Severe hypertriglyceridaemia in diabetic ketoacidosis: clinical and genetic study

Diabetic Ketoacidosis Revealing a Severe Hypertriglyceridemia and Acute Pancreatitis in Type 1 Diabetes Mellitus

Diabetic ketoacidosis (DKA) is a life-threatening acute metabolic complication occurring in patients with diabetes, especially in patients with type 1 diabetes (T1D), due to an insulin deficiency. Moderate hypertriglyceridemia is commonly observed in DKA but severe hypertriglyceridemia with a triglyceride level exceeding 10g/L is very rarely reported. We report a case of a 14-year-old boy who had type 1 diabetes for 4 years treated with insulin therapy, also having adrenal insufficiency treated with hydrocortisone who presented with ketoacidosis and excruciating abdominal pain. Investigations revealed hypertriglyceridemia at 64g/L, lipasemia at 1000 U/L, and stage E pancreatitis on abdominal CT. The patient was treated with intravenous insulin, rehydration, and fenofibrate with good clinical and biological evolution. Severe hypertriglyceridemia causing pancreatitis in type 1 diabetes mellitus is a rare but very serious complication of DKA in children.

ApoE isoform leading to hypertriglyceridemia in new onset type 1 diabetes

We report a case of pediatric diabetic ketoacidosis (DKA) with significant hypertriglyceridemia. The patient was found to have the e3/ e4 isoform of ApoE, increasing risk of hypertriglyceridemia in DKA. We suggest further genetic investigation for patients presenting with severe hypertriglyceridemia and DKA.

Severe hypertriglyceridemia at new onset type 1 diabetes mellitus

BACKGROUND

Severe hypertriglyceridemia (HTG) as well as diabetic ketoacidosis (DKA) are complications of type 1 diabetes (T1DM). HTG is an exceedingly rare complication in the pediatric population and herein we report a case of HTG at new-onset T1DM in DKA and discuss management and potential complications.

CASE PRESENTATION

An 11-year-old previously well patient with a history of fatigue and weight loss presented with: glucose >600 mg/dL, venous blood gas: pH 7.26, pCO2 20 mmHg, PO2 101 mmHg and base deficit 13 with triglyceride level 3573 mg/dL. An insulin drip was continued past criteria for discontinuation to facilitate lipoprotein lipase-based triglyceride metabolism.

CONCLUSIONS

Lipemia secondary to severe HTG, though exceedingly rare, may exist in new onset T1DM with DKA. Complicating the diagnosis is the possibility of an analytical error from lipemia causing incongruence in diagnostic criteria. Clinicians should rely on clinical criteria for management and should consider HTG if laboratory data is inconsistent with the clinical picture.

Effect of hepatic insulin expression on lipid metabolism in diabetic mice

BACKGROUND

Hypertriglyceridemia is a common lipid disorder that is characterized by elevated plasma levels of triglyceride (TG)-rich particles, such as very low-density lipoprotein (VLDL), in poorly controlled diabetes. The aim of the present study was to determine the potential therapeutic effect of hepatic insulin production on hypertriglyceridemia in mice.

METHODS

Mice were induced diabetic and hypertriglyceridemic by streptozotocin (STZ) treatment. Using an adenovirus-mediated gene transfer approach, we delivered rat preproinsulin cDNA into the liver of diabetic mice and then determined plasma TG metabolism. To investigate the mechanism by which hepatic insulin improves TG metabolism, we determined hepatic expression of apolipoprotein C-III (ApoC-III), a structural moiety and functional inhibitor of VLDL-TG catabolism.

RESULTS

Plasma VLDL-TG levels were markedly elevated in STZ-treated mice, and were accompanied by hyperglycemia and hypertriglyceridemia. These metabolic abnormalities were restored to near normal following hepatic insulin production in insulin vector-treated diabetic mice. In contrast, hypertriglyceridemia and hyperglycemia persisted in control vector-treated diabetic animals. Hepatic ApoC-III expression became deregulated secondary to insulin deficiency, contributing to impaired TG metabolism in diabetic mice. Hepatic insulin production suppressed excessive hepatic ApoC-III production to basal levels.

CONCLUSION

Hepatic insulin production is efficacious in correcting hypertriglyceridemia associated with insulin deficiency in diabetic mice.

Quantification and genotyping of lipoprotein lipase in patients with diabetic lipaemia

AIMS

To determine if diabetic lipaemia is caused by loss of function mutations in the lipoprotein lipase gene, LPL.

