High incidence of obesity and elevated serum immunoreactive insulin level in patients with paravertebral ligamentous ossification: A relationship to the development of ectopic ossification

Abstract

Insulin has been shown to stimulate bone formation, and there is a high incidence of obesity and disturbance in the glucose metabolism of patients with paravertebral ligamentous ossification (PVLO). In an effort to clarify whether there is any alteration in insulin status in PVLO patients, and whether such changes play any role in the development of PVLO, glucose metabolism and serum insulin levels are examined in 11 PVLO patients and compared with 6 control patients of similar age and activities of daily living. More than half of the patients with PVLO exceed 110% of ideal body weight, and their fasting serum immunoreactive insulin (IRI) levels are significantly higher than those of control patients. In addition, there is a significant correlation between fasting IRI and % ideal body weight in PVLO patients. These results indicate that hyperinsulinism is present in many patients with PVLO, and that obesity further aggravates the hyperinsulinism in this disorder. Thus, it is suggested that hyperinsulinism is involved in the development or aggravation of ectopic ossification in PVLO patients. The relationship between hyperinsulinism and the other factors such as genetic and physical factors as well as the changes in calcium metabolism in the development of PVLO remains to be clarified.