PHOENIX — Chronic marijuana use was found to be the cause of hypopituitarism in a 37-year-old man, a case that highlights a potentially growing problem, say physicians.

The case was reported in a poster and discussed in a press briefing here at the annual meeting of the American Association of Clinical Endocrinologists 2013 Scientific & Clinical Congress by Richard Pinsker, MD, director of the internal-medicine program at Jamaica Hospital Medical Center, New York, and Hineshkumar Upadhyay, MD, internal-medicine chief resident at Jamaica Hospital Medical Center.

Tetrahydrocannabinol (THC), the psychoactive ingredient in marijuana, can suppress multiple hypothalamic-pituitary-gonadal (HPG) axis pathways, with subsequent effects on multiple organ systems, they explained. "Any gland can be affected, including the whole pituitary," Dr. Pinsker told Medscape Medical News.

And, he said, this problem could become more common. "This is going to be very interesting, because the political climate in the US is changing, and several states have passed laws legalizing marijuana. Use will probably go up, and people won't be so afraid to come forward… We'll probably start finding all kinds of cases like this," Dr. Pinsker told the media.

Man Admitted to Smoking Marijuana for 15 Years

Dr. Hineshkumar Upadhyay

Dr. Upadhyay described the symptoms of the 37-year-old man who presented to the emergency department with dyspnea on exertion, increased fatigue, and loss of libido. On physical exam, he was found to have bibasilar rales, gynecomastia, and atrophied testes.

He had low levels of luteinizing hormone, follicular-stimulating hormone, and testosterone (0.2 mIU/mL, 1.8 mIU/mL, and 22 ng/dL, respectively), high prolactin (53.3 ng/mL), and ACTH of 6 pg/mL. He also had abnormal thyroid-function tests, normal growth-hormone levels, and low insulinlike growth factor-1.

Administration of cosyntropin produced cortisol levels of 6.4 µg/dL at 0 minutes and 9.3 µg/dL at 60 minutes, suggesting hypopituitarism.

In response to inquiry, the patient admitted smoking marijuana daily for the past 15 years. He had no history of radiation exposure or head trauma. An MRI showed a slightly enlarged pituitary gland with no identified mass, and no other potential causes of hypopituitarism could be found.

He was started on cortisone 25 mg in the morning and 12.5 mg at bedtime as well as levothyroxine 25 µg daily. His fatigue and edema improved dramatically in response to treatment, Dr. Upadhyay reported.

Dr. Richard Pinsker

This man was lucky, Dr. Pinsker stressed. "This is a very serious case, because people without pituitaries will die unless somebody picks this up, and it's not the easiest diagnosis to be made in a small hospital without good testing facilities."

While much of the evidence linking THC with pituitary damage has come from animals, "We really feel the evidence to date suggests this is a much bigger problem than has been given credit… Marijuana has always been laughed off and not taken very seriously. I think it's time physicians start having their antennas up for all the difficulties that come with this drug," Dr. Pinsker concluded

Neither Dr. Pinsker nor Dr. Upadhyay has disclosed relevant financial relationships.

American Association of Clinical Endocrinologists 2013 Scientific & Clinical Congress. Abstract 825, presented May 2, 2013.