Joseph Ribak

Asymptomatic microscopic hematuria—Is investigation necessary?

Microscopic hematuria is common in asymptomatic adults, but the benefit of screening the general population for blood in the urine has not been established. On the other hand, most studies of referred patients with putatively asymptomatic microscopic hematuria have reported a 2-11% prevalence of urothelial malignancies, leading to the recommendation that all patients with microscopic hematuria be thoroughly investigated. Urinalysis is inexpensive and highly acceptable to the general population, but is neither a sensitive, nor specific test, and has poor predictive value for urothelial malignancies, and nephrological diseases. Furthermore the benefits of early detection of such diseases has not been established. We conclude that screening urinalysis cannot be recommended. Studies are needed to determine which constellation of findings primary physicians use to select patients for referral to centers with urological and nephrological expertise.

Association of Calcitriol and Blood Pressure in Normotensive Men

The purpose of this study was to clarify the possible associations between the serum 1,25-dihydroxyvitamin D (calcitriol) level and blood pressure. Cross-sectional analysis of data was performed. Data collected included levels of serum calcitriol, parathyroid hormone, serum calcium, and blood lead; blood pressure; dietary history; and demographic and anthropometric variables. One hundred normotensive male industrial employees made up the study population. Systolic blood pressure and diastolic blood pressure were main outcome measures. After possible confounders were controlled for, multivariate analyses yielded an inverse, independent, and statistically significant association between calcitriol level and systolic blood pressure (standardized beta= -0.2704, P=.0051). A similar trend of borderline significance was found for the association between calcitriol and diastolic blood pressure (standardized beta= -0.1814, P=.0611). Parathyroid hormone, serum calcium, and blood lead levels were not associated with blood pressure. When subjects were divided into four groups by calcitriol level, those in the lowest quartile showed significantly higher systolic and diastolic blood pressures than those in the upper quartile (difference=11 mmHg, P=.007, and difference=4 mmHg, P=.071, respectively). There is an inverse association between serum calcitriol level and blood pressure. This suggests that in addition to its role in calcium homeostasis, the active metabolite of vitamin D may play a role in determining blood pressure. The differences in both systolic and diastolic blood pressures between the upper and lower quartiles of serum calcitriol were substantial and may be of clinical significance.

USEFULNESS OF THE PROTECTION MOTIVATION THEORY IN EXPLAINING HEARING PROTECTION DEVICE USE AMONG MALE INDUSTRIAL WORKERS

The present study examined the usefulness of personal variables: noise annoyance, and components of the protection motivation theory (R. W. Rogers, 1983) along with social-organizational factors in explaining hearing protection device (HPD) use among Israeli manufacturing workers. Participants were 281 men exposed to harmful noise levels for which routine HPD use is required by regulation. In practice, 3 HPD user groups were identified: nonusers (n = 38), occasional users (n = 125), and regular users (n = 118). HPD use was objectively verified. HPD use was primarily related to the personal variables but not to management pressure, coworker pressure, or family support. The most powerful predictors of HPD use were perceived self-efficacy (for long-term HPD use), perceived susceptibility (to hearing loss), and noise annoyance, together explaining 48% of the outcome variance. These findings have implications for interventions aimed at motivating workers to use HPDs regularly.

Biological monitoring of exposure to cadmium, a human carcinogen, as a result of active and passive smoking.

Cadmium (Cd), a known human carcinogen, is one of the components of tobacco and also has many industrial uses. Smoking Cd-contaminated cigarettes at work may cause an increase in blood levels and toxicity of Cd. For a population of nonexposed workers, we compared blood Cd and urine cotinine (Cot) levels as biological markers of exposure to cigarette smoke of active smokers (AS) and passive smokers (PS) with those of unexposed nonsmokers (UNS) in 158 workers. The mean Cd in AS (0.097 microgram%; ie, 0.097 microgram/100 mL whole blood) was significantly higher than in UNS (0.085 microgram%), and was very close to the mean Cd levels in PS (0.093 microgram%). Mean Cd levels in exposed past smokers (0.105 microgram% was higher than in nonexposed past smokers (P < 0.05) and in AS. The mean Cot level was significantly higher in AS than in PS or in UNS. Increased smoking was associated directly with increased blood Cd and urine Cot. Our results supported and proved quantitatively that exposure to cigarette smoke is harmful to both AS and PS, as we show that in both cases there is an increase in blood Cd. According to our results, exposure to cigarette smoke via active and passive smoking increases blood Cd by an average of 0.01 micrograms% over the background (UNS). We conclude that exposure to cigarette smoke is a confounder to be taken into account when carrying out epidemiological studies and surveillance programs on workers exposed to Cd at work.

