Hair cortisol, cortisone unrelated to cognitive function, dementia

There appears to be no longitudinal association between hair cortisol and cortisone levels with dementia and various measures of cognitive function, a recent study has found.

Drawing from waves 6–9 of the English Longitudinal Study of Ageing, researchers longitudinally evaluated 4,399 adults (aged ≥50 years, 67 percent women). Liquid chromatography-mass spectrometry was used to measure hair cortisol and cortisone, while cognition was assessed as verbal episodic memory, time orientation, and dementia.

Unadjusted regression analysis revealed that hair cortisol was associated with worse verbal episodic memory (β, 0.19; p=0.02), but not with dementia (p=0.687) or time orientation outcomes (p=0.054).

Cortisone was likewise tied to poorer verbal episodic memory (β, 0.74; p<0.001) and showed a significant interaction with time orientation (β, 0.06; p<0.001). Dementia remained unrelated to cortisone (p=0.091).

Adjusted regression models showed that advanced age, smoking, and depression were correlated with worse verbal episodic memory and time orientation.

Of note, all effects of hair cortisol and cortisone levels were statistically attenuated.

“While our study was unable to pinpoint precisely which was the main (or multiple) confounding factor, it did show that age, wealth, and hypertension appeared to attenuate the relationship between hair cortisol and verbal memory to nonsignificance,” the researchers said.

“Future research would be needed to ascertain the underlying factors which specifically may have driven spurious associations in prior research,” they added.