Effects of chronic iodine excess in a cohort of long-term American workers in West Africa

A cross-sectional survey of 102 Peace Corps volunteers in Niger, West Africa, in 1998 had previously demonstrated a high rate of thyroid dysfunction and goiter attributable to excess iodine from their water filters. The Peace Corps volunteers were followed-up a mean of 30 wk after they ceased using iodine-based water filtration systems. Goiter was present in 44% of subjects during excess iodine ingestion and in 30% after removal of excess iodine. Mean serum iodine decreased from 293 micro g/liter during excess iodine ingestion to 84 micro g/liter after cessation of excess iodine. Mean total serum T(4) values increased from 100.4 to 113.3 nmol/liter (7.8 to 8.8 micro g/dl). Mean serum free T(4) increased from 32.2 to 34.7 pmol/liter (2.5 to 2.7 ng/dl). Mean serum TSH decreased from 4.9 to 1.8 mU/liter. Mean serum thyroid peroxidase antibody levels decreased from 33,000 to 22,000 IU/liter (33 to 22 IU/ml). We found that during prolonged excess iodine exposure there were marked increases in serum total iodine concentrations, and the prevalence of goiter, elevated serum TSH values, and elevated serum thyroid peroxidase antibody values increased. The prevalence of all abnormalities decreased after removal of excess iodine from the drinking water system.     

Cardiorespiratory fitness protects against stress-related symptoms of burnout and depression

Objective

To examine how cardiorespiratory fitness and self-perceived stress are associated with burnout and depression. To determine if any relationship between stress and burnout/depression is mitigated among participants with high fitness levels.

Methods

197 participants (51% men, mean age = 39.2 years) took part in the study. The Åstrand bicycle test was used to assess cardorespiratory fitness. Burnout was measured with the Shirom–Melamed Burnout Questionnaire (SMBQ), depressive symptoms with the Hospital Anxiety and Depression Scale (HAD-D). A gender-matched stratified sample was used to ensure that participants with varying stress levels were equally represented.

Results

Participants with moderate and high fitness reported fewer symptoms of burnout and depression than participants with low fitness. Individuals with high stress who also had moderate or high fitness levels reported lower scores on the SMBQ Tension subscale and the HAD-D than individuals with high stress, but low fitness levels.

Conclusion

Better cardiovascular fitness seems to be associated with decreased symptoms of burnout and a better capacity to cope with stress.

Practical implications

Promoting and measuring cardiorespiratory fitness can motivate employees to adopt a more physically active lifestyle and thus strengthen their ability to cope with stress exposure and stress-related disorders.     

Detection of Ureaplasma urealyticum in second-trimester amniotic fluid by polymerase chain reaction correlates with subsequent preterm labor and delivery

Ureaplasma urealyticum is the microorganism most frequently isolated from the amniotic fluid of women in preterm labor. The relationship between intra-amniotic U. urealyticum in healthy second-trimester pregnant women and subsequent pregnancy outcome was investigated. Transabdominal amniotic fluid obtained from 254 asymptomatic women at 15-17 weeks' gestation were tested by polymerase chain reaction (PCR). U. urealyticum was identified in 29 subjects (11.4%). A subsequent preterm labor occurred in 17 U. urealyticum-positive women (58.6%), compared with 10 (4.4%) U. urealyticum-negative women (P<.0001). Preterm birth was documented in 7 (24.1%) U. urealyticum-positive women compared with only 1 U. urealyticum-negative woman (0.4%) (P<.0001). U. urealyticum-positive women also had a higher prevalence of preterm labor in a prior pregnancy (20.7%) than did the negative women (2.7%; P=.0008). PCR testing of second-trimester amniotic fluid for U. urealyticum can identify women at risk for subsequent preterm labor and delivery.     

