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Original Article
Lifestyle Associated Risk Factors in Adolescents Akhil Kant Singh, Ankit Maheshwari1, Nidhi Sharma1 and K. Anand Centre for Community Medicine, All India Institute of Medical Sciences, New Delhi and 1Armed Forces Medical College, Pune.
ABSTRACT Objective. The data on these risk factors in school age population is deficient in India. The present study was conducted to evaluate the prevalence of lifestyle associated risk factors for non-communicable diseases in apparently healthy school children in an urban school in Delhi using standard criteria. Methods. The study was carried out among 510 students of classes 9th-12th of a school in New Delhi and in the age group of 12 to 18 years. The students were surveyed through an age appropriate modified GSHS (Global School Based Student Health Survey) self administered questionnaire. Height and Weight were measured using standardized equipment and procedure. The blood pressure was measured using OMRON electronic B.P apparatus which were standardized daily against a mercury sphygmomanometer. The statistical analysis was done using Epinfo ver.3.3 and SPSS ver11.5. Results. The study documents the inappropriate dietary practices (fast food consumption, low fruit consumption), low physical activity, higher level of experimentation with alcohol and to a lesser extent smoking, high prevalence of obesity and hypertension in the school children. The study also showed an association between BMI, systolic and diastolic blood pressures amongst children and other lifestyle factors. Conclusion. School based interventions are required to reduce the morbidity associated with non-communicable diseases. [Indian J Pediatr 2006; 73 (10) : 901-906] E-mail :
[email protected]
Key words : Adolescence; Obesity; Hypertension; Non-communicable disease
Increasing trends of non-communicable diseases is a worldwide phenomenon. Globally, deaths from non communicable diseases are expected to climb to 49.7 million in 2020, an increase of 77% in absolute numbers and increase in their share of the total from 55% in 1990 to 73% in 2020.1 Until now risk factors like high BP, obesity, smoking, alcohol consumption, low physical activity etc. contributing to the development of non-communicable diseases were more prevalent in the developed countries1. However, the “World Health Report 2002: reducing risks, promoting healthy life”, indicates a rise in their prevalence even in the developing countries. A disturbing increase in the prevalence of overweight among children has taken place over the past twenty years in developing countries as diverse as India, Mexico, Nigeria and Tunisia.2 Non-communicable diseases like Obesity, Diabetes
Correspondence and Reprint requests : Dr. Akhil Kant Singh, Centre for Community Medicine, All India Institute of Medical Sciences, New Delhi.
Indian Journal of Pediatrics, Volume 73—October, 2006
mellitus, Hypertension, Coronary artery disease, stroke in adults have been related to the prevalence of risk factors in childhood3 hence, there is a definite need to monitor the prevalence of these risk factors in this age group and plan intervention measures for the same. MATERIAL AND METHODS The study was carried out among the students of Fr. Agnel School, Gautam Nagar, New Delhi over three days during the month of April ’06. The participating students belonged to classes 9th-12th and in the age group of 12 to 18 years. The participation in the study was voluntary. Of the 550 eligible students identified for the survey, 510 students responded (92.7% response rate). The students were surveyed through an age appropriate modified GSHS (Global School Based Student Health Survey) structured questionnaire on risk factors of non communicable diseases. Dietary practices were assessed by putting questions on dietary preference, fastfood intake, fruit consumption, extra table salt added. Physical activity was ascertained by asking for daily physical 901
