Case Study Links 'Pot' to Pituitary Damage
Published: May 3, 2013 | Updated: May 3, 2013
By Cole Petrochko, Staff Writer, MedPage Today
Reviewed by Zalman S. Agus, MD; Emeritus Professor, Perelman School of Medicine at the University of Pennsylvania
PHOENIX -- Chronic, daily pot smoking over 15 years may be draining on pituitary hormones, and may explain the "pot-head" image popularized in movies and TV, according to a case report presented here.
A hormonal evaluation of a patient with symptoms of loss of libido, fatigue, and dyspnea showed luteinizing hormone concentration of 0.2 mIU/mL, follicle-stimulating hormone concentrations of 1.8 mIU/mL, and testosterone concentrations of 22 ng/dL, according to Richard Pinsker of Jamaica Hospital Medical Center in Queens, N.Y., and colleagues.
The patient also showed deficiencies in thyroxine and cortisol production, Pinsker said during an oral presentation at the meeting of the American Association of Clinical Endocrinologists.
Tetrahydrocannabinol (THC), the psychoactive ingredient in marijuana, can impair gonadotropin-releasing hormone, as well as affecting other neural transmitters in the hypothalamus, which can result in clinical hypopituitarism, the researchers noted.
"This is a single case, but an interesting case and a hypothesis-generating case," noted R. Mack Harrell, MD, FACP, vice president of the AACE and who was not involved in the study.
He added that this case "takes it to a whole other level -- all of the pituitary hormones were out in this patient."
The study followed a 37 year-old patient who reported daily marijuana use for 15 years and presented to the Jamaica Hospital Medical Center emergency department with symptoms of increasing fatigue, loss of libido, and dyspnea on exertion.
The patient had no history of radiation exposure or head trauma and normal iron and echocardiography, but had significant symptoms of bibasilar rales, gynecomastia, and bilateral atrophied testis on physical examination.
In addition, tests for commonly prescribed opioids turned up negative.
The patient's hormones were measured and, in addition to lower levels of testosterone, follicle-stimulating hormone, and luteinizing hormone, the patient presented with elevated levels of prolactin (53.3 ng/mL), low total T3 (30 ng/dL), high T3 resin reuptake (49%), low total T4 (3.94 ug/dL), normal free T4 (0.97 ng/dL), and low thyroid-stimulating hormone (0.22 uLU/mL).
A subsequent MRI of the patient's head showed an enlarged protuberant pituitary gland without an identified mass lesion.
The patient received a morning dose of 25 mg cortisone, 12.6 mg bedtime cortisone, and daily 25 mcg levothyroxine treatment, which improved his fatigue and edema "dramatically."
Pinsker noted that this issue may be under-addressed, in part because cannabis is not frequently tested for as part of screening for hypopituitarism and due to an increasing political climate supporting marijuana legalization.
"The whole trick was to identify [the patient's marijuana use], and I think we're missing a tremendous amount of people in the United States who have had damage to their pituitary from the use of marijuana," Pinsker told MedPage Today, cautioning that "patients have to be aware and give doctors the scoop on what's going on in their outside lives."
He added that follow-up studies should look at more subjects or individual cases to see if the problem is more wide spread.
The authors declared no conflicts of interest.