Occupational exposure to urban stressors and effects on atrial natriuretic peptide: preliminary results.

PURPOSE: The aim of this pilot study is to evaluate whether occupational exposure to low doses of pollutants present in the air of the city selected for the study could cause alterations in the concentration of atrial natriuretic peptide (ANP) in workers from the Municipal Police with outdoor tasks, compared to those with indoor tasks. METHODS: A total of 208 non-smoking male and female subjects were enrolled and divided on the basis of whether their tasks were mainly outdoors or indoors. The dosage of plasma ANP was carried out on all workers included in the study. Differences between means and frequencies were compared using student's t-test for unpaired data and chi-square test with Yates' correction, and they were considered significant when the p value was <0.05. RESULTS: Even after the subdivision of the total sample on the basis of sex, mean plasma levels of ANP were higher but not statistically significant in traffic police compared with controls. CONCLUSIONS: The preliminary results suggest that further studies should be conducted before the influence of urban pollution on ANP could be confirmed or rejected.

Correlation between urinary nickel and testosterone plasma values in workers occupationally exposed to urban stressors.

BACKGROUND: The purpose of this study is to assess whether occupational exposure to low doses of nickel (Ni) present in urban air can cause alterations in the concentration of plasma testosterone in workers of the Municipal Police of a large Italian city assigned to different types of outdoor tasks. METHODS: 359 male subjects were included in the study and divided on the basis of job, age, length of service and smoking habits. The dosage of the atmospheric Ni was performed by personal dosimetries on a sample of the workers included in the study. For each worker included in the study the dosage of whole blood Ni and of the plasma testosterone was carried out. The total sample was subjected to the independent-samples T-test and the Mann-Whitney U test for variables with 2 modes (smoking cigarette) and the ANOVA test and the Kruskal Wallis test for variables with more than 2 modes (age, length of service and job function). The correlation of Pearson with p at 2 wings between the variables was evaluated in the total sample and after subdivision on the basis of smoking and on the basis of the job. After taking into account the major confounding factors the multiple linear regression was performed on the total sample and after breakdown by tasks. RESULTS: The correlation between the values of urinary Ni and the values of plasma testosterone on the total sample and for all classes of subdivision was found constantly negative. These results were confirmed by multiple linear regression, which indicated the Ni as the only significant variable that can contribute to the alterations of the testosterone. CONCLUSIONS: Based on the results, the Authors suggest that occupational exposure to low doses of Ni present in the urban environment is able to influence some lines of the hypothalamic-pituitary-gonadal axis in exposed workers.

Workers of the printing industry and hepatic damage.

BACKGROUND: Typesetting industry is still the primary instrument of communication, despite the development of new technological systems. This study focuses on the analysis of the hepatic effects induced by the use of some organic solvents employed in the printing industry. METHODS: We studied a group of 194 workers: 93 exposed and 101 not exposed. The level of the exposure to chemical pollutants were assessed through the environmental monitoring of blood concentrations and the analysis of airborne substances. The health survey was performed through the collection of the medical history and the use of hepatic tests, which were evaluated by calculating Mean, Standard Deviation, Student's t-test and X² test with Yates Correction, to investigate statistically significant differences in some hepatic parameters: AST, ALT, ALP, GGT, fractional and total bilirubin. The environmental data sometimes exceeded the TLV-TWA. RESULTS: The clinical evaluation of the hepatic parameters showed statistically significant differences as to the hematic concentrations of AST, ALT, GGT. CONCLUSIONS: The results we obtained support the hypothesis of a risk among the printing industrial workers attributable to the hepatotoxic solvents. This risk seems to be related to the use of a mixture of solvents, although at low doses, and the analysis of the results obtained confirms the validity of the investigation for the health screening protocol adopted in order to identify subjects and/or population at risk of hepatotoxicity.

Professional exposure to anaesthetic gases in health workers: estimate of some hepatic and renal tests.

