Relationship between physical activity, BMI and waist hip ratio among middle aged women in a multiethnic population: A descriptive study Annamma Mathew 1*, Shanti Fernandes 2, Jayadevan Sreedharan 3, Mehzabin Ahmed 4 1 College of Allied Health Sciences, 3 Research Division, 4 Deptarment of Pathology, Gulf Medical University, Ajman, UAE 2 Department of Obstetrics and Gynaecology, Gulf Medical College Hospital and Research Centre, Ajman, UAE *Presenting Author ABSTRACT Objective: This study was conducted to assess the relationship between physical activity and Body Mass Index (BMI) and Waist Hip Ratio of middle aged women in a multiethnic population in Ajman, UAE. Materials and Methods: A descriptive methodology was adopted. 150 women of age group 35-59 years attending GMC Hospital, Ajman participated in this research. A self-administered questionnaire was used for subjective and objective assessment, and the waist and hip circumferences were measured using a measuring tape. BMI and waist hip ratio were calculated by standard formulas. Analysis was performed on SPSS 19 version. Results: It was observed that 96% women were involved in some kind of moderate physically activity, 8.6% were involved in vigorous activity, and4% did not perform any physical activity. There is a significant difference in BMI of subjects who participated in vigorous activity but WHR did not show much variation. Conclusion: This study demonstrates that among the middle aged women there is a relationship between physical activity, BMI and waist hip ratio. Key words: waist Hip ratio, BMI, physical activity, middle aged women. INTRODUCTION Sedentary lifestyle is a type of lifestyle with no or irregular physical activity. A Body Mass Index (BMI) of >30 and a waist hip ratio (WHR) above 0.90 for males and above 0.85 for females are important indicators of lifestyle-related health problems throughout the world 1. In 2009, almost a quarter of adults (24% of men and 25% of women aged 16 or over) in England were classified as obese (BMI 30kg/m 2 or above). Thirty-nine per cent of adults had a raised waist circumference in 2009 compared to 23% in 1993. Women were more likely than men (44% and 34% respectively) to have an increased waist circumference (over 88cm for women and over 102cm for men) 2. According to several studies 3,4, women are less active than men, and this has been related to reproductive as well as social factors. World Health Organization (WHO) predicted that there will be about 2.3 billion overweight people aged 15 years and above, and over 700 million obese people worldwide in 2015 5. Physical inactivity is one of the five leading global risk factors for mortality and is estimated to cause two million deaths per year 6. Physical activity has been defined as any bodily movement produced by the contraction of skeletal muscle that increases energy expenditure above a basal level 7. The World Health Organization has agreed on an international standard for identifying overweight and obesity in the adult populations using the Body Mass Index (weight/height2) and waist hip ratio 8. The relationship between physical activity and body fat or weight is derived from the assumption that a normal-weight person s energy intake is equal or nearly equal to his/her energy expenditure 9. That is, a person becomes overweight or obese if his/her energy intake is greater than his/her energy expenditure, and one way of maintaining the energy balance is by getting rid of the extra calories by 169
GMJ, ASM 2012;1(S1):S164-S168 performing physical activity 10. It has been found that the association between physical activity and Body Mass Index (BMI) is stronger in obese individuals than in non-obese persons. Waist circumference and Waist Hip ratio is a measure of relative overall body fat distribution and has been widely used in adults to identify the physical status. Although some decrease in function, strength and stamina are unavoidable with age, the rate of decline can be diminished through supportive environments that promote better health through healthy levels of physical activity 11,12. A large body of research has established that in elderly women regular physical activity reduces the risk of premature death and disability from a variety of health conditions, including Coronary Heart Disease, Hypertension, Type II Diabetes Mellitus, Colon Cancer, Osteoarthritis and Osteoporosis 13. Research published on women 40 years and older (middle aged) who are at increased risk of both physical inactivity and chronic disease is limited 14. The prevalence of inactivity and obesity, and their negative health consequences, are rapidly increasing in both the developed and the developing countries 15. During the middle age period one faces the downhill slope of life, or an ageing process. During this period women start to experience changes in their body as they near menopause and might begin to experience pre-menopausaltype symptoms. Sometimes a few may have already attained menopause which can affect their quality of life. The other