A Profile of Early Versus Late Onset of Obesity in Postmenopausal Women

Transcription

1 JOURNAL OF WOMEN S HEALTH & GENDER-BASED MEDICINE Volume 9, Number 9, 2000 Mary Ann Liebert, Inc. A Profile of Early Versus Late Onset of Obesity in Postmenopausal Women SUSAN McCRONE, Ph.D., R.N., 1 KAREN DENNIS, Ph.D., R.N., F.A.A.N., 2 NAOMI TOMOYASU, Ph.D., 3 and JAN CARROLL, M.S., R.N. ABSTRACT Obesity is a serious health problem among women across the life span. Although people can become obese at any age, there is a large proportion of older women who have been obese since childhood. The purpose of this study was to determine whether postmenopausal women with an early versus late onset of obesity manifested differences in body habitus, eating behaviors, and mood. One hundred thirty-five postmenopausal women with obesity responded to self-report questionnaires on weight history, weight loss and maintenance expectancy, eating behaviors, and mood. Women with an early onset of obesity had a significantly higher body mass index (BMI), waist circumference, and highest attained adult body weight than women with a late onset of obesity. They had attempted a significantly larger number of diets and had lost more weight on any single diet. The groups also differed significantly on binge eating and overeating in response to negative affect. There was a tendency for women with an early onset to have more depressive and anxious symptoms. Postmenopausal women with an early onset of obesity differed physiologically and psychologically from those with a late onset. Tailoring dietary and behavioral interventions to profiles of postmenopausal women based on onset of obesity may improve the overall efficacy of weight loss programs. INTRODUCTION OBESITY IS A SIGNIFICANT public health problem among women across the life span. Obesity has been defined as a body mass index (BMI) (weight in kilograms divided by height in meters squared) greater than 30 (kg/m 2 ). 1 Despite a flourishing weight loss industry and a high rate of voluntary dieting, the prevalence of obesity continues to increase in both children and adults. 1,2 In Western countries, the proportion of the population with obesity increases steadily in each decade of life until the age of 60. Although people can become obese at almost any age, there is a substantial proportion of obese older adults who have been obese since childhood. 3 A few recent studies have examined the issue of onset of obesity, but they have focused on the incidence of obesity in adulthood related to childhood obesity and have not assessed physiological and psychological differences between adults with an early (beginning before age 18), versus late (be- University of Maryland and VA Maryland Health Care System, Baltimore, Maryland. 1 Present address: West Virginia University School of Nursing, Morgantown, West Virginia. 2 Present address: University of Central Florida School of Nursing. 3 Present address: AIDS Administration, Maryland Department of Health and Mental Hygiene. Supported by NIH RO1 NR03514 (K.D.), VA Postdoctoral Nurse Fellowship (S.M.), the Baltimore VA Geriatric Research, Education and Clinical Center, and the Geriatrics and Gerontology Education and Research Program, University of Maryland, Baltimore. 1007

2 1008 MCCRONE ET AL. ginning at or after age 18) onset of obesity. Clinical experience, however, suggested that women with an early onset of obesity have different needs from those with a late onset of obesity. These clinical insights led to the development of this study to evaluate similarities and differences between the groups based upon the onset of obesity. A review of eight prospective studies revealed that about one third of obese preschool children and about one half of obese grade school children remained obese throughout adulthood. In addition, the risk of obesity in adulthood was twice as high for obese children as for nonobese children. 4 In a longitudinal study evaluating the BMI of 555 subjects ranging in age at first measurement from 1 to 18 years, the odds ratios (OR) for being overweight (75th percentile) in adulthood (age 35) were about 2:4 for those people who had also been overweight from ages 8 to 18. Ratios were also consistently higher for subjects who were very obese as children. 5 A study examining ethnic variations in cardiovascular disease (CVD) factors among children and young adults found that BMI levels were significantly higher for black and Mexican American girls than for white girls, with ethnic differences evident by the age of 6 9 years. 6 An early onset of obesity, occurring before adulthood, in conjunction with parental obesity is strongly associated with a disproportionate number of cases of obesity in adulthood. This fraction appears to increase with the severity of obesity during childhood. 7 Lack of homogeneity among obese individuals presents a challenge to investigators and clinicians. In general, demographic data and diet history, such as age, number of previous diets, and age at onset of obesity, 8 are not successful in differentiating among obese individuals. 