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J C Levy

Publications and source records attributed to J C Levy.

At least 19 recordsLinked to original sources
PubMed2006

An association analysis of the HLA gene region in latent autoimmune diabetes in adults.

AIMS/HYPOTHESIS: Pathophysiological similarities between latent autoimmune diabetes in adults (LADA) and type 1 diabetes indicate an overlap in genetic susceptibility. HLA-DRB1 and HLA-DQB1 are major susceptibility genes for type 1 diabetes but studies of these genes in LADA have been limited. Our aim was to define patterns of HLA-encoded susceptibility/protection in a large, well characterised LADA cohort, and to establish association with disease and age at diagnosis. MATERIALS AND METHODS: Patients with LADA (n = 387, including 211 patients from the UK Prospective Diabetes Study) and non-diabetic control subjects (n = 327) were of British/Irish European origin. The HLA-DRB1 and -DQB1 genes were genotyped by sequence-specific PCR. RESULTS: As in type 1 diabetes mellitus, DRB1 0301_DQB1 0201 (odds ratio [OR] = 3.08, 95% CI 2.32-4.12, p = 1.2 x 10(-16)) and DRB1 0401_DQB1 0302 (OR = 2.57, 95% CI 1.80-3.73, p = 4.5 x 10(-8)) were the main susceptibility haplotypes in LADA, and DRB1 1501_DQB1 0602 was protective (OR = 0.21, 95% CI 0.13-0.34, p = 4.2 x 10(-13)). Differential susceptibility was conferred by DR4 subtypes: DRB1 0401 was predisposing (OR = 1.79, 95% CI 1.35-2.38, p = 2.7 x 10(-5)) whereas DRB1 0403 was protective (OR = 0.37, 95% CI 0.13-0.97, p = 0.033). The highest-risk genotypes were DRB1 0301/DRB1 0401 and DQB1 0201/DQB1 0302 (OR = 5.14, 95% CI 2.68-10.69, p = 1.3 x 10(-8); and OR = 6.88, 95% CI 3.54-14.68, p = 1.2 x 10(-11), respectively). These genotypes and those containing DRB1 0401 and DQB1 0302 associated with a younger age at diagnosis in LADA, whereas genotypes containing DRB1 1501 and DQB1 0602 associated with an older age at diagnosis. CONCLUSIONS/INTERPRETATION: Patterns of susceptibility at the HLA-DRB1 and HLA-DQB1 loci in LADA are similar to those reported for type 1 diabetes, supporting the hypothesis that autoimmune diabetes occurring in adults is an age-related extension of the pathophysiological process presenting as childhood-onset type 1 diabetes.

Adult↗
PubMed2006

Reduced beta cell function in offspring of mothers with young-onset type 2 diabetes.

AIMS/HYPOTHESIS: Animal models indicate that even exposure to mild maternal hyperglycaemia in utero is detrimental to the beta cell function of the offspring, but evidence of this in humans is limited. In Europids who are diagnosed with type 2 diabetes before the age of 50 years, the risk of diabetes in the offspring of the diabetic mothers is greatly increased compared with the risk in those born to diabetic fathers. We hypothesised that offspring born to mothers with young-onset type 2 diabetes would have been exposed to mild hyperglycaemia in utero, so we studied the impact of this on their beta cell function. SUBJECTS AND METHODS: We measured beta cell function using early insulin response (EIR) after oral glucose; insulin resistance using HOMA; and HbA(1c) in 568 non-diabetic adult offspring born to parents with type 2 diabetes (mean age 55.8 years), split according to which parent was affected (in 327 it was the mother) and parental age of diagnosis: <50 years (n=117) or > or =50 years. To reduce the impact of genetic susceptibility, the offspring of affected fathers were used as control subjects. RESULTS: Offspring of mothers with young-onset type 2 diabetes had lower EIR (log EIR 4.32, 95% CI [4.14-4.51] vs 4.63 [4.43-4.83] p=0.02) and higher HbA(1c) (4.89% [4.79-4.99] vs 4.68% [4.57-4.79] p=0.02) than the offspring of fathers with young-onset type 2 diabetes. Insulin sensitivity was similar in the two groups. There were no differences in EIR or HbA(1c) between the offspring born to mothers and fathers who were diagnosed after the age of 50 years. CONCLUSIONS/INTERPRETATION: We conclude that the offspring of mothers with young-onset type 2 diabetes have a reduction in beta cell function. This is consistent with exposure to mild maternal hyperglycaemia programming beta cell function.