noticeable sign of aging is an increase in the fat layer which starts at about the age of 35. Women gain an average of a pound and a half (600g) of fat each year during this phase due to the tendency of fat moving in because muscle moves out. After 35 years of age, women start to lose muscle and fat gets stored in the body, especially in the abdominal area. In middle-aged women, genetic factors and environmental factors have a strong influence on the amount and distribution of body fat. Among the environmental factors leading to total and central obesity is decreased physical activity 16. Physical activity is more important than energy intake and dietary composition. Women should be encouraged to maintain physical activity even if there are some limitations. Australia s national physical activity guidelines recommend that adults should have at least 30 minutes of moderate intensity activity seven days a week. Sedentary women with waist circumference of more than 85cm had almost doubled mortality risk compared to active women with waist circumference below 80cm. Physical inactivity and obesity seem to increase the total mortality risk independently and additively. There is limited research in the Arabian region on physical activity in middle aged women. This present study is an effort to find the relationship of physical activity and BMI, waist circumference and waist hip ratio in middle aged women in Ajman. MATERIALS AND METHODS 150 women in the age group 35-59 year age group attending GMC Hospital, Ajman, participated in this study. A selfadministered questionnaire was given to the participants, and participants who found it difficult to understand were provided with assistance. The questionnaire included questions about sociodemographic details including height, weight, waist and hip circumference, medical history of chronic diseases, physical activities that were carried out during the past one month, perception on their own physically activity level and the reason for being physically active or being inactive. Questions on physical activity included both of moderate level activity to vigorous level physical activity which ranged from leisure activity to house hold activity. Activities like walking, cycling, stair climbing, light gardening and house hold chores at moderate intensity were classified as moderate physical activity and those such as running, jogging, swimming and heavy gardening, climbing stairs briskly were classified as vigorous physical activity. BMI was calculated as weight in kilograms divided by the square of the height in meters. The effect of BMI was presented in four categories according to WHO recommendations 13 :<18.5kg/ m 2 (lean);18.5 24.9kg/m 2 (normal 170 GMJ, 4 th Annual Scientific Meeting of Gulf Medical University Oral Proceedings 2012
weight);25 29.9kg/m 2 (overweight) and 30 kg/m 2. The waist to hip ratio was calculated as waist girth divided by the hip girth. It is statistically proved that men with WHR of more than 0.90 and women with 0.85 are at greatest risk of health complications 14,15. The data were entered into Microsoft Excel and transferred to SPSS version 19 for statistical analysis. The student s t-test was used to find the difference in mean between those with physical activity and of those without. RESULTS The relation between moderate and vigorous level of physical activity to BMI and waist hip ratio was assessed. Out of 150 women, 144 were engaged in moderate physical activity, ranging from walking at a moderate pace to moderate household chores, and six of the women did not perform any form of physical activity. Out of 144 women who were involved in moderate physical activity, 13 also performed vigorous physical activity like jogging/running and stair climbing at fast pace. BMI, WHR were calculated from the given data and compared with those performing moderate physical activity and those without moderate physical activity, and with and without vigorous physical activity. Although it is generally expected that physically active persons would have significantly lower BMI and WHR than those without, the analysis in this study showed that there was no major significant difference in the BMI of women engaged in moderate physical activity and those who were not involved in any physical activity. Details are given in Table 1. A significant difference in the BMI of women involved in vigorous level of physical activity when compared to those involved in moderate activity was also observed. Details are given in Table 2. WHR showed no significant difference between women involved in moderate or vigorous activity. Further analysis was done to find out which type of moderate/vigorous activity had greater impact on BMI and WHR. It was observed that walking and stair climbing at moderate speed and vigorous physical activity like brisk jogging, stair climbing helped reduce BMI but had no impact on WHR, whereas brisk walking and stair climbing showed lower WHR, and brisk walking had no effect on BMI. Light aerobics, performing yoga, dancing, gardening and