PROFORMA FOR REGISTRATION OF SUBJECT FOR DISSERTATION
NAME OF THE CANDIDATE AND ADDRESS.
PABBA LAKSHMI PRIYA
C/O: VIJAY KUMAR B
#267, 12th MAIN, 5th CROSS,
HSRLAY-OUT, SECTOR 5
NAME OF THE INSTITUTION
THE OXFORD COLLEGE OF PHYSIOTHERAPY,
COURSE OF THE STUDY AND SUBJECT
MASTER OF PHYSIOTHERAPY (CARDIO-RESPIRATORY DISORDERS)
DATE OF THE ADMISSION
7th APRIL 2012
TITLE OF THE STUDY:
“A STUDY TO FIND OUT CARDIOVASCULAR RISK IN INDIAN BUS DRIVERS BY MEASURING THEIR WAIST TO HEIGHT RATIO”
BRIEF RESUME OF THE INTENDED WORK
A variety of anthropometric indices have been used as a proxy for total fat or abdominal fat to assess risk for diseases, particularly cardiovascular diseases and diabetes. The most widely recognized is the Body mass index (BMI). Although this measure is correlated with total body fat, it does not distinguish fat from muscle or between different body fat distributions 1
In the mid-20th century it was first observed that individuals with a central fat (android shape) distribution were at greater health risk than those with peripheral fat (gynoid shape) 2, 3.It has only been accepted in the last two decades that health risks (predominantly CV and diabetes) can be determined as much by the relative distribution of the excess fat as by its total amount.
The use of imaging techniques such as computed tomography (CT) 4 and MRI 1, 5 indicated that the ‘unhealthy apple shape’ is associated with a preferential deposition of fat in the internal, visceral fat depots rather than the external, subcutaneous fat depots, this fat distribution being characteristic of the more ‘healthy pear shape 4.
An attempt to assess relative fat distribution was made with the ratio of waist circumference (WC) to hip circumference. This was shown to be a good predictor of health risk and was popular for many years6. However, although very useful for risk assessment, waist-to-hip ratio is not helpful in practical risk management because both waist and hip can decrease with weight reduction and so the ratio sometimes changes very little.
It was not until the end of the last century (1995) that Waist circumference by
itself was proposed as an alternative proxy for central or abdominal obesity 7.
Waist circumference is strongly correlated with abdominal fat measures from
advanced imaging techniques, and thought to represent fat stored in visceral depots. However waist circumference may over- and under-evaluate risk for tall and short individuals with similar WC.
At about the same time, several researchers independently proposed the waist-to-height ratio (WHtR) as another proxy for central obesity, correcting the Waist circumference for the height of the individual 8-12. Similar to Waist circumference, Waist to height has been strongly correlated with abdominal fat measured using imaging techniques 1,36.
Other devices-such as measuring skinfold thickness, 13bio-impedance analysis45 and near infra–red spectroscopy61—are available and relatively inexpensive, but they have not always been completely validated and their reliability and sensitivity in less than fully standardized conditions is questionable62.In the absence of a technological solution, therefore, the emphasis has been on anthropometric measures of body mass and body-fat distribution
If an anthropometric index is to be used in a public health context and be used for screening, it is invariably useful to invoke cut-off or boundary values. The correlation of Waist circumference for height offers the advantage that it is possible that a single Waist to height boundary value may be useful in different ethnic, age and sex groups 14, while WC requires population-specific boundary values 15.
Research shows that the Waist to height, not BMI, is the most accurate assessment tool for health risk54, 55. People with the most weight around their waists are at greatest risk of diseases such as heart disease and diabetes. The most dangerous
place to carry weight is in the abdomen. Fat in the abdomen, which is associated
with a larger waist, is metabolically active and produces various hormones that can cause harmful effects, such as type-2 diabetes, elevated blood pressure46, and altered lipid (blood fat) levels53.
The best advice is, since, as a mature adult, we can't change our height, we should take special care to keep our weight and especially our abdominal girth in a
Healthy range by eating nutritiously and exercising regularly. By all means, check
Our waist measurements frequently to measure our progress, and then adjust our eating habits accordingly. And, go for regular medical checkups and discuss our
Particular situation freely with our doctor.
