The Coronary Heart Disease - Literature review Example

YourDeakin University username Your name Student number Enrolled campus Abstract It is documented that the rates of coronary heart disease, hence diabetes for physically active women is lower than for inactive women. However, it is unclear whether the association differs by women at high CHD or by intensity of activity. The objective of this study therefore, is to investigate the relation between physical activity and CHD among women. The physical activity in this case is walking. The study involves a cohort study of 39372 women aged forty five years or older. These women are health professionals and are enrolled from across the United States between the dates of September 1992 and may 1995. The outcome of the recreational activities that these women were subjected to was measured to show the correlation of coronary heart disease and energy used on all activities, walking, and vigorous activities. From this study a total of two hundred and forty four cases of coronary heart disease were seen. The relative risks (RRs), confidence interval (CI) were measured. Vigorous recreational activities were linked with lower risk of (RR, 0.63; 95% CI, 0.38-1.04 when the highest categories were compared with the lowest categories). The recreational activity of walking also showed lower risks for CHD. The conclusion therefore, is that even an activity that is light-to-moderate has a strong association with lower coronary heart disease rates in women. Consequently, women who walked at least one hour per week had lower risk. This paper therefore, seeks to justify the use of exercise or physical activity intervention to combat cardiovascular disease and hence diabetes since they are closely linked. Introduction Diabetes is defined as a group of diseases characterized by high blood glucose levels, which arise due to the defects in the production of insulin, insulin action, or both. Diabetes can result in serious complications and even premature death. However, if people with diabetes, work together with their health care providers, and support network, can be able to make a progress in controlling the disease and lowering the risk of associated complications (Feinglos & Bethel, 2008). Diabetes is heavily responsible for deaths resulting from cardiovascular disease (CVD). However, due to the deficiencies in the documentation of the death certificate this relationship is be significantly under-reported (Manson et al. 2000). At an international level, diabetes is believed to rise considerably in the next one or two decade (McCarty et al, 1996). With a population, which is increasingly becoming overweight, physically inactive, and aging the risk of contracting type 2 diabetes is high in the United States of America. Due to sheer numbers, most of this trouble is linked to Type 2 diabetes (diabetes mellitus), the most common form of diabetes, accounting for about 85% of all diabetes in United States. Type 2 diabetes is present primarily from middle age population onwards, though, in high-risk populations like Pacific Islander people and Aboriginal it may become manifest much earlier (Kriska & Hayes, 2008). This document deals entirely with Diabetes mellitus, Type 2 diabetes. Like Type 1 diabetes, diabetes mellitus (Type 2 diabetes) is characterized by high levels of blood glucose. However, different from Type 1 diabetes, the main feature of diabetes mellitus is insulin resistance instead of insulin deficiency. Consequently, The treatment of type 2 diabetes does not essentially require insulin. In fact, many people, mainly in the initial stages following diabetes diagnosis, can be effectively managed with general lifestyle and dietary modification alone or in conjunction with oral therapy. Insulin treatment may be essential for diabetes mellitus if oral medication turns to be ineffective in maintaining and lowering the blood glucose in an acceptable range. Assiduous concentration to the management of blood pressure, lipids, and weight control is also essential as these common characteristics of diabetes mellitus noticeably amplify the risk of complications, which are long term (Kriska & Hayes, 2008). In the United States, the total number of adults and children having diabetes is 25.8 million. This represents 8.3% of all the American population. Out of this number, the number of diagnosed people is 18.8 million. On the other hand, the number of undiagnosed people makes up to 18.8 million while the people having prediabetes add up to 79 million people. The statistics further reveal that for the people who are aged 20 years and above in 2010, the number of new cases being diagnosed adds up to 1.9 million. For the people under the age of 20 years, 0.26 percent, which brings the number to 215, 000, have diabetes. For the people who are 20 years of age or older, 11.3%, which brings the number to 25.6 million, have diabetes. . For the people who are 65 years of age or older, 26.9% which brings the number to 10.9 million, have diabetes. For the men who are 20 years of age or older, 11.8%, which brings the number to 13.0 million, have diabetes. On the other hand, for women who are 20 years of age or older, 10.8%, which brings the number to 