Impact of aging on the clinical features and treatment of polymyositis in adults.

OBJECTIVES

The aim of this long-term retrospective study was to compare the clinical features of elderly and younger polymyositis patients.

METHODS

The clinical records of 21 polymyositis patients hospitalized from 1988 to 2011 were reviewed to compare the clinical and therapeutic characteristics of the elderly group (N = 6; ≥ 70 years) and the younger group (N = 15; < 70 years). Correlation analysis was conducted between serum creatine kinase levels (roughly estimate of disease state) and the clinical features.

RESULTS

Aging did not affect the clinical characteristics, except for lower body weight, lactate dehydrogenase level, and creatine kinase level in the elderly group (p = 0.011, 0.003, and 0.012, respectively). Creatine kinase levels were negatively correlated with the age at diagnosis. The optimum dose and frequency of pulse steroid therapy were significantly lower in elderly patients (p = 0.018 and 0.043, respectively).

CONCLUSIONS

In polymyositis patients, aging is associated with a decrease in creatine kinase level, due in part to decreased body weight or muscle mass. This may influence the choice of therapy, such as steroid dosage and the use of immunosuppressants.