Mental stress-induced increase in blood pressure is not related to baroreflex sensitivity in middle-aged healthy men.

The baroreflex that acts to blunt blood pressure (BP) variations through opposite variations in heart rate should limit the BP increase produced by an emotional challenge. However, relations between baroreflex sensitivity and BP reactivity induced by a psychological stress in a large group of adults have never been firmly established. In 280 healthy men, rest (10 minutes) and stress (5 minutes) BP and heart rate were recorded beat to beat by a blood pressure monitor. The mental stress was elicited by a well-standardized computerized version of a word color conflict stress test (Stroop Color Test). Rest and stress baroreflex sensitivity was assessed by the cross-spectral analysis of BP and heart rate and by the sequence method. The stress-induced increase in systolic BP (22.4+/-0.1 mm Hg) was not correlated with resting baroreflex sensitivity but was slightly correlated (r=0.2, P<0.001) with BP variability assessed either by standard deviation or by mid-frequency band spectral power. Our results suggested that a centrally mediated sympathetic stimulation overcame cardiac autonomic regulation and emphasized the role of the sympathetic vasoconstriction in the pressure response at the onset of the stressing stimulation. During the sustained sympathoexcitatory phase, the cardiac baroreflex blunts BP variations but at a lower sensitivity.

Mortality experience in a polyamide-polyester factory.

Chemical workers have become increasingly concerned about the presence of carcinogens in their occupational environment. As a result, a number of studies of excess cancer mortality have been undertaken in groups of workers with well-characterized exposures. This paper reports the results of one such study carried out in a polyamide-polyester factory in France. A retrospective cohort design was chosen to evaluate the effect of exposure to phthalates, nickel catalyzers, and other chemicals in the work environment. Only a slight excess of cancers, marginally related to exposure category yet not significantly related to length of exposure, was found. The cohort, however, was young but stable, and a continued follow-up is therefore both feasible and justifiable, since it is likely to yield important information about the potential hazards associated with the tergal polymer industry.

[Professional stress and blood pressure reactivity to stress do not predict blood pressure at 5 years]. / Le stress professionnel et la réactivité pressionnelle au stress ne prédisent pas la pression artérielle à 5 ans.

High job strain has been reported to be associated with higher blood pressure. Job strain could lead to hypertension if individual perception of stress or cardiovascular reactivity to stress are high. We report the results of the first five-year follow up study, which aimed to assess the respective influences of perception of professional strain and cardiovascular reactivity to a mental stress test on BP. A cohort of 292 healthy subjects (mean +/- SEM, 38 +/- 1 years) was followed for progression to hypertension outcome which was defined as an increase in SBP or DBP higher than 7 mmHg or a DBP higher than 95 mmHg during the follow-up. The high strain (HS) group representing 20.9% of the subjects was compared with the remaining subjects (NHS). Similarly the 20.9% subjects with the highest BP stress reactivity (HR) were compared with the remaining subjects (NHR). The Kaplan-Meier survival estimates revealed that neither high job strain, nor high stress reactivity, increased incidence of progression to hypertension. Age, alcohol, salt diet, BMI, and occupation did not interfere with our results. In conclusion, high stress cardiovascular reactivity and high job strain do not appear to be major risk markers for future high BP in healthy young adults. Stress could be associated with high BP at a short term and could explain high blood pressure in a long run only in stress-sensible subjects.

[Biological and clinical prevalence of pollinosis caused by ragweeds of the upper valley of the Rhône corridor]. / Prévalence biologique et clinique de la pollinose due aux ambroisies dans la vallée supérieure du couloir rhodanien.

An epidemiological study of ragweed allergy was conducted on 646 employees belonging to 6 factories located in the Rhone valley south of the city of Lyon. Information on seasonal evocative clinical symptoms was obtained through a self-administered questionnaire. Biological prevalence was assessed by measuring anti-ragweed IgE specific antibodies. Measurements were performed by immunoenzymatic assay (W1 Phadezym RAST from Pharmacia). 34 (5,4%) subjects had evocative symptoms whereas 37 (5,9%) had increased specific IgE. Persons with the highest IgE levels were symptomatic. Concordance between symptoms and biology was 35% (12/34). Results indicate that sensitization level varies according to the location of the factory and people's residence, the risk to become allergic being of 10% in the most exposed population. This data emphasize the need to promote anti-ragweed eradication policy.

Perceived job stress but not individual cardiovascular reactivity to stress is related to higher blood pressure at work.

Psychological stress has been reported to be related to higher blood pressure (BP) and unfavorable cardiovascular profile. However, because of the complexity of personal stress management, a multilevel stress measurement strategy is needed. The aim of this cross-sectional study was to analyze the respective influences of the subjective perception of professional strain (high demand and low latitude) and cardiovascular reactivity to a stress test (Stroop stress test) on BP. Worksite BP was measured in 303 healthy normotensive subjects, 18 to 55 years of age, who worked in the same chemical company. In a subset of 70 randomly selected subjects, 24-hour ambulatory BP was performed to assess BP during working hours. The 20% of subjects who reported the highest job strain (high-strain group) or the highest BP stress reactivity (high-responder group) were compared with the remaining subjects (80%) (non-high-strain or low-responder groups). Subjects who submitted to the highest job strain had significantly higher ambulatory diastolic BP (4.5 mm Hg, P=0.015) during only working hours, whereas BP was similar during the remaining hours. Worksite BP and stress cardiovascular reactivity were similar between job strain groups. BP stress reactivity did not influence worksite and ambulatory BP. Spontaneous BP variability assessed by standard deviation and spectral analysis was equivalent between complementary groups. Prevalence of microalbuminuria was significantly higher in the high-responder group (8.2% versus 2.5% in low responders) and only slightly higher in the high-strain group (6.2% versus 3.2% in non-high strain). Potential confounding factors, such as age, gender, alcohol consumption, salt intake, body mass index, and occupation, which were equivalent between groups, did not interfere with our results. Our study quantifies high-professional strain effects on BP levels that appear to be higher only during the working period and to be independent from spontaneous BP variability and stress BP reactivity.

Mortality of a cohort in a polyamide-polyester factory in Lyon: a further follow up.

In 1981-2 a retrospective study was undertaken in a polyamide-polyester factory in Lyon, France, to evaluate the effect of exposure to phthalates, nickel catalysers, and other chemicals in the work environment. The present paper reports the results of the follow up of this cohort up to July 1986. A slightly increased risk of cancers, in particular of the lung (44 cases), marginally related to exposure category but not significantly related to duration of exposure was found. The excess of skin cancers noted previously has disappeared, whereas an excess of cases of bladder cancer (based on seven cases) may be noted, mainly among nylon workers. The cohort is still young, however, and a continued follow up is likely to yield important information about the potential hazards associated with the nylon and tergal polymer industry.