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Akhil Kant Singh et al activity (running, fast walking, biking, dancing) for atleast 30 minutes/day during the past 7 days and during a typical week. Any involvement in sports at school or in the community and the time spent at home in sitting activities like watching T.V and video games was also asked. Any single trial of smoking or alcohol was asked for and if yes then the frequency in the last 30 days for smoking and 6 months for alcohol. History of passive and parental smoking was also ascertained. Family history of hypertension and obesity in parents or grandparents was asked. Stress felt in any which way by the students (subjective) was also inquired. Subsequently anthropometric measurements and blood pressure were taken. Height was measured to the nearest millimeter using a SECA wall mounted measuring scale without footwear during maximal inspiration. The weight was measured using a SECA electronic weighing scale with students wearing light summer clothing. The blood pressure was measured using OMRON electronic blood pressure measuring devices which were standardized daily against a mercury sphygmomanometer. Measurements were taken from morning till noon and on the right arm of subjects seated and at rest for at least 5 minutes, no less than 30 minutes after any meal. Three readings were taken and the mean of the second and third readings was taken as the final observation. The statistical analysis was done using Epinfo ver3.3 and SPSS ver11.5. Chi- square test, t-test, Oneway ANOVA and multi weighted analysis with multiple linear stepwise and backward regression were applied wherever applicable. P value was taken as 85 th percentile for age as overweight and >95 th percentile for age as obese according to the American Obesity Association ( http://www.obesity.org/subs/fastfacts/ obesity_youth.shtml ) Blood Pressure Systolic Hypertension (B.P>140) was found in 11.82% boys and 3.03% girls. Combined, the prevalence of Systolic Hypertension in the sample was 7.84%. Diastolic Hypertension (B.P>90) was prevalent in 3.58% boys and 0.43% girls. Hence, the combined prevalence of diastolic hypertension was 2.15%. Mean Measurements
Total Female 1 (0.43%) 12 (5.2%) 37 (16.01%) 111 (48.05%) 64 (27.7%) 5 (2.16%) 1 (0.43%) 231 (45.3%)
Overall there was an extremely low consumption of fruits and vegetables across all groups. Only 39.4% of the children were having fruits daily.
2 19 79 251 128 27 4 510
The mean age distribution of both boys and girls included in the study was comparable with that of boys being 15.21 and girls 15.06 years. The mean Body Mass Index for boys was 20.76 and girls was 21.02 Kg/m2. Mean systolic B.P in boys was 121.9 and that for girls was 111.84 whereas the mean diastolic B.P in boys and girls respectively was 70.42 and 68.17. The risk factors associated with systolic blood pressure included sex, BMI, adding extra table salt, being obese and smoking. The other risk factors which were found to Indian Journal of Pediatrics, Volume 73—October, 2006
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Lifestyle Associated Risk Factors in Adolescents be non-contributory were fruit intake, being nonvegetarian, consuming fastfood, physical inactivity, sporting activities, alcohol intake, family history of hypertension and stress. Family history of obesity was TABLE 2. Summary of Risk Factors for Non-communicable Diseases Risk Factor
Male n=279 Female n=231
Diet(Non-Vegetarians) 170 (61%) 149 (64.6%) Fastfood >3 times/week 93 (34.4%) 68 (29.4%) Extra Salt in food/salad 88 (31.5%) 38 (16.5%) Physical activity once in the last 1 month 10 (3.6%) 3 (1.3%) Family History of Hypertension 141 (50.5%) 112 (48.5%) Family history of obesity 64 (22.9%) 69 (29.9%) Stress (Subjective) 146 (52.3%) 112 (48.5%) Prevalence of overweight or Obesity 52 (18.6%) 38 (16.5%) Prevalence of systolic hypertension 33 (11.82%) 7 (3.03%) (systolic B.P>140) Prevalence of Diastolic Hypertension 10 (3.58%) 1 (0.43%) (Diastolic B.P>90) Sex 279/510 (54.7%) 231/510(45.3%) TABLE 3. Means of Anthropometric and Blood Pressure Values in School Children Variable BMI SYSTOLIC B.P DIASTOLIC B.P
Male (N=279)
Female (N=231)
p value
20.76 ± 4.26 121.9 ± 13.81 70.42 ± 9.43
21.02 ± 4.30 111.84 ± 12.95 68.17 ± 8.58
0.498 0.000 0.005
non-contributory to increase in systolic B.P, it however gave a positive correlation with increase in diastolic B.P. Smoking was seen to be negatively affecting increase in systolic B.P. Diastolic B.P was seen to be associated with systolic B.P, showing that they both rise together. It was also noted that an increase in a unit of diastolic B.P causes the likelihood of family history of Hypertension being present more likely. Family history of hypertension was also found to be increasing the risk for developing diastolic hypertension. Smoking however, was seen not to contribute to the increase in diastolic B.P as is seen in various other studies. BMI was seen to be negatively correlated with fastfood consumption which is probably because of dietary modification instituted by the individual and his/her family. Females were seen to be having a higher BMI on an average than males in this age group. DISCUSSION The present study was a cross-sectional one focusing on risk factors contributing to the development of non communicable diseases in students from an urban school in Delhi. The strengths include the facts that the questionnaire was administered by ex-students of the school breeding familiarity amongst the students who then become more likely to come out with true response rate and the fact that the school was co-educational with equal distribution of boys and girls. The drawback of
