Interleukin-6 (IL-6) is a pleiotropic cytokine involved in the pathophysiology of various human diseases such as type 2 diabetes and obesity. IL-6 signals via a heterodimeric receptor complex consisting of a soluble IL-6 ␣-subunit (IL-6 receptor [IL6R]) and a signal transducing subunit (gp130). The IL6R gene maps to an important candidate locus for type 2 diabetes on chromosome 1q21. An Asp358Ala polymorphism of the IL6R has been reported to associate with obesity in Pima Indians. We investigated the Asp358Ala polymorphism in relation to type 2 diabetes, obesity, and other prediabetic quantitative traits among Danish whites. By applying a recessive genetic model in a case-control study of 1,349 type 2 diabetic patients and 4,596 glucose-tolerant control subjects, we found a significant difference in genotype distribution (P ‫؍‬ 0.008) and in allele frequency (Ala-allele

Food intake and weight gain are influenced by endocannabinoids whose actions are regulated by the fatty acid amide hydrolase (FAAH) enzyme. The homozygous Thr/Thr genotype of the functional Pro129Thr variant (rs324420) in the gene encoding FAAH was recently reported to associate with overweight and obesity in white and black populations. We investigated the Pro129Thr variant in relation to overweight and obesity in a relatively large population-based study sample of Danish whites (n=5,801). In case-control studies of obesity, a borderline association with the major Pro allele was identified; however, after correction for multiple testing, no association was found. Furthermore, a possible association between the major Pro allele and obesity was not supported by studies of obesity-related quantitative traits. In conclusion, in a large study sample, we were unable to find robust evidence of an association of the Pro129Thr FAAH variant with overweight, obesity, and any related quantitative traits among the examined whites.

Aims/hypothesis. The class III allele of the variablenumber-of-tandem-repeats polymorphism located 5′ of the insulin gene (INS-VNTR) has been associated with Type 2 diabetes and altered birthweight. It has also been suggested, although inconsistently, that the class III allele plays a role in glucose-induced insulin response among NGT individuals. Methods. We investigated the impact of the class III allele on Type 2 diabetes susceptibility in a case-control study involving 1462 Type 2 diabetic patients and 4931 NGT subjects. We also examined the potential impact of the class III allele in genotype-quantitative trait studies in three Danish study populations containing (i) 358 young healthy subjects; (ii) 4444 middleaged NGT subjects, 490 subjects with IFG and 678 subjects with IGT; and (iii) 221 NGT subjects, of whom one parent had Type 2 diabetes.Results. There was no difference in frequency of the class III allele or in genotype distribution between the 1462 Type 2 diabetic patients and the 4931 NGT subjects. Among the 358 young subjects the class III/III carriers had significantly reduced post-IVGTT acute serum insulin and C-peptide responses (p=0.04 and 0.03 respectively). However, among the 4444 middleaged subjects we failed to demonstrate any association between the class III allele and post-OGTT serum insulin and C-peptide levels. Conclusions/interpretation. The class III allele of the INS-VNTR does not confer susceptibility to Type 2 diabetes or consistent alterations in glucose-induced insulin release in the examined populations, which consisted of Danish Caucasians.

Abstract-PGC-1␣ is a coactivator of numerous transcription factors and is expressed in tissues with high energy demands and abundant in mitochondria. It is induced in the myocardium on fasting and physical exercise, and cardiac-specific overexpression stimulates mitochondrial biogenesis in mice. The common Gly482Ser polymorphism of PGC-1␣ has previously shown association with arterial hypertension among Austrian men. Thus, we aimed at investigating this relationship in the Danish white population. The Gly482Ser polymorphism was genotyped in a total of 2562 Danish white subjects using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) and a GenoView locked nucleic acid assay (LNA), and the relationships of this variant with blood pressure levels and arterial hypertension were analyzed. Furthermore, we performed a combined analysis of the data from the present study in combination with previously published results. The Ser/Ser genotype was significantly associated with a reduced risk of hypertension and with lower systolic, diastolic, and mean arterial blood pressure levels, predominantly among women. Finally, in a combined analysis using data obtained in both sexes, the Ser/Ser genotype group had an estimated odds ratio of 0.70 (95% confidence interval, 0.56 to 0.86) for hypertension compared with Gly/X carriers (Pϭ0.001). In conclusion, the Ser allele of PGC-1␣ Gly482Ser confers a significantly reduced risk of hypertension in whites. Further studies are needed to elucidate the differential role of this polymorphism in men and women.

HNF4A encodes an orphan nuclear receptor that plays crucial roles in regulating hepatic gluconeogenesis and insulin secretion. The aim of the present study was to examine two rare missense polymorphisms of HNF4A, Thr130Ile and Val255Met, for altered function and for association with type 2 diabetes (T2D). We have examined these polymorphisms 1) by in vitro transactivation studies and 2) by genotyping the variants in 1409 T2D patients and in 4726 glucose-tolerant Danish white subjects. When tested in COS7 cells, both the Thr130Ile and the Val255Met variants showed a significant decrease in transactivation activity compared with wild-type (73% of wild-type, P = 0.02, and 76%, P = 0.04, respectively). The Thr130Ile variant had a significantly increased carrier frequency among T2D patients compared with glucose-tolerant subjects [odds ratio, 1.26 (1.01-1.57); P = 0.04]. The rare Val255Met polymorphism had a similar frequency among T2D patients and glucose-tolerant subjects. Heterozygous glucose-tolerant carriers of the variant showed, however, decreased levels of fasting serum C-peptide (76%; P = 0.03) and decreased fasting serum triglyceride (58%; P = 0.02). In conclusion, The Thr130Ile and the Val255Met polymorphisms decrease the transcriptional activity of HNF4A, and the Thr130Ile polymorphism associates with T2D, whereas the Val255Met variant associates with a decrease in fasting serum C-peptide.