Calcium absorption declines in both sexes in the elderly, and is directly related to vitamin D metabolism. Cobalamin (vitamin B₁₂) absorption decreases in the elderly and predisposes them to subacute combined degeneration of the spinal cord.² Other vitamin B complexes may also have malabsorption, leading to neuropathies. The elderly have consistently lower levels of vitamin D. In a European study, vitamin D levels are lowest in winter in the elderly.³ This tendency of decreased sun exposure and decreased capacity of the aging kidney to convert vitamin D to active form may reduce endogenous levels of vitamin D. Western diets only supply 25% to 50% of the vitamin D daily requirement; hence, supplementation in the elderly is crucial.

Other coexisting conditions in the elderly can also cause imbalances in nutrition. Extensive use of antibiotics can cause cobalamin deficiency. Other disorders such as Alzheimer disease may cause the patient to forget about having a meal. Parkinson disease and other movement disorders may prevent patients from feeding themselves adequately. Diabetes, hypertension, and other chronic conditions may directly, or indirectly, through the drugs used for treatment, cause anorexia in the elderly.

Anorexia and decreased food intake is prevalent in the elderly population.⁴ Other than the previously noted causes of anorexia, elderly patients also suffer from psychological anorexia. It may originate from various life events such as loneliness, death of a spouse, lack of social life, estrangement from family, and loss of independence. It is important to recognize these major life events and provide the elderly population with counseling and support. Anorexia may also originate from the natural process of aging and changes within the central nervous centers for feeding and hydration. Although this change is inevitable and irreversible, it should not necessarily lead to undernourishment but merely readjust the food intake to the new levels. However, due to the complex interactions of aging, coexisting conditions, and life events occurring around aging, it may lead to malnutrition if not monitored.

The often neglected facet of malnutrition in the elderly population is the socioeconomic conditions that may hinder intake of well-balanced foods. Physicians and healthcare workers fail to take into account that most elderly people are not in control of their food intake. They may live at chronic care homes and group homes; thus they may only have access to standardized diets and have difficulty changing their diet to meet their specific health needs. Also, the elderly may not have a source of income to afford the diet or the dietary supplements we may recommend.

The elderly population is thus nutritionally vulnerable to deficiencies due to a combination of biological, social, and psychological causes. The nutritional deficiencies can affect various parts of the aging spine. Calcium and vitamin D imbalance affecting the vertebral column, vitamin B complexes such as B6 affecting the peripheral nerve conduction, decreased proteins causing paraspinal muscle atrophy, and vitamin B complex deficiency causing dorsal column symptoms illustrate a few examples. Thus it is important to anticipate these problems and actively monitor nutritional status in the elderly and supplement with easily available and affordable alternatives.

Obesity

Obesity in the elderly population is a growing problem. Obesity is defined as a body mass index (BMI) greater than 30 kg/m². A BMI between 25 to 29 kg/m² is classified as overweight. The prevalence of obesity in the general population in the United States for the year 2007 is between 25% and 29% in most states, as published by the Centers for Disease Control (CDC) in their annual report. A multicenter study in Europe called Survey in Europe on Nutrition and the Elderly: a Concerted Action (SENECA) published a report noting that 20% of the elderly population was obese.¹

Traditionally, obesity is measured as an index of height and body weight. During aging, the elderly undergo height reduction due to muscle atrophy and bone resorption. On an average, an elderly patient undergoes a 1.5 to 2 cm height reduction over a span of 10 years. Thus, BMI may not be an accurate index of obesity in the elderly. Intra-abdominal fat content assessed by abdominal girth measurement may be a better index. However, there is no established standard protocol for it yet.

In the elderly population, the spinal column and its mechanical components over the years undergo wear and tear, metabolic slowdown, and impaired repair. These predispose the aging spine to disc degeneration, osteoporosis, and muscle atrophy. Obesity and overweight further assault the aging spine. The vertebral column is a weight-bearing column transmitting the weight of the head and the torso to the pelvis, and subsequently to the lower limbs.

Obesity increases the stress on the aging vertebral column by increasing the load-bearing capacity. This excessive load-bearing of the vertebral column predisposes the spinal cord to disc degeneration, facet joint syndrome, and hyperostosis.⁵ Obesity also predisposes the elderly to nerve entrapment syndromes in the spine and in the limbs such as carpal tunnel syndrome.⁶ Radicular back pain has a higher incidence in the elderly with obesity compared to healthy elderly people.⁷ Also, back pain is more severe in obese patients compared to healthy elderly patients. The SF-36 (Short Form) physical component summary score and disease-specific measure and the Oswestry Disability Index are 1.5 times worse in obese elderly patients with spinal diseases as compared to controls.⁷ Obesity also decreases the functional status of elderly patients and predisposes them to multisystem pathologies.

The 10-year trend of obesity published by the CDC conveys a message of a growing epidemic, with a 10% increase in prevalence across the country. It is important to not only recognize obesity but also to identify overweight elderly patients and provide health education to prevent their progression to obesity.

Exercise

The aging process affects the spine extensively. The spinal cord may develop segmental degeneration or may undergo global degeneration. The disease processes affecting the aging spine may have variable rates of progression and intensity of affliction. Exercise or physical conditioning may help alleviate some of these conditions and may prevent onset of many more conditions.

Exercise or physical preconditioning is a process wherein the body is trained to attain optimal efficiency with maximal benefits and minimal discomfort. Physiologically, exercise fine tunes the underlying metabolic processes and cellular machinery by acting through specific stimuli.

During the process of aging, the spine undergoes wear and tear of its mechanical components and osteoporosis. (Refer “Histological Changes of Aging Spine.” Chapter 3) Briefly, osteoporosis is a condition, prevalent in elderly patients, in which bone mass decreases in vertebrae. This decreased bone mass predisposes the elderly to pathological fractures on minor physical trauma. Osteoporosis is amenable to exercise.

Exercise prevents osteoporosis in the vertebral column and increases bone mass. The principle of exercise in osteoporosis is based on Wolff’s law.⁸ Wolff’s law states that bone density and strength are a function of the direction and magnitude of mechanical stresses acting on that bone.⁹ Weight-bearing exercises are performed in osteoporosis patients.¹⁰ These include exercise like step training, where the patient spends 10 minutes of stepping up and down from a platform of about 6 to 8 inches in height. It is important to advise elderly patients to take adequate rest to prevent hypoxia. Also, elderly patients should be recommended to use good shock-bearing shoes and perform the exercise in a safe environment. The weight-bearing exercise facilitates osteoblastic activity and promotes increased bone mass.

Corrective exercises play a vital role in the aging spine. Corrective exercises attempt to restore normal architecture to the aging spine. In the kyphotic spines of estrogen-depleted elderly women, it may be useful to retrain the extensor muscles of the back.

For back pain, traction exercises may help relieve the pain and strengthen muscle tone. The exercises include pelvic tilts, knee to chest, lower back rotation, and hamstring stretch exercises. Low back pain may be alleviated by lumbar stabilization exercises aimed at stabilizing the spine and strengthening the muscles.

Aerobic exercises and swimming may contribute to healthy living by conditioning other organ systems but have no effect on the aging spine.¹¹