The relationship of lead in soil to lead in blood and implications for standard setting

As part of a soil lead regulation process, this review was conducted to determine the association between lead in soil and established human health effects of lead or validated biomarkers of lead exposure. We reviewed only studies where soil exposure could be distinguished from other sources of lead and whose design could reasonably be used to infer a causal relationship between soil lead and either biomarkers or health effects. No such studies of health effects were found. Studies describing a quantitative relationship between soil lead and blood lead did meet our criteria: 22 cross-sectional studies in areas with polluted soil; and three prospective studies of soil lead pollution abatement trials. The cross-sectional studies indicated that, compared to children exposed to soil lead levels of 100 ppm, those exposed to levels of 1000 ppm had mean blood lead concentrations 1.10-1.86 times higher and those exposed to soil lead levels of 2000 ppm had blood lead concentrations 1.13-2.25 times higher. The prospective studies showed effects within the ranges predicted by the cross-sectional studies. Differences in results between studies were surprisingly modest and likely explainable by random sampling error, different explanatory variables included in data analyses and differences in methods of measuring lead in environmental specimens.     

Effect of dietary calcium on blood lead concentrations in occupationally exposed and nonexposed workers

PURPOSE: Evaluation of night glare after excimer laser in situ keratomileusis (LASIK) using two different ablation zone diameters. METHODS: One hundred and twenty eyes of 60 consecutive myopic patients received LASIK with the Nidek EC-5000 excimer laser. Eyes were randomized so that every patient had a single ablation zone of 5.5 mm on one eye and an ablation zone of 5.5 mm with a transition zone of 1.0 mm diameter larger on the other eye. Night glare was measured by two methods; a spot light test and a subjective questionnaire. RESULTS: At 6 months, 54 patients (90%) were examined; results of the spot light test showed that 40 patients (74.1%) perceived more glare with the eye with the single ablation zone; the subjective questionnaire indicated that 22 patients (40.7%) had more night glare with the eye with a single ablation zone compared to the other eye. The use of the transition zone increased the required total ablation depth by 20%. CONCLUSION: The use of a peripheral transition 1.0 mm diameter larger than the ablation zone significantly decreased night glare after LASIK with slight increase in the required central ablation depth.     

The association of blood lead and blood pressure in population surveys

The association of age, body weight, body mass index (BMI) and glycosylated hemoglobin A1c (HbA1c) to blood pressure in the general population of the Ho-long area in Taiwan was examined. A total of 1341 subjects, 746 men and 595 women, aged 40-90 years, were studied. Sex-specific multiple regression analyses were carried out on variables both univariately and significantly associated with blood pressure. Results show HbA1c to be significantly associated with SBP in both males and females before age, weight and/or BMI are adjusted (p < 0.05). After controlling for these confounders, the strength of SBP-HbA1c association was slightly reduced in males, but remained significant. In contrast, there was no significance in females. Moreover, no significant relationship in DBP-HbA1c was found in either sex group. These findings suggest that although a positive correlation was found between HbA1c and SBP, HbA1c or glucose status appeared to be a less important contributing factor in hypertension than age or body weight.     

Comments on a meta-analysis of the relation between dietary calcium intake and blood pressure

