Impairments vs. diseases in the aging process

Part of a series.

Beginning at about age 40, our bodies begin a process of organ and functional decay of about 1 percent per year. Bone mineral density decline leads eventually to osteoporosis and fracture risk, cognition decline leads to memory and thinking impairments, and muscle decline leads to loss of strength while increasing the fracture risk of a fall.

According to the Centers for Disease Control, almost 30 percent of older Americans fall per year and 38 percent of those that fell reported a fall that limited activity or led to a doctor’s visit. For those over 65 years of age, falls were the most frequent cause of fatal and nonfatal injuries with 27,000 deaths and 2.8 million ER visits along with 800,000 hospitalizations.

Not surprisingly, the percentage of individuals that fell rose with increasing age as did the percentage of falls that were serious. Healthy individuals of any age were less likely to fall or have significant injury than those with poor health (69 fall-related injuries per 1000 compared to 480 per 1000.) It is estimated Centers for Disease Control that at least 25 percent of falls could be prevented by screening older adults for fall risk with gait and balance assessment, offering strength and balance exercises, managing medications known to be closely related to falls and, in many patients, prescribing added vitamin D.

Usual walking speed is an interesting measure of aging impairments. As we age, walking speed declines perhaps perceptibly beginning about age 60. It slowly starts to decline like other body functions and does so in a gradual but fairly steady rate. Mobility is actually a unifying concept in gerontology. Gait speed is adversely affected, as we might imagine, by aging impairments, chronic diseases, disuse and deconditioning. Gait speed is a very powerful predictor of multiple adverse outcomes. It is a marker for “biological vitality.”

A simple test is to ask a person to walk at their usual pace along a distance of about ten meters. This is timed, and one just checks how long it took that person to walk the distance. Any number of important outcomes can be associated with the gait performance test. As just one example, the number of deaths per hundred person-years is markedly up for those with a slow gait speed versus those with a rapid gait speed. The same can be said for admissions to nursing homes and for general well-being.

Impairments vs. diseases

It may be useful to separate out impairments due to the aging process (that’s the “old parts wear out concept”) and age prevalent diseases. As to the impairments, as a person ages, they may have difficulty with their vision, a hearing impairment, mobility impairment, cognition and memory impairments and impairments to their reflexes and balance. I think of these as not really diseases but simply the effects of age. On the other hand, there are chronic diseases such as heart failure, cancer, chronic lung disease, chronic kidney disease, osteoarthritis, and diabetes which are diseases that occur much more frequently as we age, but they are not necessarily due solely to age. That is an important concept.

For example, coronary artery disease might lead to a heart attack in a man who is 67 years old. But that heart attack didn’t occur in a vacuum just because of his age. The disease atherosclerosis really began in teenage years or the twenties and slowly but surely plaque built up in his arteries until one of the arteries became sufficiently occluded and friable that the heart attack occurred at age 67, the average age for men to have an infarct. Lung cancer is similar. On average (and averages can be quite misleading because there is a very wide range around the mean) lung cancer is diagnosed at age 72. But it didn’t just develop then. If it was caused by smoking, then it began as a teenager when the person first sneaked one of his or her father’s cigarettes and went out behind the garage for a smoke.

We might say that aging is a bigger risk factor for chronic illnesses than all other causes combined. However, it is not just aging but a lifetime of behaviors that have eventually culminated in diseases. Those behavior or lifestyles of especial importance, the “big four,” are poor nutrition (and too much of it), lack of exercise, chronic stress and tobacco. To these, we must add inadequate sleep, alcohol abuse, poor dental hygiene, drug abuse and driving impairments including alcohol, drug, and distractions such as texting.

Stephen C. Schimpff is a quasi-retired internist, professor of medicine and public policy, former CEO, University of Maryland Medical Center, and senior advisor, Sage Growth Partners. He is the author of Fixing the Primary Care Crisis: Reclaiming the Patient-Doctor Relationship and Returning Healthcare Decisions to You and Your Doctor.