After glucose was controlled, patients experienced improvement in both symptoms and laboratory measures of PMR without glucocorticoid administration or an increase in glucocorticoid dosage, according to the report in the Annals of Internal Medicine.1
“These findings were unexpected and are remarkable,” write the authors, led by Dr. Ken Yoshida of The Jikei University School of Medicine, Tokyo. “We believe that coincidental improvement is an unlikely explanation for these cases.”
PMR is a chronic inflammatory condition affecting elderly persons, the authors note in their report, and is characterized by severe pain and stiffness, mostly in the shoulders, upper arms, and pelvic girdle.
The researchers had no explanation for why controlling glucose levels may improve symptoms, but suggested that more research is in order.
“Treating PMR with glucocorticoid therapy is problematic,” the authors write. “Most patients require at least one to two years of treatment, and too many patients develop adverse effects, such as diabetes mellitus, osteoporosis and hypertension. Therefore, we propose that a randomized controlled trial be considered to determine whether improved glycemic control, perhaps with meglitinide, may allow patients with type 2 diabetes and PMR to avoid glucocorticoid treatment.”
The first case described by the researchers was a 68-year-old man with bilateral shoulder pain and morning stiffness. The patient, who fulfilled the 2012 EULAR/ACR provisional criteria for PMR had been taking NSAIDs for six weeks and had been receiving metformin to treat type 2 diabetes for five years. His labs showed: C-reactive protein (CRP) level, 62.9 mg/L (normal; <1.4 mg/L); hemoglobin mA1c (HbA1c) concentration, 7.9%; and fasting plasma glucose level, 8.88 mmol/L (160 mg/dL).
Before prescribing glucocorticoids, the researchers opted to first address his elevated glucose level by changing some of his antidiabetic medications and adding repaglinide, which improved his glycemic control. His PMR symptoms and laboratory findings improved considerably after just one week on the new regime and the biceps tenosynovitis initially detected on ultrasonography gradually resolved during the following year.
The second case involved a 72-year-old woman with bilateral shoulder pain, morning stiffness, bilateral hip pain and restricted hip mobility. She had been prescribed prednisolone, which did improve her symptoms, but when the dosage was tapered, the symptoms returned. When the researchers first saw her, she had a CRP level of 42.7 mg/L; an HbA1c concentration of 11.7%; and a postprandial glucose level of 18.6 mmol/L (335 mg/dL).