A pharmacogenetic association between a variation in calpain 10 (CAPN10) gene and the response to metformin treatment in patients with type 2 diabetes.

PURPOSE: The aim of the present study was to investigate possible associations of the single-nucleotide variants in six genes encoding the key molecules mediating the metformin pharmacodynamic effect with the response to treatment with metformin in patients with type 2 diabetes. METHODS: One hundred forty-eight drug-naïve patients with type 2 diabetes were included in the study. PRKAA1 rs249429, STK11 rs741765, PCK1 rs4810083, PPARGC1A rs10213440, HNF1A rs11086926, and CAPN10 rs3792269 variants were genotyped. The outcomes of the study were treatment success defined by achieving HbA1c <7 % and absolute reduction in HbAlc after 6-month metformin therapy. The relationships between genotypes and outcomes were evaluated in multivariate logistic and linear models. The level of statistical significance after Bonferroni correction was predefined as p<0.0083. RESULTS: The minor G-allele of CAPN10 rs3792269 A>G polymorphism was significantly associated with less treatment success with an odds ratio of 0.27 (95 % CI 0.12-0.62, p=0.002) per variant allele. When the reduction in HbA1c was analyzed as a quantitative trait, G-allele was nominally associated with a smaller reduction in HbA1c (per allele ß=-0.26, 95 % CI -0.50 to -0.02, p=0.032). The reduction in HbA1c in minor allele carriers (24 % of study population) was smaller by 0.3 % in comparison with the major allele homozygotes. CONCLUSIONS: The present study provides the first observation of an association between a variant in CAPN10 gene and the response to metformin therapy in patients with type 2 diabetes. This observation needs to be replicated in further studies in different populations.

2-(Adamantan-1-yl)-1,3-bis-(4-methyl-phen-yl)propan-2-ol.

The conformation of the title compound, C27H34O, is stabilized by a weak intra-molecular C-H⋯π inter-action. The dihedral angle between the benzene rings is 54.79 (4)°. The adamantane cage consists of three fused cyclo-hexane rings in classical chair conformations, with C-C-C angles in the range 107.75 (10)-111.35 (9)°. Although the mol-ecule contains a hy-droxy group as a conceivable hydrogen-bond donor, this group is sterically hindered by bulky substituents and no hydrogen bonds are observed in the crystal structure.

4-(Adamantan-1-yl)-2-(4-fluoro-phen-yl)quinoline.

In the mol-ecule of the title compound, C25H24FN, the dihedral angle between the best planes of the quinoline fragment (rings A and B) and the benzene ring (C) is 9.51 (4)°. In the crystal, mol-ecules are linked into centrosymmetric dimers via pairs of weak C-H⋯F inter-actions. The mol-ecules are stacked into chains along the a axis by weak off-set π-π inter-actions between the A and C rings of translation-related mol-ecules with a centroid-centroid distance of 3.6440 (2) Å.

2-(1-Adamant-yl)-1,3-diphenyl-propan-2-ol.

In the title compound, C(25)H(30)O, the adamantane cage consists of three fused cyclo-hexane rings in classical chair conformations, with C-C-C angles in the range 107.15 (9)-111.55 (9)°. The dihedral angle between the benzene rings is 46.91 (4)° and the conformation is stabilized by a weak intra-molecular C-H⋯π inter-action.

(1-Adamant-yl)(2-methyl-phen-yl)methanone.

In the title compound, C(18)H(22)O, the dihedral angle between the carbonyl and benzene planes is 69.11 (6)°. In the adamantyl group, the three fused cyclo-hexane rings have almost ideal chair conformations, with C-C-C angles in the range 108.14 (11)-110.50 (11)°. No specific inter-molecular inter-actions (other than van der Waals inter-actions) are present in the crystal.

3-(1-Adamant-yl)-6-methyl-3-(3-methyl-benz-yl)isochroman-1-one.

