Obesity Among Adults With Disabling Conditions FREE

Obesity, a leading cause of preventable deaths, is more prevalent among adults with disabilities.^1- 4 One contributing factor is physical inactivity since adults with disabling conditions or disabilities are more likely to face barriers to regular exercise. Nevertheless, healthy weight and exercise are essential goals for the entire population, and adults with disabilities should derive benefits for health and overall functioning.^1,5- 8 We examined the prevalence of obesity, weight loss attempts, and physician exercise counseling among adults with mobility and sensory disabilities and mental illness.

We pooled data from the 1994-1995 National Health Interview Survey (NHIS), the 1994-1995 Disability Supplement (NHIS-D), and the 1995 Healthy People 2000 Supplement.⁹ The NHIS is a continuing household survey of noninstitutionalized US adults (including adults in group homes) conducted by the National Center for Health Statistics. In 1994 and 1995, all respondents were asked about sociodemographic factors (core survey) and about specific sensory and physical limitations and psychiatric conditions (disability supplement). One adult from half of the households in 1995 was then asked about 6 chronic medical conditions (diabetes; chronic lung, kidney, liver, or cardiac disease; and cancer), tobacco use, attempts to lose weight and exercise counseling (Healthy People 2000 Supplement). The overall combined response rate was 87% to the core survey and NHIS-D in both years and 94% to the Healthy People 2000 Supplement. Proxies (35%) responded for adults who were unable or unavailable to answer. The National Center for Health Statistics weighted figures to account for nonresponse.⁹

We classified respondents into 6 categories, as described in detail previously: blind/low vision (blind or serious difficulty seeing); deaf/hard of hearing (difficulty hearing normal conversations or uses hearing aid); lower extremity mobility difficulty (trouble walking, climbing stairs, standing, or uses mobility aid); upper extremity mobility difficulty (difficulty reaching); hand dexterity difficulty (difficulty grasping or holding a pen); and serious mental illness (schizophrenia, major depression or paranoid, bipolar or severe personality disorder).¹⁰ We divided the physical impairment groups into 2 severity levels based on self-reports of serious difficulties or use of a wheelchair or scooter.¹⁰ Although we call these "disabilities," many people with these conditions may not view themselves as disabled.

We used SUDAAN's direct standardization method to adjust for age with the entire NHIS sample as the standard population.^11- 12 We calculated age-sex standardized rates of obesity (body mass index [BMI] >30 kg/m²), attempted weight loss, and physician exercise counseling in the previous year. We conducted logistic regression analyses of disability and obesity and simultaneously adjusted for relevant demographic factors including age, sex, race/ethnicity, education, living alone, and family income. Among the respondents to the Healthy People 2000 Supplement, we examined weight loss and exercise counseling, adjusting additionally for BMI, current smoking, and available comorbidities. We used SUDAAN to estimate SEs with Taylor series linearization. We assessed for collinearity by comparing SEs from adjusted and unadjusted models.^11- 12

Of 145 007 respondents, 25 626 reported at least 1 disabling condition. Lower extremity mobility difficulties were most common. Poverty, living alone, low education, inability to work, and smoking were more frequent among adults with than without disabilities (Table 1).

Among adults with disabling conditions, 24.9% were obese compared to 15.1% among those without disabilities. Mild, moderate, and severe obesity were more prevalent in adults with than without disabilities (Table 2). Rates of overweight were slightly lower among adults with disabilities, except for those who were deaf or hard of hearing. After full adjustment, adults with disabilities remained significantly more likely to be in the obese category; adults with lower extremity mobility difficulties were the most likely to be obese (Table 3). Although adults with upper extremity mobility difficulties were also more likely to be obese, adjusting for other disabilities attenuated this effect (adjusted odds ratios [AORs], 1.2 [95% confidence interval [CI], 1.1-1.4] and 1.1 [95% CI 1.0-1.3] for some and severe difficulty, respectively). Results were similar when we limited analyses to self-responders.

Respondents with most disabilities were as likely to attempt weight loss as adults without disabilities (Table 4). However, adults with severe lower extremity mobility difficulties were less likely and adults with mental illness were more likely to attempt weight loss. When we limited analyses to obese adults, the results were similar for those with mental illness (AOR, 1.5 [95% CI, 0.9-2.3]); but adults with severe lower extremity mobility difficulty were now as likely to attempt weight loss (AOR, 1.0 [95% CI, 0.6-1.5]). However, overweight adults (BMI, 25-29.9 kg/m²) with severe mobility difficulty were still significantly less likely to attempt weight loss (AOR, 0.4 [95% CI, 0.2-0.8]) than overweight adults without mobility difficulties.