12.6%, have diabetes (Mazze, et al. 2012) Methods Participants Participants were selected in this study from the Women’s Health Study. They were double-blind and were randomized. They were given placebo controlled trial consisting of vitamin E and low dosage aspirin for primary prevention of cancer and cardiovascular disease. Between 1992 and 1995, female health professionals from across Puerto Rico and the United States were invited . they participated by completing a baseline questionnaire that was mail based. The questionnaire captured medical history, health habits and sociodemographic characteristics (Helmrich et al. 1991). Those women who were willing and eligible to be in the trial were placed into a three-month run-in phase. During this phase, the women were given all placebos, the study pills. The women were then given run-in questionnaire to complete at the end of the run-in phase. These questionnaires indicated the recent medical history, the health habits, and the pill taking. Consequently, women who complied well and who were still willing and eligible to take part were randomized into the trial. These women begun taking randomized pill assignment. Women who totaled 39876 and who were aged 45 years and above who did not have cancer, cerebrovascular disease or coronary heart disease were assigned randomly to the tested agents. For this research, 504 women were excluded because they had missing information on weight or physical activity(Kriska & Hayes, 2008). Assessment of Physical Activity The women were asked in the run-in questionnaire to approximate the average time spent on eight categories of recreational activities in the past year. These categories included lap swimming, lower-intensity exercise like racquetball, squash, tennis, toning, stretching or yoga, aerobic dance, aerobic exercise or the utilization of exercise machines, bicycling, that included the use of stationary machines, running a ten-minute mile or faster, jogging, hiking or walking. Using the energy cost of these different activities, each group or category was assigned several resting metabolic rate score (MET Score). Because the resting metabolic rate is about 1 kcal/kg of a given body weight for every hour, the approximate energy expenditure was estimated by multiplying the body weight with the assigned resting metabolic rate and hours for every week of participation. The midpoint of time categories was used as far as the hours are concerned; the kilocalories for every week were summed from the eight groups of recreational activities as well ad from stair climbing to know the weekly energy expenditure. This particular assessment of the participants’ physical activity was found to be valid and reliable (Helmrich et al. 1991). Statistical Analysis The study considered the following physical activity dimensions. First was the energy used in all the assessed activities. Second was the energy used in recreational activities that are vigorous. Third was the energy used in walking. Recreational activities that required at least six METs, in this case lap swimming, lower-intensity exercise like racquetball, squash, tennis, toning, stretching or yoga, aerobic dance, aerobic exercise or the utilization of exercise machines, bicycling, that included the use of stationary machines, running a ten-minute mile or faster, jogging, were grouped as vigorous (Manson et al. 2000). The women participants were first grouped into approximate quartiles consisting of energy used in all activities. These quartiles were 1500 or more, 600 to 1499, 200 to 599 and less than 200 kcal/wk. The study then used proportional hazards regression to determine hazard ratios, in this case, the relative risks of coronary heart disease. These ratios were determined as a function of the above mentioned four categories or groups of physical activity. In this case, both randomization to assigned treatment age in years were controlled. From post his calculations, there was an eighty percent power of detecting a relative risk between 0.7 and 0.6, comparing lowest and highest categories (Helmrich et al. 1991). In order to examine a linear trend across the different categories of physical activity, the four categories or groups of physical activity were taken as a single ordinal variable. With the use of a multivariable model, there was an additional adjustment for other key cofounders like alcohol consumption, smoking status, parental history, postmenopausal hormone, menopausal status (postmenopausal or premenopausal), consumption of vegetables and fruits, fiber intake and saturated fat intake (Kriska et al. 1990). In the primary analyses adjustment was not made for such things as body mass index, diabetes mellitus, elevated cholesterol level, or a history of hypertension. This is because these things are biological intermediates between decreased CHD risk and physical activity. In secondary analyses however, these intermediates were adjusted.Since walking makes is a leisure activity that is most popular among women, the study examined this activity relative to coronary heart disease. In order to avoid confounding of the findings by vigorous activities, walking analyses were done among the 22 865 women (58%). These women had