In the title compound, C(28)H(32)O(2), the oxanone ring adopts distorted half-boat conformation with the following Cremer and Pople puckering parameters: Q = 0.619 (2) Å, θ = 0.75 (19) and ϕ = 172 (13)°. The dihedral angle betwen two benzene rings is 21.32 (7)°. The adamantane unit consists of three fused cyclo-hexane rings in classical chair conformations, with absolute values of C-C-C-C torsion angles in the range 57.5 (2)-60.9 (2)°. Weak inter-actions of the type C-H⋯O link mol-ecules of each enanti-omer into chains parallel to the b axis and lying about inversion centers. The crystal packing is also stabilized by inter-molecular π-π stacking inter-actions [centroid-centroid distance of 3.8566 (11) Å].

Association between TCF7L2 Genotype and Glycemic Control in Diabetic Patients Treated with Gliclazide.

Previous studies showed associations between variants in TCF7L2 gene and the therapeutic response to sulfonylureas. All sulfonylureas stimulate insulin secretion by the closure of ATP-sensitive potassium (KATP) channel. The aim of the present study was to compare TCF7L2 genotype specific effect of gliclazide binding to KATP channel A-site (Group 1) with sulfonylureas binding to AB-site (Group 2). A total of 101 patients were treated with sulfonylureas for 6 months as an add-on therapy to the previous metformin treatment. TCF7L2 rs7903146 C/T genotype was identified by real-time PCR with subsequent melting curve analysis. Analyses using the dominant genetic model showed significantly higher effect of gliclazide in the CC genotype group in comparison with combined CT + TT genotype group (1.32 ± 0.15% versus 0.73 ± 0.11%, P (adj) = 0.005). No significant difference in ΔHbA1c between the patients with CC genotype and the T-allele carriers was observed in Group 2. In the multivariate analysis, only the TCF7L2 genotype (P = 0.006) and the baseline HbA1c (P < 0.001) were significant predictors of ΔHbA1c. After introducing an interaction term between the TCF7L2 genotype and the sulfonylurea type into multivariate model, the interaction became a significant predictor (P = 0.023) of ΔHbA1c. The results indicate significantly higher difference in ΔHbA1c among the TCF7L2 genotypes in patients treated with gliclazide than in patients treated with glimepiride, glibenclamide, or glipizide.

KCNJ11 gene E23K variant and therapeutic response to sulfonylureas.

AIMS: Potassium inwardly rectifier 6.2 subunit (Kir6.2) of the ATP-sensitive potassium (K(ATP)) channel encoded by KCNJ11 gene is a therapeutical target for sulfonylureas. KCNJ11 E23K polymorphism was associated with type 2 diabetes in genetic association studies. The aim of the present pharmacogenetic study was to examine the effect of sulfonylurea treatment on glycemic control in relationship to KCNJ11 E23K variant. PATIENTS AND METHODS: One hundred and one patients with type 2 diabetes who failed to achieve HbA1c<7% on previous metformin monotherapy were included to the study. Sulfonylurea drug was given in addition to metformin. The main outcome of the study was reduction in HbA1c level (ΔHbA1c) after 6-month sulfonylurea therapy. KCNJ11 genotypes were determined by real-time PCR with melting curve analysis. RESULTS: After 6-month treatment, KCNJ11 K-allele carriers had higher decrease in HbA1c compared with EE homozygotes in the dominant genetic model (1.04±0.10 vs. 0.79±0.12%, p=0.036). In the log-additive model, greater mean reduction in HbA1c by 0.16% (95% CI 0.01-0.32, p=0.038) per each K-allele was observed. The relationship of treatment response with KCNJ11 genotype was also significant in the biggest subgroup of patients treated with gliclazide (n=55). CONCLUSIONS: Carriers of the KCNJ11 K-allele have better therapeutic response to gliclazide. This observation might help to identify patients who will have the highest benefit from sulfonylurea treatment.