The role of dietary calcium in the etiology of hypertension is controversial. In 1995, Cappuccio et al. (American Journal of Epidemiology,1995;142:935-45) examined this issue in a meta-analysis of observational studies published between 1983 and 1993. The author of the present paper reviewed the original studies underlying this meta-analysis and discovered that data from one study had been inappropriately extracted and converted, leading to an understatement of the calcium-blood pressure relation by a factor of about 30. This review also raised questions about the extraction and conversion of data from several other studies and about the statistical methods used. The author repeated the meta-analyses and discovered an unadjusted regression slope between dietary calcium and systolic blood pressure of -0.34 mmHg/100 mg per day (95% confidence interval (CI) -0.46 to -0.22) for men, -0.15 mmHg/100 mg per day (95% CI -0.19 to -0.11) for women, and -0.39 mmHg/100 mg per day (95% CI -0.47 to -0.31) for men and women. For diastolic blood pressure, the pooled regression slope for men was -0.22 mmHg/100 mg per day (95% CI -0.32 to -0.13), while for women it was -0.051 mmHg/100 mg per day (95% CI -0.090 to -0.012); for men and women it was -0.35 mmHg/100 mg per day (95% CI -0.67 to -0.02). These slopes are still modest but are larger than those reported in the original analysis. However, since all of these analyses were based on zero-order correlations or regressions, extreme caution must be exercised in interpreting the results.     

A study on the relationship between blood lead levels and anemia indicators in workers exposed to low levels of lead

To determine the effects of a vegetarian diet with avocado as a source of monounsaturated fat on serum lipids, thirteen patients with phenotype II (twelve with IIa and one with IIb) dyslipidemia were included in a prospective, transversal and comparative study in which three four-week diets randomly assigned were assessed. One vegetarian diet (ALVD) was composed of 70% carbohydrates, 10% proteins and 20% lipids. Another was composed of 60% carbohydrates, 10% proteins and 30% lipids, 75% of which was supplied by avocado (AVD). A third diet was an avocado-added free diet (FDWA). Body weight, body mass index (BMI), and serum lipids (total cholesterol (TC), high (HDL) and low density lipoprotein (LDL) cholesterol and triglycerides (TG)) were evaluated. AVD produced a significant decrease in LDL. ALVD did not change TC and LDL, while FDWA increased them slightly. The three diets reduced TG levels, but only ALVD did so significantly. All three diets reduced HDL levels, particularly ALVD, which produced the greatest reduction. Low-fat, carbohydrate-rich vegetarian diets may be harmful to hypercholesterolemic patients. The avocado addition to a vegetarian diet does not correct these undesirable effects. To obtain beneficial effects on lipid profile with avocado, lower amounts of carbohydrates and polyunsaturated fatty acids are probably needed.     

Emotionality and mental health: Longitudinal findings from the normative aging study.

The present longitudinal study examined the relation between the temperament types of emotionality and extraversion, as assessed by the Eysenck Personality Inventory-Q (Floderus, 1974), and self-reported psychological symptoms 10 years later, as assessed by the revised version of the Hopkins Symptom Checklist (SCL-90-R; Derogatis, 1983). The sample consisted of 1,324 older men, participants in the Normative Aging Study. Those high in emotionality were expected to report higher levels of symptoms than those low in emotionality. Symptoms of depression and anxiety, however, were hypothesized to be higher among emotional introverts, whereas hostility and psychoticism were expected to be higher among emotional extraverts. Canonical correlation analysis showed that emotionality and extraversion accounted for 25% of the variance in mental health 10 years later. However, emotionality accounted for most of the variance, with extraversion accounting for only 2%. The results are interpreted as support for the construct of negative affectivity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Association between blood pressure and dietary factors in the dietary and nutritional survey of British adults

