Work patterns, sleeping hours and excess weight in commercial drivers.

BACKGROUND: Work and sleep patterns for commercial motor vehicle (CMV) drivers often include long working hours, shift work and diminished sleep duration and quality, which have been linked to overweight, obesity and other problems. AIMS: To explore possible connections between work, sleep and obesity among CMV drivers. METHODS: Survey and anthropometric data were collected from male long-haul CMV drivers in central North Carolina, USA, over a period of 6 months. Drivers' body mass index (BMI) was used as a measure of total body obesity and sagittal abdominal diameter (SAD) as a measure of central adiposity. RESULTS: Among the 260 study subjects, mean BMI was 33.1 (64% were obese or morbidly obese) and mean SAD was 32.3cm, classifying 89% of drivers as being at high or very high cardiometabolic risk. About 83% of drivers worked an irregular daily schedule, 64% worked irregular total daily hours, 32% worked irregular days of the week and 46% reported getting <7h of sleep during work nights. Significant predictors of BMI included the number of hours worked daily (P < 0.05) and the age (P < 0.01) of the driver, while age was also a significant predictor for SAD (P < 0.05). Significant predictors of sleep quality included the extent of shift work (P < 0.05) and sleep duration (P < 0.001). CONCLUSIONS: Work and sleep configurations appear to affect the weight status of CMV drivers. Shift work and sleep duration are both associated with the weight status of CMV drivers, and both appear to function as indicators of their sleep quality.

Increased cardiac BNP expression associated with myocardial ischemia.

Congestive heart failure is accompanied by increased cardiac brain natriuretic peptide (BNP) gene expression with elevated plasma concentrations of BNP and its precursor, proBNP. We investigated if myocardial ischemia in the absence of overt heart failure may be another mechanism for increased myocardial BNP expression. The BNP expression was examined in hypoxic myocardium of patients undergoing coronary bypass grafting surgery, in patients with coronary artery disease and normal left ventricular function undergoing percutaneous transluminal intervention therapy, and in heart failure patients without coronary artery disease. BNP mRNA was quantified by real-time PCR, and plasma BNP and proBNP concentrations were measured with radioimmunoassays. Quantitative analysis of BNP mRNA in atrial and ventricular biopsies from coronary bypass grafting patients revealed close associations of plasma BNP and proBNP concentrations to ventricular, but not atrial, BNP mRNA levels. Plasma BNP and proBNP concentrations were markedly increased in patients with coronary artery disease but without concomitant left ventricular dysfunction. These results are compatible with the notion that myocardial ischemia, even in the absence of left ventricular dysfunction, augments cardiac BNP gene expression and increases plasma BNP and proBNP concentrations. Thus, elevated BNP and proBNP concentrations do not necessarily reflect heart failure but may also result from cardiac ischemia.

Middle cerebral artery flow velocity and blood flow during exercise and muscle ischemia in humans.

Changes in middle cerebral artery flow velocity (Vmean), measured by transcranial Doppler ultrasound, were used to determine whether increases in mean arterial pressure (MAP) or brain activation enhance cerebral perfusion during exercise. We also evaluated the role of "central command," mechanoreceptors, and/or muscle "metaboreceptors" on cerebral perfusion. Ten healthy subjects performed two levels of dynamic exercise corresponding to a heart rate of 110 (range 89-134) and 148 (129-170) beats/min, respectively, and exhaustive one-legged static knee extension. Measurements were continued during 2-2.5 min of muscle ischemia. MAP increased similarly during static [114 (102-133) mmHg] and heavy dynamic exercise [121 (104-136) mmHg] and increased during muscle ischemia after dynamic exercise. During heavy dynamic exercise, Vmean increased 24% (10-47%; P less than 0.01) over approximately 3 min despite constant arterial carbon dioxide tension. In contrast, static exercise with a higher rate of perceived exertion [18 (13-20) vs. 15 (12-18) units; P less than 0.01] was associated with no significant change in Vmean. Muscle ischemia after exercise was not associated with an elevation in Vmean, and it did not provoke an increase in Vmean after static exercise. Changes in Vmean during exercise were similar to those recorded with the initial slope index of the 133Xe clearance method. The data show that middle cerebral artery mean flow velocity reflects changes in cerebral perfusion during exercise. Furthermore, they support the hypothesis that cerebral perfusion during exercise reflects an increase in brain activation that is independent of MAP, central command, and muscle metaboreceptors but is likely to depend on influence of mechanoreceptors.

