Barbara Turczyn

The dependence between urinary mercury concentration and carotid arterial intima-media thickness in workers occupationally exposed to mercury vapour

OBJECTIVES Mechanisms of the mercury effect on arterial vessel walls include increased free radicals generation, decreased nitric oxide synthesis and increased reactivity to vasoconstrictors, leading to accelerated development of atherosclerosis and arterial hypertension. The aim of this study was to evaluate the correlation between urinary mercury (Hg-U) concentration and carotid intima-media thickness (IMT) or intraventricular septum diastolic diameter (IVSDD) to find the best markers of mercury cardiovascular toxicity. MATERIALS AND METHODS The study included 154 workers of a chemical factory using mercury in chlorine production. Urinary mercury concentration was determined by atomic absorption spectrophotometry. Serum lipids were assessed by routine methods using enzymatic assay. Serum total antioxidant status (TAS) was determined by colorimetry. Measurements of IMT and IVSDD were made by ultrasound imaging using MEDISON SA 9900 PRIME system. RESULTS The mean Hg-U concentration was 1.9+/-2.7 microg/g creatinine in women (n = 29) and 5.6+/-12.2 microg/g creatinine in men (n = 125). In the group of non-smokers (n = 102) there was a positive linear correlation between Hg-U concentration and IMT (r = 0.1728; p < 0.05) and a negative dependence between high density cholesterol (HDL-C) and IMT (r = -0.2109; p < 0.01). The negative linear correlation between serum total antioxidant status (TAS) and carotid IMT (r = -0.2142; p < 0.05), and the positive correlation between HDL-C and TAS (r = 0.1953; p < 0.05) were shown to be valid for the total studied group. Serum lipids in women were normal, but in men the mean triglyceride level was higher than normal. CONCLUSIONS The occupational exposure to mercury vapour remains in a relationship with early, asymptomatic carotid atherosclerosis. The dependence between urinary mercury elimination and carotid intima-media thickness is evidenced in non-smoking workers. Defensive anti-atherosclerotic mechanisms in these workers are strongly related with HDL. In smokers, these protective mechanisms are disturbed.

Association between the Type of Workplace and Lung Function in Copper Miners.

The aim of the analysis was to retrospectively assess changes in lung function in copper miners depending on the type of workplace. In the groups of 225 operators, 188 welders, and 475 representatives of other jobs, spirometry was performed at the start of employment and subsequently after 10, 20, and 25 years of work. Spirometry Longitudinal Data Analysis software was used to estimate changes in group means for FEV1 and FVC. Multiple linear regression analysis was used to assess an association between workplace and lung function. Lung function assessed on the basis of calculation of longitudinal FEV1 (FVC) decline was similar in all studied groups. However, multiple linear regression model used in cross-sectional analysis revealed an association between workplace and lung function. In the group of welders, FEF75 was lower in comparison to operators and other miners as early as after 10 years of work. Simultaneously, in smoking welders, the FEV1/FVC ratio was lower than in nonsmokers (p < 0,05). The interactions between type of workplace and smoking (p < 0,05) in their effect on FVC, FEV1, PEF, and FEF50 were shown. Among underground working copper miners, the group of smoking welders is especially threatened by impairment of lung ventilatory function.

Heart function in magnetic resonance imaging and the mesenteric artery reactivity in rats receiving lead-contaminated drinking water.

The aim of this study was to evaluate the effect of lead (Pb)-contaminated drinking water on magnetic resonance imaging (MRI)-estimated cardiac function, vascular reactivity, and serum lipids in rats. For 3 months, male Wistar rats, aged 4–6 weeks, were given drinking water with the addition of lead acetate at a concentration of 100 ppm Pb (10 rats) or water free from Pb (8 control rats). The cardiac MRI was performed at rest and under β-adrenergic stimulation on a 4.7 T scanner using electrocardiogram-triggered gradient echo (FLASH) cine sequence. After 1–2 weeks of the MRI test, experiments were performed ex vivo. After stabilization of perfusion pressure (PP), norepinephrine at doses from 0.01 to 5.0 μg was dissolved in Krebs solution, injected in a volume of 100 μl, and next infused at a concentration of 0.5 μg/ml into the isolated mesenteric artery. In this manner, preconstricted mesenteric bed was used to determine PP changes induced by acetylcholine, given at doses from 0.05 to 5.0 μg, before and during the infusion of nitric oxide synthase inhibitor (1.0 μg/ml). At the end, dobutamine (5 mg), followed by potassium chloride (10.5 mg), was injected. Lipid levels were determined enzymatically, blood Pb level was measured by the atomic absorption spectrophotometer. This study showed that Pb impairs the left ventricular systolic and diastolic function. Pb-induced changes in response to resistance of vessels to vasoactive agents may be secondary to the reduced left ventricular ejection fraction. The high-density lipoprotein subfraction 2 (HDL2) is involved in the cardiovascular effect of Pb.

