Outlook: Obesity Epidemic

DECEMBER 01, 2008

Ms. Farley is a freelance medical writer based in Wakefield, Rhode Island.

Higher Blood Volume in Obese Men Skews PSAs

Why are obese men more likely to be diagnosed with prostate cancer at a stage when it is more aggressive? According to researchers, the standard blood test that screens for prostate cancer is not as accurate for obese men because of their higher blood volume. By the time their blood levels are elevated enough to indicate high prostate-specific antigen (PSA) levels?the standard marker for prostate cancer?the cancer already has become advanced.

The study included approximately 3400 men who took PSA tests. Results showed that among obese men the risk of an aggressive cancer was twice as high as in normal-weight men. It is important to note that this delayed diagnosis did not occur when obese men were diagnosed via a digital rectal exam. Study author Stephen Freedland, MD, associate professor of urology and pathology at the Duke University Prostate Center, said, "I'm not sure we should check obese men more often, but we should have a higher [PSA] index of suspicion of what is normal?3.4 rather than 4; for really obese men, 3.2." The complete study appears in the journal BJU International.

Weight Problems Begin in Infancy

Developmental delays and asthma are possible risks for overweight infants, according to a recent report in Pediatrics. One study included 2139 infants under age 2 who were admitted to Bnai Zion Medical Center in Haifa, Israel; another study included 79 overweight infants and 144 normal-weight infants in a community-based assessment. Infants who were in the 85th weight-for-height percentile on 2 measurements taken 3 months apart were considered overweight.

The first study showed that infants in the 85th to 94th percentile had fewer hospital and repeat admissions than normal-weight babies. Infants in the 95th and higher percentiles, however, had higher admission rates. In the community-based study, overweight babies were more likely to snore and have developmental delays than were normal- weight babies.

It is interesting to note that, among the babies in the 2 studies, only 32% of the mothers considered their babies to be overweight. Researchers hope to stress the importance of achieving and maintaining a normal weight in infants and children.

Look for Even More Overweight Adults

The 30-year trend in weight for US adults indicates that most of them will be overweight or obese by 2030, with related health care spending projected to be as much as $956.9 billion, according to researchers at the Johns Hopkins Bloomberg School of Health, the Agency for Healthcare Research and Quality, and the University of Pennsylvania School of Medicine.

One current statistic is that 78% of African American women are overweight or obese, which supports a trend suggesting that, by 2030, 86% of all Americans will be overweight. It is predicted that most weight-related problems will be most acute among African Americans and Mexican Americans. Researchers acknowledge that these statistics can be realized if current trends remain unchanged; these numbers should serve as a wake-up call onwhat could happen if individuals do not make changes.

Research Links MSG, Obesity

A University of North Carolina at Chapel Hill's School of Public Health study shows that individuals who use monosodium glutamate (MSG) to flavor food are more likely to be overweight or obese than those who do not use it? even if physical activity and number of calories are the same for both groups.

Study participants included >750 Chinese men and women aged 40 to 59 from rural Chinese villages. Most of the participants prepared their meals at home; approximately 82% used MSG in their cooking. The participants were divided into groups, depending on the amount of MSG they used. Those in the group using the most MSG were almost 3 times as likely to be overweight than people who do not use MSG. The study, which appears in the August issue of Obesity, is the first to link MSG and obesity.

Study Identifies Obesity Gene

Scientists studied 228 women and found a variation in the human LAMA5 gene that may be responsible for a person's body shape. In response to the obesity epidemic and its associated health problems, researchers feel it is important to figure out which mechanisms control fat storage. With the help of research from a fruit fly study, scientists tested the gene variations relating to women's body shape and found 2 variants: one in women of European American descent and the other in women of African American descent:

Variant 1: Associated with weight and lean mass in both ethnic groups; also associated with height, total fat mass, and high-density lipoprotein (HDL) cholesterol in European American women.

Variant 2: Associated with triglyceride and HDL cholesterol levels in African-American women.

Researchers used fruit fly data because, according to team leader Maria De Luca, PhD, of the University of Alabama at Birmingham, "Drosophila share many components of fat biosynthesis, degradation, and regulation with humans, including many of those implicated in diabetes and obesity." The full study appears in the open access journal BMC Genetics.