What are the Complications of Obesity?

By Dace L. Trence, MD, FACE

Who would not like to look thin? Going to a wedding or reunion? Want to get into those jeans that fit so well just a few years ago? We cannot escape the changes that happen to our body over the years. But being overweight has consequences beyond how we look or how we might not fit into old clothes. Obesity is a disease because it can shorten your life and because it causes complications. Obesity causes problems with your body, your metabolism, and your mental health. Let’s discuss some of the problems caused by obesity. People with higher weights have shorter lifespans. If a person is obese at the age of 40, life will be shortened by 7 years. This shorter life expectancy is from weight-associated effects alone. Obesity also causes many life-shortening conditions:

  • Ninety percent of people who develop type 2 diabetes will have a body mass index (BMI) greater than 23.
  • The risk of getting type 2 diabetes is highest if the weight is gained during childhood and there is a family history of diabetes, abdominal obesity, or mother having had gestational diabetes.
  • If you have obesity, the chance of developing high blood pressure is up to five times greater compared to someone with a normal weight.
  • Eighty-five percent of those diagnosed with high blood pressure have a BMI above 25.
  • Increasing cholesterol levels are associated with weight increases above a BMI of as little as 21.

High cholesterol, elevated blood pressure and the presence of diabetes in turn lead to increased heart disease.

  • In a study with over 300,000 people followed-up over 7 years, every unit increase in BMI led to a 9% increased risk for heart attack.
  • In the same study there was an 8% increased risk of stroke.
  • In women with obesity plus high blood pressure, 70% will develop an enlarged heart and 14% will get heart failure.

Breathing capacity can be affected by having obesity.

  • Sleep apnea (halted breathing during sleep) is much more common in those who have obesity.
  • Asthma is more common as BMI goes up.
  • Collapse of lung tissues and more lung infections are more common after anesthesia for surgery in patients with obesity.

In joints that carry excessive weight, such as the hips and knees, arthritis tends to be a problem. There is also evidence that other joints, like the ones in the hands, might also be more involved. And gout is also more common. Not as well known is that many cancers are more common in patients with obesity.

  • The World Health Organization International Agency for Research into Cancer has estimated that being overweight (and also sedentary) might account for up to 25-30% of cancers of the breast, colon, uterus, kidney and esophagus.
  • About 10% of all cancer deaths that are not from smoking are related to obesity.
  • In women who have obesity there are more thyroid cancers, leukemias, multiple myeloma, and pancreatic cancers.
  • In men who have obesity there are more thyroid cancers, malignant melanomas, multiple myelomas, gallbladder cancers, and leukemias.

Even fertility is decreased by obesity.

  • In women, 6% of those who are obese have trouble conceiving.
  • When a pregnancy occurs, the chance of a serious event requiring hospitalization is 4-7 times greater for a woman with obesity compared to a woman who is lean.
  • Gestational diabetes, difficulty with blood pressure control (pre-eclampsia), difficulties while in labor and delivery, higher c-section rates, and more deaths of the mother and/or fetus, are all associated with obesity.
  • Children born to mothers who have obesity are more likely to be large. Large birth weight increases the risk of infants developing diabetes in later life.
  • Men are also affected by obesity. Obesity causes erectile dysfunction (impotence) and lower fertility. Many men have low testosterone (male hormone) because they have excess abdominal fat.

Gallbladder disease is more likely in obesity.

  • Compared with women who are lean, women with a BMI of over 32 have three times the risk of gallstones.
  • In women with a BMI over 45, this risk is seven times higher.
  • Changes in the liver that resemble alcoholic liver disease (known as fatty liver) can be seen with obesity. In 50% of patients, these changes will lead to fibrosis of the liver. In 30% cirrhosis will develop, and 3% will go on to develop liver failure.

Being obese also can affect kidney function. The kidney cannot filter well in people with chronic obesity. So kidney function is decreased by having excess weight alone.

Finally, the effect of obesity on emotional well-being is important to understand. In most societies, people with obesity are viewed as less desirable marriage partners, less likely to be promoted in their jobs, and tend to earn less than their more ideal-weight peers. Obesity can cost more, for example, many airlines now charge for two seats for a person with obesity. It is not surprising that obesity increases the risk of major depression. In turn, depression can lead to binge eating disorder and night eating disorder. Depression causes a vicious cycle leading to more weight gain.

Putting it all together

Obesity is a disease because it causes problems with your physical, mental and metabolic health. We have discussed examples of the complications of obesity. If you are unable to lose weight on your own, get help from your doctor. Chances are that it is not just the weight. Chances are you do have complications of obesity. Everyone who has obesity deserves a thorough medical exam at least yearly.

Clearly, the risk for many medical complications is increased with obesity. Even Hippocrates wrote so many years ago: Corpulence is not only a disease itself, but the harbinger of others.

Dace L. Trence, MD, FACE, completed undergraduate degrees in Biochemistry and Microbiology through the College of Biological Sciences at the University of Minnesota and her MD degree from the University of Minnesota Medical School. She completed an internal medicine residency through Northwestern Hospital in Minneapolis and, subsequently, returned to the University of Minnesota for Endocrine Fellowship. Dr. Trence started practice with Group Health, Inc, in Minnesota, becoming Chief of Endocrinology, initiating several programs, including a Lipids Clinic, Diabetes Foot Care Clinic, and a Diabetes and Pregnancy Clinic. After moving to Seattle to practice at Group Health of Puget Sound, becoming Chief of Endocrinology, then Chief of Medical Subspecialties, she then joined the faculty at the University of Washington. Currently she is an Associate Professor in the Department of Medicine, Director of the Diabetes Care Center and Director of the Endocrine Fellowship Program at the University of Washington.