Left ventricular diastolic function in workers occupationally exposed to mercury vapour without clinical presentation of cardiac involvement

The aim of the study was to evaluate left ventricular diastolic function in workers occupationally exposed to mercury vapour without clinical presentation of cardiac involvement. The studies included 115 workers (92 men and 23 women) occupationally exposed to mercury vapour without clinical presentation of cardiac involvement (mean age: 47.83±8.29). Blood samples were taken to determine blood lipid profile, urine was collected to estimate mercury concentration (HgU) and echocardiographic examination was performed to evaluate diastolic function of the left ventricle. In the entire group of workers occupationally exposed to mercury vapour without clinical presentation of cardiac involvement, Spearman correlations analysis demonstrated the following significant linear relationships: between body mass index (BMI) and ratio of maximal early diastolic mitral flow velocity/early diastolic mitral annular velocity (E/E`) (r=0.32, p<0.05), between serum HDL concentration and E/E` (r=-0.22, p<0.05), between HgU and E/E` (r=0.35, p<0.05), between HgU and isovolumetric relaxation time (IVRT`) (r=0.41, p<0.05), between HgU and ratio of maximal early diastolic mitral flow velocity/maximal late diastolic mitral flow velocity (E/A) (r=-0.31, p<0.05) and between serum HDL concentration and E/A (r=0.43, p<0,05). In logistic regression analysis it as shown that independent factors of left ventricular diastolic dysfunction risk in the study group included a higher urine mercury concentration, a higher value of BMI and a lower serum HDL concentration (OR(Hg-U)=1.071, OR(BMI)=1.200, OR(HDL)=0.896, p<0.05). Summing up, occupational exposure to mercury vapour may be linked to impaired left ventricular diastolic function in workers without clinical presentation of cardiac involvement.

Linseed oil increases HDL3 cholesterol and decreases blood pressure in patients diagnosed with mild hypercholesterolaemia

BACKGROUND Linseed oil has cardio-protective effects. However, its antihypertensive action has not yet been well characterised. AIM The primary purpose of the study was to evaluate the effect of short-term dietary supplementation with linseed oil on blood pressure (BP) and lipid metabolism in patients with mild hypercholesterolaemia. The secondary aim was to assess the effect of linseed oil on nitric oxide pathway and selected serum trace metals. METHODS 150 volunteers: 43 men (49.9 ± 11.5 years) and 107 women (53.2 ± 10.3 years), diagnosed with mild hyper-cholesterolaemia, were assessed prospectively for BP and lipid levels, before and after lipid-lowering diet plus linseed oil supplementation at a dose of 15 mL daily for four weeks (study groups) or four-weekly lipid-lowering diet (control group). Multivariate logistic regression analysis was used to determine the effect of linseed oil on BP after adjustment for age, sex, height, body weight, body mass index, smoking status, and alcohol consumption. RESULTS Supplementation with linseed oil significantly decreased low-density lipoprotein (LDL)- and non-high-density lipo-protein (HDL) cholesterol, and increased HDL- and HDL₃- cholesterol levels. Additionally, linseed oil decreased diastolic BP in men (95% confidence interval [CI]: -6.0 to -1.1, p < 0.006), whereas in women linseed oil reduced (p < 0.001) systolic BP (-3.6 mmHg; 95% CI: -5.8 to -1.5) as well as diastolic BP (-4 mmHg; 95% CI: -5.8 to -2.1). Women with higher BP displayed an increase in serum L-arginine level (p < 0.01). In the logistic regression model oil consumption was associated with a decrease in mean BP (adjusted odds ratio 3.85; 95% CI 1.32-11.33). CONCLUSIONS Our findings confirm the benefit of short-term linseed oil use in mild hypercholesterolaemia, particularly in patients with increased blood pressure.