METHODS

We conducted a case-control study over 2 years in two tertiary care hospitals in South Australia. Six patients with a history of diabetic lipaemia and 12 control subjects, with previous diabetic ketoacidosis and peak triglyceride concentrations < 2.4 mmol/l were included. Participants were well at the time of study investigations.

RESULTS

Only one patient with lipaemia had a loss of function mutation in LPL and no functional mutations in APOC2 or GPIHBP1 were identified. The mean lipoprotein lipase concentration was lower in patients with diabetic lipaemia than in control subjects (306 vs. 484 μg/l, P = 0.04). The mean fasting C-peptide concentration was higher in patients with diabetic lipaemia than in control subjects (771 vs. 50 pmol/l; P = 0.001).

CONCLUSIONS

Lipoprotein lipase deficiency in patients with a history of diabetic lipaemia was predominantly quantitative, rather than secondary to mutations in LPL, APOC2 or GPIHBP1. The majority of patients with severe hypertriglyceridaemia in diabetic ketoacidosis may have ketosis-prone Type 2, rather than Type 1, diabetes.

Xanthomata and diabetes in an adolescent with familial dysbetalipoproteinemia 9 yr after valproate-induced pancreatitis

A 14-yr-old girl presented with eruptive xanthomata and hypertriglyceridemia. This rare presentation led to diagnoses of diabetes and familial dysbetalipoproteinemia. Type 1 diabetes is a common childhood illness often presenting in adolescence. However, this patient's past medical history revealed valproate-induced severe acute pancreatitis with necrosis at the age of 5 yr. Diabetes, in this case, developed 9 yr later as a result of inadequate pancreatic tissue to support increasing insulin requirements during growth and adolescence. Diabetes was discovered only after the appearance of cutaneous eruptive xanthomata, which appeared due to the previously undiagnosed genetic dyslipidemia. Although the relationship between xanthomata, hypertriglyceridemia, and diabetes may be well known in adults, in children, xanthomata are very rarely the presenting feature of diabetes of any cause. The patient was treated with insulin which induced rapid resolution of hypertriglyceridemia and gradual disappearance of xanthomata. This case acknowledges the rarity of diabetes presenting with xanthomata in adolescence, highlights the importance of searching for an underlying dyslipidemia in such a case, and presents diabetes as a long-term complication of acute pancreatitis in children.

Examination of Ligand-Dependent Coactivator Recruitment by Peroxisome Proliferator-Activated Receptor-alpha (PPARalpha)

The ligand-dependent recruitment of coactivators to peroxisome proliferator-activated receptor-α (PPARα) was examined. PPAR-binding protein (PBP), PPARγ coactivator-1α (PGC-1α), steroid receptor coactivator-1 (SRC-1), and CBP/p300-interacting transactivator with ED-rich tail 2 (CITED2) affected PPARα activity in the presence of Wy-14,643. The effects on PPARα activity in light of increased or decreased expression of these coactivators were qualitatively different depending on the ligand examined. Diminished expression of PGC-1α, SRC-1, or PBP by RNAi plasmids affected natural or synthetic agonist activity whereas only Wy-14,643 was affected by decreased PGC-1α. The interaction of PPARα with an LXXLL-containing peptide library showed ligand-specific patterns, indicative of differences in conformational change. The association of coactivators to PPARα occurs predominantly via the carboxyl-terminus and mutating ⁴⁵⁶LHPLL to ⁴⁵⁶LHPAA resulted in a dominant-negative construct. This research confirms that coactivator recruitment to PPARα is ligand-dependent and that selective receptor modulators (SRMs) of this important protein are likely.

Severe hypertriglyceridemia in diabetic ketoacidosis accompanied by acute pancreatitis: case report

We report a case of diabetic ketoacidosis (DKA) and hypertriglyceridemia (severely elevated to 15,240 mg/dL) complicated by acute pancreatitis, which was treated successfully with insulin therapy and conservative management. A 20-yr-old woman with a history of type 1 diabetes came to the emergency department 7 months after discontinuing insulin therapy. DKA, severe hypertriglyceridemia and acute pancreatitis were diagnosed, with DKA suspected of contributing to the development of the other conditions. In Korea, two cases of DKA-induced hypertriglyceridemia and 13 cases of hypertriglyceridemia-induced acute pancreatitis have been previously reported separately.

Recent insights into fatty liver, metabolic dyslipidaemia and their links to insulin resistance

PURPOSE OF REVIEW

To summarize recent research into the mechanisms linking insulin resistance, nonalcoholic fatty liver disease and metabolic dyslipidaemia.