6.2NEED OF THE STUDY
The occupation of driving is associated with an increased risk of cardiovascular disease16, 17, 18. Studies in recent decades have demonstrated that workers in the transportation industry are at greater risk of an incorrect diet and sedentary behavior 19,20. Bus drivers particularly have higher mortality, morbidity, and absenteeism rates due to obesity 21,22.
Changes have also been occurring in the type of occupation in which workers are engaged, with a move from high-activity to low-activity occupations23. The clinical characterization of Professional bus drivers revealed a high frequency of cardiovascular risk factors, as obesity, Hypertension, hyperlipidemia, and hyperglycemia, as well as contributing functional Characteristics, such as a low-intensity activity, sedentary behavior, long duration in a sitting Position, and high-calorie diet, which lead to excessive weight gain and associated Co- morbidities24.
The work shift is also a risk factor of chronic disease, including cardiovascular disease and metabolic disorders, due to the altered circadian rhythm, changes in
lifestyle, tension, and stress at work i.e. driving 25, 26,27.
A study carried out in the United States involving more than 600 thousand workers found the highest prevalence of obesity to be among male employees who work in highway transportation services (31.7%) 28. In other study, done on professional bus drivers the prevalence of overweight and obesity was even higher, as more than half of the population of drivers (57.5%) was characterized as overweight and approximately 20% was considered obese, totaling 77.5% of the
Sample29. Similar results are reported in another study involving Brazilian truck
drivers, which found prevalence values of 47.8% and 16.2% for overweight and
obesity, respectively 30.
Besides increasing cardiovascular risk, obesity in this group of individuals leads to an increase in health costs related to traffic accidents31. Obesity as a coronary heart disease risk factor has been implicated along with driver’s irregular eating habits, low levels of physical activity at work and at leisure 32.
Carbon monoxide, sulphur dioxide and nitrogen oxides present in vehicle fumes, have been confirmed in escalating Coronary heart Disease risk for bus drivers47,48.
In a study 69% of bus drivers rated traffic, as a job stressor, to be a regular or major problem49 .Not only has psychological strain been noted for general drivers in traffic congestion,50 but physiological reactions in bus drivers have been also established51. Indeed, it is time pressure and impediments to the driver's primary task that makes congestion such a stressor especially where time urgency is apparent53. Prolonged job strain is said to predict high levels of coronary heart diseases33.
Abdominal circumference is a widely used measure for the distribution of fat, as it is indicative of the buildup of visceral adipose tissue or intra-abdominal fat, which, in some cases, may be more harmful than overweight and obesity in general 34. According to the National Institutes of Health, the cutoff point for abdominal
circumference in the male gender is 102 cm 35.
Waist to height is an important surrogate marker of the distribution of adiposity in the abdominal region in men36. Accordingly, we propose that Waist to height is probably the most convenient and reliable clinical measure of abdominal fat compartments37-38.
The present study is to measure their waist to height ratio to find out cardiovascular risk in Indian bus drivers who travel from medium to long distance in different work shifts. Bus drivers are provided with handouts which contains exercise programme for their risk factor modifications.
