The Long Reach of Obesity
Obesity is linked to a host of afflictions—from allergies
and asthma to arthritis and skin infections.
Sheila, a 45-year-old Oklahoma bookkeeper, has suffered from sleep apnea and asthma for as long as she can remember. The conditions have worsened. “I can go to sleep, but I don’t stay asleep,” she says. “I stop breathing and my husband wakes me up.” Frustrating her more, the fatigue has put a crimp in her exercise routine: walking briskly while carrying three-pound weights.
Sheila, who asked that her last name not be used, said the exercise is needed to help her shed some of the 165 pounds that saddle her 5’3” frame. Her body mass index, or BMI, is 28.1, less than two points short of the 30-BMI “obese” mark. Adding to the urgency, she said she has recently begun to see a larger picture emerge and has linked the 25 pounds she has put on over the past year or so to her worsening health issues. “I really didn’t think about it until about a month ago,” she said, “and I realized, you know, all the dots are starting to connect.”
There’s no dearth of public service messages warning of the heart disease and diabetes risks that come from bearing too much weight. As real and pervasive as those risks are, the tentacles of obesity reach even further. As Sheila may be learning, obesity is linked to a host of afflictions—from allergies and asthma to arthritis and skin infections—whose relationship with excess weight gets far less ink.
Half the chapters in an October 2008 American Council on Science and Health (ACSH) report on obesity and its health effects are devoted to afflictions with lesser-known links. “Some of these health problems are more associated with increasing morbidity than mortality,” says Ruth Kava, PhD, RD, the ACSH’s nutrition director. “When you’re talking about arthritis, for example, regular osteoarthritis doesn’t kill people. But it certainly makes life unpleasant. In other cases, the connections just aren’t that clear to most people.”
Some ailments, like the sleep apnea that Sheila is afflicted with, are becoming more well known because more Americans have added girth, says Kenneth Prager, MD, a pulmonary specialist and professor of clinical medicine at Columbia College of Physicians and Surgeons.
Prager says 80% of his sleep apnea and asthma patients are overweight or obese. “People who are obese may also have a higher incidence of reflux (heartburn), which can impact asthma,” he says.
Obesity can also contribute to shortness of breath from carrying more weight. Excess fat around the ribs, diaphragm and abdomen can impair breathing, particularly in severely obese people, the ACSH report says.
While sleep apnea, often marked by daytime sleepiness, is relatively new on the radar of modern medicine, 19th century doctors may also have encountered it and recognized a connection between obesity and extreme sleepiness, says the ACSH. It was sometimes known as “Pickwickian syndrome,” a reference to the sleepy overweight boy in Dickens’ The Pickwick Papers.
People with sleep apnea stop breathing for up to 30 seconds at a time, sometimes hundreds of times during the night. The type most associated with obesity is obstructive sleep apnea, in which the tongue or thick tissue at the back of the throat blocks the airway. Though the precise link with obesity isn’t clear, the ACSH explains that increased fat in the neck may narrow the upper airway.
Dickens’ character might just as well have had allergies. A study published in the May issue of the Journal of Allergy and Clinical Immunology showed that obese children and adolescents are at increased allergy risk. The study was based on data on more than 4,100 people ages 2 to 19.
Obese children and adolescents are about 25% more likely to have at least one specific immunoglobulin to an allergy, and about 60% more likely to have a food allergy, says Darryl Zeldin, MD, acting clinical director at the National Institute of Environmental Health Sciences (NIEHS), and the study’s author.
The study did not show that obesity causes allergies, only that the two conditions are linked. “We can’t tell whether the obesity preceded the allergy or not; nor could we tell that the obesity caused the allergy,” Zeldin says. “It could be that people who are allergic don’t exercise as much. It could be the reverse. The relationship is stronger for those who are obese than for those who are overweight.”
Studies have unearthed some clues about childhood obesity that may reach back long before afflicted children are even born. These studies have shown a link between maternal obesity before and during pregnancy and their obese offspring.
One study showed that maternal fat causes the placenta to provide too many nutrients to the fetus, according to the researchers at the University of Cincinnati and the Medical College of Georgia (FASEB Journal 10/1/08). And a study last year by Baylor College of Medicine researchers that was published in the International Journal of Obesity found that chemical changes in the ways genes are expressed could affect subsequent generations of mice.
