Background: Lipoprotein lipase (LPL) deficiency is an autosomal recessive disease with deficient extrahepatic removal of blood lipoproteins.
Objective and hypotheses: Primary LPL deficiency can be exacerbated by coexistent conditions such as diabetes, where relative or absolute insulin deficiency leads to an additional secondary LPL deficiency.
Method: We describe two cases in which primary LPL deficiency overlapped with previously diagnosed T2DM and with T1DM at onset, respectively.
Results: Case 1: a 17-year-old T2DM girl with positive family history for T2DM, obesity, mixed dyslipidemia and early cardiovascular diseases presented with central obesity (BMI 30.7 kg/m2, WC 99 cm), acanthosis nigricans, limb xanthomas. Laboratory showed HbA1c 123 mmol/mol, total cholesterol 562 mg/dl, triglycerides 2400 mg/dl, normal ApoA1 and ApoB, high levels of ApoB/A1 (1.94). An enlarged, steatosic liver with focal nodular hyperplasia and an ovarian cyst were evident at abdominal ultrasound. Case 2: a 7-year-old male presented with rapidly progressive polyuria, polydipsia, weight loss and impaired consciousness. A diagnosis of T1DM was reached (HbA1c 66 mmol/mol, C-peptide 0.12 ng/ml, positive β-cell antibodies). Concurrent severe hypertriglyceridemia (11 628 mg/dl) and hypercholesterolemia (1128 mg/dl) were evident. Despite the early diagnosis, the intensive intravenous rehydration and insulin therapy, clinical recovery from ketoacidosis was very slow. After stabilization of vital status, plasmapheresis was performed in order to decrease serum triglycerides (from 7430 to 2510 mg/dl) and cholesterol (from 940 to 380 mg/dl). Because of increased indexes of miocardial cytolysis, ST depression with T-wave at ECG and hypokinetic interventricular septum at echocardiogram, a non-ST segment elevation myocardial infarction was suspected. Abdominal ultrasound showed thickening of the gallbladder wall, with thick bile and hyperechogenic thinned pancreas.
Conclusion: Molecular analysis showed three heterozygous variants of the LPL gene in the first case. In the second case, a heterozygous mutation of LPL gene and a polymorphism of APOA5 gene were found.
18 Sep 2014 - 20 Sep 2014