High bone mass associated with berardinelli lipodystrophy.

OBJECTIVE

To describe an unusual case of Berardinelli-Seip syndrome with high bone mineral density (BMD).

METHODS

We report the case of a 16-year-old girl presenting with dehydration, fatigue, and myalgia, associated with severe hyperglycemia, hypernatremia, and dramatically increased levels of liver enzymes, lactate dehydrogenase, and creatine kinase in the absence of ketosis. The clinical findings and pertinent medical literature are reviewed.

RESULTS

Physical examination of the patient revealed an acromegalic appearance with enlarged hands and feet, absence of subcutaneous adipose tissue, acanthosis nigricans, and a prominent umbilicus. Clinical and laboratory findings improved during her hospitalization, but more than 200 U of insulin daily was needed to control her plasma glucose levels. Although the fasting C-peptide level was normal, the postprandial value (10.10 ng/mL) was twice as high as the upper limit of normal (1.1 to 5). The liver enzymes did not normalize. Tests for hepatitis A and C as well as hepatitis B surface antigen were negative, and her specific antibody to hepatitis B surface antigen was positive, although she had been vaccinated. She had a high triglyceride level (392 mg/dL). Ultrasonography and magnetic resonance imaging (MRI) of the abdomen revealed an enlarged fatty liver and absence of visceral fat. Cranial MRI showed normal findings. The growth hormone level was low at baseline (0.27 ng/mL) and 0.57 ng/mL after administration of bromocriptine. Serum insulinlike growth factor-I was 606.8 ng/mL. These findings ruled out the diagnosis of acromegaly. The phenotypic and laboratory findings indicated that this patient had Berardinelli-Seip syndrome or type 1 lipodystrophy. MRI evaluation of body composition revealed total absence of adipose tissue. Lumbar spine and femoral neck densitometry as well as whole-body densitometry disclosed elevated BMD compared with reference values and a low percentage of fat. Despite the high BMD, the 25-hydroxyvitamin D level was diminished (5.6 ng/mL).

CONCLUSIONS

Hyperinsulinemia could explain the high BMD through insulin-stimulating effects on osteoblast proliferation and increasing liver production of insulinlike growth factor-I, but further studies are needed to evaluate the actual mechanism and others factors influencing BMD in Berardinelli-Seip syndrome.