Lecithin derived from ω-3 PUFA fortified eggs decreases blood pressure in spontaneously hypertensive rats

Hypertension is the most common risk factor for stroke, coronary heart disease and heart failure, which are the leading causes of death worldwide. Dietary patterns and supplements intakes are becoming important factors in the hypertension. The aim of this study was to estimate the effects of new generation egg yolk phospholipids rich in lecithin (SL) esterified with omega-3 and omega-6 fatty acids on blood pressure in hypertensive rats (SHR). Here we have reported that lecithin (SL) derived from egg yolk lowers blood pressure in pathology of hypertension. The SHR rats treated with SL had significantly lower blood pressure than control group (157/104 vs. 178/121 mmHg; P < 0.05) and down-regulated mesenteric artery over-response to norepinephrine and potassium chloride, giving similar arterial response as for normotensive Wistar Kyoto rats (WKY). Hypertensive rats treated by SL demonstrated significantly lower serum level of inflammatory factors. This work also indicates that SL treatment lowers heart rate and reduces the serum level of oxidative stress marker - nitrotyrosine - by 30–34% in both hypertensive and normotensive animals. Phospholipids with lecithin derived from PUFA fortified eggs may be a valuable dietary supplement in prophylaxis of hypertension and in patients with hypertension, however, this requires further studies on humans.

Serum Lipid Transfer Proteins in Hypothyreotic Patients Are Inversely Correlated with Thyroid-Stimulating Hormone (TSH) Levels.

Background Plasma cholesteryl ester transfer protein (CETP) activity is often decreased in patients with hypothyroidism, whereas less is known about the phospholipid transfer protein (PLTP). We aimed to evaluate simultaneously serum CETP and PLTP activity in patients diagnosed with hypothyroidism. Material/Methods The selection criteria for control group members (without thyroid dysfunction) in this case to case study were levels of total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol (HDL-C), and triglycerides similar to those in study group patients (101 patients diagnosed with hypothyroidism). Serum CETP and PLTP activities were measured by homogenous fluorometric assays using synthetic donor particle substrates. Results Serum CETP and PLTP activities in hypothyreotic patients were lower (p<0.001) compared with those in healthy subjects. This lowering was associated with significant changes in HDL-C subclasses: decrease in HDL2- and increase in HDL3 cholesterol levels. Multiple linear regression analyses adjusted for age, sex, body mass index, smoking habits, and alcohol drinking showed a strong association between hypothyroidism and activity of lipid transfer proteins. A linear inverse relationship between thyroid-stimulating hormone (TSH) and CETP (r=−0.21; p<0.01) and between TSH and PLTP (r=−0.24; p<0.001) was shown. There also was a positive correlation (p<0.001) between CETP and HDL2 cholesterol (r=0.27) and between PLTP and HDL2 cholesterol (r=0.37). A negative correlation between CETP and HDL3 cholesterol (r=−0.22: p<0.01) and between PLTP and HDL3 cholesterol (r=−0.24; p<0.001) has been demonstrated as well. Conclusions The decreased HDL2 and increased HDL3 cholesterol levels in subjects with hypothyroidism are consequences of decreased activity of lipid transfer proteins. These changes are early symptoms of lipid disturbances in hypothyroidism.