doing household chores was not associated with any significant difference in BMI and WHR. Details are given in Tables1 and 2. DISCUSSION In this study we examined the relationship of physical activity with BMI and WHR and the mean change in level of physical activity and its impact on BMI and WHR. Physical activity and BMI are associated, Table1. Mean BMI of subjects with and without moderate and vigorous physical activity Activity Yes No p No. Mean SD No Mean SD Moderate intensity Walking moderate 126 26.75 4.03 17 31.21 6.62266 <0.001 speed Walking brisk pace 120 27.44 4.61 16 25.68 4.43 NS Static cycle 134 27.27 27.27 2 26.07 26.07 NS Light aerobics 134 27.31 4.62 3 26.58 4.96 NS Lightcallisthenic 133 27.36 4.61 2 23.32 1.42 NS Yoga 129 27.33 4.60 6 26.55 4.91 NS Stair climbing 51 29.77 29.77 84 25.80 25.79 <0.001 Dancing 131 27.38 4.64 5 26.11 3.76 NS Gardening 128 27.48 4.65 7 24.04 1.15 NS Household chores 17 29.27 29.26 125 27.07 27.06 NS Vigorous intensity Running /jogging 132 27.43 4.57 3 21.72 1.81 <0.05 Static cycle 128 27.55 4.60 8 23.19 1.06 <0.01 171
GMJ, ASM 2012;1(S1):S164-S168 Table 2. Mean WHR of subjects with and without moderate and vigorous physical activity Activity Yes No p No. Mean SD No Mean SD Moderate intensity Walking moderate speed 127 0.89.05409 16 0.91.12111 NS Walking brisk pace 120 0.89 0.06 17 0.86 0.07 <0.05 Static cycle 134 0.89 0.89 2 0.82 0.82 NS Light aerobics 134 0.89 0.06 3 0.85 0.05 NS Lightcallisthenic 133 0.89 0.06 2 0.89 0.03 NS Yoga 129 0.89 0.06 6 0.88 0.02 NS Stair climbing 51 0.91 0.90 84 0.88 0.87 <0.01 Dancing 131 0.89 0.06 5 0.85 0.03 NS Gardening 128 0.89 0.06 7 0.89 0.04 NS Household chores 17 0.90 0.90 126 0.89 0.88 NS Vigorous intensity Running /jogging 132 0.89 0.06 3 0.91 0.03 NS Static cycle 128 0.89 0.06 8 0.87 0.02 NS and the type or the intensity of physical activity is the major factor that affects BMI. Many studies 16-18 have evaluated the relation between physical activity and diseases like CVD, diabetes, cancer and mortality. Individuals who perform regular physical activity are less likely to have chronic diseases compared to those who lead a sedentary life-style. Wannamethee et al 17, report that moderate or high level of cardio-respiratory fitness may protect against the excess mortality among the overweight and obese individuals 18. In this study there was no significant difference in the BMI between women who had moderate physical activity and those who had asedentary life-style, whereas women with physical activity of vigorous type showed significant difference in the BMI when compared to those performing moderate activity. Studies have proved that regular physical activity of any type (work-related or leisure-time) is inversely related to all measures of obesity, viz. BMI, WHR. Thus, the higher the intensity of exercise the lower the BMI. Weight gain reduces the overall metabolic energy expenditure in middle aged women, and the increase in body fat percentage (without weight gain) causes no reduction in WHR in spite of physical activity. Moderate activity such as walking for pleasure, doing household chores(3.5-5 MET) have no effect on the BMI. In addition to the above, 30 minutes per week of a 6-MET activity such as brisk walking, jogging and brisk stair climbing are needed to have a beneficial effect. In this study we found that physical activity was positively related to BMI but showed no significant difference in the WHR. More studies on the similar topic are recommended with large sample and taking into consideration the duration of activity, body type, and metabolic index. CONCLUSION There was a significant reduction in BMI of middle aged women who performed vigorous activity but no changes were noted in WHR. Additionally, moderate physical activity did not change either BMI or WHR among the participants. REFERENCES 1. Dubbert PM, Carithers T, Sumner AE, et al. Obesity, physical inactivity, and risk for cardiovascular disease. Am J Med Sci 2002; 324: 116 126 2. Statistics on Obesity Physical Activity and Diet: England, 2011. Available from: URL: http:// www.ic.nhs.uk/webfiles/publications/003_ Health_Lifestyles/opad11/Statistics_ on_obesity_physical_activity_and_diet_ England_2011_revised_Aug11.pdf 3. Colley RC, Garriguet D, Janssen I, et al. Physical activity of Canadian adults: Accelerometer results from the 2007 to 2009 Canadian Health Measures Survey. Statistics Canada Catalogue 82-003-X. Health Reports;2011;22. 4. Blair SN, Cheng Y & Holder JS. Is physical activity or physical fitness more important in defining health benefits? Med Sci Sports Exerc 2001; 33:S379 S399. 5. World Health Organization. Fact sheet: obesity and overweight. Available from: URL: http:// www.who.int/mediacentre/factsheets/fs311/ en/ (Accessed on 5 October 2009) 6. World Health Organization. Global health risks: Mortality and burden of disease attributable to selected major risks. 2009. Available 172 GMJ, 4 th Annual Scientific Meeting of Gulf Medical University Oral Proceedings 2012
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