Incidence and remission of specific IgE aeroallergen sensitization from age of 40 to 60 years, and association with alcohol consumption.

BACKGROUND: Data on incidence and long-term persistence of IgE aeroallergen sensitization in older adults are limited. Alcohol consumption is a strong immune-modulator with a significant impact on the IgE response. OBJECTIVES: We aimed to assess the incidence and remission of aeroallergen sensitization from the age of 40 to 60 years. Furthermore, we examined the relationship of alcohol consumption to the prevalence and incidence of aeroallergen sensitization. METHODS: In 1976-1977, a total of 1,200 people born in 1936 and randomly selected from the general population were invited for a health examination (1,052 were examined). At 60 years, they were invited for a re-examination (695 were examined). Stored serum samples from both examinations were analyzed consecutively for serum-specific IgE to aeroallergens by using a qualitative multi-allergen immunoassay. RESULTS: We observed a total of 32 (7.1% of those not sensitized at 40 years) incident cases and 35 (41.1% of those sensitized at 40 years) remittent cases of aeroallergen sensitization over this 20 year period. Persistent as well as incident sensitization was significantly associated with self-reported atopic disease at 60 years. Alcohol consumption (>14 drinks per week) at 40 years was significantly associated with a higher prevalence of sensitization at 40 years, but not with the incidence of sensitization. CONCLUSIONS: In older adults, aeroallergen sensitization as reflected by serum-specific IgE positivity to aeroallergens is a dynamic process. Both persistent and incident sensitization was associated with atopic disease. Further studies are needed to clarify the influence of alcohol on the allergen-specific IgE response.

Association of a microsatellite in FASL to type II diabetes and of the FAS-670G>A genotype to insulin resistance.

Type II diabetes is caused by a failure of the pancreatic beta-cells to compensate for insulin resistance leading to hyperglycaemia. There is evidence for an essential role of an increased beta-cell apoptosis in type II diabetes. High glucose concentrations induce IL-1beta production in human beta-cells, Fas expression and concomitant apoptosis owing to a constitutive expression of FasL. FASL and FAS map to loci linked to type II diabetes and estimates of insulin resistance, respectively. We have tested two functional promoter polymorphisms, FAS-670 G>A and FASL-844C>T as well as a microsatellite in the 3' UTR of FASL for association to type II diabetes in 549 type II diabetic patients and 525 normal-glucose-tolerant (NGT) control subjects. Furthermore, we have tested these polymorphisms for association to estimates of beta-cell function and insulin resistance in NGT subjects. We found significant association to type II diabetes for the allele distribution of the FASL microsatellite (P-value 0.02, Bonferroni corrected). The FAS-670G>A was associated with homeostasis model assessment insulin resistance index and body mass index (P-values 0.02 and 0.02). We conclude that polymorphisms of FASL and FAS associate with type II diabetes and estimates of insulin resistance in Danish white subjects.

Studies of relationships between the GLUT10 Ala206Thr polymorphism and impaired insulin secretion.

AIMS: This study aimed to investigate if the previously observed association between the GLUT10 Ala206Thr polymorphism and variation in fasting and oral glucose-induced serum insulin concentrations could be replicated in a large-scale population-based cohort of Danish whites. METHODS: The GLUT10 Ala206Thr polymorphism was genotyped in a case-control study of 880 Type 2 diabetic patients and 4372 glucose-tolerant control subjects. The latter group was also enrolled in an assessment of fasting and post-OGTT circulating levels of plasma glucose and serum insulin in relation to genotype. The variant was genotyped by analysis of PCR-generated primer extension by matrix-assisted laser desorption/ionization time-of-flight analysis. RESULTS: The Ala206Thr variant was equally frequent among Type 2 diabetic patients and glucose-tolerant subjects (P = 0.9) and there was no difference in the distribution of genotype groups (P = 1.0). In the 4372 glucose-tolerant subjects there was no statistically significant association between the polymorphism and levels of fasting and post-oral glucose tolerance test plasma glucose and serum insulin along with the insulinogenic index and the homeostasis model of assessment for insulin resistance and insulin secretion. Likewise, in an age-stratified subgroup comprising 1264 subjects, we observed no relationships between the GLUT10 polymorphism and the selected metabolic features. CONCLUSIONS: The GLUT10 Ala206Thr polymorphism is not associated with Type 2 diabetes in the Danish population. Furthermore, in the present large-scale cohort, the polymorphism does not associate with phenotypes such as fasting and oral glucose-induced levels of plasma glucose and serum insulin.

