Definition of Obesity Disease

Definition of Obesity Disease- The national epidemic of obesity has now extended to older persons. Substantial evidence links overweight and obesity to an increased risk of serious comorbidities that include hypertension, dyslipidemia, heart disease, insulin resistance and diabetes, metabolic syndrome, cholelithiasis, respiratory impairment, gout, and osteoarthritis. Obesity among older persons has also been linked with increased like lihood of self-reported functional limitations, a decline in measured physical performance, and an elevated risk of functional decline. An obese Medicare beneficiary costs $1,486 more in health care expenses per year than does an individual of healthy weight. This entry focuses on obesity in the elderly to include recent trends, etiologies, impact on health and function, and potential interventions.

Defining Overweight and Obesity

Body mass index (BMI) has become a widely used formula to assess body fat indirectly. BMI is calculated as body weight in kilograms (kg) / height in meters squared (m2). In 1998, the National Institutes of Health set criteria to define overweight and obesity as BMI ≥ 25 and BMI ≥ 30, respectively, but standards have not been adopted specifically for older persons. Although BMI suffers from limitations as a proxy of measure of adiposity, it is nonetheless useful for screening applications and for guiding interventions.

Prevalence and Trends of Obesity

The prevalence of overweight and obesity in older Americans has increased dramatically (Table 1). Obesity is more prevalent among older women than among older men, and it is appreciably greater among young-older persons than among old-older persons. The prevalence of obesity declines precipitously after 80 years of age.

The Causes of Obesity

Obesity is a multifactorial chronic disease. Selected key risk factors include genetic predisposition, certain medications, lifestyle, and behavior. Studies with twins reveal marked concordance in obesity. Pairs of twins exposed to periods of positive and negative energy balance experienced greater similarities for rate of weight gain, proportion of weight gain, and body site of excessive fat deposition than did non-twin pairs. A number of gene polymorphisms have also been linked to increased risk of obesity.

via Stockvault

Weight gain is frequently experienced during middle age. The onset of menopause in women can be associated with additional weight gain. Body fat tends to peak later in women than in men and may occur as late as 50 to 60 years of age. A decrease in lean body mass (sarcopenia) and an associated decline in resting energy expenditure also occur with aging. Most obese older persons were overweight or obese as middle-aged adults and have sufferedweight excess for many years.

Polypharmacy is common among older persons, and selected medications may also contribute to weight gain. Antidepressants (e.g., fluoxetine, mirtazapine, phenelzine sulfate), antipsychotics (e.g., piperazine phenothiazine, risperidone, olanzapine), anticonvulsants (e.g., carbamazepine, valproic acid), and corticosteroids (e.g., cortisone, prednisone) are associated with increased caloric intake and increased body fat.

You must look : 11 Type of Cancer and Its Treatment

Ultimately, weight gain results from positive energy balance and excessive energy intake from food in combination with decreased energy expenditure from reduced physical activity. Food choices have a substantial influence on diet quality. Older people with higher intakes of foods with low-nutrient density (e.g., breads, sweet breads, desserts, processed meats, eggs, fats, oils) are twice as likely to be obese, twice as likely to have low serum Vitamin B12 levels, and 3 to 17 times more likely to have low nutrient intakes. Those who consume foods with highnutrient density, such as cereal, vegetables, fruits, milk, poultry, fish, and beans, benefit from lower energy intake overall; higher energy-adjusted intakes of fiber, iron, zinc, folate, and Vitamins B6, B12, and D; higher plasma Vitamin B12; and smaller waist circumferences. Sedentary living is common for older persons and contributes to reduced energy expenditure. Television watching and functional mobility limitations are important contributing factors. Recent studies have suggested that obesity is increasingly common among homebound elders. Unfortunately, many older adults accept inactivity and weight gain as a natural part of the aging process and exert minimal effort toward prevention.

