Published in UAB Insight, Fall 2004

CME Exam Coming Soon!

ABSTRACT: The percentage of overweight and obese Americans continues to climb, and obesity-related deaths threaten to overtake the number of deaths caused by tobacco use.

CME OBJECTIVE: The reader will be aware of the unprecedented obesity rates in the United States and appropriate community-based interventions.
Cora E. Lewis, MD, MSPH, grants: Pfizer, Eli Lilly, and Novartis.

Increasing public awareness about obesity and its potentially deadly side effects has failed to decrease the nation's rampant proportions of overweight and obesity. "Using the National Heart, Lung, and Blood Institute (NHLBI) guidelines for defining overweight as a body mass index (BMI) of 25 kg/m² to 29.9 kg/m² and obesity as a BMI of 30 kg/m² or greater, we estimate two thirds of American adults are overweight, and one third of those are obese, including nearly 35 million women," says UAB internist and preventive medicine specialist Cora E. Lewis, MD, MSPH. Even more disturbing, recent findings from the Centers for Disease Control and Prevention (CDC) show that between 1990 and 2000, obesity-related deaths soared from 300,000 to 400,000, closing in on tobacco-related deaths, which grew from 400,000 to 435,000 in the same period.

The unprecedented rates of obesity in the United States were recently confirmed when the 1999-2002 followup to the 1998 National Health and Nutrition Education Survey (NHANES III) was published (JAMA. 2004;291:2847-2850). Although obesity is high among both sexes, the authors noted, "In women aged 20 years and older, the prevalence of obesity differed significantly between racial/ethnic groups, with nonHispanic white women having the lowest prevalence (30.7%), nonHispanic black women having the highest (49%), and the prevalence among Mexican American women falling in-between (38.4%). The prevalence of obesity was significantly higher among women than men."

In women, overweight and obesity have been linked to increased risk for cardiovascular disease (CVD), stroke, diabetes, hypertension, high cholesterol, osteoarthritis, gallbladder disease, gout, respiratory problems, gynecological and obstetric complications, depression, and certain types of cancer, such as postmenopausal breast and endometrial cancers. In fact, a recent American Cancer Society study of more than 62,000 postmenopausal women found those who gained 20 to 30 pounds after high school were 40% more likely to develop breast cancer than women whose weight fluctuated 5 or fewer pounds; the risk doubled in women who gained more than 70 pounds (Cancer Epidemiol Biomarkers Prev. 2004;13:220-224).

Sedentary Lifestyle

Obesity cost $117 billion in 2000, according to the CDC, which estimates a 10% weight loss will reduce an overweight person's lifetime medical costs by as much as $5300. And, healthy lifestyle messages are not reaching obese children, who face a variety of costly and potentially fatal illnesses that could be prevented.

Encouragement is critical to initiating and maintaining weight loss, especially for obese adolescent girls, who report lower self-esteem and high-risk behaviors, such as smoking and drinking alcohol (Pediatrics. 2000;105:e15). "Since the prevalence of overweight in 12- to 19-year-old girls has more than tripled from 1966-1970 to 1999-2002, it is critically important for us to understand the long-term consequences overweight children face," Lewis says.

She and UAB colleague O. Dale Williams, PhD, MPH, are primary investigators of the CARDIA (Coronary Artery Risk Development in Young Adults) study, which began in 1985 with a group of 5115 black and white men and women aged 18 to 30 years. The study found a 10-year weight gain in young adults of both races and sexes led to adverse changes in their levels of low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, fasting insulin, and blood pressure, regardless of their initial weight, age, race, or gender (International Journal of Obesity. 2003;27:369-376).

Clinical Challenges

"Women tend to be fatalistic about their weight. Part of the problem is they simply feel overwhelmed. Glance at last year's list of bestsellers and notice the popularity of books detailing diet strategies. Yet, there is no decrease in levels of overweight and obesity," Lewis says. "To combat obesity, patients must first attempt to make small lifestyle changes that make a real difference. It is important for clinicians to emphasize that a reduction of as little as 10 pounds improves glucose tolerance and lipid profiles and lowers blood pressure. Some patients may have more success maintaining current weight or achieving incremental weight loss than trying to lose 50 pounds."