Unoperated aortic aneurysm: a survey of 170 patients.

From 1984 to 1993, 1,053 patients were admitted with aortic aneurysm (AA) and 170 (15%) were not operated on. The most frequent reason for nonoperative management was presumed technical inoperability. Survivals for patients with thoracic, thoracoabdominal, and abdominal AA were comparable. No significant differences in survival for patients with dissecting and nondissecting AA were detected. In all, 132 patients (78%) died and 78 (59%) of them died of rupture. Mean time to rupture was 1,300 +/- 8 days. Cumulative 5-year hazard of rupture for the dissecting AA was twice that of the nondissecting (p < 0.001). Hazards of rupture for type A and B dissections were comparable. Diameter of 6 cm or greater was associated with a fivefold increase in cumulative hazard of rupture (p < 0.001). Diameter of AA, incidence of renal failure, and arterial hypertension were predictive of mortality, whereas the first two variables were predictive of rupture. In conclusion, because the majority of patients in all subgroups died of rupture, all patients should be recognized as candidates for surgical treatment. Present data justify aggressive approach to the patient with AA 6 cm or more in diameter and type A dissections. The results suggest that type B dissections may have a more favorable course if operated on, but a prospective, randomized study is necessary to confirm this observation. We believe that older patients and those with a small aneurysm may benefit from early, elective operation.

Changes of nucleotide content in human and rat heart during cardiac surgery and ischemia.

The influence of ischemia on purine nucleotide and their catabolite concentration in human myocardium was investigated during surgery of acquired and congenital heart defects. This was compared with the influence of ischemia on rat heart. Concentrations of adenine and guanine nucleotides and their catabolites were measured in the extracts of heart biopsies taken at the onset of ischemia and at the time of reperfusion. The content of myocardial ATP in human heart decreased from the initial value of 22.3 +/- 1.1 to 14.6 +/- 1.5 nmol/mg protein and total adenine nucleotide pool decreased from 34.2 +/- 1.8 to 27.6 +/- 1.5 nmol/mg protein during the operation. Significant increases in myocardial concentrations of purine catabolites were also observed with the most prominent rise in inosine from below 0.5 at the onset of the ischemia to 3.0 +/- 0.5 nmol/mg protein at the time of reperfusion. A positive correlation was demonstrated between the concentration of purine catabolites in the heart at the end of ischemia with the decrease of both ATP and the total nucleotide pool. An interesting metabolic specificity of the ischemic human heart appeared to be only a small accumulation of inosine monophosphate (IMP). The increase of IMP in the rat heart after ischemia was several-fold higher. Thus, cardiac surgery of congenital and acquired heart defects was associated with a significant decrease in myocardial adenylate pool and a single biopsy collected at the end of ischemia seems to be sufficient to evaluate the extent of this metabolic and possibly functional impairment of the heart.

Adenylate degradation products release from the human myocardium during open heart surgery.

Purine degradation products were determined in the human heart coronary sinus effluent collected from patients undergoing cardiac surgery, during infusion of a cardioplegic solution. At the onset of cardiopulmonary bypass the mean concentrations of adenosine, inosine and hypoxanthine were 0.1, 0.5 and 0.3 mumol/l, respectively. Ischemic arrest leads to a progressive increase of the respective levels to 1.4 17.8 and 9.6 mumol/l after 60-80 min of ischemia. Xanthine concentration was undetectable (less than 0.2 mumol/l) throughout. A substantial urate release (20 mumol/l) was observed which decreased with the duration of ischemia. Xanthine oxidoreductase activity in human myocardium was found to be below the detection limit (0.1 mU/g wet weight). Thus, urate release represented wash out of urate which had accumulated in the tissue.

