Objective: To investigate whether leptin receptor Lys109Arg polymorphism influences non-alcoholic fatty liver disease.
Methods: Genomic DNA samples were extracted from blood of subjects who had received a physical examination. Genotyping was performed using oligonucleotide microarray and these fluorescence labeled PCR-amplified fragments were hybridized to allele-specific oligonucleotide probes. The relevant mutation was confirmed by sequencing analysis.
Results: A total of 180 subjects (109 males and 71 females) were included in the study, 117 of them had fatty liver disease and the other 63 had no liver problems and served as healthy controls. There were 144 (80%) subjects with GG genotype (Arg109Arg), 33 (18.3%) with GA genotype (Lys109Arg) and 3 (1.7%) with AA genotype (Lys109Lys). The distribution of leptin receptor Lys109Arg polymorphism had no significant difference (P > 0.05) between the fatty liver disease patients (95GG, 21GA and 1AA) and the healthy control subjects (49GG, 12GA and 2AA). The abdominal wall fat was significantly thicker in AA genotype subjects (4.1+/-0.4) cm than that in GA (2.8+/-0.6) cm and GG genotype subjects (2.7+/-0.7) cm (F = 5.197, P = 0.006). The serum cholesterol levels in AA genotype subjects (5.1+/-0.4) mmol/L was significantly lower than that in AG (25.5+/-6.9) mmol/L and GG genotype (27.2+/-8.4) mmol/L subjects (F = 8.164, P = 0.005). There were no significant differences in age, body mass index, hip circumference, waist circumference, blood pressure (BP), percentage of body fat, blood protein, triglyceride, HDL and fasting blood glucose between AA, GG and GA genotype subjects.
Conclusion: Leptin receptor Lys109Arg polymorphism may be involved in the regulation of distribution of abdominal wall fat thickness and cholesterol metabolism. Whether leptin receptor Lys109Arg polymorphism is in any way related to fatty liver disease is still not known.