TABLE 4. Determinants of BMI and Blood Pressure Level in School Children Independent Variables
Dependent variables BMI
Significant
DIASTOLIC B.P
SYSTOLIC B.P
Systolic B.P
Systolic B.P
Diastolic B.P
Age
Obesity (not just increase in BMI)
Sex
Fastfood consumption more than 3 times in a week
Family history of Obesity
BMI
Sex
Family history of hypertension
Extra Salt
History of ever tried smoking
Family History of Obesity Smoking>once on the last 1 month
Insignificant
Dietary preference Extra table salt Fruit consumption Physical activity Sports Alcohol Smoking Stress Family history of hypertension Family history of Obesity Systolic B.P Diastolic B.P
Indian Journal of Pediatrics, Volume 73—October, 2006
Dietary preference Extra table salt Fruit consumption Physical activity Sports Alcohol Stress Sex BMI
Dietary preference Fruit consumption Physical activity Sports Alcohol Stress Family history of hypertension
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Akhil Kant Singh et al TABLE 5. Risk Factors Associated With Increasing Bmi Model Obese (Weight > 95th percentile) Systolic Age Fastfood >3 Times/Week Sex
Unstanderdized Coefficients 6.930 0.035 0.454 -2.27 -0.668
Standredized Coefficiennts 0.238 0.008 0.121 0.071 0.239
0.774 0.117 0.098 -0.084 -0.078
Significance 0.000 0.000 0.000 0.001 0.005
TABLE 6. Risk Factors Associated With Diastolic Blood Pressure Model Systolic History of Ever Tried Smoking OBESE (Weight>95th percentile) Family History of obesity Family history of Hypertension
Unstanderdized Coefficients B STD. ERROR 0.331 -2.2 2.169 2.056 1.351
0.24 0.674 0.729 0.786 0.676
Standerdized Coeeficients B 0.520 -0.120 0.114 0.099 0.074
Significance 0.000 0.001 0.003 0.009 0.046
TABLE 7. Variables Associated With Systolic Blood Pressure Model
Unstanderdized Coefficients B Std. Error
Diastolic Sex Bmi Extra Salt Family history of being OBESE Smoking>1 time in last 1 month
0.723 8.336 0.530 4.329 -3.340 -8.249
course is that the sample is not representative of adolescent population of all socio-economic strata. The sample was not randomly selected and therefore, it would not be appropriate to generalize it to all of urban schools in Delhi. However this study definitely provides a pointer to the direction of rising non communicable diseases and their risk factors in urban school children. The present study indicates that 3.6% boys and 1.3% girls have smoked at least once in the past month. Smoking however, did not appear to contribute to an increase in systolic B.P or BMI. The diastolic B.P rather appears to be negatively correlated with smoking. Jayant et al had reported that 49.1% of ever smokers were regular smokers in english private schools7 so these children who have tried smoking in our study have a high risk of becoming regular smokers which would then increase their risk of developing non-communicable diseases. Regarding lifestyle factors, alcohol was seen to be consumed at least once by 30.1% of boys and 26.8% of the girls. Alcohol did not seem to contribute as a risk factor to developing hypertension or obesity in our study. Data from the 2001 monitoring the Future Surveys (MTF) show that 7.7 percent of 8th graders, 21.9 percent of 10th graders and 49.8 percent of 12th graders consumed alcohol within the past 30 days (Johnston, O’Malley, Bachman,2002). The trends are therefore, far more risky in a developed country like America than in India. Fruit was being consumed on a regular basis by only 904
0.055 0.997 0.119 1.14 1.129 3.072
Standardized Coefficients Beta 0.460 0.290 0.158 0.131 -0.103 -0.091
Significance 0.000 0.000 0.000 0.000 0.003 0.007
