Stephen S. Rubin, Ph.D. is a postdoctoral research fellow at the Rehabilitation Research and Training Center on Aging with Mental Retardation at University of Illinois at Chicago's (UIC's) Institute on Disability and Human Development
James H. Rimmer, Ph.D. is a professor at Northern Illinois University, and visiting professor at UIC's Institute on Disability and Human Development
Brian Chicoine, M.D. is the medical director of the Adult Down Syndrome Center Advocate Medical Group
David Braddock, Ph.D. is professor and director of UIC's Institute on Disability and Human Development.
Reprinted with permission of Stephen S. Rubin.|
This working paper was originally published in ADDVANTAGE, Volume 9, No. 1, Spring/Summer 1997.
Overweight is strongly associated with many different health problems and is a major risk factor for many other chronic diseases, including cardiovascular disease, diabetes, and lipid abnormalities. Being overweight also exacerbates other health problems such as high blood pressure, high blood cholesterol, and osteoarthritis. All of these conditions impose a serious burden on our health care system and deteriorate the quality of life for millions of Americans. It has been estimated that the economic costs of obesity in this nation is a staggering $40 billion annually, or 5.5 percent of the total cost of illness.
As part of the nation's effort to improve the health of all Americans, a major national health policy decision was formulated in the 1970's to set 10-year objectives for all Americans, including persons with disabilities. The plan was called Healthy People 2000. In the report there is an objective prevalence for all Americans. For people aged 20 and older, overweight was defined as a Body Mass Index (BMI) equal to or greater than 27.8 for men and 27.3 for women (SMI is the ratio of weight to height squared). The goal in the Healthy People 2000 report is to reduce the incidence of overweight among persons with disabilities from 36 percent to 25 percent by the year 2000. Healthy People 2000 does not contain data on specific subgroups of disabilities including adults with Down syndrome. Subsequently, when new reports are published by year 2000, there will be no way to generalize the findings and recommendations to adults with Down syndrome.
Because of the growing emphasis on reducing the incidence of overweight among all Americans, it becomes important to establish baseline data for specific subgroups of disabilities, so that specific intervention strategies can take into consideration the physical, psychological and socioeconomic factors that may interplay with the disability and the prevalence of overweight. Therefore, the purpose of this study was to determine the incidence of overweight among a large cohort of adults with Down syndrome, and to compare these data to existing standards established in the Healthy People 2000 document. An additional purpose was to compare BMI and prevalence of overweight between subjects living at home with their family to those residing in a group home.
In a previous investigation that looked at overweight prevalence among British persons with Down syndrome in 1992, Bell and Bhate evaluated the BMI of 58 adults with Down syndrome and compared them to a group of adults who did not have Down syndrome. The subjects lived with their families or in small apartments subsidized by the government. The investigators found that there was a high percentage of overweight among adults with Down syndrome compared to adults with mental retardation who did not have Down syndrome.
In the present study, SMI data were collected on persons with Down syndrome as part of a retrospective study looking at their health. Records from 283 adults with Down syndrome (146 males and 137 females) were collected from the Advocate/IDHD Adult Down Syndrome Center, one of the largest such centers in the nation. The individuals with Down syndrome ranged in age from 15 to 69 years. These individuals either lived with a family member or in a residential group setting. The criteria used for overweight were taken from the Healthy People 2000 report: overweight was defined as a BMI greater than 27.3 for women and 27.8 for men.
The present investigators found that females were significantly shorter and lighter than males but had a higher BMI. Body weight and BMI were also higher for males and females living with their families as compared to those living in the residential group setting. In both settings, a greater proportion of females to males were overweight. Forty-five percent of men and 56 percent of women were classified as overweight.
Average BMI levels were significantly different between living arrangements, regardless of sex. Within the family setting, BMI levels were above levels for obesity (SMI greater than 30), whereas within the group setting, BMI levels were lower, around 29. However, these levels were still above the Healthy People 2000 criteria for being overweight. BMI levels were also consistently higher for females in both settings. When SMI data were analyzed by age, BMI increased up until age 30, and then declined from 31 to 70.
Overweight and obesity levels are substantially higher than for the general population and should be alarming to health care professionals who are involved in treating or caring for persons with Down syndrome.
Future research should determine why there is greater prevalence of overweight among persons with Down syndrome living with their families, and why BMI levels seem to decline as our sample population ages. Perhaps the precocious aging of individuals with Down syndrome is partly responsible for the rapid declines in weight at earlier stages in life when compared to the general population.
This is the first study that has looked at the prevalence of overweight in a population of individuals with Down syndrome in the United States. In the Bell and Bhate study completed in England, the investigators used a different criteria for establishing overweight, so it is not possible to compare our results to their findings. However, our data are in agreement with theirs in that the prevalence of overweight among persons with Down syndrome is much higher than the general population.
Our findings also revealed that the prevalence data reported in the Healthy People 2000 report on persons with disabilities of 36 percent is clearly not representative of persons with Down syndrome. Since the specific disabilities were not cited in the Healthy People 2000 report, it can only be assumed that persons with Down syndrome were not represented in the sample. Based on our findings, it is clear that persons with Down syndrome represent a much higher risk than the general population for many different diseases that are related to overweight, and pose an even higher risk among a general cohort of persons with disabilities. The goal reported in Healthy People 2000 of reducing the incidence of overweight among people with disabilities to less than 25 percent is unrealistic for persons with Down syndrome, and it is therefore recommended that specific Healthy People 2000 overweight reduction goals be established separately for males and females with Down syndrome in any future reports.
|Revised: September 21, 1999.|