Genetics of the lipoprotein lipase gene and hypertriglyceridaemia

Lipoprotein lipase gene polymorphisms and risks of childhood obesity in Chinese preschool children

Childhood obesity is increasingly prevalent in the community and is related to many adult diseases. Lipoprotein lipase (LPL) plays a central role in dyslipidemia, and polymorphisms of the LPL gene may result in the disturbance in the lipid's metabolism. The aim of this study is to test the hypothesis that genetic variants of LPL and serum lipid levels are associated with the risk of childhood obesity. We genotyped +495T > G and PvuII T > C in an LPL gene and measured the serum lipid levels in a case-control study of 124 obese children and 346 frequency-matched normal controls in preschool Chinese children. The variant genotypes of LPL + 495GG and PvuII CC were associated with a significantly increased risk of childhood obesity [adjusted odds ratio (OR) = 2.39, 95% CI = 1.09-5.23 for +495 GG; adjusted OR = 2.00, 95% CI = 1.04-3.83 for PvuII CC], compared with their wild-type genotypes, respectively. In addition, compared with the lower serum level cut off by the control median, the higher level of serum triglyceride (TG) (>0.59 mmol/L) was associated with a 1.32-fold increased risk of childhood obesity, and the higher level of high density lipoprotein cholesterol (HDLC) (>1.14 mmol/L) was associated with a 36% decrease in risk of childhood obesity. Furthermore, the median levels of TG were higher in obese children carrying LPL +495TT/TG and PvuII TT/CT genotypes than those in controls, the HDLC levels were lower in obese children carrying LPL +495TG and PvuII CT/CC genotypes than those in controls. In conclusion, the LPL gene +495T > G and PvuII T > C polymorphisms may modulate the magnitude of dyslipidemia in Chinese early-onset obesity.

Primeiro relato de uma criança Brasileira portadora da mutação G188E do gene da lipoproteína lipase

OBJETIVO: Relatar o caso de uma criança com hipertrigliceridemia grave por mutações do gene da lipoproteína lipase. DESCRIÇÃO DE CASO: Menino de três anos que apresentou, com um mês de idade, soro lipêmico. Seu perfil lipídico indicou hipertrigliceridemia grave, com concentrações de triglicerídeos plasmáticos iguais a 25000mg/dL. Foi detectada a mutação G188E no éxon 5 da lipoproteína lipase em homozigose na criança e em heterozigose nos pais. COMENTÁRIOS: A deficiência da lipoproteína lípase é uma doença de herança autossômica recessiva e esses pacientes evoluem com hipertrigliceridemia grave.

Association of HindIII and PvuII genetic polymorphisms of lipoprotein lipase with lipid metabolism and macrovascular events in type 2 diabetic patients

AIM

Lipoprotein lipase (LPL) is a key enzyme of lipid metabolism, and its genetic polymorphism may be a candidate for modulating lipid parameters in type 2 diabetic subjects (D2).

METHODS

In a group of 404 type 2 diabetic patients, aged 59.5+/-10.8y, BMI=28.9+/-5.3 kg/m2, HbA1c=8.2+/-1.9%, we studied the H and P polymorphisms at the LPL locus detectable with the restriction enzymes HindIII and PvuII. Patients were separated into 229 males (17H1H1, 84H1H2, 128H2H2 and 51P1P1, 110P1P2, 68P2P2) and 175 females (16H1H1, 69H1H2, 90H2H2 and 51P1P1, 85P1P2, 39P2P2), and compared on the basis of their lipid parameters and their macrovascular complications.

RESULTS

Triglyceride (TG) and HDL-cholesterol(c) concentrations differed between patients with and without coronary heart disease (CHD) (3.44+/-2.09 and 1.96+/-1.40 mmol/l for TGs and 1.05+/-0.24 and 1.34+/-0.40 mmol/l for HDL-c, P<0.001). HDL-c concentrations were lower in male H2H2 and P2P2 subjects (P<0.001), and TG levels were higher in male H2H2 and P2P2 subjects (P<0.0001 for Hind III and P<0.05 for PvuII). Allele frequency of the HindIII and PvuII restriction site was similar to those reported in other Caucasian populations and the presence of the H2/P2 variants was significantly higher in CHD patients. The prevalence of CHD in this population was 18% but was 29% in H2H2 and 38% in P2P2 subjects (P<0.02).

CONCLUSION

Thus, HindIII and PvuII polymorphisms seem to exert a modulating role on lipid profile particularly in male D2, contributing to increase the risk of macrovascular events.