Thomas Drivsholm

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

Aims/hypothesisTo 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.MethodsAn 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.ResultsAbnormal 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/interpretationIn 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.

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

Abstract.Aim/hypothesis: This study aimed to investigate if variability in the peroxisome proliferator-activated receptor-γ 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-γ2 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-γ2 was observed. Conclusion/interpretation: A widespread Gly482Ser polymorphism of PGC-1 is associated with a 1.34 genotype relative risk of Type II diabetes. [Diabetologia (2001) 44: 2220–2226]

Studies of the Pro12Ala polymorphism of the peroxisome proliferator-activated receptor-γ2 (PPAR-γ2) gene in relation to insulin sensitivity among glucose tolerant Caucasians

Abstract.Aims/hypothesis: We examined whether the Pro12-Ala polymorphism of the human peroxisome proliferator-activated receptor-γ2 (PPAR-γ2) 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· min–1· [mU/l]–1· 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-γ2 polymorphism is associated with improved whole body insulin sensitivity among Swedish Caucasians. [Diabetologia (2001) 44: 1170–1176]

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

SUMMARY

Representativeness in population-based studies: A detailed description of non-response in a Danish cohort study:

Background: Decreasing rates of participation in population-based studies increasingly challenge the interpretation of study results, in both analytic and descriptive epidemiology. Consequently, estimates of possible differences between participants and non-participants are increasingly important for the interpretation of study results and generalization to the background population. Methods: An age-specific, population-based cohort of 1,198 individuals was examined at age 40, 45, 51, and 60. Participants were compared with non-participants and when possible also with the background population using a wide range of detailed information on somatic and mental health collected at each examination, including data from a clinical examination, biochemical measurements, questionnaires, interviews, and public registers. Results: Participation rates were higher than 80% at examinations at age 40, 45, and 51, but decreased to 65% at age 60. At the baseline investigation at age 40, analyses indicated that participants were representative of the cohort as well as the background population. However, the mortality rate was higher among non-participants in the succeeding 20 years. Among living cohort members at the 60-year examination, non-participants had lower socioeconomic status, higher hospitalization rate, and a worse overall health profile than participants. Conclusions: The detailed data presented reinforce the contention that the health profile of non-participants is typically worse than that of participants. The results also indicate that while data from public registers give easily accessible information about non-participants, these crude proxy measures of health may not be enough to document representativeness.

The BIGTT Test A novel test for simultaneous measurement of pancreatic β-cell function, insulin sensitivity, and glucose tolerance

OBJECTIVE—Insulin resistance and impaired β-cell function are key elements in the pathogenesis of type 2 diabetes. We aimed to develop valid algorithms for estimation of the insulin sensitivity index (SI) and acute insulin response (AIR) derived from simple and cheap physiological measurements that could be used in large-scale metabolic, genetic, and epidemiological studies. RESEARCH DESIGN AND METHODS—For our purpose, data from an oral glucose tolerance test (OGTT) (18 samples during 240 min) and a tolbutamide-modified intravenous glucose tolerance test (IVGTT) (33 samples during 180 min) from 258 individuals with fasting plasma glucose <7 mmol/l and 2-h plasma glucose <7.8 mmol/l were used for model development and internal validation. Data from an additional 28 individuals were used for external validation. Bergman’s minimal model was used to calculate SI, and the trapezoidal method was used to calculate AIR0–8 min. Multiple linear regression was applied to derive predictive equations of log(SI) and log(AIR0–8 min) using data on sex, BMI, plasma glucose, and serum insulin levels obtained during the OGTT. RESULTS—We demonstrate that it is possible to obtain estimates of SI (BIGTT-SI) and AIR (BIGTT-AIR) that are highly correlated to IVGTT-derived values of SI (R2 = 0.77) and AIR (R2 = 0.54). In the two validation datasets we obtained similar results. CONCLUSIONS—Data from OGTTs can provide accurate measures of insulin sensitivity and β-cell function, which can be used in large scale metabolic, genetic, and epidemiological studies.

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

Background: Peroxisome proliferator activated receptor-γ coactivator-1β (PGC-1β) is a recently identified homologue of the tissue specific coactivator PGC-1α, a coactivator of transcription factors such as the peroxisome proliferators activated receptors and nuclear respiratory factors. PGC-1α is involved in adipogenesis, mitochondrial biogenesis, fatty acid β 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-1β may contribute to the pathogenesis of obesity, with a widespread Ala203 allele being a risk factor for the development of this common disorder.

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/hypothesisThe 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.MethodsWe 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.ResultsThere 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/interpretationThe 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.

PGC-1α Gly482Ser Polymorphism Associates With Hypertension Among Danish Whites

PGC-1α 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-1α 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 (P=0.001). In conclusion, the Ser allele of PGC-1α 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.

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

Aims/hypothesisPolymorphisms 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.MethodsThe 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.ResultsThere 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/interpretationThe 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.