Hypertriglyceridemia in Youth

Diagnosis and stabilisation of familial chylomicronemia syndrome in two infants presenting with hypertriglyceridemia-induced acute pancreatitis

Familial chylomicronemia syndrome (FCS) is a rare disorder of triglyceride (TG) metabolism caused by loss of function variants in one of five known canonical genes involved in chylomicron lipolysis and clearance-LPL, APOC2, APOA5, LMF1, and GPIHBP1. Pathogenic variants in LPL, which encodes the hydrolytic enzyme lipoprotein lipase, account for over 80%-90% of cases. FCS may present in infancy with hypertriglyceridemia-induced acute pancreatitis and is challenging to manage both acutely and in the long-term. Here, we report our experience managing two unrelated infants consecutively diagnosed with hypertriglyceridemia-induced acute pancreatitis caused by LPL deficiency. Both had elevated TGs at presentation (205 and 30 mmol/L, respectively) and molecular genetic testing confirmed each infant carried a different homozygous pathogenic variant in the LPL gene, specifically, c.987C>A (p.Tyr329Ter) and c.632C>A (p.Thr211Lys). The more severely affected infant had cutaneous xanthomata, lipemia retinalis and lipemic plasma at presentation, and required management in an intensive care setting. Acute stabilisation was achieved using insulin and heparin infusions together with the iterative implementation of a fat-restricted diet, low in long chain triglycerides (LCT) and supplemented with medium chain triglycerides (MCT). In both cases, provision of adequate caloric intake (~110-120 kcal/kg/day) was also found to be important for a sustained TG reduction during the acute phase of management. In summary, a high index of suspicion is required to diagnose FCS in infants with hypertriglyceridemia-induced acute pancreatitis, management of which can be challenging, highlighting the need for more evidence-based recommendations.

Hyperlipidemia and Cardiovascular Risk in Children and Adolescents

Atherosclerotic cardiovascular disease (ASCVD) represents the major cause of morbidity and mortality worldwide. The onset of the atherosclerosis process occurs during childhood and adolescence, subsequently leading to the onset of cardiovascular disease as young adults. Several cardiovascular risk factors can be identified in children and adolescents; however, hyperlipidemia, in conjunction with the global obesity epidemic, has emerged as the most prevalent, playing a key role in the development of ASCVD. Therefore, screening for hyperlipidemia is strongly recommended to detect high-risk children presenting with these disorders, as these patients deserve more intensive investigation and intervention. Treatment should be initiated as early as possible in order to reduce the risk of future ASCVD. In this review, we will discuss lipid metabolism and hyperlipidemia, focusing on correlations with cardiovascular risk and screening and therapeutic management to reduce or almost completely avoid the development of ASCVD.