Evidence of an association between genetic variation of the coactivator PGC-1beta and obesity.

BACKGROUND: Peroxisome proliferator activated receptor-gamma coactivator-1beta (PGC-1beta) is a recently identified homologue of the tissue specific coactivator PGC-1alpha, a coactivator of transcription factors such as the peroxisome proliferators activated receptors and nuclear respiratory factors. PGC-1alpha is involved in adipogenesis, mitochondrial biogenesis, fatty acid beta oxidation, and hepatic gluconeogenesis. METHODS: We studied variation in the coding region of human PPARGC1B in Danish whites and related these variations to the prevalence of obesity and type 2 diabetes in population based samples. RESULTS: Twenty nucleotide variants were identified. In a study of 525 glucose tolerant subjects, the Ala203Pro and Val279Ile variants were in almost complete linkage disequilibrium (R2 = 0.958). In a case-control study of obesity involving a total of 7790 subjects, the 203Pro allele was significantly less frequent among obese participants (p = 0.004; minor allele frequencies: normal weight subjects 8.1% (95% confidence interval: 7.5 to 8.8), overweight subjects 7.6% (7.0 to 8.3), obese subjects 6.5% (5.6 to 7.3)). In a case-control study involving 1433 patients with type 2 diabetes and 4935 glucose tolerant control subjects, none of the examined variants were associated with type 2 diabetes. CONCLUSIONS: Variation of PGC-1beta may contribute to the pathogenesis of obesity, with a widespread Ala203 allele being a risk factor for the development of this common disorder.

Variation near the hepatocyte nuclear factor (HNF)-4alpha gene associates with type 2 diabetes in the Danish population.

AIMS/HYPOTHESIS: The hepatocyte nuclear factor (HNF)-4alpha is an orphan nuclear receptor, which plays crucial roles in regulating hepatic gluconeogenesis and insulin secretion. The gene encoding HNF-4alpha (HNF4A) is located on chromosome 20q12-q13 in a region that in several studies has shown linkage with type 2 diabetes. Recently, two independent studies identified single nucleotide polymorphisms (SNPs) in a 90-kb region spanning HNF4A, which showed strong association with type 2 diabetes in the Finnish and Ashkenazi Jewish populations. In an attempt to replicate and extend these findings, we selected four SNPs in the same HNF4A region, which in the Finnish and Ashkenazi Jewish populations were associated with type 2 diabetes, and examined their relationships with type 2 diabetes and prediabetic phenotypes in the Danish Caucasian population. METHODS: The rs1884614, rs2425637, rs1885088 and rs3818247 were analysed in case-control studies of 1387, 1429, 1417 and 1371 type 2 diabetic patients and 4766, 4727, 4665 and 4748 glucose-tolerant subjects respectively. Genotype-quantitative trait analyses comprised 4430, 4394, 4336 and 4413 middle-aged glucose-tolerant subjects from the population-based Inter99 cohort for the rs1884614, rs2425637, rs1885088 and rs3818247 respectively. RESULTS: The risk allele of the rs1884614, which is located 4 kb upstream of the HNF4A P2 promoter, was associated with type 2 diabetes (odds ratio [OR]=1.14, p=0.02) and with a subtle increase in post-OGTT plasma glucose levels in glucose-tolerant subjects (additive model, p=0.05). CONCLUSIONS/INTERPRETATION: Consistent with results from studies of Finnish and Ashkenazi Jewish subjects, variation near the P2 region of HNF4A is associated with type 2 diabetes in the Danish population.

Routine diagnosis of Type 2 diabetes mellitus in general practice and hospitals: how do patients differ?

OBJECTIVE: To study how Type 2 diabetic patients diagnosed by routine case-finding in primary care differ from patients diagnosed in secondary care with regard to clinical characteristics, symptom-burden and prevalence of complications. RESEARCH DESIGN AND METHODS: A Danish population-based sample of 1633 newly diagnosed Type 2 diabetic patients, of whom we had detailed information of sociodemographic and clinical characteristics, biochemical measurements, and complications among 1381. Blood and urine analyses were centralized. RESULTS: Of the patients, 76.8% were diagnosed in general practice. Compared with those diagnosed in secondary care, patients diagnosed in general practice on average had higher levels of cardiovascular risk factors (BMI: 29.8 vs. 28.5 kg/m2, P < 0.001; systolic blood pressure: 149.4 vs. 143.2 mmHg, P < 0.001; diastolic blood pressure: 85.2 vs. 82.5 mmHg, P < 0.001; haemoglobin A(1c): 10.1 vs. 8.4%, P < 0.0001; total cholesterol: 6.4 vs. 6.1 mmol/l, P < 0.01), more frequently presented with hyperglycaemic symptoms (80.1 vs. 63.4%, P < 0.0001), while fewer had macrovascular complications (28.5 vs. 43.6%, P < 0.0001). CONCLUSIONS: Judged from their risk profile, Type 2 diabetic patients diagnosed in primary care are at no less risk of developing diabetic complications than those diagnosed in secondary care.