9 Obese women tend to eat more in response to emotional arousal, not just hunger, and to have a more negative self-image than their nonobese counterparts. 10 Previous studies have determined that negative mood 11 and stress 12 are major triggers for binge eating in women. Few recent studies have examined the issue of onset of obesity, and none have investigated whether there are differences in demographics, diet history, eating behaviors, and mood between individuals with early versus late onset of obesity. This study was designed to assess whether there were differences in the weight, body habitus, weight history, eating behavior, and psychological profiles of obese postmenopausal women who experienced an early versus late onset of obesity. The evaluation of women based on the onset of obesity could provide new directions for tailoring interventions that target the different behavioral needs of the two groups. MATERIALS AND METHODS One hundred thirty-five obese (BMI , mean 6 SD) postmenopausal women age ( years) were recruited from the Baltimore area to participate in a large, longitudinal, universitybased weight loss study examining the effect of diet and exercise on metabolic and psychological outcomes. Because this sample was taken from the baseline measures of the larger study, the inclusion criteria for the larger study were used. Inclusion criteria were (1) postmenopausal (no menses) for at least 1 year; (3) BMI 27 40, (3) absence of any metabolic, endocrine, pulmonary, musculoskeletal, renal, or cardiovascular disease that might affect weight, metabolic outcomes, or both, (4) no medication, including estrogen, that might affect glucose metabolism, lipoprotein lipids, or blood pressure, (5) nonsmoker, (6) no evidence of clinical depression, as measured by a cutoff of 16 on the Center for Epidemiological Studies Depression Scale (CES-D), 13 and (7) only a moderate consumption of alcohol. The majority of the subjects were Caucasian (71%) and African American (25%), ranging in age from 50 to 67 years. Age at onset of obesity was determined by a self-report questionnaire on weight history administered at baseline as part of an initial assessment for inclusion in a larger weight loss intervention study. All the women in this sample met the inclusion criteria but may not have entered or completed the larger study. Early onset obesity (,18 years) was defined as obesity occurring in childhood and adolescence based on the perception of the respondent, and late onset obesity ($18 years) was defined as obesity occurring in adulthood. Prior to data collection, the study was approved by the University of Maryland, Baltimore, Institutional Review Board, and written informed consent was obtained. Women completed self-report questionnaires as part of a screening process to determine their eligibility to participate in a larger obesity treatment study. Body weight and

3 PROFILE OF OBESITY ONSET 1009 height without shores were obtained to calculate BMI. Waist/hip ratio (WHR) was calculated by dividing the minimal circumference at the waist by the circumference at the maximum gluteal protuberance. A number of self-report questionnaires were administered to determine weight history, history of weight loss, and maintenance expectancies. A questionnaire designed by the investigator and used in previous research 14 was used to ascertain the weight history. Women identified their highest and lowest adult weights and the age at which these occurred, the number of weight loss attempts in which they lost 10 or more pounds, and the most weight they had ever lost on a diet. Women used a graded scale (0 100%) to report how certain they were that they would be successful at losing weight and how certain they were that they would be able to maintain weight loss following treatment. Eating behaviors were also evaluated using a series of self-report questionnaires. The Binge Eating Scale (BES) 15 is a 16-item sale that assesses behaviors related to binge eating. Indicators of binge eating include eating what is subjectively perceived to be large amounts of food and feelings/cognitions, such as guilt and fear of being unable to stop. This questionnaire has good internal consistency reliability and construct validity. Following the procedures of Marcus et al., 16 women with scores of 17 or less were classified as nonbingers, and those with scores of 18 and greater were classified as bingers. The Eating Self-Efficacy Scale (ESES) 17 is a 25- item scale that measures difficulty in overeating in varius psychological states and social situations identified as the negative affect and social eating subscales. Each subscale (negative affect or social situations) demonstrated internal consistency ( ) and test-retest reliability (0.70), as well as construct and predictive validity in developmental studies. The Eating Behavior Inventory (EBI) 18 assesses the use of behavioral modification techniques, such as self-monitoring of food intake, shopping patterns, and meal planning habits, demonstrated to be conductive to weight loss. It is a 26- item scale with established split-half reliability of 0.62 and