doi: 10.1161/01.CIR.0000065143.66694.D5
(Circulation. 2003;107:e9014.)
© 2003 American Heart Association, Inc.
Cardiovascular News
Circulation Newswriter
Intensity of Physical Exercise Depends on Where You Start
If a person thinks he or she is exercising hard or at least moderately, the risk of coronary heart disease in that individual goes down—even if the person is not meeting current recommendations for activity, according to researchers from Harvard University School of Medicine and The Brigham and Woman’s Hospital, both in Boston, Mass, in a report in this week’s issue of Circulation (Circulation. 2003;107:1110–1116).
In this study led by I-Min Lee, ScD, MBBS, an Associate Professor of Medicine at Harvard, researchers monitored 7337 men aged an average of 66 years for an average of 7 years. In the beginning, the men reported their actual activities and their perceived level of exertion when they did exercise. During the follow-up period, 551 men developed coronary heart disease. After adjusting for a variety of factors, the researchers found that the relative risks of those who perceived their exercise exertion as moderate was 0.86; somewhat strong, 0.69; strong or even more intense, 0.72, when compared to those who perceived their exercise as weak or less intensive. "This inverse association extended to men not fulfilling current recommendations" of expending at least 1000 kcal per week or not engaging in activities of at least 3 metabolic equivalents for 30 minutes daily.
The researchers concluded: "Recommendations for ‘moderate’-intensity physical activity may need to consider individual fitness levels instead of globally prescribing activities" at certain levels. They also said, "Our findings in no way negate current activity recommendations—men who expended >1000 kcal/week or who exercised at vigorous absolute intensity had lower CHD rates than those who did not. However, the findings do offer encouragement for older persons who may be unable or unwilling to follow current recommendations. With the high prevalence of individuals not meeting current activity recommendations, there is a need to clarify the thresholds of physical activity for specific health benefits."
Lose a Tooth, Risk Your Health
Loss of a tooth was significantly associated with peripheral artery disease (PAD), especially among men with periodontal disease, in this study led by researchers from Harvard School of Public Health, School of Medicine, and School of Dental Medicine in Boston, Mass, as well as the College of Dental Medicine at Kaohsiung Medical University in Taiwan. The study appears in this week’s issue of Circulation (Circulation. 2003;107:1152–1157).
In this study led by Hsin-Chia Hung, DDS, DrPH, of Harvard and Taiwan, 45 136 male health professionals free of cardiovascular disease at baseline were monitored for 12 years. During that period, the researchers identified 342 cases of cardiovascular disease. When they evaluated the different measures of oral diseases against the occurrence of peripheral arterial disease, they found that the cumulative incidence of tooth loss was significantly associated with elevated risk of peripheral artery disease occurring sometime in the future. The relative risk for a history of periodontal disease was 1.41. It was 1.39 for tooth loss during the follow-up period. In men with a history of periodontal disease, the relative risk of tooth loss increased to 1.88.
The authors wrote: "We further explored the potential induction periods for incident tooth loss and found that tooth loss in the previous 2 to 6 years was more strongly associated with PAD [peripheral arterial disease] than tooth loss in the previous 2 years or 6 to 8 years. The association between tooth loss and PAD was somewhat lower after 6 years, suggesting that 6 years may be too distant and 2 years may be too recent for tooth loss to have an impact on PAD. Alternatively, it is possible that these differences may be chance findings; hence the need for future studies with repeated measurements of oral diseases."
In their conclusion, the authors wrote: "We found that incident tooth loss was significantly associated with PAD, especially among men with periodontal disease. The results support a potential oral infection-inflammation pathway with PAD."
Preventing Recurrence Thromboembolism
Low-intensity, long-term treatment with warfarin was so effective at preventing recurrent thromboembolism that the Prevention of Recurrent Venous Thromboembolism (PREVENT) trial was ended early. It was released early online by the New England Journal of Medicine and is scheduled for publication in the April 10, 2003, issue of the publication.
In the article, the authors led by Paul M Ridker, MD, of the Center for Cardiovascular Disease Prevention at Brigham and Women’s Hospital and Harvard University School of Medicine in Boston, Mass, concluded: "Long-term, low-intensity warfarin therapy is a highly effective method of preventing recurrent thromboembolism."
They noted that standard therapy to prevent such blood clots includes 3 to 12 months of treatment with warfarin at full dose. However, they were seeking a long-term treatment for the condition. No such therapy had been validated in scientific trials, they wrote.
In this study, patients with idiopathic venous thromboembolism who had received full-dose anticoagulation therapy for an average of 6.5 months were randomly assigned to receive low-intensity warfarin or placebo. The patients were to be monitored until they experienced a recurrent thromboembolism, major hemorrhage, or death.
After enrolling 508 patients who had undergone randomization and had been monitored for as long as 4.3 years and a mean of 2.1 years, the investigators were told to stop the trial because the treatment demonstrated a definite advantage. In the treatment group, 14 of 255 patients had experienced a recurrent thromboembolism compared with 37 of 253 assigned to placebo. The risk reduction of this event was 64%. Major hemorrhage was identified in 2 patients on placebo and 5 on warfarin. Eight patients in the placebo group and 4 in the treatment group died.
"Low-intensity warfarin was thus associated with a 48% reduction in the composite end point of recurrent venous thromboembolism, major hemorrhage or death," the authors wrote.
In an accompanying editorial, Andrew I. Schafer, MD, of the University of Pennsylvania School of Medicine in Philadelphia, Pa, wrote: "It is reasonable for clinicians to adopt, at least for now, this regimen for secondary prophylaxis against venous thromboembolism for patients who require more than 3 months of anticoagulation therapy after an initial event."
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