6.3REVIEW OF THE LITERATURE
1) C. Bigert, P. Gustavsson, J. Hallqvist et al.,(2003) in their study on “Myocardial infarction among professional drivers Epidemiology'', They concluded that Professional drivers are at an increased risk of myocardial infarction but the underlying causes for this increased risk are uncertain.19
2) M. A. Winkleby, D. R. Ragland, et al.,(1988) in their study on “Excess risk of sickness and disease in bus drivers: a review and synthesis of epidemiological studies'', concluded that bus drivers have higher rates of mortality, morbidity, and absence due to illness when compared to employees from a wide range of other occupational groups.22
3) C. Bigert, K. Klerdalet al,(1977-96) in their study on “Time trends in the incidence of Myocardial infarction among professional drivers in
Stockholm,” Occupational and Environmental Medicine (2004), stated on time trends in the incidence of first myocardial infarction (MI) among bus, taxi, and lorry drivers in Stockholm.17
4) P. D. Wang and R. S. Lin,(2001) “Coronary heart disease risk factors in urban bus drivers,” suggested that exposure to the occupation of driving a bus may carry an increased risk of CHD and that drivers who develop signs of cardiovascular illness should be transferred to non-driving occupations within the company.18
5) J. P. Després, B. J. Arsenault, et al, (2008).In their study on “Abdominal obesity: the cholesterol of the 21st century?” They suggested that exposure to the
and that drivers who develop signs of cardiovascular illness should be transferred to non-driving occupations within the company.24
6) Hedberg G, Jacobsson K A, et al. (1993). In their study on "Risk indicators of
Ischemic heart disease among male professional drivers in Sweden". Their results showed that significantly more drivers than referents were overweight, smokers, and shift workers; were sedentary in their leisure time; and had a work situation characterized by high demands, low decision latitude, and low social support32
7) Morris et al. 1953a, b, 1966; Heady et al. (1961).Study on "Coronary heart disease and physical activity of work". Morris and his employees found 80 cases of coronary heart disease (angina pectoris, myocardial infarction and immediate mortality from CHD) in 30,726 person-years for drivers, and 31 cases in 19,166 person-years for conductors. Statistical tests suggest that, the distribution of the various types of first presentation of coronary heart disease differs in the conductors of central buses from that of the drivers of central buses; likewise, the distribution of cases in the tram and trolleybus conductors differs from that in their drivers.59,60
8) Lee CM,Huxley RRet al,(2008) study on "Indices of abdominal obesity are better discriminators of cardiovascular risk factors than BMI: a meta-analysis", They concluded that Statistical evidence supports the superiority of measures of
centralized obesity, especially WHtR, over BMI, for detecting cardiovascular risk factors in both men and women.37
9) Michaels &Zoloth, (1991); Stern, Halperin, &McCammon, (1988) ,In their
study on "Mortality among Urban Bus Drivers", they said that Carbon monoxide,
sulphur dioxide and nitrogen oxides present in vehicle fumes, have been confirmed in escalating Coronary heart disease risk for bus drivers.47
10) Björntorp P(1988) study on "The associations between obesity, adipose tissue distribution and disease", Concluded that obesity and abdominal distribution of adipose tissue constitute two separate entities with different pathogenesis, clinical consequences and probably treatment.6
11) Dalton M, Cameron AJ et al,(2003) study on “Waist circumference, waist-hip ratio and body mass index and their correlation with cardiovascular disease risk factors in Australian adults", They concluded that Waist circumference, BMI and WHR identified different proportions of the population, as measured by both prevalence of obesity and cardiovascular disease (CVD) risk factors. Whilst WHR had the strongest correlations with CVD risk factors before adjustment for age, the three obesity measures performed similarly after adjustment for age. Given the difficulty of using age-adjusted associations in the clinical setting, these results suggest that given appropriate cut-off points, WHR is the most useful measure of obesity to use to identify individuals with CVD risk factors.39
12)S.D. Hsieh, H. Yoshinaga (1995) study on "Abdominal fat distribution and coronary heart disease risk factors in men- waist/height ratio as a simple and useful predictor ".They concluded that Waist/height ratio, an index of abdominal obesity, may be a better predictor of multiple CHD risk factors in men than waist/hip ratio in mass epidemiologic studies.9
