News in brief - April 26, 2004

Correlation between aging population and increases in blindness - STD awareness still lacking - Hormone levels may indicate colorectal cancer risk

Correlation between aging population and increases in blindness

The number of blind people in the United States will increase by 70% to 1.6 million by 2020, with a similar increase for people with low vision, according to an article in the April Archives of Ophthalmology.

The increases will be due largely to aging of the population, said the authors. They also found differing causes for blindness depending on race. The leading cause of blindness for whites is age-related macular degeneration, while cataracts and glaucoma cause more blindness among blacks. Among Hispanics, the leading cause of blindness was glaucoma.

The researchers, from Johns Hopkins' Wilmer Eye Institute and the Eye Diseases Prevalence Research Group, estimated the prevalences of various causes of blindness and low vision in the United States by age, race/ethnicity and gender and estimated the change in these prevalence figures over the next 20 years. Estimates were based on recent population-based studies in the United States, Australia and Europe and on 2000 U.S. Census data and projected U.S. population figures for 2020.

STD awareness still lacking

While many Americans believe they take the necessary precautions to protect themselves from sexually transmitted diseases, many don't use protection on a regular basis and, in fact, are placing themselves and partners at risk.

The American Social Health Assn. contracted with Harris Interactive to survey 1,155 adults ages 18 to 35 between March 3 and 8 about their knowledge of STDs. The survey was funded by GlaxoSmithKline.

The survey revealed that more than half of those queried were either unsure of their vaccination status against hepatitis A and hepatitis B or know that they had not been vaccinated for the only STDs that can be prevented by vaccination.

Those surveyed also said they felt they knew more about STDs that they did about other common diseases, like heart disease, diabetes and depression. Yet many failed to recognize that hepatitis A and B can be sexually transmitted.

ASHA noted that one in every four Americans will contract an STD sometime, yet nearly seven of every 10 people surveyed said they were not concerned about contracting an STD.

Hormone levels may indicate colorectal cancer risk

Elevated levels of plasma C-peptide, an indicator of insulin production, may suggest an increased risk for colorectal cancer, according to a study in this month's Journal of the National Cancer Institute.

Researchers at Brigham and Women's Hospital in Boston tested samples collected from 176 participants in the Physicians' Health Study who developed the cancer and compared them to 294 healthy controls. Elevated insulin production as indicated by high levels of the peptide correlated with cancer risk independent of body mass index.

Because increased insulin production is associated with a poor diet and lack of exercise, the authors suggested that this risk could be modified with lifestyle changes.

"By reducing risk factors associated with high insulin production, specifically through modifying dietary behaviors and exercising more, individuals can take their health into their own hands," said Jing Ma, MD, PhD, lead author and associate epidemiologist at Brigham and Women's Hospital.