“That ill health is a consequence of the way work is organized has generated a sizeable scientific research literature since the 1970s. Researchers in the field of occupational health and social epidemiology have developed models of psychosocial stressors that measure the complex ways in which the organization of work impacts the health of working populations. The building of a scientific knowledge base around occupational stress highlights the ways in which the “social,” particularly work organization, is related to the prevalence of both physical health problems in working populations (including cardiovascular disease and hypertension) and mental health problems (including psychological distress, anxiety, burnout, and depression). The key measures of work organization related to health include job characteristics such as job strain (the combination of high psychological demands and low decision latitude or control), social support, and effort-reward imbalance; as well as work hours, shift work, and the influence of downsizing, outsourcing, and flexible labor patterns.”
Taken from: Schnall PL, Dobson M, Rosskam E, Editors Unhealthy Work: Causes, Consequences, Cures. Baywood Publishing, 2009.
“In a review conducted in 2000, a majority of the 11 cross-sectional studies of job strain (or its components) and ABP (Ambulatory Blood Pressure) among men found a relationship between job strain and higher work ABP [56]. In the five studies where ABP measurements were also made outside of work, men with job strain also had higher non-work systolic ABP, showing that the impact of job strain on ABP occurred across the whole day and night. Of the six cross-sectional studies of job strain and ABP among women published by 2000, four showed that women with job strain had higher work systolic ABP [94]. Workers with job strain typically have about 4-8 mm Hg higher work systolic ABP than those without job strain. The only longitudinal (long-term) study of job strain and ABP, the New York City Work Site Blood Pressure Study (WSBPS), began in 1985. At the first round of data collection (Time 1), men with job strain showed increases in the size of their heart’s left ventricle, a sign of damage to the heart [95], and had higher levels of work, home, and sleep ABP, after taking into account other risk factors, such as age, race, and weight, than men without job strain [96, 97]. These findings were recently replicated by the Belgian Job Stress Project [98]. Since the study participants returned 3 years later (Time 2), had their BP measured, and completed questionnaires about their jobs, it was possible to create a measure of chronic or longer-term exposure to job strain. Men facing job strain at both Time 1 and Time 2 (longer-term exposure) had an 11-12 mm Hg higher systolic and 6-9 mm Hg higher diastolic work ABP than men not facing job strain at either time. This difference is substantial, more than twice the difference between African Americans and whites in this sample and more than the effect on BP in this study sample of aging 25 years or gaining 50 pounds in weight [99]. To give an idea of the potential benefit of leaving a situation of job strain, those men reporting job strain at Time 1 but no job strain at Time 2 showed a drop in blood pressure 5.3 mm Hg systolic ABP at work and 4.7 mm Hg systolic ABP at home [99].”
Taken from: Schnall PL, Dobson M, Rosskam E, Editors Unhealthy Work: Causes, Consequences, Cures. Baywood Publishing, 2009.
56. Belkic, K., P. A. Landsbergis, P. Schnall, et al., Psychosocial Factors: Review of the Empirical Data among Men, in The Workplace and Cardiovascular Disease Occu- pational Medicine: State of the Art Reviews, Schnall, P., K. Belkic, P. A. Landsbergis, and D. Baker (eds.), Hanley and Belfus, Philadelphia, PA, pp. 24-46, 2000.
94. Brisson, C., Women, Work and Cardiovascular Disease, in The Workplace and Cardiovascular Disease Occupational Medicine: State of the Art Reviews, Schnall, P., K. Belkic, P. A. Landsbergis, and D. E. Baker (eds.), Hanley and Belfus, Philadelphia, pp. 49-57, 2000.
95. Schnall, P. L., C. Pieper, J. E. Schwartz, et al., The Relationship between ‘Job Strain,’ Workplace Diastolic Blood Pressure, and Left Ventricular Mass Index. Results of a Case-Control Study [published erratum appears in JAMA 1992 Mar 4;267(9):1209], Journal of the American Medical Association, 263:14, pp. 1929-1935, 1990.
