👤 Wanee Plengpanich

Severe hypertriglyceridemia usually results from a combination of genetic and environmental factors. Few data exist on the genetics of severe hypertriglyceridemia in Asian populations. To examine the genetic variants of 3 candidate genes known to influence triglyceride metabolism, LPL, APOC2, and APOA5, which encode lipoprotein lipase, apolipoprotein C-II, and apolipoprotein A-V, respectively, in a large group of Thai subjects with severe hypertriglyceridemia. We identified sequence variants of LPL, APOC2, and APOA5 by sequencing exons and exon-intron junctions in 101 subjects with triglyceride levels ≥ 10 mmol/L (886 mg/dL) and compared with those of 111 normotriglyceridemic subjects. Six different rare variants in LPL were found in 13 patients, 2 of which were novel (1 heterozygous missense variant: p.Arg270Gly and 1 frameshift variant: p.Asp308Glyfs*3). Four previously identified heterozygous missense variants in LPL were p.Ala98Thr, p.Leu279Val, p.Leu279Arg, and p.Arg432Thr. Collectively, these rare variants were found only in the hypertriglyceridemic group but not in the control group (13% vs 0%, P < .0001). One common variant in APOA5 (p.Gly185Cys, rs2075291) was found at a higher frequency in the hypertriglyceridemic group compared with the control group (25% vs 6%, respectively, P < .0005). Altogether, rare variants in LPL or APOA5 and/or the common APOA5 p.Gly185Cys variant were found in 37% of the hypertriglyceridemic group vs 6% in the controls (P = 3.1 × 10(-8)). No rare variant in APOC2 was identified. Rare variants in LPL and a common variant in APOA5 were more commonly found in Thai subjects with severe hypertriglyceridemia. A common p.Gly185Cys APOA5 variant, in particular, was quite prevalent and potentially contributed to hypertriglyceridemia in this group of patients. Show less

During critical illnesses, alterations in lipid metabolism occur. We examined levels of apolipoprotein A-V, a novel regulator of triglyceride metabolism, during sepsis in humans. Seventy-five cases of sepsis and 75 cases of acute illnesses not associated with infection were recruited. Lipids and apolipoprotein A-V levels were measured by enzymatic methods and enzyme-linked immunosorbent assay, respectively, within 24 hours of diagnosis. Fifty healthy controls were also enrolled. During sepsis and acute illnesses, serum total cholesterol and high-density lipoprotein cholesterol levels were significantly lower than those in controls. Serum triglyceride levels, however, were not significantly different. Similarly, serum apolipoprotein A-V levels during sepsis were not significantly different from those during acute illnesses and those in controls (expressed as median [interquartile range]: 149.6 [97.5-257.1] vs 157.9 [98.4-238.2] and 155.9 [91.5-253.8] ng/mL, respectively; P = .98); and they were not correlated with serum triglyceride levels. Low apolipoprotein A-V levels were associated with higher mortality, but the association became nonsignificant after adjusting for high-density lipoprotein cholesterol levels. During sepsis or acute illnesses, serum apolipoprotein A-V levels were not significantly different from those in controls. Furthermore, apolipoprotein A-V levels were not linearly correlated with triglyceride levels, suggesting that it might not be a major determinant of triglyceride levels during sepsis. Show less