OBJECTIVES: The aim of this study is to estimate whether the occupational exposure to low dose of anaesthetic gases could cause alterations of haematochemical hepatic and renal parameters in the health workers of a city hospital. MATERIALS AND METHODS: After excluding the main confounding factors, 154 exposed subjects and 98 not exposed controls were included in the study. The exposed subjects were divided in more exposed (group 1: n.54) and less exposed (group 2: n.100). Each worker included in this study underwent the CBC test (Complete Blood Count test). The differences between means were compared using the Student T test for unpaired data and considered significant when the p value was < 0.05. RESULTS: The mean values of serum albumin, alpha 1, alpha 2, beta and gamma globulins were significantly decreased in health workers of both groups compared to controls. The mean values of serum creatinine and gamma-GT were significantly higher in health workers of group 2 compared to controls. CONCLUSIONS: The obtained results suggest that occupational exposure to low dose of anaesthetic gases could influence haematochemical hepatic and renal parameters in exposed health workers.

Professional exposure to ionizing radiations in health workers and white blood cells.

BACKGROUND: The aim of this study is to estimate if low dose of occupational exposure to ionizing radiations can cause alterations of plasma concentrations of total white blood cells, lymphocytes, monocytes and granulocytes (eosinophils, basophils, neutrophils), in the health workers of a big hospital. METHODS: 266 non smokers subjects of both sexes (133 health workers and 133 controls) were included in this study, compared on the basis of sex, age and working seniority. The complete blood count (CBC) was performed in all included workers. RESULTS: The differences between the mean values were compared using Student T-test for unpaired data. The frequencies of the single variables were compared using Chi (2) test with Yates correction. The differences were considered significant when the P values were < 0.05. The mean values and the distribution of the mean values of total white blood cell were significantly decreased in health workers of both sexes compared to controls. The average values of granulocytes neutrophils were significantly low in female health workers compared to female controls. CONCLUSIONS: The obtained results suggest that low dose of occupational exposure to ionizing radiations is able to influence some lines of the hematopoietic system in exposed workers.

Perceived stress and stress-related parameters.

BACKGROUND: The purpose of this study is to evaluate, using a questionnaire developed by our research group, whether occupational exposure to physical, chemical and psychosocial urban stressors can lead to alterations in perceived stress in a group of both male and female outdoor workers. The study also examines possible correlations between the levels of stress as inferred from the scores of the questionnaire and the levels of certain stress-related parameters (prolactin levels, consumption of coffee, chocolate, alcohol and cigarette smoking). METHODS: We evaluated a final sample of 480 subjects (342 male and 138 female). All workers included in the study were divided into three groups on the basis of scores of the questionnaire. RESULTS: About 60% of workers showed a moderate or severe stress condition, with a statistically significant prevalence of female workers and younger subjects. There was a statistically significant correlation between the questionnaire score and the mean levels of stress-related parameters. The increase of perceived stress increases significantly the mean levels of prolactin and the consumption of coffee, chocolate and cigarettes. There was no statistically significant differences for alcohol consumption. CONCLUSIONS: The results show that exposure to chemical physical and psycho-social urban stressors can influence perceived stress in outdoor workers. The questionnaire used in our research could be an useful instruments for physicians during the health surveillance visits

Occupational exposure to traffic pollutants and peripheral blood counts.

Aim of the study is to evaluate whether occupational exposure to low doses of pollutants present in the air of the city selected for the study could cause alterations in peripheral blood counts in workers of the Municipal Police with outdoor tasks vs workers with indoor tasks. 279 non smoker males were enrolled and divided on the basis of their different kind of task. The dosage of air pollutants was carried out through the use of personal air samplers on a representative group of workers. Data obtained were subject to statistical evaluation consisting of Homogeneity of variance test, ANOVA univariate test with post hoc Bonferroni correction, Jonckheere-Terpstra test and multiple linear regression analysis. The differences were considered statistically significant when p values were lower than 0.05. Mean levels of RBC, HB, MCHC, WBC and neutrophil cells were significantly higher in traffic policemen and police drivers compared to controls (workers with indoor tasks). Mean levels of MCV, MCH and lymphocytes were significantly lower in traffic policemen and police drivers compared to controls. These results were confirmed by Multiple linear regression test and Jonckheere-Terpstra test. The results suggest that prolonged occupational exposure to low doses of traffic pollutants can alter some lines of the hematopoietic system in exposed workers.