Adult↗
PubMed2006

GAD antibodies in probands and their relatives in a cohort clinically selected for Type 2 diabetes.

AIMS: A subset of patients who present as if they have Type 2 diabetes have positive pancreatic autoantibodies, and have been referred to as having latent autoimmune diabetes in adults (LADA). We assessed the prevalence and clinical characteristics of patients with glutamic acid decarboxylase antibodies (GADA) in a cohort clinically selected for Type 2 diabetes and determined the presence of diabetes and GADA in their first-degree relatives. METHODS: GADA were measured in 2059 subjects, not known to be related, and clinically selected as having Type 2 diabetes for genetic studies. Clinical characteristics were compared in GADA positive and GADA negative subjects. Diabetes and GAD antibody status were compared in 208 first-degree relatives of GADA positive and GADA negative probands. RESULTS: Of the subjects, 136 (7%) were GADA positive. Compared with the GADA negative subjects, they were slimmer (P < 0.001), diagnosed at a younger age (P = 0.011) and progressed to insulin faster (P < 0.001). Thirty-three per cent of GADA positive subjects had a first-degree relative with diabetes compared with 42% of GADA negative subjects (P = 0.034). The overall prevalence of GADA was similar in the first-degree relatives of GADA positive and GADA negative probands (4 v 5%), and 19 of 22 (86%) diabetic relatives of GADA positive probands were GADA negative. CONCLUSION: Despite clinically selecting a Type 2 diabetes cohort, 7% were GADA positive with an altered phenotype. These GADA positive patients had a strong family history of non-autoimmune diabetes. This suggests that, in this subgroup of patients, autoimmune pancreatic beta-cell destruction occurs on a background of Type 2 diabetes genetic susceptibility.

Adult↗
PubMed2005

Unzipping DNA from the condensed globule state-effects of unraveling.

We have studied theoretically the unzipping of a double-stranded DNA from a condensed globule state by an external force. At constant force, we found that the double-stranded DNA unzips an at critical force Fc and the number of unzipped monomers M goes as M approximately (Fc - F)-3, for both the homogeneous and heterogeneous double-stranded DNA sequence. This is different from the case of unzipping from an extended coil state in which the number of unzipped monomers M goes as M approximately (Fc - F)-chi, where the exponent chi is either 1 or 2 depending on whether the double-stranded DNA sequence is homogeneous or heterogeneous, respectively. In the case of unzipping at constant extension, we found that for a double-stranded DNA with a very large number N of base pairs, the force remains almost constant as a function of the extension, before the unraveling transition, at which the force drops abruptly to zero. Right at the unraveling transition, the number of base pairs remaining in the condensed globule state is still very large and goes as N(3/4), in agreement with theoretical predictions of the unraveling transition of polymers stretched by an external force.

Base Sequence↗
PubMed2005

Large-scale studies of the association between variation at the TNF/LTA locus and susceptibility to type 2 diabetes.

AIMS/HYPOTHESIS: The proinflammatory cytokine TNF-alpha has been implicated in the pathogenesis of insulin resistance and type 2 diabetes, and variation in the gene encoding TNF-alpha (TNF) has shown inconsistent associations with susceptibility to both conditions. Additionally, the coding non-synonymous variant T60N in the neighbouring LTA gene has been reported to be associated with type 2 diabetes. The present study aimed to obtain a robust assessment of the role of variation in the tightly linked TNF/LTA region in diabetes susceptibility by genotyping TNF and LTA variants in large case-control resources. MATERIALS AND METHODS: The G-308A and G-238A TNF promoter variants and the LTA T60N polymorphism were genotyped in two UK case samples that were ascertained for positive family history and/or early onset of type 2 diabetes (combined n=858) and in 1,257 ethnically matched controls. RESULTS: There were no significant associations between the T60N, G-308A or G-238A genotype and type 2 diabetes in the combined analysis (exact Cochran-Mantel-Haenszel statistic for ordered genotypes for T60N, p=0.69; for G-308A, p=0.51; for G-238A, p=0.16). CONCLUSIONS/INTERPRETATION: The present study, one of the largest association analyses yet reported at this locus, provides no evidence that the specific TNF or LTA variants examined influence susceptibility to type 2 diabetes. More comprehensive studies of the TNF/LTA locus in substantially larger sample sets are required to establish whether genome sequence variation at this locus truly influences susceptibility to type 2 diabetes.

Adult↗
PubMed2005

Insulin sensitivity at diagnosis of Type 2 diabetes is not associated with subsequent cardiovascular disease (UKPDS 67).

