Cholesterol Watch

Vigorous Exercise Associated With Decreased Risk of MI

In a study published in the October 2011 issue of Medicine & Science in Sports & Exercise, researchers found that men who participated in 3 or more hours of vigorous exercise a week were 22% less likely to experience a myocardial infarction (MI) (95% confidence interval = 0.61-0.98).

The case-control study used a modified Paffenbarger physical activity questionnaire, which distinguishes vigorous activities from ones that require less exertion. Swimming, jogging, running, and playing football were some physical activities considered vigorous. Of 18,225 men from the Health Professionals Follow-up Study, 412 had new cases of MI. These men were then matched in a 1 to 2 ratio to controls who did not experience an MI.

The outcome of the study, the authors proposed, may be due to the favorable effects that exercise had on biomarkers such as high-density lipoprotein (HDL) cholesterol, vitamin D, apolipoprotein B, and hemoglobin A1C (HbA1C). For example, higher levels of HDL and vitamin D were found in those who exercised versus those who did not. Men who exercised also had lower apolipoprotein B and HbA1C values.

Regarding the new finding that higher vitamin D levels may figure into the MI risk—exercise equation, Andrea Chomistek, research fellow in the department of nutrition at the Harvard School of Public Health and lead author of the study, said, “This likely comes from being outside more…I don’t think you’d get the same increase in vitamin D by staying inside and running on the treadmill.” Despite their findings, the authors concluded that “Future research should explore benefits of exercise beyond these biomarkers of risk.”

Statins and Improved Outcomes in Head Injury

The statins, well known for their ability to reduce LDL and CV risk, may find a role in older patients with head trauma, a new study suggests. In the October 2011 issue of The Journal of Trauma, scientists published data indicating that patients who were taking statins before their head injury fared better in terms of in-hospital mortality and functional recovery at 12 months. In those with multiple CV problems, however, no improvements were seen.

Researchers used data from the National Study of Costs and Outcomes of Trauma. The study population included men 65 years or older with an Abbreviated Injury Score of 3 or more. Patients were excluded from the study if they expired within a day of admission or had fixed, dilated pupils upon examination. The sample size of the study was 523 patients. The Extended Glasgow Outcome Scale was used to measure how well patients recovered after their injury.

Patients who were taking statins before their traumatic head injury were 76% less likely to die in the hospital than those who were not. Although differences in recovery at 3 months did not meet statistical significance, they did at 12 months—with those taking statins 13% more likely to have a good recovery. This study adds to the growing literature that suggests statins may be used to treat more than just lipid disorders.

Hot Flashes and Night Sweats Linked with High Lipid Levels

Scientists have recently found a link between the frequency of vasomotor symptoms in menopause and lipid levels. In the Study of Women’s Health Across the Nation (SWAN), researchers followed 3201 women and found that those who had more frequent episodes of hot flashes and night sweats also had higher levels of low-density lipoprotein (LDL), HDL, apolipoprotein A and B, and triglycerides. The associations for apolipoprotein A and B remained statistically significant after adjustment for follicle-stimulating hormone and estradiol, 2 hormones that were also measured by blood draw.

The women were assessed at baseline and then yearly for 7 years. The frequency of hot flashes (also known as hot flushes) or night sweats fell into 3 categories: 0, 1 to 5, or 6 or more days in the past 2 weeks. In addition to the comprehensive lipid panel, body mass index (BMI) and affect were recorded. Results were adjusted for multiple covariates including age, BMI, parity, and the use of certain medications.

The SWAN study is interesting because it potentially connects menopausal symptoms to cardiovascular (CV) risk. Scientists are not drawing any hard conclusions just yet, especially because more frequent hot flashes were linked with higher levels of both LDL and HDL, the “bad” and “good” cholesterol, respectively. Nonetheless, the authors conclude that the link between symptoms and CV risk warrants further investigation.

Fast Fact: According to the Centers for Disease Control and Prevention, 2 of every 3 adults with high cholesterol do not have their condition under control.