals under occupational and normal environmental exposure (91 and 95%, respectively). Adjusting for urinary dilution had a great effect on the fraction of the total variance attributable to between-individual variation among individuals with normal lead exposure but only a minor effect among those who were occupationally exposed. Variance analysis showed that blood concentrations were also the best discriminating biomarker for cadmium.Erythrocyte lead was, in a univariate model, associated with an increased risk of developing end-stage renal disease [odds ratio (OR) = 1.54 for an interquartile range increase, with a 95% confidence interval (CI) = 1.18-2.00], while erythrocyte mercury was negatively associated (OR = 0.75 for an interquartile range increase, with a 95% CI = 0.56-0.99). For erythrocyte cadmium, the OR was 1.15 with a 95% CI of 0.99-1.34. Associations with lead and cadmium were only seen among men. In the study on kidney recovery, the proportion of individuals with albumin level above the 95th percentile decreased between baseline and follow up, but no decrease was found for the tubular markers N-acetyl-β‑d-glucosaminidase and β2-microglobulin. Metallothionein polymorphisms modified cadmium-associated effects on N-acetyl-β‑d-glucosaminidase and β2-microglobulin levels but did not modify cadmium-associated change in any of the kidney function markers between baseline and follow up after a substantial decrease in exposure.Blood concentrations of lead and cadmium are the biomarkers with the best ability to discriminate between individuals with different mean concentrations. Adjustment for urinary dilution has great influence on the fraction of the total variance attributed to between individual variation among urine samples with low lead concentrations, but only a small influence on samples with high lead concentrations. This suggests a difference in excretion. The association between end-stage renal disease and low-level lead exposure, as assessed through prospective erythrocyte samples, gives reason for concern, although further studies are needed to determine causality. A cadmium-associated increase in albumin is reversible after a substantial reduction in exposure, but this is not the case for the observed tubular effects. The tubular kidney effects of cadmium might be modified by the MT1A rs11076161 polymorphism.
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