Changes in superior mesenteric artery Doppler waveform during reduction of cardiac stroke volume and hypotension.

Influence of stroke volume reduction and hypotension on the superior mesenteric artery (SMA) Doppler waveform was evaluated during head-up tilt-induced central hypovolemia in 11 healthy volunteers. During normotensive reduction in stroke volume, peak systolic velocity (pV), mean velocity, pulsatility and resistivity indices decreased, while diastolic velocities increased. During hypotension, a further decrease in pV was accompanied by maintained elevation of diastolic velocities and reduction in pulsatility and resistivity indices. Power of backscattered Doppler wave was elevated throughout the hypovolemia. Alterations in pV and pulsatility indices were closely related to changes in stroke volume, and a negative correlation was found between diastolic velocities and stroke volume. regression analysis showed no significant relation between variations in velocity parameters and blood pressure. Results of the study indicate that alterations in stroke volume induce consequential changes in the SMA Doppler waveform. These changes originate from both direct influence of stroke volume and/or pressure on blood flow velocity, and alterations in SMA peripheral resistance that follow variations in stroke volume. Presented interdependencies should be taken into consideration while studying mesenteric physiology with the use of Doppler technique and while interpreting the duplex results in patients suffering from diseases that may influence flow velocity and mimic or obscure Doppler effects of the SMA stenosis.

Isolated avulsion of the popliteus tendon.

We report four patients with a mean age of 17 years (14 to 22) with external rotation injuries of the knee in slight flexion. Radiographs showed a small fragment in the area of the lateral femoral condyle. At operation, the fragment, consisting of the femoral insertion of the popliteus, was anatomically reduced and fixed. At a mean follow-up of 35 months all the knees had an excellent function score. An isolated lesion of the popliteus often presents as a tendon avulsion whereas major damage to the posterolateral corner of the knee involves combined ligamentous injuries. In patients with an acute haemarthrosis and lateral pain in a stable knee, the diagnosis of isolated avulsion of the popliteus tendon should be suspected. Arthroscopy with special attention to the lateral gutter is indicated. We advise anatomical reduction and fixation of the fragment to prevent possible long-term effects on other posterolateral structures.

Shape and function of the unilateral cleft nose in adolescents following modified Millard lip repair.

24 patients with unilateral clefts operated on (at age of 6 months) according to the Millard (1964) procedure were examined at an average age of 10.1 years. Nasal shape and function were evaluated. No change of nasal shape was found during the observation period. The results were superior to those attained by the author with the Tennison-Trauner (1952, 1957) procedure in 6 cases. 13 of the Millard (1964) cases are not expected to need secondary nasal correction at a later date.

Speech results of the Zürich approach in the treatment of unilateral cleft lip and palate.

The purpose of this study was to describe perceptually the speech articulation, voice quality, and velopharyngeal competency of subjects with complete unilateral cleft lip and palate treated by the Zürich approach. The mean age of the 37 subjects was 10.5 years. Although only one subject had had secondary palatal management, no subject was rated as exhibiting a severe articulation or nasality problem. Subjects were rated as exhibiting adequate to marginal velopharyngeal competency 94.5 percent of the time, and the incidence of compensatory articulation errors was low. In comparison with other studies that evaluated the two-stage palatal repair, the Zürich approach appears to give the better results. The type of initial soft palate repair is probably the significant factor which contributes to the better speech of these subjects.

Surgery for abdominal aortic aneurysms. A survey of 656 patients.

