Background

Recent genome-wide association studies revealed the relevance of LR11, a family member of LDL receptors as a genetic risk factor for obesity. In addition, loss of LR11 expression in mice with targeted LR11 disruption is protected from diet-induced obesity, suggesting an unknown function for this receptor in metabolic regulation. However, the role of LR11 gene at human adipose tissue in the pathophysiology of obesity is still unclear. The aim of this study is to clarify the relationship between LR11 expression at human adipose tissue and various obesity-related metabolic conditions.

Methods

Consecutive series of 75(male 37, female 38) Japanese patients with obesity (BMI>35kg/m2) who underwent bariatric surgery in Toho University Sakura Medical Center (Chiba, Japan) were recruited to this study. Samples of omental adipose tissue were collected during bariatric surgery. Levels of LR11 mRNA expression were analyzed by q-PCR. The study retrospectively examined BMI, visceral/subcutaneous fat area(VFA/SFA: evaluated by CT scan), blood pressure, glycolipid metabolic parameters and liver/kidney functions. The study was approved by the Ethics Committee of Toho University Sakura Medical Center (approval no. S18061).

Results

Mean age 42.7, BMI 43.7kg/m2, SBP 133mHg, DBP 80mmHg, FPG 122mg/dl, HbA1c 6.8%, IRI 10.8μIU/ml, HOMA-R 3.3, TG 148mg/dl, HDL-C 43mg/dl, LDL-C 121md/dl, AST 35IU/L, ALT 44IU/L, γGTP 47IU/L, Cr 0.79mg/dl, Alb index 243mg/gCr. Expression levels of LR11 mRNA at omental adipose tissue showed normal distribution, and there was no gender difference. Simple regression analysis showed significant correlations of LR11 expression level with SBP (r=0.381), FPG(r=0.317), HbA1c(r=0.335) and IRI(r=0.398), but not with BMI, VFA and SFA. Multiple regression analysis revealed independently correlation of SBP(β=0.426) and HOMA-R(β=0.438) with LR11 expression level.

Conclusions

Expression level of LR11 gene at omental fat tissue associates with insulin resistance in patients with morbid obesity.