39.4% of the children. It did not seem to contribute in any way as a risk factor. These findings are still much higher than findings of WHO ICMR study conducted in Ballabgarh by Anand et al5 whereby regular consumption of 5 portions of fruit was found to be in less than 1% of the screened population. Regarding consumption of fastfood, it appeared that children with higher BMI’s were actually consuming lesser fastfood (p=0.001) which can best be explained on the basis of dietary modification instituted at home considering their being overweight. Adding extra table salt was seen to cause a rise in systolic B.P (p=0.000). An overview of observational data obtained from population studies suggested that a difference in sodium intake of 100mmol/day was associated with average differences in systolic B.P of 5 mmHg at age 15-19 years and 10 mmHg at 60-69 years4 Neither Physical activity for more than 60 minutes daily nor active involvement in sports have shown to be affecting the BMI or the systolic and diastolic B.P. Males (45.5%) were seen to be more physically active and engaged in sports more than females (30.7%). The observed gender differences in physical activity performed in the schools were also reported by McKenzie et al from Southern California USA. 6 They too had observed a higher participation of males in moderate to severe physical activity in school both during P.E class and otherwise during lunch time and before/after school. Indian Journal of Pediatrics, Volume 73—October, 2006
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Lifestyle Associated Risk Factors in Adolescents Further, the overall level of participation in physical activity were low. Family History of Hypertension has a positive a correlation with Diastloic B.P (p=0.046), systolic B.P however, was not significantly affected by family history. Family history of obesity gives a contradictory result of having negative correlation with systolic B.P (p=0.003) and a positive correlation with increase in diastolic B.P (p=0.009). In other words, children with family history of obesity tended to have lower systolic blood pressure but higher diastolic blood pressures. Stress did not appear to be contributory to the risk factors in this age group however, a large number of students (50.6%) committed to be under some form of stress or the other. Increase in BMI contributed to increase in Systolic B.P (p=0.000) and diastolic B.P (p=0.003). According, to Mohan et al, the BMI of hypertensive adolescents in both rural and urban areas were significantly higher than respective normotensive population. 8 He et al., in a matched study (1 obese and 1 non-obese child) of 1322 Chinese children, showed that the mean difference between pairs was of approximately 5mmHg for systolic B.P and 4mmHg for Diastolic B.P with the highest levels among obese children.9 Khadilkar et al had estimated that the prevalence of obesity according to the IOTF cut off points was 5.7% whereas, the prevalence of overweight was 19.9% in 1228 urban affluent school boys in Pune.10 Other studies have demonstrated similar trends of increasing blood pressure. Blood pressure has increased over the past decade among children and adolescents. This increase is partially attributable to an increased prevalence of overweight. 11 Gupta et al studied atherosclerosis risk factors-tobacco use, obesity, hypertension, total cholesterol level and dietary intake of atherogenic nutrients in 237 adolescent school children aged 13-17 in Rajasthan. This study showed a higher prevalence of metabolic and dietary coronary risk factors among adolescent of the middle and upper middle class in India.12 A study conducted by Watkins et al in Northern Ireland showed that the B.P in adolescents had actually dropped in the past decade,13 the exact reasons for this they were not able to quantify. CONCLUSION The increase in childhood obesity over the past several decades, together with the associated health problems and costs, is a cause of grave concern among health care professionals and parents. In the developed countries the level of childhood obesity has reached epidemic proportions; over the past 25 years the prevalence of overweight or obesity doubled in American children ages 6 to 11 years of age and tripled in American adolescents ages 12 to 17 years.15 This can largely be attributed to the transformation in the lifestyles of young children from Indian Journal of Pediatrics, Volume 73—October, 2006