96. Landsbergis, P. A., P. L. Schnall, K. Warren, T. G. Pickering, and J. E. Schwartz, Association between Ambulatory Blood Pressure and Alternative Formulations of Job Strain, Scandinavian Journal of Work, Environment and Health, 20:5, pp. 349-363, 1994.
97. Schnall, P. L., J. E. Schwartz, P. A. Landsbergis, K. Warren, and T. G. Pickering, Relation between Job Strain, Alcohol, and Ambulatory Blood Pressure, Hypertension, 19, pp. 488-494, 1992.
98. Clays, E., F. Leynen, D. De Bacquer, et al., High Job Strain and Ambulatory Blood Pressure in Middle-Aged Men and Women from the Belgian Job Stress Study, Journal of Occupational and Environmental Medicine, 49, pp. 360-367, 2007.
99. Schnall, P. L., P. A. Landsbergis, J. Schwartz, K. Warren, and T. G. Pickering, A Longitudinal Study of Job Strain and Ambulatory Blood Pressure: Results from a Three-Year Follow-Up, Psychosomatic Medicine, 60, pp. 697-706, 1998.
DIABETES & OBESITY:
“Studies show that diabetes impacts employment, absenteeism, and work productivity [55, 76] and that obesity is strongly associated with absenteeism and other health risks [47]. Moreover, obesity also may act as a co-risk factor for the development of a number of work-related diseases, such as occupational asthma and cardiovascular disease. It is theorized that obesity may modify the worker’s response to occupational stress, immune response to chemical exposures, and risk of disease from occupational neurotoxins [47].
Work-induced risk factors, such as long work hours and sedentary work, are contributing to the epidemic of obesity, one which will be far greater than the epidemic of the present, while the changing ethnic fabric of the population in the coming decades will no doubt exacerbate significantly the epidemic of diabetes. The anticipated and alarming growth in the epidemics of obesity and diabetes, influenced by both changing patterns of work and ethnicity, will act like a tsunami, contributing to both hypertension and cardiovascular diseases which will, in turn, have tremendous impacts at both the societal and individual levels. Given the poor efforts toward preventing and treating the present epidemics of obesity and diabetes, there is little reason to think that status quo measures will be more successful in addressing epidemics of a far greater scale. Prevention is, and will continue to be, critical.”
Taken from: Schnall PL, Dobson M, Rosskam E, Editors Unhealthy Work: Causes, Consequences, Cures. Baywood Publishing, 2009.
47. Schulte, P. A., G. R. Wagner, A. Ostry, et al., Work, Obesity, and Occupational Safety and Health, 97:3, pp. 428-436, 2007.
55. Stewart, W. F., J. A. Ricci, E. Chee, A. G. Hirsch, and N. A. Brandenburg, Lost Productive Time and Costs Due to Diabetes and Diabetic Neuropathic Pain in the US Workforce, Journal of Occupational and Environmental Medicine, 49:6, pp. 672-679,
2007.
76. Tunceli, K., C. J. Bradley, D. Nerenz, L. K. Williams, M. Pladevall, and J. Elston Lafata, The Impact of Diabetes on Employment and Work Productivity, Diabetes Care, 28:11, pp. 2662-2667, 2005.
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There are several methods used to calculate distribution of body fat:
1. Waist-hip ratios are valuable in clinical use as they are easily measured and analyzed. It is the method used to primarily measure abdominal and visceral fat, as more fat is located in the waist area and less in the hip area. Waist refers to the circumference of the body at the level of the umbilicus (belly button) and hip refers to circumference of the body around the trochanter (at the level of the hip). The normal waist-hip ratio for men is 1.0, and for women is 0.8. Individuals with ratios above the normal are considered upper-body obese.
