Annals of Internal Medicine tip sheet for Jan. 17, 2006

Exercise Reduces Risk for Dementia by 30% to 40%, New Study Finds
A large prospective study -- perhaps the most definitive yet of the relationship between exercise and dementia -- found that older adults who exercised at least three times per week were less likely to develop dementia than those who were less active (Article, p. 73). The study participants were 65 or older with normal mental function at the beginning of the study. They were followed for six years. Of the 1,740 subjects, 158 developed dementia, including 107 who developed Alzheimer’s disease. Statistically, the annual rate of dementia was 13.0 per 1,000 person-years for people who exercised three or more times per week, compared with 19.7 per 1,000 person-years for those who exercised fewer than three times per week. An editorial writer says that future research should try to determine whether exercise causes a lower rate of dementia or whether physical activity is a proxy for "life engagement" or other lifestyle or sociodemographic characteristics that are truly associated with development of dementia (Editorial, p. 135). Also needed is research to determine the "type, frequency, intensity or duration of physical activity that is most beneficial in preventing cognitive deterioration."

NOTES TO EDITORS: The entire article is available to the public on Jan. 17, 2006, at The editorial is available at The article is the subject of a video news release. Call for coordinates. A study participant may be available for interview.

Help "Problem Doctors" by National Effort to Improve Hospital Systems
"At least one third of all physicians will experience … a condition that impairs their ability to practice medicine safely," say authors of an article in the "Improving Patient Care" series in Annals of Internal Medicine (Improving Patient Care, p. 107). Hospitals, where a credentialing process is already in place, are the place to implement a nationwide system to monitor physician performance based on validated clinical and behavioral measures. The authors describe such a national system but say that hospitals must be supported by "those that already bear a fiduciary responsibility for ensuring safe, competent care": the state medical boards, medical specialty boards, and the Joint Commission on Accreditation of Healthcare Organizations.

Wealth Disparities Are Not the Cause of Disparate Death Rates from MI
Although some studies have found that wealthier patients have lower death rates after myocardial infarctions than poorer patients, a new study finds that income status was not a determining factor when high and low income groups were adjusted statistically to make them equal for factors such as age, sex, ethnicity, social support, cardiovascular history and risk, and other health conditions (Article, p. 82). When compared to the relative minor role of wealth, more important risk factors for heart attacks were older age and more risk factors for cardiovascular disease before the heart attack. This study looked at 3,407 Canadians hospitalized for acute myocardial infarction between 1999 and 2003 in a universal health system in which everyone has access to medical services regardless of income. An editorialist points out that the key question is "what is the cause of the causes?" (Editorial, p. 137.) In other words, what is it about being poor that leads to the biological precursors of death after myocardial infarction?


This release has been updated since its original posting.

Annals of Internal Medicine is published by the American College of Physicians. These highlights are not intended to substitute for articles as sources of information. For an embargoed copy of an article, call 1-800-523-1546, ext. 2656, or 215-351-2656.

Last reviewed: By John M. Grohol, Psy.D. on 30 Apr 2016
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