A comparison of coronary artery stenting with angioplasty for isolated stenosis of the proximal left anterior descending coronary artery: five year clinical follow up.

BACKGROUND: Stent implantation for isolated stenosis of the proximal left anterior descending coronary artery (LAD) with preserved left ventricular function has been found to have a better clinical and angiographic outcome at one year than balloon angioplasty (PTCA). OBJECTIVE: To establish whether those results are maintained at five year follow up. METHODS: Patients were followed at least every six months. For those who died during follow up, data were obtained from medical records. MAIN OUTCOME MEASURES: Freedom from death, non-fatal myocardial infarction, cerebrovascular accident, and repeated target lesion revascularisation. Secondary end points were revascularisation in a remote region and freedom from angina. RESULTS: Follow up was complete in all patients. At five years, the primary end point was reached more often by patients randomised to stent implantation than to PTCA (80% v 53%; odds ratio (OR) 0.29 (95% confidence interval (CI) 0.13 to 0.69); p = 0.0034). In the PTCA group, 35% of patients underwent target lesion revascularisation v 15% in the stent group (OR 0.33, 95% CI 0.13 to 0.80; p = 0.014). There was a trend towards increased mortality in the PTCA group than in the stent group (17% v 7%; OR 0.36, 95% CI 0.10 to 1.21; p = 0.098). No significant differences were found between PTCA and stent groups for non-fatal myocardial infarction (8% v 5%; OR 0.58, 95% CI 0.13 to 2.54; p = 0.46) or cerebrovascular accident (2% v 0%). CONCLUSIONS: In patients with isolated stenosis of the proximal LAD, a five year clinical follow up confirmed a better outcome in those treated with stenting than with PTCA.

Unstable angina and elevated c-reactive protein levels predict enhanced vasoreactivity of the culprit lesion.

BACKGROUND: Because plaque inflammation may modulate coronary vasomotion, the association between systemic levels of C-reactive protein (CRP) and coronary vasoreactivity was assessed in patients with stable or unstable angina. METHODS AND RESULTS: In 31 patients with stable angina and 23 patients with unstable angina undergoing coronary angiography, minimal luminal diameter (MLD) of the culprit lesion was measured by quantitative coronary angiography at baseline, during the cold pressor test (CPT), and after intracoronary administration of nitroglycerin (NTG) and expressed as percent change from baseline. MLD of patients with unstable angina exhibited a greater reduction during CPT and a greater increase after NTG than did patients with stable angina (-17+/-14% versus -5+/-12%, P=0.0013, and 34+/-25% versus 8+/-20%, P<0.001, respectively). According to preprocedural serum levels of CRP, 36 patients had normal (

The use over time of statins in coronary patients in an Italian tertiary referral center.

BACKGROUND: In the last decade, large-scale clinical trials have consistently shown that therapy with statins is of great benefit to patients with and at risk of developing coronary artery disease. We assessed, in a sample of patients with coronary artery disease in whom coronary angiography was indicated and hospitalized in the last 10 years, the use of statins at admission. METHODS: One hundred patients with stable coronary artery disease were randomly selected per year from 1991 to 2000. The final study population consisted of 1000 patients. The prescription of statins for > or = 6 months before hospital admission was determined from a hospital-wide clinical database. RESULTS: From 1995, the prevalence of patients treated with statins at hospital admission progressively increased. In 1991, only 2% of patients were treated with statins before hospital admission while in the year 2000, 38% of patients were receiving this treatment. The mean prevalence of patients treated with statins before and after 1995 was 3 vs 22% (p < 0.0001) respectively. The distribution of the demographic and clinical parameters and the prevalence of conventional cardiovascular risk factors were similar in patients treated or not treated with statins. CONCLUSIONS: After 1994, in coincidence with the publication of the results of clinical trials showing the benefit of statins in patients with coronary artery disease, the use of these drugs increased significantly. This finding suggests that the widespread diffusion of the results of the major clinical trials and of guidelines drawn up by medical associations have had a significant impact on statin prescription in patients with coronary artery disease. Nevertheless our data also indicate that, despite overwhelming evidence on the benefits of statin therapy, in current clinical practice cardiologists are not optimally utilizing lipid management and that statins are frequently prescribed without an appropriate analysis of risk factors.

