Heart Fat May Be Associated With Nighttime Blood Pressure Fluctuations in Healthy Young Adults

A fat layer surrounding the heart may help reveal how much blood pressure rises and falls during the night, even among people who appear healthy. In a cross-sectional study of 172 apparently healthy adults ages 18 to 41, researchers found that epicardial fat thickness — a measure of the visceral fat around the heart — was positively linked with several measures of 24-hour blood pressure variability, with the clearest relationship seen for nighttime systolic blood pressure variability. The study, published in Artery Research, is among the first to examine this connection in people without hypertension, diabetes, or other chronic illness.

Blood pressure variability refers to changes in blood pressure over time and can be assessed over short, medium, and long intervals. Higher variability has been associated with major health risks, including cardiovascular disease, stroke, kidney disease, dementia, and death. According to the authors, those links can also apply to people whose blood pressure is otherwise normal. Epicardial adipose tissue is a metabolically active fat depot that surrounds the heart and releases inflammatory signals, which may contribute to both local and systemic inflammation. Greater epicardial fat thickness has been tied to coronary and myocardial disease, as well as metabolic syndrome, diabetes, and liver disease, making it a recognized marker of cardiometabolic risk.

Earlier studies had mostly examined the relationship between epicardial fat and blood pressure variability in people with hypertension or other elevated risks. The researchers wanted to know whether the same pattern might already be present in young adults with low cardiovascular risk, a group they say had not been specifically studied before. Participants were recruited from a cardiology outpatient clinic after presenting with atypical chest pain, meaning non-anginal, non-exertional chest discomfort without signs suggesting acute coronary syndrome. All volunteers had normal physical exams, resting electrocardiograms, and routine laboratory results. Anyone with known chronic cardiovascular, metabolic, renal, hepatic, or inflammatory disease, regular medication use, active or recent infection, obesity, or evidence of systemic inflammation was excluded.

The study was prospective and cross-sectional. Each participant underwent transthoracic echocardiography, during which epicardial fat thickness was measured in the parasternal long-axis view with an M-mode cursor placed perpendicular to the aortic annulus along the free wall of the right ventricle at end-diastole. Three consecutive cardiac cycles were averaged. The authors note that echocardiography is a low-cost, radiation-free, and reproducible substitute that correlates well with MRI- and CT-based epicardial fat measurements, though it is more operator-dependent and less sensitive than three-dimensional imaging methods.

To assess blood pressure variability, participants wore a 24-hour ambulatory blood pressure monitor starting between 08:00 and 10:00 on a typical working day. Readings were taken every 30 minutes during daytime hours and nighttime hours. Results were considered valid only if at least 80 percent of scheduled readings were obtained, with at least 70 percent valid in both daytime and nighttime periods. Participants kept sleep and wake diaries and were told to continue their normal daily routines. Blood pressure dipping status was calculated as the percentage drop in average nighttime blood pressure compared with daytime levels, with a decline of 10 percent or more classified as dipping.

The group’s mean age was 29.08 years, 39 percent were male, and average body mass index was 23.36 kg/m². Mean epicardial fat thickness was 4.1 millimeters. Pearson correlation analysis found significant positive associations between epicardial fat thickness and 24-hour systolic blood pressure variability (r = 0.171, p = 0.028), 24-hour diastolic variability (r = 0.173, p = 0.025), nighttime systolic variability (r = 0.193, p = 0.012), and nighttime diastolic variability (r = 0.183, p = 0.018). There were no significant correlations with the ambulatory arterial stiffness index, the ambulatory blood pressure smoothing index, or dipping patterns. Epicardial fat was also significantly thicker in men than in women, although none of the blood pressure variability measures differed significantly by sex.

To see whether the epicardial fat association held after adjustment, the researchers built a multiple linear regression model for nighttime systolic blood pressure variability that included clinically relevant variables and those that were significant in univariate analysis. The model was statistically significant and explained 11.0 percent of the variance (R² = 0.110, adjusted R² = 0.084), with a Cohen’s f² of 0.124, described as a small-to-medium effect. In that model, epicardial fat thickness, smoking, and the platelet-to-basophil ratio were independently associated with nighttime systolic variability, while age and thyroid-stimulating hormone were not. The authors stress that these regression results are correlational and exploratory: they show that the variables remain related after adjustment, but they do not prove that epicardial fat causes blood pressure variability or the other way around.

Why did the association appear strongest for nighttime systolic variability? The authors suggest, based on prior research, that epicardial adipose tissue may affect autonomic function and vascular reactivity through pro-inflammatory and pro-atherogenic mediators, and that nighttime may be when these effects are most visible because influences such as physical activity, stress, and eating recede. They also note that systolic pressure is generally more sensitive than diastolic pressure to arterial elasticity, sympathetic activity, and cardiac output, whereas diastolic pressure in healthy young people depends more on peripheral resistance and arterial relaxation, which tend to be stable. The study did not directly measure autonomic activity, inflammation, or vascular function, so these explanations remain hypothetical.

The authors also acknowledge several limitations. Because the study was cross-sectional, it cannot determine causality or the direction of the relationship. The sample consisted only of healthy young adults with low cardiovascular risk, so the findings may not apply to older adults or to people with hypertension or metabolic syndrome. Since participants were recruited from a cardiology clinic because of atypical chest pain, selection bias cannot be excluded, and the sample may not fully represent asymptomatic young adults in the broader community. The model’s modest explanatory power may reflect limited variation in fat thickness and blood pressure variability among healthy young people, as well as the lack of data on genetics, diet, lifestyle, sleep, and stress. Standardized resting office blood pressure measurements were also unavailable, so the researchers could not test whether the association was independent of resting blood pressure.

If future longitudinal studies confirm the findings, the authors suggest that measuring epicardial fat and monitoring ambulatory blood pressure variability could one day be explored as part of cardiovascular risk screening in young adults. For now, the main message is cautious: the fat around the heart appears to be linked with nighttime swings in systolic blood pressure before overt cardiovascular disease develops, but longer-term and mechanistic studies are needed to determine whether one change tracks the other and which, if either, drives the association.

Subject of Research: The association between epicardial fat thickness and ambulatory blood pressure variability in healthy young adults.

Article Title: Epicardial Fat Thickness and Nighttime Systolic Blood Pressure Variability in Healthy Young Adults

Article References: Sarıoğlu, G., & Yiğit, Y. (2026). Epicardial Fat Thickness and Nighttime Systolic Blood Pressure Variability in Healthy Young Adults. Artery Research, 32(1), Article 28. https://doi.org/10.1007/s44200-026-00126-x

Image Credits: AI Generated

Keywords: epicardial fat thickness, blood pressure variability, ambulatory blood pressure monitoring, young adults, cardiometabolic risk, echocardiography, nighttime systolic BPV, cross-sectional study, visceral fat, cardiovascular risk screening, Epicardial, Thickness

Cite Scienmag News

Ophelia Keating. (October 29, 2026). Heart Fat Linked to Nighttime Blood Pressure Swings in Healthy Young Adults. Scienmag. https://scienmag.com/heart-fat-linked-to-nighttime-blood-pressure-swings-in-healthy-young-adults/

Ophelia Keating. "Heart Fat Linked to Nighttime Blood Pressure Swings in Healthy Young Adults." Scienmag, 29 October 2026, https://scienmag.com/heart-fat-linked-to-nighttime-blood-pressure-swings-in-healthy-young-adults/. Accessed 29 October 2026.