Symptoms, signs and complications in newly diagnosed type 2 diabetic patients, and their relationship to glycaemia, blood pressure and weight.

AIMS/HYPOTHESIS: To document the prevalence of typical diabetic symptoms, signs and complications in the diagnosis of type 2 diabetes mellitus, examine their pre-diagnostic duration, and analyse associations with glycaemic level, blood pressure (BP), and weight. METHODS: An epidemiological population-based study of 1137 Danish patients with type 2 diabetes newly diagnosed by general practitioners (GPs). GPs and patients together filled in a questionnaire about typical symptoms, signs and complications preceding the diagnosis. RESULTS: Abnormal thirst, frequent urination, weight loss, genital itching, stomatitis, visual disturbances, fatigue, confusion and (in men) balanitis were associated with glycaemic level irrespective of age, sex, BMI, BP, complications and antihypertensive treatment. Eighty-nine percent of the patients presented with one or more of these hyperglycaemic symptoms and signs, and the pre-diagnostic duration was typically less than 3 months. Only a few symptoms, signs and complications were associated with weight and BP. CONCLUSIONS/INTERPRETATION: In patients newly diagnosed with type 2 diabetes in family practice, typical diabetic symptoms, signs and complications are common. Typical diabetic symptoms and signs are associated with hyperglycaemia. The pre-diagnostic duration of hyperglycaemic symptoms and signs were typically short, thus questioning the feasibility of early detection relying on increased anticipatory care by GPs. In contrast, elevated levels of cardiovascular risk factors and longer pre-diagnostic duration of cardiovascular complications suggest these might have a central role in an early diagnosis of type 2 diabetes.

Large-scale studies of the functional K variant of the butyrylcholinesterase gene in relation to Type 2 diabetes and insulin secretion.

AIMS/HYPOTHESIS: Polymorphisms of the butyrylcholinesterase gene (BCHE) are reported to associate with Alzheimer's disease and a recent study found a significant association of the BCHE K variant (G1615A/Ala539Thr) with Type 2 diabetes. The objectives of our study were to examine whether the BCHE K variant is associated with Type 2 diabetes or estimates of pancreatic beta cell function in large-scale populations of glucose-tolerant Caucasians. METHODS: The variant was genotyped in association studies comprising a total of 1408 Type 2 diabetic patients and 4935 glucose-tolerant control subjects. Genotype-phenotype studies were carried out in the 4935 glucose-tolerant control subjects. RESULTS: There was no difference in allele frequency between Type 2 diabetic patients and control subjects (20.3% [95% confidence interval: 18.8-21.8] vs 20.4% [19.6-21.2], non-significant). In the genotype-phenotype studies we found no consistent association with BMI, fasting or post-OGTT plasma glucose, serum insulin or serum C-peptide levels. CONCLUSIONS/INTERPRETATION: The present study does not support the suggestion that the BCHE K polymorphism is associated with Type 2 diabetes or with estimates of pancreatic beta cell function in large-scale Danish Caucasian populations.

Large-scale studies of the HphI insulin gene variable-number-of-tandem-repeats polymorphism in relation to Type 2 diabetes mellitus and insulin release.

AIMS/HYPOTHESIS: The class III allele of the variable-number-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 middle-aged 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 middle-aged 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.

The FOXC2 -512C>T variant is associated with hypertriglyceridaemia and increased serum C-peptide in Danish Caucasian glucose-tolerant subjects.