test-retest reliability of Good internal consistency, reliability, and concurrent and discriminant validity have also been established. Because mood is often affected by and affects eating behaviors, depression and anxiety were evaluated. The CES-D 13 was developed for use in general as well as clinically depressed populations, measuring an individuals level of depressed symptomatology. Unlike other scales, it does not contain items that reflect diminished intake or changes in eating patterns as symptoms of depression, which might be natural occurrences in obese individuals trying to lose weight. In Radloff s developmental studies, this 20-item Likert-type scale revealed internal consistency reliabilities ranging from 0.85 to 0.94, and test-retest reliabilities of as well as construct and criterion-related validity. The Spielberger State-Trait Inventory (Form Y- 2) 19 is a 40-item scale that has been tested extensively in both research and clinical environments. In this study, only the trait scale (20 items) was administered. Because stress is a major impetus to eat and the number one predictor of relapse after weight loss, the trait form of this measure was used to evaluate the relatively stable feelings of tension, apprehension, nervousness, and worry. It has a 4-point Likert-type format and strong evidence for reliability and validity. Internal consistency reliabilities are.0.90, and test-retest reliability typically exceeds Contrasted groups concurrent, divergent, and criterion-related validity have been demonstrated and replicated. Independent sample t tests were used to compare body habitus, weight history, weight loss and maintenance expectancy, eating behaviors, and mood between women with an early versus late onset of obesity. Chi-square analysis was used to determine group differences on demographic data. RESULTS Of the 135 women in this study, 43 reported an early (,18 years) and 92 a late ($18 years) onset of obesity (Table 1). There were no significant differences in age between those with an early versus late onset of obesity. A greater percentage of women with an early onset of obesity (25%) were single as compared with those with a late onset (13%). Women with a late onset tended to be better educated, with nearly 83% having completed some college. Chi-square statistics for categorical data revealed no significant differences between the groups. Although women with an early onset of obesity had a significantly higher BMI and waist circumference than women with a late onset (Table 2), differences in weight and height did

4 1010 MCCRONE ET AL. TABLE 1. DEMOGRAPHIC CHARACTERISTICS OF WOMEN WITH EARLY VERSUS LATE ONSET OF OBESITY a Total sample Early onset Late onset Age (years) Ethnicity White 71.2% 83.3% 65.6% African American 25.0% 14.3% 30.0% Other 3.8% 2.4% 4.4% Marital status Single 16.5% 25.0% 12.6% Married 56.7% 60.0% 55.2% Divorced/separated 26.8% 15.0% 32.3% Education,High school 8.7% 7.5% 9.2% High school 11.8% 20.0% 8.0% Some college 48.8% 40.0% 52.9% College graduate 30.7% 32.5% 29.9% Work status Retired 24.8% 25.6% 24.4% Employed 63.2% 61.5% 64.1% Unemployed 12.0% 12.8% 11.5% a No significant differences were noted in chi-square analyses not reach significance. In terms of weight history, there were a number of significant differences between the women in the two groups (Table 3). The average maximum weight ever attained for the early onset group was significantly higher than that of the late onset group. In addition, the early onset group attained their highest weight at an average age of 52, which was significantly younger than the late onset group, who reached their maximum weight at age 57. In contrast, the lowest adult weight for the early onset group was significantly higher than that of the late onset group and occurred at an older age (32 years versus 29 years). The early onset group had attempted twice as many weight loss diets as the late onset group and had lost significantly more weight at each attempt. Despite having dealt with weight problems for a longer time, the early onset group had a tendency to be more certain about losing weight but had no greater certainty of maintaining their weight loss. In regard to their eating behaviors (Table 4), the early onset group reported significantly greater difficulty controlling overeating during times of negative affect as well as more binge eating symptomatology. However, the use of behaviors conducive to weight management was not significantly different between the groups. Although self-reported depression was relatively low across all women in the sample, the early onset group showed a tendency to be more depressed ( versus ) (p, 0.09) and more anxious ( versus ) (p ) than the late onset group. DISCUSSION These results raise some important issues for tailoring interventions to treat obesity in postmenopausal women. Women who have dealt with obesity since childhood seem to portray a TABLE 2. MEASURES OF BODY HABITUS OF WOMEN WITH EARLY VERSUS LATE ONSET OF OBESITY Total sample Early onset Late onset BMI (kg/m 2 ) * Weight (kg) Height (m) Waist circumference (cm) * *p, 0.05.

