Study results did not find an association between increased pineal gland calcification and sleep quality after adjusting for demographics, suggesting that PGC may not necessarily indicate pineal dysfunction but could reflect adaptive physiological mechanisms.
The study population had a mean pineal gland calcification volume of 51 µL with substantial variability.
Forty percent of participants had poor sleep quality as measured by the Pittsburgh Sleep Quality Index.
Locally-Weighted Scatterplot Smoothing revealed a linear relationship between continuous PGC volumes and PSQI scores.
An unadjusted regression model showed a significant association between PGC volume tertiles and PSQI scores, but this association lost statistical significance after adjustment for age and sex.
The association between PGC volume tertiles and poor sleep quality (binary outcome) was non-significant in both unadjusted and adjusted logistic regression models.
The authors concluded that increased pineal gland calcification is not associated with worse sleep quality and may reflect adaptive physiological mechanisms rather than pineal dysfunction.
This research examined whether calcification (hardening with calcium deposits) of the pineal gland — a small brain structure involved in producing the sleep hormone melatonin — is linked to poorer sleep quality in adults. The study enrolled 1,009 adults aged 40 and older living in rural coastal Ecuador, measuring pineal gland calcification volumes using CT brain scans and assessing sleep quality using a standardized questionnaire called the Pittsburgh Sleep Quality Index. About 40% of participants reported poor sleep quality, and the average calcification volume showed wide variation among individuals. When researchers first looked at the data without accounting for other factors, larger pineal gland calcification volumes appeared to be associated with worse sleep scores. However, once age and sex were taken into account, this association disappeared entirely. Similarly, larger calcification volumes were not associated with a higher likelihood of having poor sleep quality in either unadjusted or adjusted analyses. This suggests that the initial apparent relationship was likely driven by the fact that calcification naturally increases with age, and older people also tend to sleep worse — rather than calcification itself causing sleep problems. This research suggests that pineal gland calcification, which is very common in adults, may not impair the gland's ability to regulate sleep and could instead be a normal part of aging rather than a sign of dysfunction. These findings add important population-level evidence to a previously inconclusive body of literature, and indicate that the presence of pineal calcification on a brain scan should not automatically be interpreted as a cause of sleep complaints.
Del Brutto O, Mera R, Arias E, Rumbea D, Patel V, Castillo P. (2026). Automated measurement of pineal gland calcification volumes and sleep quality in adults living in costal Ecuador.. Arquivos de neuro-psiquiatria. https://doi.org/10.1055/s-0045-1814399