13) J AtherosclerThromb,et al.( 2002),study on "Waist-to-height ratio is the best predictor of cardiovascular disease risk factors in Japanese schoolchildren". They concluded that W/Ht ratio is the best predictor of cardiovascular risk factors in
Japanese schoolchildren. They propose using W/Ht ratio for detecting cardiovascular disease risk in children.57
14)Schneider HJ, KlotscheJ,et al, (2011) “Measuring abdominal obesity: effects of height on distribution of cardio-metabolic risk factors risk using waist circumference and waist-to-height ratio”. They found that short subjects have higher levels of risk factors and a 30% higher prevalence of the metabolic syndrome than tall subjects if grouped by WC but not if grouped by WHtR. These findings support our hypothesis that risk stratification by WC is biased by height. They suggested that WHtR instead of WC should be implemented in obesity guidelines and in the definition of the metabolic syndrome.54
15)Browning LM, Hsieh SD, Ashwell M (2010).In their study on, “A systematic review of waist-to-height ratio as a screening tool for the prediction of cardiovascular disease and diabetes: 0.5 could be a suitable global boundary
Value”. They concluded that waist to height ratio as a predictor of diabetes, CVDandrelated risk factors, and the usefulness of the global boundary value of 0.5, will encourage the use of this index.58
16) Marta Guasch-Ferré, 1, 2 MònicaBulló et al, (2012), on"Waist-to-Height Ratio and Cardiovascular Risk Factors in Elderly Individuals at High Cardiovascular Risk". They concluded that measures of abdominal obesity showed higher discriminative ability for diabetes mellitus, high fasting plasma glucose, atherogenic, dyslipidemia and metabolic syndrome than BMI or weight in a large cohort of elderly Mediterranean individuals at high cardiovascular risk. No significant differences were found between the predictive abilities of waist-to-height ratio and waist circumference on the metabolic disease.56
To find out cardiovascular risk in Indian bus drivers by measuring their waist to height ratio.
To create awareness about importance of exercise in maintaining their health and cardiovascular fitness.
MATERIAL AND METHODS
STUDY DESIGN AND SETTING
Cross-sectional survey study.
SOURCES OF DATA:
Bus drivers working in KSRTC and APSRTC depots of Bangalore division
PLACE OF STUDY:
Male Indian drivers who are in active service in KSRTC and APSRTC.
All bus drivers engaged in active service.
Bus drivers who are willing to participate in the study.
Smokers and alcoholics.
Bus drivers associated with co-morbid condition and its medications.
SAMPLING METHOD: Random Allocation
Permission for conducting the study from the KSRTC and APSRTC management Bangalore division will be obtained prior to the study.
Informed consent will be obtained from each subject for screening.
Height and waist will be measured using standardized units by measuring tape.
Driver’s health screening will be conducted at bus depot premises in liaison with the KSRTC and APSRTC management.
To measure the waist circumference accurately, the measurement will be taken in mid-way between the lower rib and the iliac crest (the top of the pelvic bone at the hip). This is the method recommended by the World Health Organization.
The Waist-to-Height ratio is determined by dividing the waist circumference by the height. Waist-to-Height ratios of 0.542-45or greater are indicative of intra-
abdominal fat for both men and women and are associated with a greater risk of cardiovascular disease and values above 0.6 indicate substantially increased risk 41.
Waist to height is measured to find out their cardiovascular risk. It will be
Calculated by dividing the waist (in inch) by height (in inch).A value of 0.5 is
Considered as boundary cutoff value42-44.
The following chart helps to determine if the Waist to height falls in a healthy range (these ratios are in percentages)40.
Ratio less than 35: Abnormally Slim to Underweight
Ratio 35 to 43: Extremely slim
Ratio 43 to 46: Slender and Healthy
Ratio 46 to 53: Healthy, Normal, Attractive Weight
Ratio 53 to 58: Overweight
Ratio 58 to 63: Extremely Overweight/Obese
Ratio over 63: Highly Obese
Duration of the study:
Single time study
No follow up
7.4 Does the study require any intervention to be conducted on patients or other humans or animals?
No, this study does not require any intervention.
Has the ethical consent for the study has been obtained from the institution?
Yes it has been obtained from my institution.
Ethical clearance form is attached as appendix (I).
The informed consent will be obtained prior to the study from each subject and is attached as appendix (II).
1. Soto Gonzalez A, Bellido D, Buno MM, et al. (2007) Predictors of the metabolic
syndrome and correlation with computed axial tomography. Nutrition 23, 36–45.