During the last few decades, the industrial production and use of Cd resulted in the release of significant quantities of Cd into the environment. Concern about health risks of human exposure to this toxic metal, which may be contained in soil and other environmental compartments, has increased significantly in recent years. Soil ingestion is a potentially important pathway of exposure to soil-absorbed environmental contaminants, especially for young children exhibiting hand-to-mouth behavior. Health risk assessments are usually based on unchanged bioavailability of soil-absorbed pollutants, e.g., heavy metals, neglecting interactions of metals with the soil matrix, which may lead to relatively lower bioavailability. This study was conducted to determine the bioavailability of Cd absorbed to soil in rats. Eight-week-old male Lewis rats were given either a soil polluted with CdCl2 (150 micrograms Cd/rat) dissolved in 5% gun acacia or an equal amount of Cd as CdCl2 dissolved in saline. Control rats were gavaged with isotonic saline. Cd concentrations in liver, kidney, brain, heart, and blood, as well as Cd content of urine and feces were analyzed using graphite furnace atomic absorption spectrometry. Tissue Cd concentrations in soil-treated animals were significantly lower than the tissue concentrations in the Cd-saline group; in the liver and kidneys of the Cd-saline and Cd-soil groups, 4 and 2.7% respectively, of the original doses were recovered. Relative bioavailability, calculated on the basis of blood Cd levels for the Cd-soil group as compared to the Cd-saline group, appeared to be 43%. No differences in the excretion pattern of Cd into feces were observed between the Cd-saline and Cd-soil groups. After 6 days, over 91% of the original dose was recovered in the feces of both Cd-treated groups. Cd excretion via urine was very low, but in the Cd-soil group a significant increase in urinary Cd was observed as compared to the control group. However, the amount of Cd excreted into urine of the Cd-soil group during the experimental period corresponded to only 0.01% of the original dose. In the Cd-saline group, no additional Cd was excreted into urine as compared to the control group. These results indicate that the soil matrix significantly reduced the absorption of Cd in the gastrointestinal tract. Consequently, exposure assessment models, assuming an unaffected bioavailability of soil-absorbed Cd, overestimate the internal dose and thereby overestimate health risks associated with direct ingestion of soil particles.     

Women''s anger: relationship of suppression to blood pressure

Myeloablative therapy followed by allogeneic bone marrow transplantation (BMT) has proven to be curative therapy in patients with hematologic malignancies. Relapse, however, remains a major cause of treatment failure for patients with advanced disease. During the past 15 years, we have gained considerable experience with the combination of fractionated total-body irradiation (FTBI) and etoposide followed by allogeneic BMT for hematologic malignancies. In an attempt to decrease post-transplant relapse rates, 67 patients under the age of 50 years with high-risk or advanced-stage hematological malignancies received an intensified regimen of FTBI and etoposide plus cyclophosphamide followed by BMT from a genotypically-matched related donor. The regimen consisted of 1320 cGy of FTBI in 11 fractions, 60 mg/kg of etoposide (VP-16), and 60 mg/kg of cyclophosphamide (CY). Fifty-three patients received cyclosporine and prednisone for graft-vs.-host disease (GVHD) prophylaxis and 14 patients received cyclosporine, methotrexate, and prednisone. Diagnosis at BMT included 45 patients with acute leukemia, 7 patients with chronic leukemia, and 15 patients with high-grade non-Hodgkin's lymphoma (NHL). Actuarial disease-free survival (DFS) at 3 years was 42% +/- 12% for the entire group with a median follow-up of 50 months (range 20-74) for 28 patients who remain alive in continued complete remission (CR). Actuarial 3-year-DFS was 38% +/- 14% in 52 patients with acute or chronic leukemia and 60% +/- 25% in 15 patients with NHL with relapse rates of 45% +/- 16% and 21% +/- 11%, respectively. DFS at 3 years was 40% +/- 18% in 32 patients with acute leukemia in 1st relapse or 2nd CR or chronic myelogenous leukemia in accelerated phase, and was 32% +/- 22% in 20 patients with more advanced disease. Regimen related mortality occurred in 9 patients (4, veno-occlusive disease of the liver; 2, multi-organ failure; 1, diffuse alveolar hemorrhage; 1, central nervous system (CNS) hemorrhage; 1, adult respiratory distress syndrome (ARDS). The combination of FTBI, etoposide, and cyclophosphamide followed by allogeneic BMT is an effective and relatively well-tolerated regimen for patients with advanced hematologic malignancies. The role for this regimen should be further defined by prospective clinical trials.     