Endothelial activation in patients with cardiac syndrome X.

BACKGROUND: The presence of endothelial dysfunction with increased endothelin-1 plasma concentrations in patients with cardiac syndrome X is still under debate. The aim of the present study was to evaluate the presence of endothelial dysfunction in patients with cardiac syndrome X. METHODS AND RESULTS: ++Endothelin-1 levels were evaluated with a sensitive radioimmunoassay with previous purification through reverse phase HPLC in 24 patients (3 men and 21 women, mean age 54+/-7 years) with typical angina, instrumental evidence of ischemia, and normal coronary angiograms both under baseline conditions and after oral glucose load (75 g D-glucose). We also measured plasma nitrite-plus-nitrate levels, a sharp index of endothelial nitric oxide production, and circulating concentrations of the soluble fraction of the endothelial adhesion molecule vascular cell adhesion molecule-1, a well-recognized marker of early endothelial dysfunction. Fourteen healthy subjects (1 man and 13 women, mean age 47+/-15 years) served as controls. There were no significant differences in baseline plasma endothelin-1 concentrations between patients and control subjects (0.55+/-0.34 versus 0.48+/-0.22 pg/mL, P=0.503). Plasma nitrite-plus-nitrate and soluble vascular cell adhesion molecule-1 concentrations were also similar between the 2 groups. After glucose ingestion, circulating endothelin-1 concentrations were significantly higher in patients with cardiac syndrome X than in control subjects (P<0.03 at 60, 90, and 120 minutes). CONCLUSIONS: Our findings show that no basal endothelial damage is present in patients with cardiac syndrome X. Nevertheless, increased responsiveness of endothelin-1 to glucose loading suggests that patients with cardiac syndrome X present an increased susceptibility to releasing endothelin-1 under stressful circumstances.

Predictive value of C-reactive protein in patients with unstable angina pectoris undergoing coronary artery stent implantation.

This study was aimed at establishing the relation between baseline C-reactive protein levels and 12-month outcome in patients with unstable angina successfully treated with coronary artery stent implantation. Our results suggest that in patients with unstable angina and 1-vessel coronary disease successfully treated with coronary artery stent implantation, normal baseline serum levels of C-reactive protein identify a subgroup of patients at low risk of cardiac events during follow-up.

Ischemic preconditioning during coronary angioplasty is preserved in elderly patients.

BACKGROUND: To establish whether the adaptation to ischemia observed in humans during percutaneous transluminal coronary angioplasty (PTCA) after repeated balloon inflations, i.e. a clinical correlate of ischemic preconditioning, is preserved in elderly patients. METHODS: We studied 53 consecutive patients undergoing successful angioplasty for an isolated stenosis of a major epicardial coronary artery. On the basis of age, patients were separated into terciles: patients in the lower and middle terciles were grouped together (Group 1, adult patients, n = 24, mean age 50 +/- 6 years) and compared with those in the upper tercile (Group 2, elderly patients, n = 29, mean age 68 +/- 3 years). Intracoronary electrocardiogram was obtained at the end of the first two balloon inflations. Collateral recruitment during repeated balloon inflations was assessed by using an intracoronary Doppler guide wire (23 patients) or by using an intracoronary pressure guide wire (30 patients). RESULTS: In Group 1, ST-segment changes during the second inflation were significantly less than those at the end of the first inflation (6 +/- 3 vs 13 +/- 5 mm, p < 0.001). Similarly, in Group 2, ST-segment changes during the second inflation were significantly less than those at the end of the first inflation (6 +/- 4 vs 13 +/- 6 mm, p < 0.001). In both groups, collateral recruitment did not change from the first inflation to the second inflation (p = 0.1). CONCLUSIONS: Our study confirms that adaptation to ischemia during repeated balloon inflations in the setting of PTCA is independent of collateral recruitment and, therefore, is mainly due to ischemic preconditioning. More importantly, our study indicates that ischemic preconditioning is preserved in elderly patients.