Between 1979 and 1988, 656 patients were operated upon for abdominal aortic aneurysm. Elective operation was performed in 287 patients (44%) and acute operation in 369 patients. A ruptured aneurysm was found in 218 patients (33%). Patients with arteriosclerotic heart disease, hypertension, impaired renal function or chronic pulmonary disease showed an increased perioperative mortality. Development of postoperative cardiac and renal complications could not be related to previous cardiac or renal diseases. The major postoperative complications were renal failure in 81 patients (12%), pulmonary insufficiency in 77 patients (11%) and cardiac complications in 96 patients (13%). Failure of one or more organs occurred in 153 patients (23%) and the mortality rate for patients with multiorgan failure was 68%. Complications leading to reoperation occurred in 93 patients (14%). The perioperative mortality was 18.8%. The mortality for elective cases was 4.8%, for symptomatic cases 17.2% and 37% for ruptured aneurysms. The five-year survival rate was 48% for ruptured aneurysms, 70% for symptomatic cases and 75% for elective cases. After six months the life expectancy in these three groups of patients were identical and comparable to the expected survival for a sex and age matched control population.

The influence of significant others on attitudes, subjective norms and intentions regarding dietary supplement use among adolescent athletes.

Dietary supplement use has increased significantly over the past decade. The use of supplements among adolescents seems to be influenced by their beliefs and attitudes. The influence of coaches, parents, and athletic trainers also may be important. The purpose of this study was (1) to determine whether attitudes are a better predictor of adolescents' intentions to use dietary supplements than are subjective norms, and (2) to assess the influence of significant others (coaches, parents, and trainers) on attitudes, subjective norms, and intentions among adolescent athletes. Adolescents (N = 1,626) who were enrolled in grades six through twelve in nine public schools completed a self-report questionnaire that measured attitudes, subjective norms, and intentions regarding dietary supplement use. Results indicated that attitudes were a better predictor of intentions to use dietary supplements than were subjective norms. It was also found that trainers had more influence on the attitudes, subjective norms, and intentions of adolescents regarding supplement use than did parents and coaches. Implications for prevention are addressed.

Early orthopaedic stabilization of the praemaxilla in complete bilateral cleft lip and palate in combination with the Celesnik lip repair.

Co-ordination of maxillary orthopaedics with two-stage lip surgery according to the Celesnik principle for complete BCLP is described, and the results of the procedure are analyzed at the 10 to 15 year age level. Taking advantage of the effects of growth within the first 6 to 8 months of the patient's life, orthopaedics and concomitant surgery achieve a considerable degree of alignment and stabilization of the praemaxilla within the alveolar arch without reverting to any active orthopaedic retrusion. Around age 10 the praemaxilla has assumed a normal sagittal position relative to the anterior cranial base. Due to relatively short and retropositioned mandibles all cases in the sample investigated display rather receding 'Class II type' profiles in early adolescence.

Associations between academic performance of division 1 college athletes and their perceptions of the effects of anabolic steroids.

Data on the relationship between academic performance (grade point average) of college athletes and their perceptions of the effects of anabolic steroids on their sport and their performance were collected from Division 1 athletes (N = 1,638) representing 12 varsity sports chosen from five universities nationwide. The response rate was 74%. Analysis yielded differences between athletes with high and low GPAs in perceptions of the effects of anabolic steroids. The lower the GPA, the less likely the athletes were to believe that anabolic steroids are a threat to health, are a problem in their sport, and are addictive. Also, they were more likely to believe that anabolic steroids enhance performance.

Proprioceptive responses under rising and falling BACs: a test of the Mellanby effect.

This study examined proprioceptive responses under equivalent rising and falling blood alcohol concentrations (BAC), using a repeated-measures design. Seven volunteer subjects, 21 to 35 years of age, participated in the study. After alcohol consumption, BAC readings were obtained every 5 minutes, and the proprioceptive responses were measured at the following BAC levels (in %): 0 (baseline), rising 0.05, 0.075, 0.1, falling 0.075, and 0.05. The analysis focused on the comparisons of these measures at the equivalent rising and falling 0.05% and at the 0.075% BACs. Results showed that the proprioceptive response was less accurate during the rising than the falling BACs.

Changes in body size of elite high school football players: 1963-1989.

