Below is information about articles being published in Annals of Internal Medicine. The information is not intended to substitute for the full article as a source of information. Annals of Internal Medicine attribution is required for all coverage.
Study author provides practical tips for reducing sedentary time
Accumulated evidence suggests that sitting for prolonged periods of time increases risk for heart disease, diabetes, cancer, and death, regardless of whether a person exercises regularly or not. The article is published in Annals of Internal Medicine.
More than one half of the average personís waking life involves sedentary activity, such as watching television, working at a computer, or commuting. Studies have explored the independent association between prolonged sitting and health outcomes after adjusting for physical activity; however, the magnitude, consistency, and manner of association between sedentary time and outcomes independent of physical activity remain unclear.
Researchers conducted a systematic review and meta-analysis of published research to quantitatively evaluate the association between sedentary time and health outcomes independent of physical activity participation among adults. The evidence shows that prolonged sitting is independently associated with negative health outcomes and mortality. However, the deleterious effects of sitting time on health are more pronounced among those who do little or no exercise than among those who exercise regularly.
Tips from the author on reducing sedentary time
Study author, David Alter, MD, PhD, Senior Scientist at Toronto Rehabilitation Institute-University Health Network and Institute for Clinical Evaluative Sciences, says that exercising one hour per day should not give us the right of passage or peace of mind to remain seated for the remaining 23. He offers simple strategies for becoming less sedentary, such as taking a 1-3 minute break every half hour or so throughout the day to stand (standing burns twice as many calories as sitting) or move around at work. Standing or exercising while watching television can also help. He tells his patients to set achievable goals and scale up slowly. For example, start by reducing sitting times by 15-20 minutes per day and set weekly goals to improve from there. Over time, one should aim for 2-3 fewer sedentary hours in a 12 hour day.
Socially disadvantaged pregnant women with HIV who initiate HAART (highly active antiretroviral treatment) for the first time during pregnancy face a greater risk for having detectable virus at delivery, according to a study published in Annals of Internal Medicine. Having a high viral load at delivery puts women at risk for poor health and their infants at risk for infection. HAART has been shown to reduce viral load and is widely used in the United States, yet some women still have detectable virus at delivery. Using data from the International Maternal, Pediatric, Adolescent AIDS Clinical Trials (IMPAACT) Group Protocol 1025 study, researchers sought to identify factors associated with having detectable virus at delivery. Of the 671 women included in the study, all of whom initiated HAART for the first time during pregnancy, 13.1 percent had detectable virus at delivery. Those women were more likely than those with undetectable virus to be black, have a low education level, have initiated HAART and/or prenatal care in the third trimester, and have poor HAART adherence. The authors suggest that interventions for this population should promote early prenatal care, early HAART initiation, and medication adherence.
A small study being published in Annals of Internal Medicine may reveal an important discovery about idiopathic pulmonary arterial hypertension (IPAH), a rare and deadly disease. Patients with IPAH fall into two categories: those who respond to acute exposure to vasodilators, and those who donít. Nonresponders (about 95 percent of IPAH patients) have varying prognoses. The few who do respond improve with long-term therapy and have an excellent prognosis. This disparity in outcomes has fueled speculation that vasodilator-responsive and nonresponsive IPAH are distinct diseases. This observational study of 14 patients with IPAH provides the strongest evidence to date that vasodilator-responsive IPAH is characterized by immediately reversible vasoconstriction, whereas nonresponsive IPAH involves irreversible vascular obliteration. Therefore, despite sharing the baseline hemodynamic profile of IPAH, responders and nonresponders represent different vascular phenotypes and perhaps different diseases.