Industrial accidents are related to relative body weight : the Israeli CORDIS study

OBJECTIVES: The accident rate might be influenced by intrinsic characteristics of the workers, by risks inherent in the work environment, or a combination of these factors. As increased weight may be associated with sleep disturbances and fatigue, a high body mass index (BMI) might be an independent risk factor for accidents in industrial workers. METHODS: 3801 men were examined and followed up for two years for the occurrence of accidents. The objective environmental conditions were recorded and translated into a single score of ergonomic stress levels. Height and weight were recorded, as were possible confounding factors including measures of fatigue, type A personality, total night time sleep, job satisfaction, somatic complaints, smoking, and education levels. RESULTS: Both BMI and ergonomic stress levels independently predicted involvement in accidents (two or more) with those in the highest BMI quartile who worked in an environment with high ergonomic stress levels having a 4-6 times increased risk of accidents compared with those in the lowest BMI quartile who worked in an environment with low ergonomic stress levels (95% confidence interval (95% CI) 2.4-9.0, P < 0.001). Although increasing somatic complaints and a low educational level also were predictors of accidents, they did not mediate the effect of the BMI on the accident rate. Increasing age, less smoking, and decreased sleep hours were significantly associated with an increased BMI, but the association of BMI and involvement in accidents also could not be explained by those factors or the other confounders. CONCLUSIONS: BMI independently influences the accident rate. Further studies warranted to confirm these findings and to explore mechanisms supporting biological plausibility.

Summer-Winter Differences in 24 h Variability of Heart Rate:

Objective To examine possible seasonal changes in heart rate variability (HRV). Background Greater than normal mortality from cardiovascular disease (CVD) in the winter has been reported for many countries and might be partly explained by considering seasonal changes in CVD risk factors. Depression of HRV is an independent predictor of arrhythmic complications and of cardiac death, and it is also among the variables that may be affected by the season of the year. Methods We compared pairs of 24 h HRV data of 120 healthy men who were examined once in the summer and once in the winter. Multivariate analyses were performed for each dependent variable (HRV indexes) in separate statistical models with age, resting heart rate, serum level of cholesterol, cigarette smoking, body mass index, sports habits, alcohol consumption, systolic blood pressure, physical activity at work, years of education, consumption of energy, and season as the independent variables. Results Although there were no seasonal differences in mean R–R interval, all indexes of HRV were found to be lower in the summer than they were during winter. Differences and 95% confidence intervals were standard deviation (SD) of coupling intervals between normal beats 12 ms, 6–17 ms; SD of 5 min mean R–R intervals 14 ms, 8–20 ms; mean of all 5 min SD of R-R intervals 2.0 ms, 0.6–2.5 ms; proportion of adjacent R-R intervals differing by > 50 ms 1.5%, 0.6–2.5% and root mean square of the difference between successive normal intervals 3.1 ms, 1.5–4 ms. Multivariate analyses showed that HRV in the winter was less than that in the summer even after adjustment for age, serum level of cholesterol, systolic blood pressure, and body mass index. Conclusions HRV indexes of healthy men vary physiologically by season, with lowest values obtained in the winter. Since low HRV is linked to pathologic conditions, the significance of seasonal changes for those suffering from CVD and their possible contribution to the greater mortality rates in winter have to be considered.