The Impact of Obesity

Obesity-associated comorbidities include hypertension, dyslipidemia, heart disease, insulin resistance and diabetes, metabolic syndrome, cholelithiasis, respiratory impairment, gout, and osteoarthritis of the knee. Hypertension, affecting more than 50 million Americans, is one of the most common chronic diseases in the United States. Hypertension is associated with increased risk of cardiovascular disease, stroke, and renal failure. The strongest predictors of blood pressure in humans are BMI and weight. Weight loss, even in modest amounts, has been shown to reduce both blood pressure and the need for blood pressure medications. The risk of older people developing type 2 diabetes also increases with obesity. Findings from the second National Health and Nutrition Examination Survey (NHANES II, 1976 to 1980) showed that the risk of developing diabetes was 3.8 times greater for obese individuals 45 to 75 years of age. Diet and exercise can improve glycemic control in those with diabetes; moreover, dietand exercise alone can sometimes curtail the need for pharmacological treatment. Together, dyslipidemia, hypertension, and diabetes comprise metabolic syndrome, which is both prevalent among obese older persons and strongly associated with risk of cardiovascular disease.

via mastercenterweightloss

Many older adults suffer from arthritis, most commonly osteoarthritis. Obese adults are particularly vulnerable to the development of destructive joint disease of the knees secondary to mass-related shear forces and inflammation. Knee osteoarthritis can lead to poor balance, decreased mobility, and muscle atrophy, ultimately leading to physical disability. Not only is obesity associated with increased risk of developing chronic diseases, it also is associated with increased prevalence of functional impairments, especially mobility. High current or past BMI is associated with increased risk of reporting functional limitations. These findings have been confirmed with objective physical performance testing. Obesity also places a person at risk for functional decline, as supported by observations in longitudinal outcome studies. Increasingly, many homebound older persons are found to be obese.

Intervention and Treatment

The 1998 National Institutes of Health guidelines suggest that individual determinations should be made as to the appropriateness of weight reduction interventions for older persons. Nonvolitional weight loss in older persons often portends an ominous outcome because it is a proxy indicator of underlying inflammatory condition or disease. Another concern is that weight loss in postmenopausal women may be associated with a modest reduction in bone mineral density. Nevertheless, the longitudinal Nurses Health Study found that weight loss among overweight/obese women was associated with improvements in self-reported physical function and lower levels of bodily pain.

A tailored intervention for older persons might include large-font instructional materials, supplementation of calcium and Vitamin D, and realistic moderate weight loss and physical activity goals. Weight loss medications and bariatric surgery have not been tested adequately in older adults to warrant recommendations for their use. Few weight reduction intervention studies have been conducted in older persons. The Trial of Nonpharmacologic Interventions in the Elderly (TONE) was a randomized controlled study that compared the efficacies of reduced sodium intake, weight loss, both reduced sodium intake and weight loss, and usual care in the treatment of hypertension in older people. The results indicated that a decrease in both sodium intake and body weight reduced the amount of antihypertensive medication needed. Messier and colleagues studied obese older persons with knee osteoarthritis. After the participants completed a 6-month intervention program consisting of diet and/or aerobic/strength exercises, it was observed that the combination of both weight loss and exercise, rather than weight loss alone, contributed to improvements in physical performance, pain, and disability. Gordon Jensen and colleagues enrolled community-dwelling obese women 60 to 75 years of age in a 3-month weight-reduction program with diet modification and exercise. Self-selected obese older women who achieved moderate weight loss and physical activity goals were found to have improved laboratory, physical performance, self-reported function, vitality, and quality of life outcomes. For many frail older persons, emphasis should perhaps be placed on the prevention of further weight gain with the promotion of strength and flexibility.

Conclusion
It is evident that the prevalence of obesity is increasing among older persons. A serious burden of chronic disease and functional decline may result. Age alone should not dictate restricted access to treatment for obese older people. Reasonable intervention goals should be considered based on patient's wishes and individual opportunity for health improvement.