reported no form of vigorous recreational activity. In separate models, relative risks of coronary heart disease were estimated for walking pace and time spent walking (Helmrich et al. 1991). Results After observing participants for an average of five years, 244 participants showed confirmed cases of coronary heart disease. The characteristics of the most active women and less active women were also noted. For the more active women, their mean body mass index was lower than that for the less active women. In addition, women whose physical activity levels were higher were found to have lesser chances of smoking cigarettes but higher chances of consuming alcohol. The diet of these kinds of women was also found to be healthier. They consumed more vegetables and fruits, more fiber and less saturated fat, these women also had higher chances of using postmenopausal hormones. In addition, the prevalence of diabetes mellitus, elevated cholesterol level and hypertension was lower when the physical activity was at higher levels (Kriska & Hayes, 2008). The assessment was also done to discover whether there was an inverse relationship between walking and subsequent coronary heart disease among those women who did not take part in vigorous activities. Among all participants 58 percent of women, representing 22, 865 recorded no vigorous activity. The only activity they did was mainly walking. It was found that there was an inverse relationship between both the usual walking pace ant time spent walking when analyzed separately. Consequently, those women who spent at least one hour in every week walking or who had a walking pace, which was at least 3.0 mph or 4.8 km/h experienced the coronary heart diseas risk that was about half that of women who spent no time walking regularly. The two variables, pace of walking and time spent walking were examined to ascertain the one that was more important in reducing the risk of coronary heart disease. The P value for linear trend was 0.01 and5.5 for the time spent walking and pace of walking respectively. In this case, time spent in walking is associated with lower coronary heart disase (Kriska & Hayes, 2008). Discussion and conclusion Now, diabetes is regarded as a cardiovascular disease equivalent because of the high cases of cardiovascular complications seen in diabetics. The subgroup analyses focusing on the main lipid lowering trials support this idea. These lipid lowering trials include the Heart Protection Study, the CARE trial, and the 4S trial. Because of this both the third report by the National Cholesterol Education Program Expert Panel and the ADA make a recommendation of a goal LDL40 (American Diabetes Association, 2004). According to another research, a large retrospective study in type 1 diabetes revealed that regular exercise greatly minimized nephropathy. However, the same exercise had no effect on retinopathy. According to Nurses Health Study report, type 2 diabetic women who used at least four hours each week in performing moderate exercise like walking or vigorous exercise were 40 percent less likely to risk developing cardiovascular disease, for instance stroke and the coronary heart disease, than those who did no exercise. Exercise was also found to improve the cardiovascular outcomes according to a prospective cohort study conducted using 2896 adults who were type 2 diabetic (Kriska et al. 1990). In every week, these adults walked at least for two hours. The control experiment constituted of inactive adults. Consequently, the results were that for those who exercised, the risk rate was 1.4 percent per year. On the other hand, the inactive adults had a risk rate of 2.1 percent per year. The protective effect did not depend on physical limitations, co morbid conditions, duration of diabetes, body mass index, race, age, and sex. It was possible to prevent one death per year for every 61 adults having diabetes by persuading them to walk at least two hours for every week. References: Helmrich, S.P., Ragland, D.R., Leung, A.B., and Paffenbarger, R.S., 1991, Physical Activity and Reduced Occurrence of Non-Insulin-Dependent Diabetes Mellitus. N Engl J Med 1991; 325:147-152July 18, 1991DOI: 10.1056/NEJM199107183250302 Hu F. B., Sigal R.J., Rich-Edwards J.W., Colditz G.A., Solomon, C.G., Willett, W.C., Speizer, F.E. and Manson, J. E., 1999. Walking Compared With Vigorous Physical Activity and Risk of Type 2 Diabetes in WomenA Prospective Study FREE.JAMA. 1999;282(15):1433-1439. doi:10.1001/jama.282.15.1433. Kriska, A. & Hayes, C., 2008., Role of physical activity in diabetes management and prevention. Journal of the American Dietetic Association 2008 Vol. 108 No. 4, Suppl. 1 pp. S19-S23 Kriska, A.M., Knowler, W.C., LaPorte, R.E., Drash, A.L., Wing, R.R., Blair, S.N., Bennett, P.H.and Kuller, L.H. 1990, Development of Questionnaire to Examine Relationship of Physical Activity and Diabetes in Pima Indians. Diabetes Care April 1990 vol. 13 no. 4 401-411 Manson, J.E., Stampfer, M.J., Colditz, G.A., Willett, W.C., Rosner, B., Hennekens, C.H., Speizer, F.E., Rimm, E.B. and Krolewski A.S. 2000.Physical activity and incidence of non- insulin-dependent diabetes mellitus in women. The Lancet, Volume 338, Issue 8770, Pages 774-778 Read More