More time spent sitting, reclining or lying down during the day may increase the risk of cardiovascular disease (CVD) and death, according to a study in JACC, the flagship journal of the American College of Cardiology, and presented at the American Heart Association’s Scientific Sessions 2024.

More than roughly 10-and-a-half hours of sedentary behavior per day was significantly linked with future heart failure (HF) and cardiovascular (CV) death, even among people meeting recommended levels of exercise.

“Our findings support cutting back on sedentary time to reduce cardiovascular risk, with 10.6 hours a day marking a potentially key threshold tied to higher heart failure and cardiovascular mortality,” said Shaan Khurshid, MD, MPH, a cardiologist at the Massachusetts General Hospital and co-senior author of the study. “Too much sitting or lying down can be harmful for heart health, even for those who are active.”

Insufficient exercise is a known risk factor for cardiovascular disease (CVD). Over 150 minutes of moderate-to-vigorous physical activity per week is recommended by current guidelines to promote heart health. However, study experts say exercise is only a small fraction of overall daily activity, and the current guidelines don’t provide specific guidance on sedentary behavior which accounts for a much larger portion of daily activity, despite evidence that it’s directly linked with CVD risk.

This study examined the amount of sedentary time at which CVD risk is greatest and explored how sedentary behavior and physical activity together impact the chances of atrial fibrillation (AF), heart failure (HF), myocardial infarction (MI) and CV mortality.

Among the 89,530 study participants of the UK biobank, the average age was 62 years and 56.4% were women. Participants submitted data from a wrist-worn triaxial accelerometer that captured movement over seven days. The average sedentary time per day was 9.4 hours.

After an average follow-up of eight years, 3,638 individuals (4.9%) developed incident AF, 1,854 (2.1%) developed incident HF, 1,610 (1.84%) developed indecent MI and 846 (0.94%) died of CV causes, respectively.

The effects of sedentary time varied by outcome. For AF and MI, the risk increased steadily over time without major shifts. For HF and CV mortality, increase in risk was minimal until sedentary time exceeded about 10.6 hours a day, at which point risk rose significantly, showing a “threshold” effect for the behavior.

For study participants who met the recommended 150 minutes of moderate-to-vigorous physical activity or more, the effects of sedentary behavior on AF and MI risks were substantially reduced, but effects on higher risk of HF and CV mortality remained prominent.

“Future guidelines and public health efforts should stress the importance of cutting down on sedentary time,” Khurshid said. “Avoiding more than 10.6 hours per day may be a realistic minimal target for better heart health.”

In an accompanying editorial comment, Charles Eaton, MD, MS, Director of the Brown University Department of Family Medicine, said the use of wearable accelerometers has shown that exercise is significantly over-estimated by self-report and sedentary behavior is under-estimated.

Eaton said that replacing just 30 minutes of excessive sitting time each day with any type of physical activity can lower heart health risks. Adding moderate-to-vigorous activity cut the risk of HF by 15% and CV mortality by 10%, and even light activity made a difference by reducing HF risk by 6% and CV mortality by 9%.

“This study adds to the growing evidence of a strong link between sedentary behavior and cardiovascular health,” said Harlan M. Krumholz, MD, SM, Harold H. Hines Jr. Professor at Yale School of Medicine and Editor-in-Chief of JACC. “The findings strongly suggest that we need to get people moving to promote better health.”

Running, cycling, or swimming – if you regularly exercise, you’re on track for a long and healthy life.

This is according to a study – “Cardiorespiratory fitness is a strong and consistent predictor of morbidity and mortality among adults: an overview of meta-analyses representing over 20.9 million observations from 199 unique cohort studies” – that was published in the British Journal of Sports Medicine.

The study comprised of 26 systematic reviews with meta-analysis representing more than 20.9 million observations from 199 unique cohort studies. It is the first study to collate all the scientific evidence that looked at the prospective link between cardiorespiratory fitness and health outcomes among adults.

The study found that:

• for every 1-MET increase in cardiorespiratory fitness – the amount of energy used for quiet sitting – a person can reduce their risk of death by 11-17%, and specifically, their risk of heart disease by 18%.
• an increased cardio fitness level will reduce your risk of death from any cause by 11-17%.