AIMS/HYPOTHESIS: The transcription factor FOXC2 plays a key role in adipocyte differentiation and the FOXC2 gene is a candidate gene for Type 2 diabetes, obesity and dyslipidaemia. We investigated whether the FOXC2 -512C>T promoter variant is associated with Type 2 diabetes or its intermediary phenotypes in glucose tolerant subjects. METHODS: The variant was genotyped using PCR-RFLP in 705 unrelated Type 2 diabetic patients, 505 unrelated glucose-tolerant control subjects and 219 glucose-tolerant offspring of Type 2 diabetic probands. RESULTS: The frequency of the T-allele was 58% (95% CI 56-61%) and 59% (56-62%) among the Type 2 diabetic patients and the unrelated glucose-tolerant control subjects, respectively ( p=0.6). Among the glucose-tolerant subjects, the T-allele carriers had higher fasting serum triglyceride ( p=0.03), fasting serum C-peptide concentrations ( p=0.009) and insulinogenic index ( p=0.04). Furthermore, in glucose-tolerant women, the waist-to-hip ratio was significantly higher in carriers of the T-allele. CONCLUSION/INTERPRETATION: Our data suggest that the FOXC2 -512C>T variant is not associated with Type 2 diabetes. However, among glucose-tolerant subjects the variant is associated with hypertriglyceridaemia and increased fasting serum C-peptide.

Inflammation, thrombosis and atherosclerosis: results of the Glostrup study.

Inflammation and thrombosis are important mechanisms in cardiovascular disease, as illustrated by the consistent association between inflammatory and hemostatic variables and the risk of cardiovascular events in epidemiological studies. However, the relationship between plasma concentrations of inflammatory and hemostatic markers and the severity of atherosclerosis is not yet well studied. We have evaluated 325 men and 370 women of 60 years, participating in the Danish Glostrup study. We diagnosed atherosclerosis by ultrasonographic measurement of intima-media thickness (IMT) of the right carotid artery and the assessment of plaque occurrence. Plasma samples were analyzed for the concentration of C-reactive protein (CRP), fibrinogen, d-dimer, plasminogen activator inhibitor type-1 (PAI-1) antigen and activity, tissue-type plasminogen activator (t-PA) antigen and activity, factor VII (FVII) antigen, FVII coagulant activity (FVII:C) and activated FVII (FVIIa). DNA variations were determined for fibrinogen, PAI-1, t-PA, FVII, factor XIII and methylene tetrahydrofolate reductase (MTHFR). Subjects with high IMT (upper 10% of distribution, n = 63) had higher CRP levels [2.2 mg L-1 (SE 0.3)] than subjects with IMT in the lowest tertile (n = 217) [1.7 mg L-1 (SE 0.1), P = 0.04], whereas there was no association between the hemostatic variables and IMT. There was an association between fibrinogen and d-dimer concentrations and number of plaques (P < 0.01), whereas there were no associations between CRP and the other hemostatic variables and the number of plaques. Genetic variation in the t-PA and MTHFR gene was associated with IMT. In conclusion, in the Glostrup population study, thrombosis and inflammation are associated with the severity of atherosclerosis, as reflected by IMT and plaque occurrence.

Studies of the Pro12Ala polymorphism of the peroxisome proliferator-activated receptor-gamma2 (PPAR-gamma2) gene in relation to insulin sensitivity among glucose tolerant caucasians.

AIMS/HYPOTHESIS: We examined whether the Pro12-Ala polymorphism of the human peroxisome proliferator-activated receptor-gamma2 (PPAR-gamma2) gene was related to altered insulin sensitivity among glucose-tolerant subjects or a lower accumulated incidence or prevalence of IGT and Type II (non-insulin-dependent) diabetes mellitus among Scandinavian Caucasians. METHODS: The Pro12Ala polymorphism was examined using PCR-RFLP Whole-body insulin sensitivity measured under hyperinsulinaemic-euglycaemic conditions was estimated in a population-based sample of 616 glucose tolerant Swedish Caucasian men at age 70. In addition, insulin sensitivity index was measured using IVGTT and Bergman minimal modelling in a population-based sample of 364 young healthy Danish Caucasians. Finally, we evaluated whether the polymorphism predicted Type II diabetes and IGT in 841 seventy-year-old Swedish men. A case-control study was carried out in 654 unrelated Danish Type II diabetic patients and 742 Danish glucose tolerant subjects matched for age and sex. RESULTS: Whole-body insulin sensitivity was significantly improved in carriers compared with non-carriers of the Ala-allele of the codon 12 polymorphism in Swedish Caucasian men (6.0+/-2.5 vs 5.6+/-2.5 mg kg(-1) x min(-1) x mU/l](-1) x 100, p = 0.044). The same tendency, but not significant, was observed in the insulin sensitivity index among the group of young healthy Danish Caucasians. The incidence of Type II diabetes and IGT among the Swedish subjects at the age of 70 was similar in the three genotype-groups of the Pro12Ala variant and the Ala-allele was not related to a lower prevalence of Type II diabetes in Danish Caucasians. CONCLUSION/INTERPRETATION: The Ala-allele of the PPAR-gamma2 polymorphism is associated with improved whole body insulin sensitivity among Swedish Caucasians.