An examination of the heights and weights of members of the Parade Magazine's High School All-American Football Teams from 1963-1971 indicates no significant changes in the Body Mass Index of these elite athletes whereas an increased pattern in Body Mass Index was noted within this group from 1972-1989. The large increases in Body Mass Index after 1971 among the All-American high school football players raise interesting research questions; in particular, what portion of these gains can be attributed to improved nutrition and training techniques and what portion is the result of use of performance enhancing drugs such as anabolic steroids?

Physiological sensations of initial smoking in the development of regular smoking behavior.

This study examined the relationships between adolescents' physiological sensations of smoking during initiation and early experience. For a national sample of a birth cohort of 2,043 adolescents, ages 15 to 22 years at the follow-up, variables of interest included measures of smoking behavior and physiological sensations reported from the initial smoking experience. Analysis showed that adolescents experimenting with smoking were more likely to become regular smokers over three years if they indicated that they felt relaxed, felt dizzy, did not feel sick, and did not cough during the initial smoking experience. Antismoking interventions may impede the transition to regular smoking by helping adolescents interpret the physiological sensations as negative and unhealthy.

[Hemodynamic assessment of cerebrovascular circulation using transcranial Doppler ultrasound in patients with carotid stenosis]. / Haemodynamisk vurdering af det cerebrale kredsløb med transkranial Doppler-ultralyd hos patienter med carotisstenose.

Transcranial Doppler-ultrasound (TCD) is a new non-invasive technique which renders continuous monitoring of the rate of flow in the major intracerebral arteries possible. The method appears, therefore, to be attractive for perioperative monitoring of patients submitted to operation on account of carotid stenosis. Seventeen patients were included in this preliminary investigation. These patients were submitted for thromboarterectomy of the internal carotid artery. Preoperatively the average flow rate (Vmean) in the ipsilateral medial cerebral artery measured at rest was 54 cm/second (range 34-94) as compared with 57 cm/second (range 32-86) in the contralateral medial cerebral artery. During occlusion, Vmean in the ipsilateral medial cerebral artery decreased momentarily, on an average 35% (p less than 0.001), and returned to the preoperative level after reopening of the internal carotid artery. Corresponding but no significant changes were observed in the pulsatile index. The preliminary experience suggests that TCD is scarcely useful as a diagnostic method in individual cases but that it is well suited for continuous monitoring of changes in cerebral circulating during surgery on the internal cerebral artery. Further assessment of the technique is necessary before the method can be employed routinely, mainly on account of the great interindividual scatter.

[Surgery of ruptured abdominal aortic aneurysm. Are the results compatible with the effort?]. / Operation for rumperet abdominalt aorta-aneurisme. Stoar resultaterne mål med indsatsen?

During 1979-1988 218 patients were operated on for ruptured abdominal aortic aneurysm. On admission 110 patients (50%) were in shock. Patients with a systolic blood pressure less than 100 mmHg, anuria on admission, peroperative bleeding of more than five litres and aged more than 70 years had an increased mortality. The intraoperative mortality was 15% and the postoperative mortality 21%. The perioperative mortality decreased from 45% in 1979 to 32% in 1988. The most frequent complications were renal failure and respiratory insufficiency, both were associated with a mortality of more than 50%. The five year survival was 48%. This study has revealed that patients with ruptured abdominal aortic aneurysm have an acceptable prognosis. The investigation emphasizes the importance of early diagnosis and elective operation to avoid rupture.

[Mortality and survival after surgery for abdominal aortic aneurysm. A 10-year follow-up]. / Letalitet og overlevelse efter operation for abdominalt aorta-aneurisme. En ti års opgørelse.

From 1979-1988, 656 patients were operated for abdominal aortic aneurysm. The perioperative mortality was 18%. The mortalities for elective, symptomatic and ruptured aneurysms were 5%, 17% and 38% respectively. The overall five year survival rate was 58%. In 87% of the patients one or more risk factor was found. Survival was unaffected in patients with a single risk factor, whereas patients with two or more risk factors had lower five year survival. Postoperative organ failure increased the perioperative mortality and the five year survival in patients with multiorgan failure was 20%. In view of the fact that 56% of the patients are operated on as emergencies, this study stresses the importance of early diagnosis and elective treatment.