The Study Of Association Of Leptin And Polymorphism Of Leptin Receptor Gene With Bone Metabolism In Type 2 Diabetes Mellitus

Objective To investigate the association of bone mineral density and osteoporosis with leptin in type 2 diabetes mellitus in Yunnan Province.Methods Unrelated 239 T2DM cases and 287 healthy normal controls (NC) were randomly collected. Serum leptin,glucose, insulin,C-peptide,lipid, sex hormone,PTH and HbAlc were detected. Simultaneously BMD values were determined by dual energy X-ray absorptiometry.Results①There were significant differences in age, weigt, WC, BMI, W/H, blood pressure, HDL-C, fasting plasma glucose, uric acid, aspartate amino transferase and blood urea nitrogen between T2DM and NC groups.②In NC group,serum leptin concentration was positively correlated with TC and HDL-C (P< 0.05).In T2DM group, leptin was positively correlated with BMI, Waist circumferenc(WC),120 min C-peptide (P<0.05)and was negatively correlated with Height and estrogen ((P<0.05).③In T2DM group,BMD values at all sites was positively correlated with BMI and estrogen,BMD values at all sites was negatively correlated with PTH. There was a positive correlation between BMDvalues at L1-4 and fasting plasma glucose,estrogen, and there was a negative correlation between BMD values at L1-4 and PTH. In NC group, BMD at L1-4 was positively correlated with BMI,WC, WHR,systolic blood pressure, uric acid and negatively correlated with TG, HDL-C.④In each group or two groups combined, serum leptin concentration in the female body were significantly higher than that of male (P<0.001).⑤No significant difference could be found between leptin and BMD values at all sites in both T2DM and NC groups.Conclusion①In NC group,serum leptin concentration was positively correlated with TC and HDL-C. In T2DM group, leptin was positively correlated with BMI, WC,120 min C-peptide, and was negatively correlated with Height and estrogen.②BMD values was positively correlated with BMI, WC and WHR. In NC group, there was a negative correlation between BMD values and lipids. In T2DM group, BMD values in various parts ware negatively correlated with blood pressure, BMD values at right arm was negatively correlated with fasting plasma glucose. No significant differences could be found between BMD values and lipids.③No significant differences could be found in serum leptin levels among BMD values and osteoporosis in T2DM group,NC group and two groups combined.Objective To analysis the distribution of Gln223Arg polymorphism of leptin receptor gene (LEPR), and to investigate the association between LEPR Gln223Arg polymorphism and bone mineral density and osteoporosis in T2DM in Yunnan province.Methods Unrelated 239 T2DM cases and healthy control of 287 cases were randomly collected. Genomic DNA was extracted and LEPR Gln223Arg polymorphism was determined with PCR-RFLP method.Results①The frequencies of AA, AG and GG of Gln223Arg genotypes were 2.8%,21.7% and 75.5%, the frequencies of the G and A alleles were 75.5% and 21.7%.②No significant differences could be found among osteoporosis and AA, AG and GG genotypes in both T2DM group and NC group.③In T2DM group, compared with AG and AA carriers, GG carrier of Gln223Arg LEPR had significantly higher systemic and L4 BMD values, while AG carriers had significant higher systemic and L4 BMD values than AA carriers (P<0.05). There were no significant differences in BMD values at L1-4, L4 and other sites among GG, AG and AA carriers in NC group.④In NC group, compared with AG and AA carriers of Gln223 Arg LEPR,leptin level with GG carrier was significantly higher(P=0.021), but no significant differences was found among GG, AG and AA carriers in T2DM group.Conclusion LEPR Gln223Arg polymorphism has associated with both the peak bone mass at system and L4 in T2DM and at L1-4 in NC group.The subjects carrying the GG genotype of LEPR had significantly higher BMD values, suggesting G allele may be a protective factor of bone mass.