RECENT FINDINGS

Pathologically increased nonesterified fatty acids have widely been viewed as a key driver of hepatic insulin resistance/nonalcoholic fatty liver disease/metabolic dyslipidaemia. However, this may have been overestimated, and growing evidence now also implicates dysregulated hepatic de-novo lipogenesis in the pathogenesis of these phenomena. This is driven by the action of hyperinsulinaemia on the liver, mediated by PI3 kinase, though consensus on the downstream effectors remains to be reached. Endoplasmic reticulum stress and/or components of the attendant unfolded protein response have also emerged as players in dysregulated hepatic metabolism due to nutritional overload. Several points of convergence between metabolic and unfolded protein response pathways have been described, notably centring on the transcription factor XBP1.

SUMMARY

Insulin resistance, nonalcoholic fatty liver disease and metabolic dyslipidaemia are inextricably linked and need to be considered together. Modelling and dissecting prevalent forms of the disease is complex, but unrestrained de-novo lipogenesis driven by hyperinsulinaemia appears to play an important role. Endoplasmic reticulum stress and the associated unfolded protein response may also contribute to cellular mismatch between triglyceride secretion/metabolism and synthesis, though a complete picture has yet to emerge.

Extreme diabetic lipaemia associated with a novel lipoprotein lipase gene mutation

Diabetic lipaemia, severe hypertriglyceridaemia associated with diabetic ketoacidosis, is a well recognised, but rare condition. Why this occurs in some patients and not others is unknown. We report a case of extreme lipaemia in a 20-year-old woman with type 1 diabetes who presented to hospital with diabetic ketoacidosis (DKA). At admission the patient's blood was grossly lipaemic and plasma lipid analyses showed triglyceride and cholesterol concentrations of 379 mmol/L and 52 mmol/L, respectively. She had no peripheral stigmata of chronic hyperlipidaemia and 1 year previously her plasma triglyceride and total cholesterol concentrations were 2.5 mmol/L and 4.4 mmol/L respectively. She was treated with insulin and the hypertriglyceridaemia resolved over several days. Because of the marked hypertriglyceridaemia, lipoprotein lipase (LPL) genetic testing was performed. Sequencing of the LPL gene revealed that she was heterozygous for the common S447X LPL variant and heterozygous for a novel missense mutation in exon five (I225N). Ile(225) is highly conserved among species and this mutation is predicted to impair function of the mature LPL protein. We conclude that heterozygosity for LPL mutations may predispose to transient severe hypertriglyceridaemia, when combined with insulin deficiency.

Diabetic lipemia with eruptive xanthomatosis in a lean young female with apolipoprotein E4/4

Eruptive xanthomas in adults are usually indicative of chylomicronemia. Although diabetes mellitus is the most common secondary cause of chylomicronemia, which is designated as diabetic lipemia, the clinical characteristics of diabetes with regard to development of xanthomas are not well defined. In this paper, we describe a young female who displayed eruptive xanthomas as an initial manifestation of diabetic lipemia. The patient was a 20-year-old female with a body mass index of 18.9 kg/m2 and Marfanoid appearance. Her past history was unremarkable, except for patent ductus arteriosus and mild mental retardation. She was admitted to our division for eruptive xanthomas on the extremities and marked hyperglycemia (random glucose, 520 mg/dl) and hypertriglyceridemia (6880 mg/dl). She was diagnosed with Type 2 diabetes based on the positive family history of diabetes, residual secretory capacity of insulin, and absence of autoantibodies related to Type 1 diabetes. Based on the increase in the concentrations of both chylomicrons and very low density lipoproteins, type V hyperlipoproteinemia was diagnosed. After the initiation of insulin therapy, both hypertriglyceridemia and eruptive xanthomas subsided, without administering any hypolipidemic agents. Minimal model analysis of a frequently sampled intravenous glucose tolerance test revealed severe insulin resistance, despite the absence of obesity. Post-heparin lipoprotein lipase (LPL) activity was moderately decreased, and common mutations in the LPL gene were not demonstrated by genetic screening. The apolipoprotein E phenotype was E4/4, which is known to be associated with type V hyperlipoproteinemia. Hypoadiponectinemia of 1.7 microg/ml was also revealed, which may, in part, account for the insulin resistance and decreased LPL activity. In conclusion, the clustering of apolipoprotein E4/4 and hypoadiponectinemia, in addition to insulin resistance and poor glycemic control, might have resulted in hypertriglyceridemia with eruptive xanthomatosis in this subject.