5 PROFILE OF OBESITY ONSET 1011 TABLE 3. WEIGHT HISTORY OF WOMEN WITH EARLY VERSUS LATE ONSET OF OBESITY Total Early onset Late onset sample (,18 years) ($18 years) Most ever weighed (kg) a ** Age at most weighed (years) ** Least ever weighed (kg) *** Age at least weighed (years) * Weight lost attempts * (0 100) (0 100) (0 50) Most weight lost on a diet ** (kg) Certainty of losing weight Certainty of keeping off lost weight a Mean 6 SD. *p, **p, ***p, different body habitus, behavioral, and weight history profile than those who became obese later in life. Demographically, a larger percentage of women with an early onset of obesity were white and single and tended to be less well educated than the last onset group. The higher percentage of early onset women who were white is in contrast to the work of Winkleby et al., 6 who found a higher percentage of obesity in black and Hispanic children. This difference could be explained by the small number of African American women in this study and by selection bias that may have occurred because of the location of the larger study in an urban hospital. This finding would need to be replicated using a sample with a larger number of ethnically diverse subjects. In relation to body habitus, these findings are congruent with the work of Noble, 20 who also TABLE 4. identified a higher BMI in women with an early onset of obesity, but this study adds the important component of a greater waist circumference. The significantly higher BMI and waist circumference in early onset women is of particular concern because of the strong association with the metabolic syndrome of hyperlipidemia, hypertension, and type 2 diabetes 21 and accelerated atherosclerosis and CVD death. 22 As these conditions are major risk factors for CVD complications, such as stroke and myocardial infarction, women with an early onset of obesity could be at a greater risk for the development of these diseases. Additionally, because waist circumference is strongly associated with abdominal fat and excess abdominal fat is an independent predictor of CVD, these women could be at an even greater risk. 23 Although a difference in BMI of 2.4 and in EATING BEHAVIORS OF WOMEN WITH EARLY VERSUS LATE ONSET OF OBESITY Total Early Late sample onset onset Eating self-efficacy a Negative affect subscale b ** Social eating subscale Binge eating scale a * Number scoring above (40%) 22 (51%) 31 (33%) (n, %) Eating behaviors conducive to weight loss a Lower scores are better. b Mean 6 SD. *p, **p, 0.01 versus early onset.

6 1012 waist circumference of 5.6 cm between the groups at this level of obesity may not seem clinically significant, it is consistent with other research findings. If early onset postmenopausal women are reaching their highest weight earlier, the number of years of obesity may place an added burden on an aging cardiovascular system. The early versus late onset obese women also differed in their weight history. Women with an early onset of obesity reported highest and lowest body weights that were significantly greater than women with a late onset. Although the highest weights occurred within the fifth decade of life for both groups, women with an early onset attained this weight 5 years earlier than those with a late onset. This suggests the trajectory of weight gain is different for these two groups. Although the early onset women in this study had engaged in more weight loss attempts, probably because they had been dealing with obesity for a longer period of time, they had a tendency to be more certain about losing weight and were as certain as the late onset women that they would maintain their weight loss. Perhaps this optimism can be attributed to success at previous weight loss efforts, with the early onset women losing significantly more weight on diets than the late onset women. However, treatment of obesity in adult women remains an area in which little success has been achieved, as long-term follow-up indicates that most patients return to their baseline weights within 3 5 years after termination of treatment. 24 Characteristics of eating behaviors also differed significantly between women with an early versus late onset of obesity. Women with an early onset of obesity reported significantly greater negative affect eating, reflecting the use of eating as a coping mechanism to deal with feelings of depression, anger, and anxiety. Obese women in general tend to eat more in response to emotional arousal, not just hunger, than nonobese women, 14,25 and this seems particularly true for women with an early onset of obesity. Although the women with an early onset had a tendency to score higher on the self-reported depression and anxiety scales, they did not manifest significant differences in depression or anxiety from women with late onset obesity. This may be related to the exclusion criteria for the study (CES-D, 16), as other investigators have found that childhood onset obesity is associated with higher levels of psy- chological distress and psychiatric symptomatology. 26 Over half of the women with an early onset of obesity compared with a third of the women with a late onset scored over 18 on the BES, which is suggestive of a problem with binge eating. Strong associations among binge eating, depressive symptomatology, and psychological distress have already been identified by other investigators. 16 This suggests that the emotional needs women try to meet through food may need to be addressed before weight loss efforts can be successful and sustained. These findings have implications for the refinement and planning of future weight loss interventions for older obese women. There are, however, a number of limitations of the study that affect its generalizability. This study includes a relatively small and homogeneous sample. Selfreport measures were administered requesting that women recall previous weight history information. Because the larger study excluded postmenopausal women taking hormone replacement therapy, the results of this study can not be generalized to this group of women. Despite these limitations, it is important for clinicians to take a complete weight history, with onset and family history of obesity included. Eating behaviors and mood assessment scales should be administered to determine if binge eating, depression, or anxiety is contributing to the obesity. Tailoring components of obesity treatment to address the factors associated with the onset of obesity may improve affective states and the long-term success of weight loss programs. Given differences in BMI and waist circumference that predispose women to higher CVD risk, the negative affective component of eating, the number of diets attempted, and the difference in weight gain trajectory, it appears that women with an early onset of obesity need to begin these tailored behavioral weight loss interventions early in life and continue them across the life span. REFERENCES MCCRONE ET AL. 1. Troiano RP, Flegal KM, Kuczmarski RJ, Campbell SM, Johnson CL. Overweight prevalence and trends for children and adolescents: The National Health and Nutrition Examinations Surveys, 1963 to Arch Pediatr Adolesc Med 1995;149:1085.