Senior author Grant Tomkinson said that cardiorespiratory fitness is probably the most important type of fitness for good health. “Cardiorespiratory fitness (or CRF) is your ability to perform physical activity for a long period of time like running, cycling, and swimming. And in this study, we found prolonged cardiorespiratory fitness is strongly and consistently associated with all types of premature death and incident disease – spanning heart failure, depression, diabetes, dementia and even cancer.”

Tomkinson added that the researchers “summarized the evidence linking CRF to numerous health outcomes and found that those with low levels of CRF are far more likely to die early or develop chronic conditions like heart disease later in life.” Specifically, “we found that every 1-MET increase in CRF, which is the amount of energy used when sitting quietly, reduced the risk of early death from any cause and heart failure by 11–17% and 18%, respectively. For most people, a 1-MET increase in CRF can be achieved through a regular aerobic exercise program.”

For Tomkinson, the message is quite simple: if you do a lot of “huff and puff” exercise, then your risk of dying early or developing diseases in the future is reduced. If you avoid exercise your health may suffer.

Chronic health conditions are an ongoing cause of poor health, disability, and premature death. In Australia, an estimated 11.6 million people (47%) have a chronic and debilitating health conditions, which contributes to two thirds of the burden of disease.

“Clearly, cardiorespiratory fitness is as an important factor for good health. If you are already exercising, this is good news; but if you know you need to up your fitness and movement, then this is a timely reminder,” co-author Dr Justin Lang said.

People can make meaningful improvements through additional moderate physical activity, such as brisk walking at least 150 minutes a week, or kayaking (which means grabbing the Best Folding Kayak).

“And as they improve their fitness, their risk of death and disease will decline. But the onus for improvement should not just sit with the individual, it should also be routinely assessed in clinical and public health practice, so that we can support people to improve their health outcomes,” Lang said.

Through regular assessment, clinicians and exercise professionals could better identify adults at greater risk of early death and initiate exercise programs aimed at increasing CRF through regular physical activity.

Researchers at the University of Auckland are running a trial of castor oil as a potential safe and natural treatment for dry-eye disease following a successful pilot study.

While exact figures aren’t available for New Zealand, in Australia, it is estimated dry-eye disease affects around 58% of the population aged over 50. Advancing age, menopause, increased screen time, contact lens wear are just some of the risk factors for developing dry eye disease.

Blepharitis is the most common cause of dry-eye disease, accounting for more than 80 percent of cases. It is a chronic condition with no known cure.

“Currently, patients are left grappling with symptoms of dryness, grittiness and, in some cases, watery eyes that feel uncomfortable impacting on their quality of life and work productivity,” says doctoral candidate and lead clinical investigator Catherine Jennings.

Current treatments, such as antibacterials and anti-inflammatories, are generally unsuitable for long-term use, due to significant side-effects and potential for antimicrobial resistance.

“Often patients are left feeling helpless when attempting to manage a chronic condition,” Jennings says.

The current trial is of a product containing cold-pressed castor oil enhanced with mānuka and kanuka oils applied using a rollerball attached to a small glass bottle.

“The previous pilot study, conducted by our research team, was unique in its use of castor oil in such an application on the eyelids, with the product not known to be used anywhere else in the world for treating blepharitis,” says Jennings.

Castor oil comes from a flowering tropical or subtropical shrub from the species Riccinus communis. It has been used therapeutically for millenia, including more recently in eye cosmetics and eye makeup removers.

In the pilot study, 26 patients with blepharitis were treated with cold-pressed castor oil over four weeks. They had measurable improvements in symptoms, such as reduced redness of the lid margin, decreased thickening of the eyelid, and a decline in bacterial profusion, as well as reduced eyelash crusting.

Building on the success of the pilot study, the research team is now engaged in the more extensive double-blinded, randomised and placebo-controlled study. They are aiming to recruit 92 participants and generate robust scientific evidence for clinicians.

The ultimate goal is to sustainably improve quality of life for this large group of patients using a natural, safe and effective product, principal investigator Professor Jennifer Craig says.

“Castor oil has been proposed as a natural product that could offer a safe, effective and easy-to-use alternative to existing therapies,” Craig says.

“My hope is this study will produce evidence-based guidance for clinicians with regard to offering castor oil as a possible management option for patients suffering from blepharitis, so they continue to enjoy a great quality of life, read the books they love, be productive in their work environment and enjoy other visual hobbies.”