Algogenic effects of the proximal and distal intracoronary infusion of adenosine. Pathophysiologic implications on the mechanisms of ischemic cardiac pain.

BACKGROUND: It has been hypothesized that ischemic cardiac pain might be due to a spatially restricted intense stimulation of non-specific cardiac receptors. If this hypothesis is correct a strong stimulation with an adequate stimulus of a limited myocardial region should cause more pain than a weaker stimulation of a larger myocardial region. METHODS: To test this hypothesis, we carried out a systematic study in 8 male patients (mean age 52 +/- 9 years) with uncomplicated stable angina pectoris and significant isolated proximal left anterior descending coronary artery stenosis in whom the same amount of adenosine, a known mediator of cardiac and muscular ischemic pain, was infused at the proximal and distal site of the left anterior descending coronary artery. Increasing doubling doses (from 108 to 3456 micrograms/min) or adenosine were infused for periods of 2 min each into the left anterior descending coronary artery through a 2.8 F catheter. Adenosine was infused in each patient both proximally to the first diagonal branch and distally to the last diagonal branch of the left anterior descending coronary artery. The initial infusion site, proximal or distal, was randomized. At the beginning of the study patients were asked to promptly report the onset of pain. Time to onset of adenosine-induced pain and maximal pain severity (assessed by a visual analog scale) were recorded. Twelve electrocardiographic leads were recorded throughout the study. RESULTS: Seven patients experienced pain during adenosine infusion both at the proximal and distal level. One patient experienced pain only during adenosine infusion at the proximal site. In all patients pain occurred earlier (176 +/- 125 vs 343 +/- 207 s, p = 0.005) and its severity was greater (51 mm, range 20-95, vs 27 mm, range 0-69, p = 0.002) during infusion at the proximal site. No patient exhibited electrocardiographic changes during the study. CONCLUSIONS: Adenosine infusion at a proximal coronary site causes pain which occurs earlier and is more severe than that experienced during its infusion at a distal site. These findings suggest that the intensity of ischemic cardiac pain is determined by the number of stimulated receptors rather than by the intensity of their stimulation.

Coronary flow reserve early and late after minimally invasive coronary artery bypass grafting in patients with totally occluded left anterior descending coronary artery.

BACKGROUND: The impairment of flow reserve of the left anterior descending coronary artery in the early postoperative period in patients receiving a left internal thoracic artery graft has been related to the effects of cardiopulmonary bypass. Indeed, the late improvement in flow has been attributed to a late increase in left internal thoracic artery diameter. METHODS: We evaluated 12 patients who underwent minimally invasive direct coronary artery bypass surgery with the internal thoracic artery used to graft an occluded left anterior descending artery without extracorporeal circulation. Early and 6 months after the operation, patients underwent a second angiogram of the left internal thoracic artery graft and assessment of coronary flow reserve by use of an intracoronary 0.014-inch Doppler guide wire. RESULTS: At the late study, coronary flow reserve had increased compared with the early postoperative data from 1.8 +/- 0.4 (standard deviation) to 2.5 +/- 0.6 (P =.002) because of a significant decrease in baseline averaged peak velocity (32.4 +/- 6.2 vs 21.3 +/- 6.4 cm/s, P =.002), whereas the hyperemic values were similar (51 +/- 6 vs 53.7 +/- 21.9 cm/s, P =.6). The diameters of the thoracic artery (2.1 +/- 0.3 vs 2.2 +/- 0.3 mm, P =. 7) and the left anterior descending coronary artery (1.8 +/- 0.1 vs 1.8 +/- 0.2 mm, P =.5), as well as myocardial oxygen consumption (106 +/- 14 vs 101 +/- 16 mm Hg. beats/min. 10(-2), P =.5), were unchanged. CONCLUSIONS: Our findings suggest that the late improvement in coronary flow reserve is independent of the diameter of the graft and probably reflects an early distal coronary vessel dysfunction, which normalizes with time.