To help support patients with dietary and exercise interventions, Lewis suggests recommending community resources, such as nutritionists and psychologists who can help obese people resist unhealthy lifestyle temptations society offers. "Avoid setting people up for failure by asking them to meet unachievable goals. Especially in rural areas, be aware that without a walking trail, shopping mall, or community fitness center, there may be nowhere to go. As physicians, we must be healthy lifestyle advocates, which includes researching environmental interventions. Perhaps local schools can make athletic fields available after hours, or civic leaders can incorporate walking spaces and fitness areas within their communities."

She suggests taking advantage of Robert Wood Johnson Foundation opportunities, such as Active Living research grants, that help communities promote healthy lifestyles by making changes in a town's design, policy, transportation, and architecture to encourage physical activity.

Finding a safe place to exercise regularly is essential for overweight women, especially those prone to abdominal obesity, which is central to the metabolic syndrome and also a strong predictor of diabetes. Women with type 2 diabetes who are overweight or obese are at particularly high risk for CVD morbidity and mortality, yet studies show men are often treated for CVD more aggressively than women.

"Historically, women have been underrepresented in many clinical trials, accounting for only 25% of participants in cardiovascular research studies, for example," Lewis says. "The premature end of the National Institutes of Health Women's Health Initiative hormone replacement therapy study and the Heart and Estrogen/Progestin Study underscores that estrogen is not the great women's health protector science once hoped for. We must address obesity and its negative effects on women's overall health, especially Hispanics and African Americans, who are at elevated risk for cardiovascular disease and diabetes," she emphasizes.

Few Americans achieve recommended levels of physical activity, and that number is not improving, but the reasons for the rapid increase of obesity in women remain undefined. Whether genetic predisposition or social stressors are involved is unclear, but a recent study in the Journal of Applied Social Psychology (2004;34:538-562) found women who were frustrated following a stressful day ate more fatty foods compared with women whose stress levels were lower, and men chose the same snack regardless of their stress levels.

Long-term Loss

Lewis directs UAB's arm of the multicenter Look AHEAD (Action for Health in Diabetes) clinical trial, which will evaluate whether weight loss prevents CVD in adults with type 2 diabetes. The 10-year study, funded by the NHLBI and the National Institute of Diabetes and Digestive and Kidney Diseases, will follow more than 5000 obese type 2 diabetics, aged 45 years and older, to measure clinical outcomes of CVD and provide longitudinal evidence-based information. Following initial patient selection, biannual telephone interviews and annual visits evaluating hypertension, lipids, and glycemic control are required. Investigators are particularly interested in hospitalizations or death from cardiovascular events, such as myocardial infarction or stroke.

"Although short-term weight loss ameliorates obesity-related metabolic abnormalities and cardiovascular disease risk factors, the long-term consequences of intentional weight loss in overweight or obese individuals with type 2 diabetes have not been adequately examined," Lewis explains. Participants will be randomized to either a lifestyle intervention promoting weight loss through diet and physical activity, with a subgroup protocol for those who need orlistat (Xenical), or a diabetes support and education group. Researchers hope to achieve an average weight loss of at least 7% and will explore secondary endpoints such as osteopenia, quality of life, and the cost-effectiveness of weight-loss interventions, compared with related health-care savings.

Lewis suggests consulting NHLBI guidelines on overweight and obesity for evaluating risk factor profiles and appropriately considering medications or surgery. "Helping women lose and maintain weight requires intensive effort and a community of support, but we believe the lifetime rewards are well worth the initial time spent, a premise the Look AHEAD study will explore."

Classification Of Overweight
And Obesity

	BMI kg/m2	Disease Risk * (relative to normal weight and waist circumference)
		Men <40 in Women <35 in	>40 in >35 in
UNDERWEIGHT	<18.5	—	—
NORMAL	18.5-24.9	—	—
OVERWEIGHT	25.0-29.9	Increased	High
OBESITY	30.0-34.9 35.0-39.9	High Very High	Very High Very High
EXTREME OBESITY	>40	Extremely High	Extremely High
*Disease risk for type 2 diabetes, hypertension, and CVD. Adapted from "Obesity: Preventing and Managing the Global Epidemic." Report of a World Health Organization consultation on obesity. Geneva: WHO, 1998.
National Heart, Lung, and Blood Institute Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults www.nhlbi.nih.gov/guidelines/obesity/ob_home.htm

For more information:
Dr. Cora Lewis
1.800.UAB.MIST
mist@uabmc.edu