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In a stride towards integrating wearable technology with clinical health monitoring, researchers have identified a new fitness metric, Daily Heart Rate Per Step (DHRPS) that shows stronger associations with identifying cardiovascular disease (CVD) risk than traditional indicators such as step counts or average heart rate. The study , published in the Journal of the American Heart Association , analysed data from nearly 7,000 participants who volunteered their Fitbit data as part of the National Institutes of Health’s All of Us Research Program. The research team, led by scientists from Northwestern University’s Feinberg School of Medicine and Lurie Children’s Hospital of Chicago, developed DHRPS as a simple ratio: an individual’s average daily heart rate divided by the number of steps taken per day.
The higher the DHRPS, the more heartbeats per step, is an indication of lower cardiovascular efficiency and potentially poorer heart health. Co-relation with six conditions Using 5.8 million person-days of Fitbit data and over 50 billion recorded steps, the study included 6,947 adults who shared at least 10 days of data along with linked electronic health records (EHRs).
Researchers tested whether DHRPS correlated with six key cardiovascular conditions, type 2 diabetes, hypertension, heart failure, stroke, coronary atherosclerosis, and myocardial infarction. They found that individuals in the highest DHRPS quartile (indicating higher heart rates and fewer steps) had significantly higher odds of having all six conditions, even after adjusting for age, sex, BMI, race, step count, and heart rate alone. For instance, high DHRPS was associated with 2.
03 times higher odds of type 2 diabetes, 1.63 times higher odds of hypertension, and 1.77 times higher odds of heart failure.
The study underscored that DHRPS could be easily calculated, low-cost biomarkers using data already collected by widely available devices. “The study clearly shows that those with a higher DHRPS value are more likely to develop chronic conditions, the top three being diabetes, brain stroke, and heart failure. When there’s pressure on the heart, these individuals are more prone to cardiac failure.
It also correlates with hypertension and the risk of heart attacks. So, this index isn’t just theoretical, it has practical relevance for predicting metabolic and cardiovascular health risks,” said Kiran Madala, Professor and HOD of Anaesthesia at Gandhi Medical College, Hyderabad, commenting on the research. Beyond heartbeats and step counts The researchers didn’t stop at these six conditions.
They ran a phenome-wide association study (PheWAS), examining DHRPS across 1,789 disease codes in 17 categories. The result revealed that 518 conditions were significantly associated with DHRPS, especially those already known to be cardiovascular risk factors, such as obesity, sleep apnoea, and type 2 diabetes. Compared to using step count or heart rate alone, DHRPS consistently showed higher statistical significance and stronger regression scores, suggesting it provides a more nuanced reflection of heart health and physical fitness.
Sudhir Kumar, consultant neurologist at Apollo Hospitals, Hyderabad, said the value of the DHRPS index lay not in introducing a new concept, but in repackaging familiar data into an easily understandable metric. “There’s nothing fundamentally new here. But what they’ve done is, they have created a new ratio, the DHRPS, and used it to build public awareness.
The core idea is quite simple, the lower your heart rate in relation to your step count, the better your cardiovascular fitness. If your heart rate is high and your step count is low, that ratio increases, and that’s not a good thing. So, to reduce this ratio, you either bring your heart rate down or increase your step count or ideally both,” he said.
Fitness tests and self-rated health In a small subgroup of participants who also underwent treadmill-based cardiovascular stress tests, DHRPS showed stronger correlations with maximum metabolic equivalents (METs), a measure of cardiorespiratory fitness, than either heart rate or steps. It also correlated better with how participants rated their own physical health in surveys. In other words, people who felt healthier typically had a lower DHRPS, reinforcing its potential as a reflection of overall fitness.
Dr Madala noted, “Standard medical literature says even professional athletes can have resting heart rates as low as 40. For the general population, a resting heart rate between 60 and 72 is ideal. Many people think 72 is normal, but it’s actually on the higher end of the spectrum.
The ideal is to stay closer to 60.” What makes DHRPS unique? Heart rate and step count have long been used separately to estimate cardiovascular health. But DHRPS bridges both of these, in a reflection of how the body’s cardiovascular system responds to physical activity.
A lower DHRPS implies a more efficient heart, lower beats per higher number of steps while a higher DHRPS suggests increased heart strain even for lesser activity. According to the study, this integration captures deeper physiological responses, such as autonomic nervous system function and coronary flow reserve, which are often missed by simple metrics like total steps or average heart rate. Implications for public health The study suggests that DHRPS could complement existing CVD risk scores, offering an accessible tool for early risk detection.
Given the increasing adoption of fitness trackers, DHRPS could potentially allow millions of users to better understand their heart health without visiting a clinic. “What this index does is link resting heart rate, walking or running heart rate, and step count into one meaningful number. It gives a clearer picture of fitness — and more importantly, of risk.
Whether we’re talking about diabetes, obesity, hypertension, stroke, or even lifespan, all these outcomes correlated with cardiovascular efficiency. A lower DHRPS reflects better health and longevity,” said Dr Kumar. Published - April 12, 2025 09:00 am IST Copy link Email Facebook Twitter Telegram LinkedIn WhatsApp Reddit cardiovascular disease / CARDIAC ARREST / Cardiology / heart disease / medical research / health.