Ischemic preconditioning in humans: models, mediators, and clinical relevance.

Ischemic preconditioning, a powerful form of endogenous protection against myocardial infarction, has been demonstrated in several animal species and, recently, in isolated human cardiomyocytes. For both logistic and ethical reasons, no clinical study can meet the strict conditions of experimental studies on preconditioning with infarct size as the end-point. Nevertheless, the demonstration of adaptation to ischemia observed during in vitro studies on human atrial trabeculae, in patients in the setting of coronary bypass surgery, and in the setting of coronary angioplasty in the absence of collateral vessel recruitment strongly suggests that ischemic preconditioning occurs in humans. This notion is further supported by the observation that in these human models, the adaptation to ischemia is influenced by drugs acting on K(ATP) channels and on purinergic and alpha-adrenergic receptors, similar to what is observed in accepted experimental models of ischemic preconditioning. This important form of myocardial endogenous protection may also play a role in the warm-up phenomenon and in mediating the beneficial effects of preinfarction angina. The demonstration of ischemic preconditioning in humans and the identification of some of its mediators suggests that in patients at high risk for myocardial infarction, drugs known to block this endogenous form of protection should be used with caution, whereas drugs known to elicit preconditioning might have a relevant therapeutic role.

Effect of acetylsalicylate on cardiac and muscular pain induced by intracoronary and intra-arterial infusion of bradykinin in humans.

OBJECTIVES: This study assessed the algesic activity of bradykinin (BK) in humans and the effects of acetylsalicylate on muscular and cardiac BK-induced pain. BACKGROUND: Bradykinin is released by the ischemic myocardium and may be involved in the genesis of ischemic pain. METHODS: Increasing doses of BK (from 30 to 960 ng/min) were randomly infused, for periods of 2 min each, into the iliac artery of 10 patients. The same protocol was repeated 30 min after the IV administration of 1 g of acetylsalicylate. In eight other patients with coronary artery disease, the same increasing doses of BK, for periods of 2 min each, were infused into the left coronary artery. The same protocol was repeated 30 min after the IV administration of 1 g of acetylsalicylate. Time to pain onset and maximal pain severity were obtained. RESULTS: Before acetylsalicylate administration, all patients experienced pain during intra-iliac infusion of BK. After acetylsalicylate, eight patients did not experience any pain during BK infusion (p = 0.0014), and in the two remaining patients, time to pain onset and maximal pain severity were similar to those recorded before acetylsalicylate. Before acetylsalicylate administration, all patients experienced pain similar to their habitual angina during intracoronary BK infusion. After acetylsalicylate, six patients did not experience any pain during BK infusion (p = 0.0098), whereas in the two remaining patients time to pain onset and maximal pain severity were similar to those recorded before acetylsalicylate. CONCLUSIONS: Intra-iliac infusion of BK causes muscular pain, and its intracoronary infusion in patients with coronary artery disease causes cardiac pain, which is similar to their habitual angina. The BK-induced pain is abolished or reduced by acetylsalicylate, thus suggesting that acetylsalicylate-sensitive mediators, such as prostaglandins, are involved in its pathogenesis.

Coronary artery stent placement in patients with variant angina refractory to medical treatment.

We performed a prospective study to establish the efficacy of coronary stent placement in a highly selected group of patients with focal coronary artery spasm in whom anginal attacks could not be prevented by full medical therapy. The results of this study indicate that intracoronary stent placement may represent an alternative and feasible treatment for patients with vasospastic angina refractory to aggressive medical therapy.