Studies of the variability of the hepatocyte nuclear factor-1beta (HNF-1beta / TCF2) and the dimerization cofactor of HNF-1 (DcoH / PCBD) genes in relation to type 2 diabetes mellitus and beta-cell function.

Mutations in the homeodomain-containing transcription factor hepatocyte nuclear factor-1beta (HNF-1beta) are known to cause a rare subtype of maturity-onset diabetes of the young (MODY5), which is associated with early-onset progressive non-diabetic renal dysfunction. To investigate whether mutations in HNF-1 are implicated in the pathogenesis of MODY or late-onset diabetes with and without nephropathy in Danish Caucasians we examined the HNF-1beta (TCF2) and the dimerization cofactor of HNF-1 (DCoH, PCBD) genes for mutations in 11 MODY probands, 28 type 2 diabetic patients with nephropathy, and 46 type 2 diabetic patients with an impaired beta-cell function by combined single-strand conformation polymorphism (SSCP) and heteroduplex analysis. Analysis of the promoter and nine exons including intron-exon boundaries of the HNF-1beta gene revealed one novel silent polymorphism and three previously reported intronic variants. The silent polymorphism (I91I) was found in one patient with late-onset type 2 diabetes. One of the intronic variant (IVS6+26T-->C) was examined further. Among 584 type 2 diabetic patients the allelic frequency was 13.1% (11.2-15.0%) compared to 11.6% (8.6-14.5%) in 229 glucose tolerant control subjects (NS). No difference in insulin secretion during an OGTT was seen between carriers of the different IVS6+26T-->C genotypes among the 229 middle-aged control subjects, nor among 302 glucose tolerant 60-year-old Danish Caucasians. Mutation analysis of the four exons comprising the DCoH gene revealed a previously described A-->G polymorphism located in the 3' untranslated region, which was not investigated further. In conclusion, mutations in HNF-1beta and DCoH are not a major cause of MODY or late onset type 2 diabetes in Danish Caucasian subjects.

Studies of genetic variability of the glucose transporter 2 promoter in patients with type 2 diabetes mellitus.

This study was performed to test the hypothesis that genetic variation in the promoter of the glucose transporter 2 (GLUT2) might predispose to prediabetic phenotypes or type 2 diabetes. A total of 1611 bp comprising the minimal promoter region of the GLUT2 gene were examined by combined single-strand conformational polymorphism and heteroduplex analysis followed by direct sequencing of identified variants on genomic DNA from 96 randomly recruited Danish type 2 diabetic patients. We identified 4 nucleotide variants, -447g-->a, -149c-->a, -122t-->c, and -44g-->a. None of the variants were positioned in known or presumed transcription factor binding sites, TATA-box, or transcriptional start site. Association studies of the -149c-->a, -122t-->c, and -44g-->a variants revealed that the variants were as prevalent in 320 type 2 diabetic patients [11.0% (95% confidence interval, 8.4-13.6), 9.8% (7.4-12.2), and 29.0% (24.4-33.6), respectively] as in 241 age-matched glucose-tolerant subjects [13.1% (9.8-16.4), 11.2% (8.3-14.1), and 33.4% (28.8-38.0), respectively]. The -447g-->a mutation was only identified in a single diabetic patient and did not show cosegregation with diabetes in the family of the proband. The three common variants showed in a primary genotype-phenotype study comprising 241 glucose-tolerant middle-aged subjects association to increased plasma glucose levels during an oral glucose tolerance test. However, this result could not be replicated in a second sample of 298 60-yr-old glucose-tolerant subjects. In conclusion, we found no evidence supporting the hypothesis that genetic variability in the minimal promoter of the GLUT2 is associated with type 2 diabetes or prediabetic phenotypes in the Danish population.

A prevalent polymorphism in the promoter of the UCP3 gene and its relationship to body mass index and long term body weight change in the Danish population.

