ORIGINAL ARTICLE
Prevalence and associated factors related to disordered eating in high school adolescents of Guadalajara, according to sex† Bertha Lidia Nuño-Gutiérrez,* Alfredo Celis-de la Rosa,** Claudia Unikel-Santoncini*** * Epidemiologic and Adolescent Health Services Research Unit (Unidad de Investigación Epidemiológica y en Servicios de Salud del Adolescente), IMSS/Universidad de Guadalajara. ** Clinical Research Unit (Unidad de Investigación Clínica), IMSS/Universidad de Guadalajara. *** Epidemiological and Psychosocial Research Head Office (Dirección de Investigaciones Epidemiológicas y Psicosociales). Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz. ABSTRACT Objective. To determine the prevalence and associated factors to disordered eating (DE) in adolescents across sex. Material and methods. A sectional and analytic study was carried out with 1,134 first grade students at a public high school. We evaluated self-esteem, impulsiveness, depressive symptoms, suicidal ideation, leisure, locus of control, relationship with father/mother, stress and DE by means of previous validated and standardized scales. Results. A prevalence of 7.2% of disordered eating was obtained; 2.8% for men and 10.3% for women. In men, the risk analysis maintained association for impulsivity, depressive symptoms, suicidal ideation and stress. After the multivariate analysis only depression and stress retained association. In the case of women, in the risk analysis they retained association for impulsiveness, depressive symptoms, suicidal ideation and stress. After the multivariate analysis, only impulsiveness, suicidal ideation and stress retained association. Conclusions. DE prevalence was higher in the case of women. Associated factors for men were depressive symptoms and stress, while for women the associated factors were impulsiveness, suicidal ideation and stress.
Prevalencia y factores asociados a las conductas alimentarias de riesgo en adolescentes escolares de Guadalajara según sexo RESUMEN Objetivo. Determinar la prevalencia y factores asociados a conductas alimentarias de riesgo (CAR) en adolescentes según sexo. Material y métodos. Estudio transversal analítico con 1,134 estudiantes de primer año de bachillerato de una preparatoria pública. Se evaluó autoestima, impulsividad, síntomas depresivos, ideación suicida, recreación, locus de control, relación con padre/madre, estrés y CAR mediante escalas validadas y estandarizadas. Resultados. Prevalencia de CAR 7.2%; 2.8% para hombres y 10.3% para mujeres. En los hombres en el análisis de riesgo, retuvieron asociación impulsividad, síntomas depresivos, ideación suicida y estrés. Después del análisis multivariado sólo depresión y estrés retuvieron asociación. En mujeres en el análisis de riesgo, retuvieron asociación impulsividad, síntomas depresivos, ideación suicida y estrés. Después del análisis multivariado sólo impulsividad, ideación suicida y estrés retuvieron asociación. Conclusiones. La prevalencia de CAR fue mayor en mujeres. Los factores asociados en hombres fueron síntomas depresivos y estrés, para mujeres impulsividad, ideación suicida y estrés.
Key words. Adolescents. Disordered Eating. Youth. Eating Disorders. Mental Health.
Palabras clave. Adolescentes. Conductas alimentarias de riesgo. Jóvenes. Trastornos de conducta alimentaria. Salud mental.
INTRODUCTION
(ED) began in Mexico. Although the greatest number of treatment centers and of researchers devoted to the study of this problem are concentrated in the city of Mexico, in recent years the number of care
Twenty years have gone by since specialized attention and systematic research on eating disorders †
Translated from Spanish by Mónica Portnoy,
[email protected], August 2009.
