Chronic stress measured through hair cortisol concentration shows no meaningful link to most measures of cardiac structure or function in middle-aged adults, according to observational findings published October 7 in the journal Heart.
Hair Cortisol Concentration and Cardiac Phenotypes
The study evaluated 3,005 participants aged 50 to 64 years from a Swedish imaging-based cohort, where 64% of the participants were women and the mean age was 56.9 years. Investigators measured cortisol concentrations in the proximal portions of scalp hair to capture systemic stress exposure over several months. They assessed 19 individual echocardiographic measures and grouped them into broad categories, including structural or volumetric remodeling, cardiac output or flow, and diastolic function or myocardial mechanics. Together, these phenotypes accounted for 45.5% of the total variation observed across all measures.
Statistical models controlled for age, sex, body mass index, smoking habits, alcohol intake, and physical activity levels. After full adjustment, the researchers found no meaningful association between hair cortisol concentrations and the three primary heart phenotypes derived from the echocardiographic data. Most of the 19 individual echocardiographic measures displayed very small effects with no clear directional relationship to chronic stress indicators.
Left Atrial Volume and Adjusted Analysis Results
Among all evaluated parameters, only left atrial end-systolic volume index showed a minor positive association with long-term cortisol levels. The adjusted analysis demonstrated that each one-unit higher log10-transformed concentration of cortisol in hair corresponded to a 0.178 standard deviation higher left atrial end-systolic volume index. This translated to a predicted difference of 0.734 mL/m² across the interquartile range of hair cortisol concentrations. Sensitivity analyses confirmed similar patterns, and researchers observed no consistent interactions when comparing results between male and female participants.
Although elevated hair cortisol has been associated with increased CVD risk, the present findings do not support a relationship with echocardiographic measures of cardiac structure or function in the studied population, suggesting that any such effects may be mediated through alternative physiological pathways,
the study authors wrote.
Study Limitations and Funding Disclosures
The cross-sectional design prevents the establishment of cause-and-effect relationships between chronic stress and cardiac dimensions. Investigators also relied on self-reported questionnaires to gather lifestyle data regarding smoking, alcohol consumption, and physical activity. Furthermore, the cohort consisted of generally healthy middle-aged adults, which restricts the generalizability of these findings to younger demographics, older populations, or individuals with pre-existing cardiovascular diseases.
Three authors reported serving as fellows or associated clinical fellows of the Wallenberg Centre for Molecular Medicine and received funding from the Knut and Alice Wallenberg Foundation. Additional financial support came from Dr. P Håkanssons Foundation, while the hair cortisol analysis received grants from Swedish AFA Insurance and the County Council of Östergötland. The authors declared no competing interests.
Frequently Asked Questions
How was chronic stress measured in the study participants?
Researchers measured cortisol concentrations in the proximal sections of scalp hair, which captures cumulative systemic cortisol exposure over several preceding months rather than transient daily fluctuations.
What specific cardiac measure showed a slight association with hair cortisol?
Left atrial end-systolic volume index demonstrated a modest increase associated with higher hair cortisol levels, resulting in a predicted difference of 0.734 mL/m² across the interquartile range.
Who led the research team and where was the study published?
The study was led by Simon Söderholm at Linköping University in Linköping, Sweden, and was published online on October 7 in the medical journal Heart.
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