2. Body Mass Index (BMI) is commonly used to compare subjects in a research study. It can be calculated using the formula, weight (kg)/height(m)2. The average male BMI is 25 (considered normal). A body mass index of 28 for males is considered overweight, while 31 depicts obesity. For females, the numbers are slightly smaller: 21 is normal, 25 is overweight, and 29 is obese.
Both waist-hip ratios and BMI are good predictors of hypertension.
3. Skin fold thickness is another measure of percentage of body fat and distribution of body fat. Skinfolds of the subscapular and triceps among others are measured to calculate subcutaneous fat. An analysis reported in the Health and Nutrition Examination Survey (HANES) suggests that centrally located fat measured by the subscapular skinfolds are better predictors of hypertension than the triceps skinfold. In addition, CT and MR scans measure subcutaneous and visceral fat. Other determinations of fat have been accomplished by underwater weighing and fat biopsy.
Genetics (data from studies of twins), overeating, smoking cessation, alcohol consumption, lack of exercise, change in life-style, energy intake vs. energy expenditure (consider resting metabolic expenditure), environmental factors, salt/potassium retention, major depression/anxiety/other psychological, medical illness, medications, during and after pregnancy, cultural (perceptions on obesity), socioeconomic factors.
Fatigue (especially with exercise), shortness of breath, decreased energy, palpitations, irregular heart beat, edema (especially swelling of the feet and legs), sleep apnea (Pickwickian syndrome), respiratory obstruction (for obesity to cause sleep apnea and repitory obstruction it must be severe).
Hypertension (increased blood pressure), coronary heart disease, predisposition to diabetes, hyperlipidemia (increased cholesterol level), metabolic abnormalities, increased risk for gallbladder disease, gout, some types of cancer, development of osteoarthritis of the weight-bearing joints.
Being overweight is a significant risk factor for the development of hypertension. The prevalence of hypertension in the U.S. is greatly increased by the fact that one quarter to one half of all adults (prevalence varies by study) are overweight. Although the association between higher body fat and blood pressure has been recognized for years, recent studies have discovered a 50% to 300% higher incidence of hypertension among adults who consider themselves overweight compared to those classified as normal weight. Similar findings are revealed from studies involving children and young adults, in which the correlation coefficient between weight and blood pressure has been observed to be as high as 0.4. Two proposed mechanisms underlying this correlation are the stimulation of sodium retention and increased catecholamine release, which are results of increased sodium sensitivity and hyperinsulinemia. Age, gender, and race are modifiers/confounders of obesity, and should be considered when studying preventive interventions. Hypertension and obesity treatment are necessary to avoid potential morbidity and mortality from coronary heart disease or stroke.
1. Nonpharmacologic treatment of mild hypertension could include dietary salt restriction (NaCl), dietary potassium supplementation, and/or weight reduction, physical exercise, meditation and other therapies (e.g., biofeedback).
Salt restriction is recommended for those individuals with hypertension who are “salt-sensitive,” or are prone to retaining sodium, gaining weight, and developing a rise in blood pressure as a result of a high-salt diet. Those who are “salt-resistant,” on the other hand, do not experience change in weight or blood pressure on either high or low-salt diets. For the salt-sensitive population, extreme amounts of salt restriction are not needed for improvement of blood pressure. Several studies have shown that diets containing 1600 to 2300 mg of sodium per day are associated with average reductions in systolic pressure of -9 to -15 mm Hg and in diastolic pressure of -7 to -16 mm Hg in salt sensitive individuals. Thus, salt restriction in this range is recommended in the dietary management of most individuals with hypertension.
The blood pressure lowering effect of supplemental potassium may be greater in patients receiving a high-salt diet. The amount of dietary potassium required to obtain this effect, however, is not easily obtained.
Six controlled studies of patients with hypertension concluded that short-term weight loss is usually associated with a reduction of blood pressure. In patients who experienced a weight loss of 11.7 kg (~25.7 lb.), an average blood pressure reduction of -20.7/-12.7 mm Hg was recorded. A similar study found that a decrease in blood pressure of -2.5/-1.5 mm Hg per kilogram of reduction of weight, further demonstrated a significant correlation between weight change and blood pressure change.