286 de Investigación Clínica / Vol. 61, Núm. 4 Unikel-Santoncini et al. Revista / Julio-Agosto, C, 2009 / Prevalence pp 286-293 and associated factors. Rev Invest Clin 2009; 61 (4): 286-293 Full text of this article available in internet:: www.imbiomed.com.mx
centers in other regions of the country and the studies in urban and rural areas have increased.1-8 The National Survey on Psychiatric Epidemiology 2001-20029 (ENEP for its initials in Spanish), carried out to a population within 18 and 65 years old calculated a prevalence of 1.8% of bulimia nervosa in women and of 0.6% in men and no cases of anorexia nervosa were reported. This prevalence is similar to the one reported in international studies, which fluctuates between 1 and 1.5%. It is considered that the prevalence of bulimia nervosa surpasses at least twice that of anorexia nervosa and that the prevalence of the partial syndromes exceeds twice that of complete syndromes. 10 Longitudinal studies suggest that a progression in the degree of eating pathology takes place in the general population, in such a way that who diets to lose weight, sometimes can become pathological dietitians and can develop a partial or complete syndrome. The continuum theory points out that most people who diet develop a severe pathology, for which is important the early detection due to the fact that it is impossible to know which individuals will develop greater severity.11 The 2006 National Health and Nutrition Survey12 carried out with 25,166 adolescents between 10 and 19 years old, both from urban and rural areas, reported a national prevalence of DE of 0.7% (0.4% for men and 0.9% for women), the percentage of weight gain concern reached 7% in the case of men and up to 26% in the case of women; 9% of men practiced binge eating, while women used this practice in 12% of the cases; excessive exercising showed 2.4% for men, while women reported up to 7% in fasting practices, 2.5% in weight loss diets and excessive exercising and one percent of them told they were using duretics in order to lose weight. Highest percentages of weight gain concern, binge eating practices and excessive exercising were found in northern and center-western regions, and Jalisco belongs to the latter one. Although some studies have been carried out in the state of Jalisco, most of them are graduate dissertations for psychology and nutrition studies which have estimated the DE prevalence and have identified associated factors of individual, family and social order.13 However, the methodology used has been varied and little systematized, which responds to the considerable variability found in the DE and ED proportions found. The percentages found in women vary between 3% in high school students,5 14% in college students,8 to 8%14 and 16% in university students.8 In the case of men, percentages go from
0.2% in high school students5 to 7% in college students.14 Explanatory models on the ED etiology have reached the conclusion that they are pathologies of multicausal origin, in which factors of sociocultural, family, biological, and individual order are involved.13 Those who are carrying out research in the area, have identified some of these factors as precursors, such as self-esteem and negative affect (depression and anxiety); while other factors correlate importantly and play the role of illness detonators, such as environmental stressors, or some personality characteristics like cognitive styles, the locus of control or impulsiveness.10 Although there exists a long trajectory in the study of family dynamics in eating disorders, more recently the influence of critical comments on physical appearance has been studied,15 particularly, some rearing practices such as father’s control and criticism, or mother’s demands, which are considered to increase the risk of DE, while maternal love acts like a protective factor.8,16 Besides, we have found that people who present DE usually have difficulty in their interpersonal relationships and they tend to isolate themselves or to establish troubled relationships, which hinders to establish social and support networks.17 However, the study of these psychosocial factors has been carried out in an isolated way and these factors have not been explored in Mexico before, which brought us to determine the objective of this study as the estimation of DE prevalence and its association with psychosocial factors in students according to sex. MATERIAL AND METHODS The present one was an analytical, cross sectional study which included the total number of first and second semester students of high school Number 5 belonging to the University of Guadalajara which integrates a cohort and whose first evaluation was in the second school semester of 2006. For data gathering we evaluated nine indicators of mental health by means of a self-reported survey that comprised 220 questions. The outcome variable was DE, evaluated through the Brief Questionnaire of Risky Eating Behaviors (Cuestionario Breve de Conductas Alimentarias de Riesgo, CBCAR, by its initials in Spanish),18 validated in adolescent women and youth from the Federal District.19 This questionnaire was developed following the diagnostic criteria of the DSM IV. Its internal reliability was of
Unikel-Santoncini C, et al. Prevalence and associated factors. Rev Invest Clin 2009; 61 (4): 286-293
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0.83, the sensibility of 0.81 and the specificity of 0.78 with a cutoff point of > 10. DE is defined as those eating behaviors which do not fulfill the frequency and intensity of eating disorders according to the diagnostic criteria of the DSM-IV.19 The Brief Questionnaire includes a question about the concern of weight gain and nine questions on eating behaviors with the aim of losing weight during the three previous months to the application of the survey (dieting, binge eating, self-induced vomiting, fasting, excessive exercising, use of laxatives, pills and diuretics), with four answering options: • • • •
Never or hardly ever, Sometimes, Frequently (twice a week) and Very frequently (more than twice a week).
