Low-dose aspirin may not be effective in preventing cardiovascular events in people weighing 70 kg (154 pounds) or more, a Lancet study suggests.
Researchers analyzed 10 trials that evaluated aspirin versus controls for primary prevention of cardiovascular events in 120,000 people.
Daily, low-dose aspirin (75–100 mg) was associated with reduced risk for cardiovascular events among those weighing less than 70 kg (odds ratio, 0.77), but there was no significant effect for heavier patients — roughly 80% of men in the study and nearly half of women weighed 70 kg or more. In the heavier group, low-dose aspirin may be even less effective in smokers and in those who take enteric-coated aspirin.
High-dose aspirin (300–325 or 500 mg), meanwhile, appeared to be effective in reducing primary cardiovascular events only patients weighing 70 kg or more (OR, 0.79).
Commentators said that people with more body mass may have more esterases, which clear aspirin and would reduce the bioavailability of the drug.
The authors conclude: “A one-dose-fits-all approach to aspirin is unlikely to be optimal, and a more tailored strategy is required.
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Background: NEJM Journal Watch Cardiology coverage of antiplatelet activity of enteric-coated aspirin
The latest recommendation from the US preventive task force is to take aspirin (low dose) to prevent both heart disease and colon cancer in adults aged 50-59, who have significant risk factors.
The guidelines are published in the Annals of Internal Medicine:
- Low-dose aspirin is recommended for adults aged 50–59 who have at least a 10% risk for a cardiovascular event in the next decade, low bleeding risk, and a life expectancy of at least 10 years; patients must also be willing to take aspirin daily for at least 10 years.
- For adults aged 60–69 fitting the above criteria, the decision to start aspirin should be an individual one.
- For patients younger than 50 and older than 69, there is not enough evidence to make recommendations.
90% of heart attacks can be prevented by working on these 9 modifiable risk factors–
- High cholesterol
- Psychosocial stressors
- High blood pressure
- Abdominal fat
- No alcohol intake
- Inadequate exercise
- Irregular consumption of fruits and vegetables
Lancet reports yearly screening for ovarian cancer, using a pelvic ultrasound and checking a blood marker CA125, might reduce deaths from ovarian cancers. The study was done in UK in over 200,000 post menopausal women with no family or personal history of ovarian cancer and they were followed for a period of 11 years.
During the follow-up, the incidence of ovarian cancer mortality was not significantly lower in the screening group than in the no-screening group. However, the effect of screening became significant after 7 years. In addition, in a prespecified secondary analysis that excluded women with CA125 levels suggesting cancer at baseline, screening was associated with a 20% reduction in ovarian cancer mortality relative to no screening.
Annals of Internal Medicine reports that people who have a normal body mass index (weight to height ratio) but abdominal fat are at high risk for heart related deaths.
Using National Health and Nutrition Examination Survey data, researchers studied more than 15,000 adults with BMIs greater than 18.5. Normal being 18-24.
After a mean follow-up of 14 years, waist-to-hip ratio (WHR), but not BMI, was associated with higher overall mortality risk. Among men with normal BMI, those with central obesity had an 87% higher total mortality risk than men without central obesity. Similarly, women with normal-weight central obesity had a 48% higher mortality risk than women with similar BMI but no central obesity.
The recommended waist circumference for men is less than 102 cm, and for women is less than 88 cm.
Nicotinamide (a form of vitamin B3, Niacin) reduces the incidence of nonmelanoma skin cancers in high-risk adults. High risk was defined as having had 2 cases of skin cancer- either squamous cell or basal cell, in the past 5 years.
This study was done on over 400 adults in Australia, who were randomized to receive oral niacin (500 mg) or placebo twice daily for a year. During the study, the average number of new skin cancers was significantly lower with vitamin B3. Significant reductions were observed for both squamous cell and basal cell cancers. In addition, the number of actinic keratoses, which can turn cancerous, was significantly lower among niacin recipients as early as 3 months after supplementation began. Adverse events did not differ between the groups.
The authors conclude that “nicotinamide is widely accessible as an inexpensive over-the-counter vitamin supplement and presents a new chemopreventive opportunity against non-melanoma skin cancers.”