Compared with those without disabilities, most respondents with disabilities were as likely to report exercise counseling. Exceptions included adults with severe upper or lower extremity mobility difficulties (Table 4). When we limited analyses to obese adults, counseling differences for adults with severe upper extremity mobility difficulty were no longer statistically significant (AOR, 0.6 [95% CI, 0.3-1.2]).

We found that obesity was more prevalent in adults with disabling sensory, physical, and mental health conditions than in the general US population. Most adults with disabilities were as likely to attempt weight loss or report exercise counseling as adults without disabilities. However, attempted weight loss was less common for nonobese adults with lower extremity mobility difficulties and more common for those with mental illness. Adults with severe upper or lower extremity difficulties reported lower rates of physician exercise counseling.

Our results are consistent with previous studies showing an association between obesity and disability. Numerous studies suggest that obesity increases the risk of developing physical disability.^2- 3 However, few studies have examined obesity prevalence in populations with specific types of disabilities and mental illness.^13- 14 Unlike many other studies, which use a broad definition of disability based on limited functioning, we assessed obesity among adults with physical and sensory impairments, and mental health conditions using a national sample.

Obesity is a serious public health concern that not only increases mortality and morbidity, but also diminishes quality of life.^1,4,15 Our estimates of higher obesity rates among those with disabilities are likely underestimates because the prevalence of obesity has increased since 1994.¹⁶ Furthermore, we did not consider weight loss associated with drug addiction or eating disorders such as anorexia nervosa or bulimia, particularly among those with some types of mental illness who are likely to have higher rates of these conditions. Interestingly, most adults with disabilities were as likely as those without disabilities to attempt weight loss, which suggests that adults with disabilities share concerns about their weight. The finding that most adults with and without disabilities reported exercise counseling at similar rates is encouraging, but must be interpreted in light of overall low levels of physician counseling about exercise and weight control.^17- 18

Particularly troubling is the prevalence of obesity in those with mobility difficulties, especially since population-standardized BMI categories likely underestimate health risks for adults with reduced lean muscle mass. Fortunately, obese adults with severe mobility difficulties were as likely to attempt weight loss as obese adults without these difficulties. However, overweight adults with these impairments were substantially less likely to attempt weight loss compared with overweight adults without mobility impairments, even though being overweight confers substantial health risk and predisposes one to developing obesity.¹⁵ Furthermore, regardless of BMI, adults with mobility difficulties were less likely to report exercise counseling. Physicians may hesitate to encourage exercise because they perceive greater impediments to physical activity.¹⁹ Although exercise contributes only moderately to weight loss, it is important for weight maintenance since inactivity contributes to a "vicious cycle" where inactivity contributes to obesity, obesity exacerbates disability, and disability impedes exercise.^1,19

Adults with mental illness were also distinct as the only group to attempt weight loss more frequently than the general population. This may be partly due to weight gain induced by psychotropic medications, a common reason for medication nonadherence. Higher weight loss attempts may be provoked by this phenomenon.²⁰

Interestingly, adults who were deaf or hard of hearing were also more likely to be obese. This group may have fewer "apparent" barriers to exercise than adults with other disabilities, but clearly more research is needed to understand the reasons for this excess risk of obesity.

Guidelines that recommend obesity screening presumably apply to adults with disabilities, but few offer guidance on how to counsel this population.^1,5- 6 Effective counseling must address obstacles to weight control and exercise, such as time constraints, limited availability of exercise places or equipment, and inadequate reimbursement for weight control treatment.²¹ Furthermore, adults with disabilities must confront environmental and disability-specific barriers, such as availability of accessible facilities and transportation. Additionally, physical impairments, including pain and weakness, may hinder or preclude certain physical activities.

Our study has limitations. Weight and height figures were self-reported and may be inaccurate: overweight respondents are more likely to underestimate weight and overestimate height than thinner respondents, and those who cannot stand on a scale or see scale readings may be more prone to reporting imprecise weights.²² Proxies may provide incorrect information, although analyses restricted to self-responders were similar to the overall sample. Unfortunately, the NHIS did not assess potential contributors to obesity, such as energy intake or physical activity among adults with disabilities, and did not address nutritional counseling, which is central to weight management. Finally, because we did not have information on the temporal relationship of disability and obesity, we could not draw inferences on causality.

Nonetheless, our study demonstrates that obesity is more prevalent in adults with disabling sensory, mobility, and mental health conditions. Physicians should recognize that patients with disabilities face increased risks for obesity and address their weight concerns. Additional studies and more detailed clinical guidelines are needed to help physicians promote weight control and exercise among adults with disabilities.