Variability of the uncoupling protein 3 (UCP3) promoter has been associated with increased body mass index (BMI) and altered lipid profiles. Here we tested the hypothesis that variation of the UCP3 promoter is associated with either juvenile or maturity-onset obesity or body weight change over a 26-yr follow-up among Danish subjects. Mutation screening of approximately 1 kb 5' upstream of the UCP3 gene revealed one previously described -55 C-->T variant. The frequency of the polymorphism was evaluated by restriction fragment length polymorphism analysis in four groups of subjects: 1) a group of 744 obese Danish men who at the draft board examinations had a body mass index (BMI) of at least 31 kg/m(2), 2) a randomly selected control group consisting of 857 draftees, 3) 258 middle-aged subjects, and 4) 409 60-yr-old subjects. The frequency of the T allele was 26.0% (95% confidence interval, 23.8-28.2%) among the obese draftees and 26.9% (24.8-29.0%) in the control group (P = 0.6). The variant was not associated with BMI at a young age or with weight gain after a 26-yr follow-up. The frequency of the T allele was 29.5% (25.6-33.4%) in the middle-aged group and 25.8% (22.8-28.8%) among the 60-yr-old subjects. The polymorphism was not associated with increased BMI or percent body fat in these 2 groups. It is concluded that this variant does not play a major role in the development of common obesity among Danish subjects.

Increasing prevalence of diabetes mellitus and impaired glucose tolerance among 60-year-old Danes.

AIMS: The age-specific prevalence of diabetes mellitus and impaired glucose tolerance (IGT) was estimated in 60-year-old individuals in 1996/97 and compared to the prevalence in 1974/75. The study also examined whether or not the change in prevalence of diabetes and IGT could be explained by changes in body mass index (BMI) and physical activity. METHODS: Diabetes and IGT were diagnosed by a standardized oral glucose tolerance test (OGTT) in two Danish population-based, age-specific, birth cohorts. RESULTS: The prevalence of diabetes in 1996/97 was 12.3% among 60-year-old men and 6.8% among women, representing an increase in diabetes of 58% in men and 21% in women compared to 1974/75. The prevalence of IGT was 15.9% among men and 13.1% among women, representing increases of 109 and 16%, respectively. A concurrent increase in BMI in the 22-year period between the two studies explained the increase found in the prevalence of diabetes and IGT. CONCLUSIONS: A marked increase in the prevalence of diabetes and IGT among 60-year-old individuals over a 22-year period was observed - especially in men. The increase was fully explained by a concurrent increase in BMI.

Mutation analysis of peroxisome proliferator-activated receptor-gamma coactivator-1 (PGC-1) and relationships of identified amino acid polymorphisms to Type II diabetes mellitus.

AIM/HYPOTHESIS: This study aimed to investigate if variability in the peroxisome proliferator-activated receptor-gamma coactivator-1 (PGC-1) gene is associated with Type II (non-insulin-dependent) diabetes mellitus. METHODS: The PGC-1 gene was examined in 53 Type II diabetic patients applying single strand conformational polymorphism analysis followed by nucleotide sequencing. Identified variants were genotyped in an association study comprising 483 Type II diabetic patients and 216 glucose-tolerant control subjects. A replication study was done in an additional 201 Type II diabetic patients and 293 glucose-tolerant subjects. Furthermore, a potential interaction between the Pro12Ala polymorphism of PPAR-gamma2 and the PGC-1 Gly482Ser variant on risk of Type II diabetes was investigated. RESULTS: A total of seven variants (Ser74Leu, IVS2 + 52C-->A, Thr394Thr, Asp475Asp, Gly482Ser, Thr528Thr, and Thr612Met) were identified and investigated in an association study. Six of the variants showed no association with Type II diabetes in the initial study. However, the Gly482Ser polymorphism, was more frequent among Type II diabetic patients (37.0 %) than among glucose-tolerant subjects (30.8 %) (p = 0.032). In a replication study the difference in allele frequencies of the Gly482Ser variant remained significant (p = 0.0135). The combined study yielded an allele frequency of 37.3 % (34.7-39.9) for Type II diabetic patients and 30.5 % (27.7-33.4) for glucose-tolerant subjects (p = 0.0007). No interaction between this variant and the Pro12Ala polymorphism of PPAR-gamma2 was observed. CONCLUSION/INTERPRETATION: A widespread Gly482Ser polymorphism of PGC-1 is associated with a 1.34 genotype relative risk of Type II diabetes.