Study of subcutaneous fat in children with juvenile dermatomyositis

Abstract

Lipodystrophy is a recently recognized complication of juvenile dermatomyositis (juvenile DM). Until now, the diagnosis has been based only on the physical appearance of the patient. We quantified the patterns of fat distribution in a cohort of patients with juvenile DM. Twenty patients with juvenile DM were enrolled along with a matching number of controls. Both groups underwent standard anthropometric measurements including assessment of skinfold thickness using Harpenden Skinfold Caliper (Holtain, Dyfed, UK). Glucose tolerance test and serum lipid estimates were performed in the study group but not in controls. Patients with juvenile DM had lower mean weight, height, and mid-upper-arm circumference as compared with controls; these differences were statistically significant (P < or = 0.05). Eight (40%) of 20 patients had lipodystrophy on physical appearance. When assessed by skinfold caliper, there was loss of subcutaneous fat at the mid-axillary site in 65% of patients, at the subscapular in 60%, and at the suprailiac site in 55%. Serum triglyceride levels were increased in 12 of the 18 patients who underwent this test. Oral glucose tolerance test results were normal in all 20 patients. Sixty-five percent of our patients with juvenile DM were found to have loss of subcutaneous fat on quantification compared with 40% on physical appearance alone. Maximum fat loss occurred at the mid-axillary skinfold site. A significant number of patients with juvenile DM (66%) had hypertriglyceridemia. We hypothesize that lipodystrophy and hypertriglyceridemia could well be integral components of what may be an expanded juvenile DM syndrome.