Lower limbs edema by insulin glargine treatment: two other cases in pediatrics.

Abstract

Marta, 13 years aged, suffered from type 1 diabetes from the age of 9 years. She was admitted in our clinic for a progressive appearance of edema in both legs (Fig. 1). The edema was located in the pretibial and ankle region, bilaterally, mainly on the left; the skin was normal, not hot and not erythematous. Femoral and popliteal pulses were normal. Left and right ankle diameters were, respectively, 29.5 and 28 cm. The family history was negative for diseases associated with edema. The metabolic control has always been good (yearly mean HbA1c 7.5 % 58 mmol/mol). She was on multi-daily injections (MDI) therapy, and the need of insulin was 0.7 U/kg/day. Up to 3 months before the occurrence of edema, she had been treated with human insulin (Humulin R and Humulin I ). During the adolescence, as the lifestyle was changing, we decided to start basal bolus therapy. Boluses of fast analogues were administered on the arms and in abdomen, while insulin glargine was administered exclusively on both thighs, alternating the right and the left thigh every day. All the most common causes of edema have been ruled out with specific investigations: Color Doppler ultrasound of the arteries and veins of the limbs excluded vascular diseases; ECG and transthoracic echocardiography excluded cardiac failure. Blood count, C-reactive protein (CRP) and VES, serum electrolytes, protein electrophoresis and the liver, thyroid and kidney function tests were within the normal range. Moreover, we rejected other causes of edema due to infection diseases. To exclude obstruction of the inferior vena cava or the thoracic duct, the patient underwent, respectively, abdominal ultrasound and chest X-rays, which did not show pathognomonic features. In addition, we also ruled out the Turner syndrome with the high-definition karyotype study. Medical history, clinical examination and laboratory findings excluded the involvement of systemic diseases. No other medicaments except for insulin had been assumed so, suspecting that the cause of the edema could have been the local mechanism of absorption of basal insulin, we replaced insulin glargine with rapid and intermediate human insulin. After 1-month edema was still present, but significantly reduced (diameter 25 cm in both legs). The complete resolution occurred after 3 months from the suspension of glargine even if a slight worsening of metabolic control (HbA1c 8.5 % 69 mmol/mol) was observed. Managed by Antonio Secchi.