Monday, December 10, 2018

A Sunny Workout is Best

Want to get fit? Check your vitamin D levels. Cardiorespiratory fitness (CRF) may well be linked to serum vitamin D levels. A study, published in the European Journal of Preventive Cardiology (October 2018), looked at data from nearly 2,000 participants in the National Health and Nutrition Survey. Subjects were between the ages of 20 and 49.

Researchers used VO2 max as an indicator of cardiorespiratory fitness. Used to establish the aerobic endurance of an athlete, VO2 max is the amount of oxygen a person can utilize during intense exercise. By putting a face mask on the subject, the volume and gas concentrations of inspired and expired air can be directly measured.

Of the 1995 participants, 45.2% were women, 49.1% were white, 13% were hypertensive and 4% had diabetes. Vitamin D levels did not vary between matched subjects with confounding variables like diabetes, high blood pressure, age, sex, race, CRP levels, BMI, etc. The one variable that did make a difference between matched subjects was serum vitamin D levels. The researchers found that serum vitamin D levels had a significant effect on cardiorespiratory fitness (VO2 max). Those in the highest quadrille had a VO2 max 2.9 higher on average than those in the lowest quadrille.

According to the authors, “We found a strong independent association between vitamin D levels and CRF, which was robust to potential confounding variables. Future studies are needed to explore the underlying biological mechanisms of the observed association. Clinical trials of vitamin D supplementation are required to validate the relationship.” 

Vitamin D levels have been associated with other cardiovascular issues. Low levels are linked to a higher risk of hypertension, poor outcomes for congestive heart failure patients and overall cardiac mortality. Now we can add cardiorespiratory fitness to that list. Because CRP status may be an indicator of cardiovascular risk, the American Heart Association has recommended that CRP be measured in routine clinical practice.

Friday, December 7, 2018

Higher Risk Thresholds May Be Needed for Starting Statins for Primary CVD Prevention, Study Suggests

The guideline-recommended risk thresholds for initiating statins for primary prevention of cardiovascular disease may be too low, a modeling study in the Annals of Internal Medicine suggests.

Researchers performed a network meta-analysis of studies comparing four low- or moderate-dose statins with no statins in patients aged 40 to 75 with no CVD history. They balanced statins' potential benefit of CVD event prevention with potential harms, like myopathy, hepatic or renal dysfunction, cataracts, hemorrhagic stroke, type 2 diabetes, and cancer.

Most current guidelines recommend statin initiation when a person's 10-year CVD risk is 7.5%–10%. In this study, the benefits only began to outweigh the risks when CVD risk was 14% for men aged 40 to 49. For men 70 to 75 years, the threshold was 21%. For women, thresholds ranged from 17% to 22%.

The authors conclude: "Our results suggest that guidelines should use higher 10-year risk thresholds when recommending statins for primary prevention of CVD and should consider different recommendations based on sex, age group, and statin type."

Of note, guidelines released last month by the American College of Cardiology and American Heart Association consider a 10-year risk score of 7.5%–19.9% to denote "intermediate risk."

Wednesday, December 5, 2018

Wisdom Wednesday: U.S. Life Expectancy Down, Overdose and Suicide Rates Up

U.S. life expectancy at birth has declined for the second year in a row, from 78.7 years in 2015 to 78.6 years in 2016, according to the latest CDC data.

Notable increases were observed in drug overdose deaths and suicides. The overdose rate nearly doubled from 2006 to 2016, hitting 19.8 deaths per 100,000. Meanwhile, suicide rates rose steadily among adults aged 25–44 years, reaching 16.9 deaths per 100,000 — higher than the heart disease death rate. Among those aged 15–24 years, suicide became the second leading cause of death in 2016, and among children aged 1–14 years, the rate reached 0.8 per 100,000.

CDC Director Dr. Robert Redfield said in a statement, "These sobering statistics are a wakeup call that we are losing too many Americans, too early and too often, to conditions that are preventable. ... we must all work together to reverse this trend and help ensure that all Americans live longer and healthier lives."

My Take:
In 2016, the top 10 leading causes of death were heart disease, cancer, unintentional injuries, chronic lower respiratory diseases, stroke, Alzheimer’s disease, diabetes, influenza and pneumonia, kidney disease, and suicide. Metabolic syndrome, a preventable condition is a direct cause in half of the top causes of death.

Monday, December 3, 2018

Strength Training Bests Aerobics for Cardioprotection

Static exercise, such as strength training, might be superior to dynamic exercise, such as walking or cycling, for conferring protection against cardiovascular disease (CVD), new research suggests.

Using data for the 2005/06 National Health and Nutrition Examination Survey (NHANES), Maia P. Smith, PhD, assistant professor, Department of Public Health and Preventive Medicine, St. George’s University, West Indies, found that 36% of adults 21 to 44 years of age and 25% of adults older than 45 years engaged in static activity, compared with 28% and 21%, respectively, of adults engaging in dynamic activity.

Although both activities were associated with 30% to 70% lower rates of CVD risk factors, the associations were strongest in the static activity group. “In over 4000 American adults from a representative sample, I found that static activity – strength training – appeared more cardioprotective than dynamic activity – in this case walking and biking,” Smith told Medscape Cardiology.

“The odds of having a given risk factor – hypertension, overweight/obesity, diabetes, or high cholesterol – were between one-third and two-thirds lower for those who engaged in static activity that for those who engaged in no activity, but although dynamic activity wasn’t as good as static, it still had some benefits, especially for [those who were] overweight,” she said.

Commenting on the study, Richard C. Becker, MD, professor of medicine, University of Cincinnati College of Medicine, noted that the Physical Activity Guidelines for Americans, highlight moderate-intensity aerobic activity of at least 150 minutes per week and muscle-strengthening activity 2 days per week.