Guam Regional Medical City has added longtime Guam physician Dr. Joel Marc Rubio to its specialty care team, expanding local access to endocrinology services.
In an announcement Friday, GRMC said Rubio — recognized as Guam’s first endocrinologist — brings decades of experience treating complex hormonal and metabolic disorders. He specializes in diabetes, thyroid disease, osteoporosis, adrenal and pituitary conditions, hormonal imbalances, and lipid and weight-related disorders.
Hospital officials said his addition strengthens care for patients managing chronic illnesses, including diabetes, which remains a major health concern on Guam. While several endocrinology providers now serve the island, GRMC noted Rubio pioneered the specialty locally and has played a key role in advancing endocrine care.
Rubio earned his medical degree from the University of the East–Ramon Magsaysay Memorial Medical Center in the Philippines. He completed his internal medicine residency at Saint Barnabas Hospital under the Cornell University training program in New York and later completed a fellowship in endocrinology at the State University of New York at Stony Brook. His postgraduate training also includes thyroid ultrasound and biopsy, obesity medicine, nuclear endocrinology and procedural medicine.
Throughout his career, Rubio has held leadership and academic roles in Guam and the mainland United States, including serving as a founding partner and head of clinical services at Health Partners, LLC. He has also contributed to physician education and medical research.
“Dr. Rubio’s expertise and long-standing dedication to Guam’s medical community reflect our commitment to providing specialized, high-quality care close to home,” said Barbiejane Ubay, GRMC clinic manager for outpatient specialty services.
GRMC said Rubio will work with multidisciplinary teams to support prevention, early diagnosis and advanced treatment of endocrine and metabolic conditions.