Disease Trends in the U.S.: Aging, Obesity & Health Risks

Introduction: U.S. Population and Aging Trends

About 4.5% of the world's population is comprised of people living in the United States. The country has the world's third largest population, and statistical analysis shows that approximately 155 million people have been added to the U.S. population — an increase of nearly 105% over the past 50 years (Kotkin, 2010). In addition, the U.S. population has also experienced qualitative change. According to the Population Reference Bureau, it has become larger, older, and increasingly diverse (Kotkin, 2010). Females over the age of 45 continue to outnumber males in similar age groups; however, this ratio is narrowing. The most significant change in U.S. population trends is the growth of the 70+ and 80+ age bands in demographic models, indicating that average life expectancy is increasing and is predicted to continue doing so in the coming years (Kotkin, 2010).

Many factors are responsible for these shifts in age trends. Life expectancy has greatly increased alongside scientific advancements. For example, infant mortality rates were previously quite high due to diseases caused by drinking contaminated water. Recent technological advances have helped overcome this problem through the installation of filtration plants and the chlorination of drinking water, thereby reducing infant mortality. Other environmental factors contributing to changing age trends include a marked decline in the use of toxic chemicals such as lead and mercury by industrial factories, as well as improved toxicity-testing procedures now available to health organizations. Through such measures, people face a lesser chance of contracting diseases caused by those toxins and can live healthier, longer lives. Excessive sun exposure, overeating, and a sedentary lifestyle have also contributed to accelerating the rate of aging among U.S. residents (Mulvihill, 1995). Organizations such as the Environmental Protection Agency (EPA) strive to minimize the health risks caused by environmental problems.

Health Complications Associated with Aging

With the sharp increase in the rate of aging in the country, the risk of medical complications such as cardiovascular disease and diabetes has also risen. Heart disease is very likely to occur in women after menopause, usually after the age of 55, and in men after the age of 45 (Hearthealthywomen.org, n.d.). Moreover, as a person ages, the buildup of fatty deposits in the coronary arteries — a condition known as atherosclerosis — may become large enough to cause blockages that cut off blood supply to the heart, resulting in angina and/or myocardial infarction (heart attack). Hypertension, or high blood pressure, is also very common in older patients. Statistical studies show that more than 70 million Americans suffer from cardiovascular diseases, and 40% of them are aged 65 or above (Hearthealthywomen.org, n.d.). Furthermore, 83% of deaths attributable to cardiovascular diseases involve patients aged 65 or above. It is expected that as the percentage of senior citizens grows in the coming years, cardiovascular disease will become even more prevalent in U.S. society.

The National Health and Nutrition Examination Survey (NHANES III) has provided evidence that the number of Americans suffering from insulin resistance syndrome is approximately 70 to 80 million, and nearly 40% of them are over the age of 65 (Seibel, 2010). Insulin resistance syndrome is the major cause of type 2 diabetes (Seibel, 2010). Type 2 diabetes usually occurs in middle or older age, and the risk of contracting this disease increases significantly after the age of 45 in both males and females (Seibel, 2010). It is caused in part by the over-expression of the gene producing catalase in human mitochondria. Hypertension and elevated cholesterol levels, which are very common in elderly patients, also raise the chances of developing this form of diabetes. It is expected that the number of elderly patients with this medical problem will continue to grow.

Obesity Trends in the United States

Another major health issue that has become increasingly common in the U.S. over recent years is obesity. Obesity rates in the U.S. continue to top all related charts. Between 1997 and 2010, obesity rates increased significantly from 19.4% to 35.7% and are expected to continue rising in the coming years (Wihbey, 2012). Studies have also shown that obesity has historically been more prevalent among females than males, though that gap has stabilized; in contrast, obesity rates in men have been rising in recent years, as shown by surveys published in The Journal of the American Medical Association (JAMA) (Wihbey, 2012). Obesity rates among U.S. children have also risen to approximately 19.6% over the last three decades. It is predicted that obesity rates will continue to increase, with the greatest number of cases found in people between the ages of 30 and 65.

The Cleveland Clinic suggests that environment plays a major role in the spread of obesity. It is the combination of environmental and genetic factors that determines a person's body weight (Finkelstein & Zuckerman, 2008). Nutrition and health officials have described modern society as "obesogenic," meaning it has the potential to promote obesity (Finkelstein & Zuckerman, 2008). In such a society, food intake is energy-dense while physical activity is minimized. Technological advances in the 21st century have reduced the need for physical exertion (Finkelstein & Zuckerman, 2008). In an era when even routine tasks like washing dishes and opening a garage door were done manually, obesity rates were considerably lower. Now that machines have replaced many human physical activities, it is unsurprising that obesity is becoming more prevalent each year. The types of foods commonly consumed in the U.S. today are also calorie-dense and high in fat, which greatly contributes to increased body weight. Coupled with fewer accessible options for exercise and healthy living, these factors have made it difficult for many people to maintain a healthy lifestyle, and obesity continues to prevail (Finkelstein & Zuckerman, 2008).