7 PROFILE OF OBESITY ONSET Galuska D, Serdula M, Pamuk E, Byers T. Trends in overweight among U.S. adults from : A multi-state telephone survey. Am J Public Health 1996; 86: Bouchard C. Obesity in adulthood The importance of childhood and parental obesity. N Engl J Med 1997;337: Reaven K, Serdula MK, Ivery D, et al. Do obese children become obese adults? A review of the literature. Prev Med 1993;22: Guo SS, Roche AF, Chumlea WC, Gardner JD, Siervogel RM. The predictive value of childhood body mass index values for overweight at age 35 y. Am J Clin Nutr 1994;59: Winkleby MA, Robinson TN, Sundquist J, Kraemer HC. Ethnic variation in cardiovascular disease risk factors among children and young adults: Findings from the Third National Health and Nutrition Examination Survey, JAMA 1999;281: Whitaker RC, Wright JA, Pepe MS, Seidel KD, Dietz WH. Predicting obesity in young adulthood from childhood and parental obesity. N Engl J Med 1997; 337: Dubbert PM, Wilson CT. Goal-setting and spouse involvement in the treatment of obesity. Behav Res Ther 1984;22: Stotland S, Zuroff D. Relations between multiple measures of dieting self-efficacy and weight change in behavioral weight control program. Behav Ther 1991; 22: Thompson JK. Body image disturbance: Assessment and treatment. In: Goldstein AP, Krasper L, Garfield SL, eds. Psychology practitioner guidebook. New York: Pergamon Press, Fairburn CG, Wilson GT, eds. Binge eating: Nature, assessment, and treatment. New York: Guilford Press, Wing RR, Marcus MD, Epstein LH, Kupfer D. Mood and weight loss in a behavioral treatment program. J Consult Clin Psychol 1983;5: Radloff LS. The CES-D Scale: A self-report depression scale for research in the general population. Appl Psychol Meas 1977;1: Dennis KE, Goldberg AP. Weight control self-efficacy types and transitions affect weight-loss outcomes in obese women. Addict Behav 1996;21: Gormally J, Black S, Daston S, Rardin T. The assessment of binge eating severity among obese persons. Addict Behav 1982;7: Marcus MD, Wing RR, Hopkins J. Obese binge eaters: Affect, cognitions, and response to behavioral weight control. J Consult Clin Psychol 1988;56: Glynn SM, Ruderman AJ. The development and validation of an Eating Self-Efficacy Scale. Cogn Ther Res 1986;10: O Neil PM, Currey HS, Hirsch AA, et al. Development and validation of the Eating Behavior Inventory. J Behav Assess 1979: Speilberger C. STAI Self-evaluation questionnaire. Palo Alto: Consulting Psychologists Press, Noble RE. The incidence of parental obesity in overweight individuals. Int J Eat Disord 1997;22: DeFronzo RA, Ferrannini E. Insulin resistance: A multifaceted syndrome responsible for NIDDM, obesity, hypertension, dyslipidimia, and atherosclerotic cardiovascular disease. Diabetes Care 1991;14: Lapidus L, Bengtson C, Larsson B, Pennert K, Rybo E, Sjostrom L. Distribution of adipose tissue and risk of cardiovascular disease and death: A 12-year follow-up of participants in the population study of women in Gothenberg, Sweden. Br Med J 1984;289: National Stroke Association. The road ahead: A stroke recovery guide. Englewood, CO: National Stroke Association, Brownell KD, Jeffery RW. Improving long-term weight loss: Pushing the limits of treatment. Behav Ther 1987;18: Hooker D, Convisser E. Women s eating problems: An analysis of a coping mechanism. Personnel and Guidance 1983: Mills JK, Andrianopoulos GD. The relationship between childhood onset obesity and psychopathology in adulthood. J Psychol 1993;127:547. Address reprint requests to: Susan McCrone, Ph.D., R.N. West Virginia University School of Nursing 6500 Health Sciences South P.O. Box 9630 Morgantown, WV