Published: Apr 19, 2013 | Updated: Apr 19, 2013
By Kristina Fiore , Staff Writer, MedPage Today
Story Source

Action Points

• Elevated hair cortisol levels over time signaled an increased risk of cardiovascular disease.
• Point out that although there were no associations between hair cortisol levels and noncardiovascular disease, top quartile patients had a greater risk of type 2 diabetes.

Levels of cortisol in the hair that remained elevated over time signaled an increased risk of cardiovascular disease, researchers found.

Patients with hair cortisol levels in the highest quartile had a significantly increased risk of cardiovascular disease compared with those in the lowest quartile (OR 2.7, P=0.01), Laura Manenschijn, MD, of Erasmus Medical Center in The Netherlands, and colleagues reported online in the Journal of Clinical Endocrinology and Metabolism.

“Because scalp hair can capture information about how cortisol levels have changed over time, hair analysis gives us a better tool for evaluating that risk,” Manenschijn said in a statement.

Stress has long been associated with an increased risk of cardiovascular disease. Cortisol is a known hormone marker of stress, but researchers note that measuring it in serum or saliva only affords a brief, cross-sectional look at hormone levels that could by confounded by a host of factors. Measuring cortisol in hair, however, provides a way to study long-term cortisol exposure, they said.

So they looked at a sample of 283 older patients — median age 75 — who were selected from a large Dutch cohort study called the Longitudinal Aging Study Amsterdam (LASA).

They took hair samples from patients — about 150 strands each — and looked at the top 3 cm of hair that were closest to the scalp to assess about 3 months’ worth of cortisol exposure.

Data on coronary heart disease, stroke, peripheral arterial disease, diabetes, and other conditions were self-reported.

Overall, hair cortisol levels were significantly lower in women than in men (21 pg/mg versus 26.3 pg/mg, P<0.001).

Manenschijn and colleagues found that those in the highest quartile of cortisol had a significantly increased risk of cardiovascular disease compared with those in the lowest quartile (OR 2.7, P=0.01).

Specifically, these patients also had an increased risk of coronary heart disease and peripheral arterial disease (P=0.03 and P=0.05, respectively), though there was not a significantly increased risk of stroke.

Top quartile patients did, however, have a greater risk of type 2 diabetes (OR 3.2, P=0.04).

There were no associations between hair cortisol levels and noncardiovascular disease, and the researchers noted that there was no relationship between hair cortisol and body mass index (BMI).

The latter point adds fuel to the fire that BMI “may not be a reliable marker of body fat and therefore not an accurate predictor of cardiovascular disease and mortality at older age,” they wrote.

The study was limited by self-reported data and by the low prevalence of chronic disease, such as stroke, which may have resulted in limited statistical power.

But the researchers still concluded that long-term elevations in cortisol are likely an important indicator of cardiovascular risk, and that future studies are needed to clarify its role as a predictor of heart disease that can inform new treatment or prevention strategies.