Physical exercise is a critical component of any program to reduce and control weight on a long term basis. See the following website for additional information on exercise (link under construction).
2. Pharmacologic treatment of hypertension is essential when the disease has advanced to a more chronic phase. The most common forms of treatment are diuretics, beta blockers, and calcium channel blockers. Controversial and expensive alternatives to dieting in treating obesity are surgery and/or liposuction, which should be used only as a last alternative. Future research for treating obesity includes inhibiting gastric emptying, stimulating lipid oxidation, increasing thermogenesis, and blocking carbohydrate or lipid digestion.
Dietary change, exercise, behavior modification, drug treatment, and/or a combination of these interventions. Limitations on dietary intake, the most common method used for weight loss, can last several weeks to months, depending on individual need and motivation. Altering dietary proportions of fat, protein, carbohydrate, using macronutrient substitutes, and taking vitamins, diet supplements or meal replacements are all techniques to modify food intake. In addition, low calorie diets (1000-1500 calories/day) and very low calorie diets (800 or less calories/day) help patients lose weight. Physician supervision is recommended, however, to prevent adverse side effects, such as excessive loss of lean body mass, particularly in individuals with chronic health problems such as hypertension. Eating and chewing food slowly will send nervous system signals to the stomach that it is “full,” and will assist in weight loss and deter weight gain after dieting, especially if a healthy diet is selected. Exercising is another way to lose weight, although the average weight loss from exercise alone is 4-7 lb. (8.8-15.4 kg.), greater weight loss is possible. Regular workouts are advantageous to increasing high-density lipoprotein cholesterol and lean body mass, and diminishing rapid weight gain. Along with changing eating patterns and increasing physical activity, behavior modification produces gradual change.
Four steps to behavior modification include: 1) identifying eating or related life-style behaviors to be modified, 2) setting specific behavioral goals, 3) modifying determinants of the behavior to be changed, and 4) reinforcing the desired behavior. Drug treatment is another method used for weight loss. With prolonged use, however, loss of weight is minimized as it reaches a plateau. Some side effects are common. An example of an over the counter drug is phenylpropanolamine which, however, has a negative effect on blood pressure, and little is known about it’s long-term side-effects.
On average, 1-1.5 lb./week (~.45-.68 kg./week) are lost by combining excercise, reducing dietary intake, and behavior modification. Successful weight loss involves a combination of these methods that are suitable to the individual in a slow and steady process. Remember who won the race.
References:
1. Fraser G. Preventive Cardiology. Oxford University Press, New York, 1986, pp. 134-5.
2. Gerber L, Schnall P, and Pickering T. Body fat and its distribution in relation to casual and ambulatory blood pressure. Endocrinology and Metabolism Clinics of North America, Sept. 1995, 24(3).
3. Hurst JW, Logue RB, Rackley CE, et. al. The Heart, Sixth Edition. McGraw-Hill Book Company, New York, 1986, pp. 1078-9.
4. Methods for voluntary weight loss and control. NIH Technology Assessment Statement, 1992 March 30-April 1,(10).
5. Moore T and McKnight J. Dietary factors and blood pressure regulation. Endocrinology and Metabolism Clinics of North America, Sept. 1995, 24(3).
“Cardiovascular disease (CVD), including heart disease and stroke, is the major cause of disease and death in the industrialized world and is projected to become the most common cause of death worldwide by the year 2020. CVD and hypertension (high blood pressure) appear to be epidemics of recent historical origin, developing along with industrialization and urbanization, and now increasing in the context of economic globalization. Modern medicine focuses on individual risk factors for hypertension and CVD, often ignoring the important role that social factors, such as social class, work organization, and work-related psychosocial stressors, play in the development of hypertension and CVD. Social factors need to be fully integrated into explanations of disease development.