The predicting variables evaluated were the following: 1. Daily Stress.20, 21 2. Chance locus of control;22 affectivity23 and internality.22 3. Rosenberg self-esteem scale,24 validated and revalidated for Mexican junior high and high school students.20, 21, 25, 26 4. Impulsiveness,27 validated for adolescent Mexican students.20, 21, 26 5. Depressive Symptoms (CES-D),28 validated and revalidated for adolescent Mexican junior high and high school students.20,21,29 6. Suicidal ideation,30 validated and revalidated for adolescent Mexican junior high and high school students.20,21,29 7. Leisure through the scale of spare time use from the National Students Survey (Encuesta Nacional de Estudiantes).31 8. Relationship with father/mother,27 validated and revalidated for adolescent Mexican students.20,21
All these scales have Likert type answers and the cutoff point for each one (presence/absence, high/low) has been defined by calculating the average plus/less one standard deviation for each sex.20-31 Additionally, sociodemographic and school environment data such as age, sex, semester, shift, school calendar, if he/she was a regular or irregular student and if he/she had been a student or if he/she worked besides studying during the previous year to the survey application were explored. Surveys application was carried out in the classrooms by a team of high school teachers previously
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qualified. The rate of listed students’ location by classrooms was of 93%, since there were students that had deserted or they had changed to another school. There were some cases of irregular students who were studying the third semester, but who were repeating second semester subjects. Once the study objective had been explained to the students, they were requested for their written informed consent. The rate of acceptance was of 100%. The project was presented and approved by the school authorities. For the statistical analysis, the studied sample was divided according to sex, and for each sex DE prevalence associated to each studied risk factor was considered. For the raw Odds Ratios (OR) we used 2x2 contingency tables, and the statistical significance was calculated by means of a Chi-square test with three degrees of freedom. For the adjusted Odds Ratios we used logistic regression. 32 The significance level was defined as α = 0.05. The Odds Ratios are presented with a confidence interval of 95%. Finally, from the outcomes of the logistic regression, we present a model predictive. The statistical analysis has been made using SPSS 15 for Windows. RESULTS Table 1. Sociodemographic features of the sample. Feature Age (average)
Men n = 463 (%)
Women n = 671 (%)
15.3
15.0
Semester: First Second Third
168 (36) 291 (63) 4 (0.9)
225 (33.5) 443 (66) 3 (0.5)
Shift: Morning Evening
251 (54) 212 (46)
367 (55) 303 (45)
Last year activity: He/she hasn’t been a student 105 (23)* Student 256 (55)* He/she studied and worked 89 (19)*
164 (25)* 422 (63)* 59 (9.0)*
Type of student: Regular Irregular
618 (92) 41 (6)
417 (90) 33 (7)
Disoreded eating in the last three months: Present 13 (2.8)* Absent 450 (97.2)
69 (10.3)* 602 (89.7)
* p < 0.05. Statistical significance value is the comparison between men vs. women by means of a proportion analysis as well as the use of the chi-square test with one degree of freedom.
Unikel-Santoncini C, et al. Prevalence and associated factors. Rev Invest Clin 2009; 61 (4): 286-293
Table 2. Disordered eating frequencies comparison according to answering options in men and women high school students from the Brief Questionnaire on Risky Eating Behavior (CBCAR). Eating behavior
Never-hardly ever Men n (%)
Concern on weight gaining Binge eating Lack of control when eating Self-induced vomiting Fasting Dieting Excessive exercising Pills use Diuretics use Laxatives use
242 215 346 437 409 369 323 431 405 397
(52.3) (46.4) (74.4) (94.4) (88.3) (79.7) (50.1) (93.1) (87.5) (85.7)
Sometimes
Women n (%)
Men n (%)
Women n (%)
Frequently (twice a week) Men Women n (%) n (%)
164 359 470 602 522 424 252 622 586 579
118 (25.5) 168 (36.3) 89 (19.2) 8 (1.7) 25 (5.4) 65 (14.0) 103 (22.2) 13 (2.8) 14 (3.9) 17 (3.7)
192 (28.6) 197 (29.1) 125 (18.6) 39 (5.8) 84 (12.5) 145 (21.6) 225 (33.5) 20 (3.0) 13 (1.9) 15 (2.2)
43 (9.3) 41 (8.9) 11 (2.4) 2 (0.4) 10 (2.2) 13 (2.8) 56 (12.1) 3 (0.6) 1 (0.2) 2 (0.4)
(24.4) (53.5) (70.0) (89.7) (77.8) (63.2) (37.6) (92.7) (87.3) (86.3)
90 (13.4) 62 (9.2) 36 (5.4) 7 (1.0) 26 (3.9) 36 (5.4) 80 (11.9) 5 (0.7) 2 (0.3) 3 (0.4)
Very frequently more than twice a week) Men Women n (%) n (%)
P*
51 (11.0) 26 (5.6) 6 (1.3) 4 (0.9) 8 (1.7) 6 (1.3) 62 (13.4) 4 (0.9) 2 (0.4) 3 (0.6)