A randomized controlled trial of oral selegiline plus nicotine skin patch compared with placebo plus nicotine skin patch for smoking cessation

Objectives To compare the effect of oral selegiline plus nicotine patch with placebo plus nicotine patch on smoking cessation rates. Design Randomized double‐blind placebo‐controlled trial. Setting Three community‐based clinics. Participants One hundred and nine male and female smokers aged 18–55 years, who smoked at least 15 cigarettes/day. Interventions Oral selegiline, 2.5 mg, or placebo twice/day initiated 1 week before the quit day, followed by 5 mg oral selegiline or placebo twice daily for 26 weeks, plus active nicotine skin patch to all participants for the first 8 weeks only. Measures of continuous abstinence rates up to 52 weeks, withdrawal symptoms, blood pressure and adverse events incidence. Findings Twenty‐five per cent (14 of 56) were continuously abstinent for 52 weeks in the selegiline plus nicotine group compared with 11% (6 of 53) in the placebo plus nicotine group (P = 0.08). Craving for cigarettes was lower in the selegiline plus nicotine group 4 weeks after quit day (P = 0.02). Conclusions Adding selegiline to nicotine patch was associated with a doubling of the 52‐week continuous abstinence rate, but this difference was not statistically significant. Selegiline significantly reduced craving for cigarettes and appeared to mitigate the need for nicotine replacement therapy. The results suggest that selegiline is a promising drug for future smoking cessation research.     

A prospective study of the effects of cigarette smoking and alcohol abuse on mortality

Objective:To compare the relative risks of alcohol abuse and cigarette smoking. Design:Cohort studies utilizing a 12-to-16-year follow-up of 47-to-52-year old men. Participants and setting:237 Caucasian college sophomores (COLLEGE sample) and 366 socially disadvantaged junior high school students (CORE-CITY sample) selected in 1940–43 for relative mental health and for interdisciplinary study. Main results:The presence of many risk factors for death, including alcohol abuse and smoking, had been assessed prior to age 47 (CORE-CITY sample) and age 52 (COLLEGE sample). Over the next 12 years (CORE-CITY sample) and the next 16 years (COLLEGE sample), the men’s mortality was monitored. Heavy use of cigarettes and alcohol abuse were highly correlated. When the effect of alcohol abuse was controlled, heavy smoking was associated with elevated mortality risks in both samples, although this was not statistically significant in the CORE-CITY sample. When smoking was controlled, the odds ratios for mortality from alcohol abuse were substantial in both samples. Conclusions:These results and a literature review suggest that insufficient alcohol abuse histories may lead clinicians to underestimate the mortality risk of alcohol abuse. Supported by research grants K05-MH00364, MH39799, and MH42248 from the National Institute of Mental Health.     

Release of cardiac bio-markers during high mechanical index contrast-enhanced echocardiography in humans.

BACKGROUND: Recent experimental data have shown that the combined exposure of rodent hearts to high acoustic pressure and ultrasound contrast agents can induce vascular injury and cell damage. The aim of the present work was to test whether similar effects can be observed in humans. METHODS AND RESULTS: Twenty patients underwent simultaneous arterial and coronary sinus blood sampling during contrast-enhanced echocardiography using Perfluorocarbon-enhanced Sonicated Dextrose Albumin. Control subjects were compared to groups of patients exposed to either high mechanical index (MI = 1.5) triggered second harmonic (1.3-2.6 MHz) imaging or low mechanical index (MI = 0.2) real-time power modulation imaging for 15 min. No significant changes arterio-venous differences in lactate, total creatine kinase (CK) and myoglobin occurred over time in the three groups. Similarly, the arterio-venous difference in CK-MB and troponin I remained stable over time in control and low-MI patients. By contrast, these two parameters progressively increased over time in the high-MI group (P < 0.05 vs. baseline and vs. controls). CONCLUSION: Our data suggest that high-MI contrast-enhanced echocardiography can cause subclinical release of cardiac bio-markers in humans, while low-MI real-time imaging appears to be safer.