Increased CVD risk has been associated with job characteristics such as long work hours, shift work, “job strain” (a combination of high psychological work demands and low job decision latitude, or job control), high job efforts combined with low job rewards, injustice, job insecurity, and work that involves maintaining a high level of vigilance in order to avoid disaster, such as loss of human life. Sources of stress on the job (job stressors), besides acting directly on the human nervous system, may increase the risk of hypertension and CVD through a variety of mechanisms, including inhibiting healthy behaviors such as smoking cessation and exercise, or by producing psychological distress, such as anxiety and depression. Public health strategies are needed to address the pandemic of CVD, including worksite surveillance, development of the field of occupational cardiology, integration of health promotion with occupational health approaches, and job redesign.”*
*Taken from: Schnall PL, Dobson M, Rosskam E, Editors Unhealthy Work: Causes, Consequences, Cures. Baywood Publishing, 2009.
When stress becomes a prolonged or chronic experience, it can result in psychological distress, including generalized anxiety, burnout, and depressive symptoms. Work-related stress can also be a factor in exacerbating pre-existing mental illnesses and may even precipitate clinically diagnosable symptoms of depression. A growing body of empirical evidence in the occupational health field is making connections between the way work is organized and burnout, as well as more long-term adverse psychological health outcomes such as chronic anxiety and clinical depression. In turn, psychological distress has been linked to absenteeism, “presenteeism,” job dissatisfaction, and turnover [1-3]. The wear and tear of long working hours and physical harm to the body motivated the social reforms of the early years of industrialization, including the 8-hour work day and the 40-hour work week. Laws were established to allow for physical and mental recovery time from work; they are now seriously compromised to the detriment of the psychological (and physical) well-being of workers. Not only should the psychological effects of work stress be a concern for individuals, but also for employers, labor unions, and society as a whole.
‘Musculoskeletal disorders include a wide range of inflammatory and degenerative conditions affecting the muscles, tendons, ligaments, joints, peripheral nerves, and supporting blood vessels. These include clinical syndromes such as tendon inflammations and related conditions (tenosynovitis, epicondylitis, bursitis), nerve compression disorders (carpal tunnel syndrome, sciatica), and osteoarthrosis, as well as less well standardized conditions such as myalgia, low back pain and other regional pain syndromes not attributable to known pathology. Body regions most commonly involved are the low back, neck, shoulder, forearm, and hand, although recently the lower extremity has received more attention.
Musculoskeletal disorders (MSDs) are widespread in many countries, with substantial costs and impact on quality of life. Although not uniquely caused by work, they constitute a major proportion of all registered and/or compensable work-related diseases in many countries. Accurate data on the incidence and prevalence of musculoskeletal disorders are difficult to obtain, and official statistics are difficult to compare across countries. Nevertheless, MSDs are the single largest category of work-related illness, representing a third or more of all registered occupational diseases in the United States, the Nordic countries, and Japan [6,49,54,73]. Numerous surveys of working populations have reported upper extremity symptom prevalences of 20 to 30% or even higher. In the United States, Canada, Finland, Sweden, and England, musculoskeletal disorders cause more work absenteeism or disability than any other group of diseases [4,15,39,54,63,65].
MSDs occur in certain industries and occupations with rates up to three or four times higher than the overall frequency. High-risk sectors include nursing facilities; air transportation; mining; food processing; leather tanning; and heavy and light manufacturing (vehicles, furniture, appliances, electrical and electronic products, textiles, apparel and shoes) [6]. Upper extremity musculoskeletal disorders are also highly prevalent in manual-intensive occupations, such as clerical work, postal service, cleaning, industrial inspection and packaging [63]. Back and lower limb disorders occur disproportionately among truck drivers, warehouse workers, airplane baggage handlers, construction trades, nurses, nursing aides and other patient-care workers, and operators of cranes and other large vehi- cles [54].