being physically active and consuming more of home cooked food to being more and more home bound, spending time on the internet, video games and T.V and the easy accessibility of fastfood with growing prosperity. Similar kind of a change in lifestyle is also taking place quite steadily in children of developing countries especially in urban areas and more so in the affluent class. It has been shown in various studies that the prevalence of risk factors for non-communicable diseases in childhood and adolescence bears significant tendency towards development of disease in adulthood. 17, 18, 19 Several studies have shown that primary prevention of these disorders by risk factor education in the community has better benefits compared to secondary prevention for cardio vascular mortality as well as morbidity. 20,21,22 Intervention is therefore, a necessary step at school level itself for the prevention of non-communicable diseases. Among all settings school is a priority setting to target adolescents because it offers substantial opportunities for prevention.23 REFERENCES 1. The Executive summary of the Global Burden of Disease Study, Harvard University Press. Available online at www.hsph.harvard.edu/organizations/bdu/GBDSeries.html (verified on 30/05/06) 2. de Onis M, Blossner M. Prevalence and trends of overweight among pre-school children in Developing countries. American Journal of Clinical Nutrition 2000; 72 : 1032-1039. 3. Freedman DS, Dietz WH, Srinivasan SR, Berenson GS. The relation of overweight to cardiovascular risk factors among children and adolescents: the Bogalusa Heart Study. Pediatrics 1999; 103 (pt 1) : 1175–1182. 4. Law MR, Frost CD, Wald NJ. By how much does salt reduction lower Blood Pressure? III-Analysis of data from trials of salt reduction. BMJ 1991; 302 : 819-824. 5. Anand K, Kapoor SK. Report on development of Sentinel Health Monitoring Centers in India-Ballabgarh center, funded by WHO-New Delhi, ICMR, CRHSP, AIIMS, July, 2004. 6. McKenzie TL, Marshall SJ, Sallis JF, Conway TL. Leisure time physical activity in school environments:an observational study using SOPLAY. Preventive Medicine 2000; 30 : 70-77. 7. Jayant K, Notani PN, Gualti SS et al. Tobacco usage in school children in Bombay, India. A study of knowledge, attitude and practise. Indian Journal of Cancer 1991; 28 : 139-147. 8. Mohan B, Kumar N, Aslam N et al. Prevalence of sustained hypertension and obesity in urban and rural school going children in Ludhiana. Indian Heart Journal 2004; 56(4) : 310-314. 9. He Q, Ding ZY, Fong DY, Karlberg J. Blood Pressure is associated with BMI in both normal and obese children. Hypertension 2000; 36 : 165-170. 10. Khadilkar VV, Khadilkar AV. Prevalence of Obesity in affluent school boys in Pune. Indian Pediatrics 2004; 41 : 857-858. 11. Munter P, He J, Cutler JA, Wildman RP, Whelton Pk. Department of Epidemiology, School of Public Health and Tropical Medicine, Tulane University, New Orleans, La 70112, USA.
[email protected] PMID: 15126439 [PubMed indexed for MEDLINE 12. Gupta R, Goyale A, Kashyap S et al. Prevalence of atherosclerosis risk factors in adolescent school children. Indian Pediatrics 1997; 34 : 923-927.
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Akhil Kant Singh et al 13. Watkins D, McCarron P, Murray L, Cran G, Boreham C, Robson P, McGartland C, Smith G. BMJ. 2004 July 17; 329(7458) : 139. 14. Hofmann AD. Obesity. In Hofmann AD, Greydanus DE, eds. Adolescent Medicine, 3rd ed., Stamford, CT, Appleton & Lange, 1997; 663-682. 15. Dietz WH. Overweight in childhood and adolescence. N Engl J Med 2004; 350 : 855-857. 16. Sinalko AR, hypertension in children. NEJM 1996; 335 : 1968 1973. 17. McCarron P, Davey Smith G, Okasha M, McEwen J. Blood pressure in young adulthood and mortality from cardiovascular disease. Lancet 2000; 355 : 1430-1431. 18. Kurpad AV, Swaminathan S, Bhat S. IAP National Task Force for Childhood Prevention of Adult Diseases; the effect of childhood physical activity on prevention of adult diseases.
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Indian Pediatrics 2004;(41) : 37-62. 19. Whitaker RC, Wright JA, Pepe MS et al. Predicting obesity in young adulthood from childhood and parental obesity. NEJM 1997; 337 : 869-873. 20. Beaglehole R. Medical management and the decline in mortality from coronary heart disease. BMJ 1986; 292 : 33-35. 21. Capewell S, Morrison CE, McMurray JJ. Contribution of modern cardio vascular treatment and risk factor changes to the decline in coronary heart disease mortality in Scotland between 1975-1994.Heart.1999;81:380-386 22. Unal B, Critchley JA, Capewell S. Explaining the decline in CHD in England and Wales between 1981-2000. Circulation 2004; 109 : 1101-1107. 23. WHO Information Series on School Health, Document Five: Tobacco Use Prevention: an important entry point for the development of health promoting school. Geneva, WHO, 1999.
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