The relationship of education to blood pressure: findings on 40,000 employed Chicagoans

The relationship of education to both actual blood pressure and the prevalence of high blood pressure, based on a systolic pressure of 160 mm Hg or greater or a diastolic pressure of 95 mm Hg or greater, was analyzed among 27,033 men and women, white and black, age 25-44 and 45-64, from the Chicago Heart Association Detection Project in Industry. The educational status of each individual was categorized as not a high school graduate, high school graduate, some college, or college graduate. A statistically significant inverse association between education and high blood pressure was present in all groups of whites. This association could not be "accounted for" by differences in age, relative weight, and heart rate among the educational strata. Controlling for these variables did, however, lessen the association. Among black males a significant inverse association between education level and blood pressure was found for the younger group. For the older black males there was a clear inverse association although with the small numbers it did not achieve statistical significance. For black females there was no clear association.     

Influence of dietary fats upon systolic blood pressure in the rat

Studies were performed to determine whether feeding diets with differing fatty acid content and composition had an influence on systolic blood pressure in the rat. Weanling male rats were fed standard laboratory chow (2.9% fat in total), or synthetic diets (10% fat in total) containing fish oil, butter, coconut oil or corn oil, for 5 weeks. Coconut oil and butter diets were rich in saturated fatty acids, whilst fish oil and corn oil were rich in the n-3 and n-6 unsaturated fatty acids respectively. Systolic blood pressure was measured using an indirect tail-cuff method at the end of the feeding period, and compared to a group of weanling rats. Feeding the different diets did not alter the growth of the rats, so all animals were of similar weights at the time of blood pressure determination. Control (chow fed) animals, at nine weeks of age, had higher systolic blood pressures than the weanling, baseline control group. Fish oil fed rats had similar pressures to the chow fed rats. Corn oil fed rats had significantly lower systolic pressures than the controls. The rats led the diets rich in saturated fatty acids (butter and coconut oil) had significantly higher blood pressures than all other groups. Systolic blood pressure was found to be significantly related to the dietary intakes of saturated and unsaturated fatty acids. The dietary intake of linoleic acid was significantly higher in corn oil fed rats than in other groups. Systolic blood pressure was inversely related to linoleic acid intake. Feeding a diet rich in saturated fatty acids significantly increases blood pressure in the rat. A high intake of n-6 fatty acids, and in particular linoleic acid, appears to have a hypotensive effect. Prenatal exposure of the rats to a maternal low protein diet, abolished the hypertensive effects of the coconut oil diet and the hypotensive effect of the corn oil diet upon young adult females. The intrauterine environment may, therefore, be an important determinant of the effects of these fatty acids on blood pressure in later life.     

Construct validation of optimism and pessimism in older men: Findings from the normative aging study.

Validation of M. F. Scheier and C. S. Carver's (1985) Life Orientation Test has identified associations between bipolar optimism and several external constructs. However, optimism and pessimism may not be bipolar, but rather separate constructs. Furthermore, these constructs may be indistinguishable from personality traits, such as neuroticism and extraversion. This study examined the associations of separate optimism and pessimism measures with self-reports of hassles, psychological symptoms, and illness severity, controlling for personality. Ss were 1,192 men from the Normative Aging Study. Findings suggest that optimism and pessimism are separate and that their relations to external criteria remain, although attenuated, when neuroticism and extraversion are controlled. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The relationship between health status and blood pressure in urban African Americans

African Americans have higher rates of hypertension and poorer health status than their white counterparts. This study assessed the relationship between health status, cardiovascular risk factors, and measured blood pressure. Free blood pressure screenings were performed at businesses and organizations located in west Baltimore. All individuals with cardiovascular risk factors were offered health education. Also, participants with a measured blood pressure of > or = 140/90 mm Hg were referred for free medical treatment. Participants completed a questionnaire that included demographics, cardiovascular risk factors, the Medical Outcomes Study SF 36, and two tests on cholesterol and heart disease knowledge. A total of 1389 African-American men and women were screened; 20% were found to have high normal blood pressure and 31% had stage 1 hypertension or higher. Those with hypertension reported lower physical functioning and poorer general health than those without high blood pressure. When compared with US normative data, participants reported higher levels in vitality and physical and emotional role functioning, more bodily pain, and poorer general health, but they were similar in physical functioning, social functioning, and mental health. Preliminary data suggest that hypertension does have an effect on health function.     