More Than Skin Deep
Obesity may be responsible for a number of skin disorders, including pressure sores, caused by constant pressure on an area because mobility is impaired, says the ACSH. Friction, warmth and moisture, the group adds, can inflame and infect skin folds, those areas where skin touches skin, which are deeper in obese people. Diabetes and increased sweating, also linked to obesity, exacerbate these skin problems.
Obese people have an increased incidence of psoriasis, too, the ACSH says, though obesity is not necessarily a cause of the inflammatory skin disease.
The undersides of skin folds are not the only place where hidden medical problems lurk. Obesity may be masking other diseases and making diagnoses more difficult. “It can be harder to evaluate people with obesity,” says Ruth Ann Marrie, MD, PhD. “You may not be able to go on an MRI machine. Some tests become more difficult to do. There are those kinds of issues that can interfere with our ability to even sort out what’s going on.”
That hindrance may be at work in diagnosing multiple sclerosis. Obese people may not be diagnosed with MS as early as others or may have a more severe case of the disease at diagnosis, according to a study led by Marrie that was published in an online edition of the journal Neurology (10/29/08).
Marrie cautions that the study was not designed to show why MS diagnoses were delayed. “One possibility could be that it is harder to diagnose; there could be other factors,” she said. Nor did the study explain why the disease was more pronounced at diagnosis. “If we went back and adjusted for the time lag between onset and diagnosis, there’s still a difference in disability so it’s not all about a lag in diagnosis,” she says.
The study suggests that in some people with chronic diseases, “it’s not appropriate to assume that every new symptom is related to that disease because there may be another disease emerging, such as MS,” says Marrie.
In a similar vein, pulmonologist Prager believes that healthcare practitioners with obese patients need to take extra consideration in making a diagnosis. “When an obese patient comes to a doctor and says, ‘I’m short of breath,’ the tendency may be to ascribe the shortness of breath to obesity,” Prager says, “whereas the patient might have an underlying lung problem, like asthma.”
A Matter of the Mind
Obesity-related ailments are not just the domain of the body. Because an overweight and obese appearance does not fit in with the standard image of normalcy, obesity has been linked to depression.
Because obesity has become more widespread, however, the stigma is probably attached to more severe obesity than it used to be, observes Nigel Bark, MD, associate professor of clinical psychiatry at Albert Einstein College of Medicine. “We’ve become used to us all being a bit fatter than we were 20 or 30 years ago,” Bark says. “The bar has been raised.”
But obesity has been linked to a more severe mental affliction—dementia. People in their 40s who have a large belly face an increased risk of developing Alzheimer’s disease or other dementia when they reach their 70s (Neurology 3/26/08). Because the connection was made to abdomenal fat, even people who were not overweight faced the risk.
People with normal body weight and high abdomen measurements were 89% more likely to have dementia, according to the study of more than 6,500 men and women ages 40 to 45. Overweight people were 82% more likely if they had a low stomach measurement, but more than twice as likely if the measurement was high. And obese people were 81% more at risk if they had a low belly measurement, but more than three times as likely with a high measurement.
Reversing the damage and illnesses brought on by obesity is possible in some, but not all, cases. Shedding just 10 pounds can lower blood pressure, for instance. Sleep apnea, similarly, “can be greatly ameliorated if not cured by sufficient weight loss,” says Prager.
Moderate weight loss could reverse another obesity-linked affliction—urinary incontinence—in women who are overweight or obese, reports the April issue of Harvard Women’s Health Watch. In the study, women assigned to an intensive diet and exercise program lost an average of 17 pounds after six months and had 47% fewer incontinence episodes.
The erosion of cartilage that occurs with osteoarthritis, however, is largely irreversible, says Gilbert Ross, MD. (Osteoarthritis occurs mostly in the knees, hips and hands, and evidence linking obesity with the condition is strongest in the knee, says the ACSH.) Cartilage repair, Ross says, “is minimal and slow.” But weight loss and anti-inflammatory treatment can slow and halt the process “to a great degree,” he adds.
If fear is a motivation to lose weight, obesity has enough tentacles—fatal and not—reaching throughout the body to stock your mental arsenal to overflowing.