Serum CETP and PLTP activity in middle-aged men living in urban or rural area of the Lower Silesia region. PURE Poland sub-study

Introduction The dependence of lipid transfer proteins on significant pro-atherogenic factors is unclear. The aim of the study was to evaluate serum cholesteryl ester transfer protein (CETP) and phospholipid transfer protein (PLTP) activity in relation to lipid disturbances in men living in an urban or rural area. Material and methods A group of 427 men, volunteers for the Prospective Urban Rural Epidemiology (PURE) sub-study – 263 urban inhabitants (aged 51.9 ±6.0) and 164 residents of villages (aged 51.1 ±5.9) – were examined. In the multivariable linear regression model, the following factors were included as potential confounders: age, body mass index (BMI), smoking, alcohol consumption, hs-C-reactive protein reaction (hs-CRP) and co-existence of chronic diseases. Results In multiple linear regression models, site of residence (urban or rural area) was the most important independent and consistent predictor of CETP and PLTP activity; β coefficients (95% CI) for CETP (0.18) and PLTP (–0.29) were significant at levels of p < 0.001. Three-way analysis of variance showed no effect of smoking or moderate alcohol consumption on lipid transfer proteins; however, CETP activity showed an interaction effect between these risk factors. In the group of all men, CETP activity was significantly and positively correlated with total cholesterol (r = 0.24), low-density lipoprotein cholesterol (r = 0.18), and non-high density lipoprotein cholesterol (r = 0.21), whereas PLTP activity was correlated with BMI (r = 0.12). Body mass index in rural men was higher than in the urban male population. Conclusions Increased PLTP activity, recognized as a pro-atherogenic factor, and decreased CETP activity, known as a protective factor, both observed in men living in rural areas, are probably conditioned by nutritional and/or genetic factors.

Postprandial decrease in LDL-cholesterol in menwith metabolic syndrome

Abstract Background: In some epidemiological studies, blood lipids are determined at non-fasting state, which may impact cardiovascular risk estimation. The aim of this study was to evaluate postprandial LDL-C changes in men with newly diagnosed metabolic syndrome (MetSy). Methods: 36 male patients were examined: 12 men with and 24 men without MetSy. The fat tolerance test was performed before and after a three-month hypolipidemic treatment. Serum lipids were measured using routine methods, lipid peroxides (LPO) colorimetrically, apoli- poproteins A-I, B, and hsCRP immunoturbidimetrically. Results: The postprandial increase in triglycerides was associated with a decrease in LDL-C and a small decrease in apo B. In men with MetSy, the mean change in LDL-C (-19.5 ± 2.3 mg/dl) was greater than in healthy men (-5.7 ± 3.8 mg/dl). All lipid changes (ΔTG, ΔLDL-C and ΔLPO) were linearly dependent on the postprandial non-LDL-choles- terol. After three months of hypolipidemic treatment, in all men with MetSy, the apoB/apoA-I ratio remained the same as before the therapy. Conclusion: In men diagnosed with MetSy, postprandial decreases in LDL-cholesterol may cause underestimation of cardiovascular risk. After three months of hypolipidemic treatment, there was only a partial reduction in this risk, as the apoB/apoA-I ratio remained the same.

Serum cystathionine β-synthase (CBS), cystathionine γ-lyase (CSE ) and cytochrome c oxidase (COX) in copper mine miners potentially expose d to hydrogen sulfide

BACKGROUND The aim of the study was to evaluate serum levels of the target enzyme for H2S toxicity--cytochrome c oxidase (COX) and enzymes involved in the synthesis of H2S--cystathionine β-synthase (CBS) and cystathionine γ-lyase (CSE) in copper mine miners. MATERIAL AND METHODS The initial and basic study was conducted respectively in 237 and 88 miners, working in 2 mining shafts: I--no H2S emissions recorded in the last 10 years (study group A) and II--H2S emissions occurred (study group B). A medical examination was performed and 10 ml of blood was collected from miners immediately after exiting the mine. RESULTS There were no clinical or biochemical changes typical for H2S toxicity. Sulfhemoglobine was undetectable and there were no changes in the red-ox system. However, in group B, regulatory changes were found; a tendency to higher concentration of CBS and CSE, a higher activity of angiotensin converting enzyme (ACE) compared to group A (p<0.05) and a linear relationship between ACE and CSE (r=0.6927; p<0.001). It has been shown that cigarette smoking decreases COX (p<0.05), however, in miners working in shaft II, the decreased level of COX may result also from the presence of H2S in the gaseous emissions. CONCLUSIONS COX concentration can be a sensitive indicator of exposure to H2S. The measurements of blood H2S concentrations carried out in workplaces should explain the cause of the changes observed in the COX, CBS and CSE activity.