Body Mass Index is Associated with Differential Seasonal Change in Ambulatory Blood Pressure Levels

Seasonal changes in blood pressure may be partially explained in thermoregulatory terms. We hypothesized that the seasonal variation in blood pressure is related to body mass index, due to the increased thermoregulatory requirements of leaner individuals. Ambulatory systolic and diastolic blood pressure were monitored once each in summer and winter in 101 healthy normotensive men aged 28 to 63 years. Environmental conditions and body mass index were measured. The population was divided according to quartiles of body mass index. The percentage of subjects with systolic blood pressure increases of more than 10 mm Hg from summer to winter was highest among subjects in the lowest body mass index category, and lowest among those in the highest body mass index category (35% and 8%, respectively, P < .0001). After adjusting for possible confounders, the change in mean systolic blood pressure from summer to winter was inversely associated with body mass index (beta = -0.26, P = .0149). There was no association between diastolic blood pressure change and body mass index. The increase in systolic blood pressure from summer to winter is inversely and independently associated with body mass index. Hypertension research and epidemiological blood pressure studies should take into account the interaction between season, body mass index, and blood pressure. It may also be important to assess hypertension and response to antihypertensive treatment in relation to season, particularly in lean hypertensives.

Referral to Occupational Medicine Clinics and Resumption of Employment After Myocardial Infarction

Rehabilitation after acute myocardial infarction (AMI) consists of education, exercise, and an encouragement to return to work (RTW). This study attempts to (1) determine whether the time interval between AMI and the visit at occupational medicine (OM) clinics predicts resumption of full employment, and (2) estimate the incidence of work-related recurrent AMI after RTW. We followed 216 consecutive AMI patients at a single OM clinic. The independent variables were clinical and personal data, physical workload and time between AMI, and first visit to the OM clinic. The outcome variables were full employment 24 months after the acute event and recurrent AMI during this period. Of all patients, 168 attempted RTW. Of these, 18 stopped working subsequently. Of the remaining 150 patients, 54 returned to part-time work and 96 were employed full-time after 2 years. Logistic regression indicated that a failure to resume full employment was independently associated with diabetes, older age, Q wave AMI, angina before AMI, heavy work, and a late visit to the OM clinic. For each months delay in referral to the OM clinic, there was a 30% decrease in the chance for full employment 24 months after AMI. Six (4%) of the 150 patients who resumed employment sustained a recurrent AMI, two of them while at work. A delayed referral to the OM clinic was associated with work disability after AMI. Late referrals to OM clinics should receive a more intensive and sustained rehabilitation than early referrals. Whether an earlier referral to OM clinics will result in increased RTW rates is unknown. Patients who attempted to resume employment had a 1.2% risk of a recurrent ischemic event at their workplace.

Heat stress and helicopter pilot errors.

Helicopter pilots are subjected to degrees of heat stress that under laboratory conditions result in decreased performance. However, the effect of heat stress on the frequency of helicopter pilot errors is uncertain. The purpose of this study is to determine whether there is an association between ambient heat stress and pilot error. The records of 500 helicopter accidents and incidents due to pilot error during the months May through October were selected at random. On the day of the event, ambient dry bulb and wet bulb temperatures were recorded and compared to temperature and humidity readings on 1000 days chosen at random over the same time period, after eliminating days where events occurred. There was a significant difference between the dry temperature distributions of the days with pilot error compared with the control group (chi 2 = 47.54, P < .0001). A dose-response relationship was found, with a significantly lower risk when ambient dry bulb temperatures were 25 to 29 degrees C (odds ratio, 0.6; 95% confidence interval, 0.5 to 0.8, P < .0001), an increased risk of 1.6 (1.3 to 2.0, P < .0001) at 30 to 34 degrees C, and the highest risk at 35 degrees C or more (6.2, 95% confidence interval, 2.1 to 21.8, P < .0002). There is a dose-response relationship between ambient heat stress and pilot error in Israel military helicopter pilots. This is the first study outside the laboratory showing a connection between heat stress and accidents due to human error. Further studies are required to substantiate our findings and to determine whether extrapolation to other settings is warranted.

Preventing burnout: increasing professional self efficacy in primary care nurses in a Balint Group.

Nursing is reported to be a stressful occupation, and chronic stress is often associated with burnout. Many ways of reducing stress have been proposed. Of these, the Balint group method provides a forum in which health professionals can present and attempt to resolve stressful situations with clients, coworkers, or other professionals. Balint groups help health professionals improve coping with psychosocial stressors in a supporting and accepting group atmosphere. This article reports changes in professional self efficacy associated with reduced burnout in a group of 13 nurses working in community based primary care clinics. Results showed significant increases in awareness and ability cognitions after the Balint group and reduced emotional exhaustion and cognitive weariness. The ramifications of these findings are discussed.