2. Vague J (1946) Le traitment des obesities (Treatment of obesity). Marseille Med 83,
3. Vague J (1956) The degree of masculine differentiation of obesities: a factor
determining predisposition to diabetes, atherosclerosis, gout, and uric calculus
disease. Am J ClinNutr 4, 20–34?
4. Ashwell M, Cole TJ & Dixon AK (1985) Obesity: new insight into the
anthropometric classiﬁcation of fat distribution shown by computed tomography.
BMJ 290, 1692–1694.
5. Seidell JC, Cigolini M, Charzewska J, et al. (1990) Fat distribution in European
Review category: Exemption from review Expedited review Full Review
We hereby declare that the project titled, “A STUDY TO FIND OUT CARDIOVASCULAR RISK IN INDIAN BUS DRIVERS BY MEASURING THEIR WAIST TO HEIGHT RATIO", carried out by Pabba Lakshmi Priya, of 1st year MPT has been brought forward for scrutiny to the Board Members.
Involvement of special groups: yes/ No
If yes: pregnant/nursing women/children/economically Disadvantaged/
Socially Disadvantaged/mentally challenged
Type of study: cross sectional survey/case control/cohort/RCT/other study
AV Need: yes/No
After analyzing the objectives, subjects involved and the methodology of the project, the following conclusions were drawn.
The project does not involve any mental or physical harm to the subjects involved with the study. The performance of the study procedure will not cause any injury to the subjects.. The informed consent form prepared ensures that, the experimenter explains the procedure of the study to the subject; their voluntary participation is confirmed and the identification of the subject are maintained confidential.
More over the finding of the study will benefit similar subjects, the profession and the society. Hence the review board has no objection on the conduct of study.
Chairman Vice Chairman
ETHICAL CONSENT FORM
I, the undersigned, have fully understood that
…………………………….. is being a subject for undertaking the scientific study titled “A STUDY TO FIND OUT CARDIOVASCULAR RISK IN INDIAN BUS DRIVERS BY MEASURING THEIR WAIST TO HEIGHT RATIO”.
I have been made aware of the purpose of this study. I understand that I have to cooperate with the researcher for this study and their copy of the consent form has been given to me for my reference.
Date: Permission of the subject
TITLE: “A STUDY TO FIND OUT CARDIOVASCULAR RISK IN INDIAN BUS DRIVERS BY MEASURING THEIR WAIST TO HEIGHT RATIO”
INVESTIGATOR: Pabba Lakshmi Priya
PURPOSE OF RESEARCH:
I ………………………………………… voluntary agree to participate in this study, which is being conducted by researcher.
I understand that, my waist to height ratio will be measured by Pabba Lakshmi Priya. The testing protocol is explained to me and it will take few minutes
I understand that my participation in the study to find out the cardiovascular risk factor which will be beneficial for me. The recorded data will help the study well.
I understand that medical information produced by this study will be confidential. Data will not be assessed by anyone else without permission. If the data are used for publication in medical literature or for teaching purpose, no names will be used.
Pabba Lakshmi Priya has explained to me that photographs are required in order to illustrate various aspects of the study for thesis or other articles, and at presentations or conferences. These images may also be converted to electronic formats for use in multimedia presentations and documents accessible to others by computers for the purpose of sharing the results of the study and for promoting this research. By giving my consent I authorize Pabba Lakshmi Priya to use any of the photographs taken of me in printed format, in slides for presentation, and in electronic format.
REQUEST FOR MORE INFORMATION:
I understand that I ask any question about the study at any time. Pabba Lakshmi Priya is available to answer my questions. Copy of this concern form will be given to me to keep for my careful reading.
REFUSAL OF PARTICIPATION:
I understand that my participation is voluntary and I may refuse to withdraw consent and discontinue participation at any time .I also understand that she may not include my participation in the study at any time after she has explained me the reasons for doing so.
INVESTIGATOR: PABBA LAKSHMI PRIYA
INVESTIGATOR'S SIGNATURE DATE
I confirm that Pabba Lakshmi Priya has explained me the purpose of the study, the study procedure and the possible risk and the benefits that I may experience. I have read and fully understood this study and voluntarily provide consent to be a subject in this research project.