Mental health differences among retirees and workers: Findings from the normative aging study.

Researchers during the past decade have found little effect of retirement on physical health. However, retirement entails a number of losses, and its effect on mental health, as measured by the prevalence of psychological symptoms, is unclear. We examined psychological symptoms in a sample of 1,513 older men, participants in the Normative Aging Study, using the SCL-90-R (Derogatis, 1983). Analyses of variance indicated that retirees reported more psychological symptoms than did workers, even after controlling for physical health status. Exploratory analyses examining the circumstances of retirement found no effects for length of retirement or part-time employment, but did find effects for the timing of retirement. Both early and late retirees reported more psychological symptoms. Late workers (aged 66 and older) reported the fewest symptoms. Reasons for these findings are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dietary calcium, calcium supplementation, and blood pressure in African American adolescents

BACKGROUND: Intake of calcium from the diet is inversely associated with blood pressure in observational studies and animal models but randomized trials in humans have found only small effects of calcium supplementation on blood pressure. A blood pressure-lowering effect of calcium supplementation may thus be restricted to persons with a low intake of calcium from the diet and specific genetic or other characteristics. OBJECTIVE: A randomized trial was conducted to assess the effect of calcium supplementation on blood pressure in African American adolescents. Rapid growth during adolescence may increase calcium requirements, and avoidance of milk and milk products by some African Americans can result in low intake of calcium. DESIGN: One hundred sixteen adolescents (65 girls, 51 boys; mean age: 15.8 y) were given calcium (1.5 g/d) or placebo for 8 wk in a randomized, double-blind, crossover design. Blood pressure was measured after 2, 4, and 8 wk. Dietary calcium was determined with a validated food-frequency questionnaire. RESULTS: The net effect (+/-SE) of calcium supplementation on diastolic blood pressure was a reduction of 1.9 +/- 1.1 mm Hg (P = 0.04, one-tailed t test). Blood pressure reduction was greater in adolescents with lower intake of calcium from the diet (P = 0.003, one-tailed t test for interaction): -4.9 +/- 1.6, -2.3 +/- 1.6, and 1.4 +/- 1.8 mm Hg for change in the lower (0.024-0.067 g Ca/MJ), middle (0.069-0.091 g Ca/MJ), and upper (0.093-0.217 g Ca/MJ) tertiles, respectively. No main effect on systolic blood pressure was detected. CONCLUSION: These findings suggest that calcium supplementation may lower diastolic blood pressure in African American adolescents with low dietary intakes of calcium.     

The effect of dietary sodium intake on the blood pressure and cardiac output responses to angiotensin II in unanaesthetized rats

1. Dose-response curves for the pressor activity of angiotensin II have been determined in unanaesthetized rats receiving diets containing 2-5% (w/w) or 0-007% (w/w) sodium and administered in various sequences. 2. Dose-response curves were shifted to the left in rats on a high-, compared with a low-, sodium intake. This response was maintained for 7 days on changing from high to low sodium. 3. There was no difference in the relation between the fall of cardiac output and the rise of blood pressure in any of the experimental groups. 4. Dose-response curves for peripheral resistance showed the same directional change as seen for the pressor response in rats on high- and low-sodium diets. Since depression of cardiac output was proportional to the pressure rise, the absolute change in peripheral resistance was greater than the blood pressure response. The proportional changes were similar. 5. It is concluded that alterations in the pressor response to angiotensin caused by changes in sodium loading are attributable to changes in peripheral resistance and not to changes in the cardiac output response to the acute rise in blood pressure.