AIMS: Insulin resistance is common in Type 2 diabetes which, in turn, is associated with a markedly increased risk of cardiovascular disease. Whether insulin sensitivity measured after diagnosis of diabetes is associated with incident cardiovascular disease was evaluated in this prospective study. METHODS: Three thousand five hundred and eighty-two subjects with newly diagnosed diabetes, recruited to the UK Prospective Diabetes Study (UKPDS), free of cardiovascular disease, and with complete information on insulin sensitivity and potential confounders, were followed prospectively to the first occurrence of (i) fatal or non-fatal myocardial infarction, MI (ii) fatal or non-fatal stroke, and (iii) coronary heart disease, CHD (fatal or non-fatal MI, sudden death or ischaemic heart disease). Insulin sensitivity was measured by Homeostatic Model Assessment (HOMA). RESULTS: Insulin sensitivity as measured by HOMA was not associated with subsequent MI, stroke, or CHD in univariate or multivariate models controlling for age, sex, ethnicity, HbA(1c), body mass index, plasma triglycerides, cholesterol and smoking. The hazard ratio associated with a doubling of insulin sensitivity with fatal or non-fatal MI in a multivariate model was 0.92 (95% confidence interval, CI, 0.80-1.05). These results were not changed by the exclusion of overweight patients randomized to metformin. DISCUSSION: Estimation of insulin sensitivity provides no additional useful information with respect to the risk of the first occurrence of cardiovascular disease in patients with newly diagnosed Type 2 diabetes. Among patients with Type 2 diabetes, insulin resistance is not a risk factor for cardiovascular disease.

Adult↗
PubMed2005

Examining the relationships between the Pro12Ala variant in PPARG and Type 2 diabetes-related traits in UK samples.

AIMS: The Pro12Ala polymorphism in the PPARG gene alters amino acid sequence and has shown consistent association with susceptibility to Type 2 diabetes in several populations. The present study makes use of large, well-characterized case-control resources to enhance understanding of this susceptibility effect by examining related traits, such as body mass index (BMI), waist-hip ratio and age at diagnosis. METHODS: The Pro12Ala variant was genotyped in two UK case samples, ascertained for positive family history and/or early onset of Type 2 diabetes (combined n=971); and in 1257 ethnically matched control subjects. RESULTS: There were significant associations of the Pro12Ala single nucleotide polymorphism (SNP) genotypes with diabetes in both case-control comparisons (P=0.025 and P=0.039). Comparing individuals homozygous for the Pro allele, with those carrying an Ala allele, the combined odds ratio for diabetes was 1.40 (95% CIs, 1.12-1.76, P=0.0031). There was no association between the variant and either waist-hip ratio or age at diagnosis. Proline homozygosity was associated with increased BMI in one patient group (P=0.013) and decreased BMI in the other (P=0.038). CONCLUSIONS: This study confirms that variation within PPARG influences susceptibility to Type 2 diabetes in UK samples. However, the relationship between PPARG variation and BMI is more complex, and studies in much larger sample sets will be required to more precisely characterize the effect of this variant on adiposity.

Age of Onset↗
PubMed2004

Analysis of the contribution to type 2 diabetes susceptibility of sequence variation in the gene encoding stearoyl-CoA desaturase, a key regulator of lipid and carbohydrate metabolism.

AIMS/HYPOTHESIS: Stearoyl-CoA desaturase (SCD) is emerging as a key regulator of lipid and carbohydrate metabolism. Scd-null mice display a beneficial metabolic phenotype characterised by resistance to obesity, diabetes and hyperlipidaemia. The human homologue, SCD, maps to a region of chromosome 10 linked to type 2 diabetes, and SCD activity correlates with insulin sensitivity. Given this strong positional and biological candidacy, the present study sought to establish whether sequence variation in SCD influences susceptibility to type 2 diabetes and related traits. METHODS: The SCD gene was resequenced in 23 diabetic subjects. Six variants within coding and adjacent sequence, including a non-synonymous SNP in exon 5 (M224L), were selected for genotyping in a primary set of 608 diabetic subjects and 600 control subjects. RESULTS: There was no association (at the allele, genotype or haplotype level) with type 2 diabetes, although genotype frequencies at the +14301 A>C SNP in the 3' untranslated region showed borderline association (p~0.06) when evidence for linkage was taken into account. However, replication studies (350 young-onset diabetic patients; 747 controls) failed to confirm any relationship with diabetes for this variant. No significant associations were seen for diabetes-related traits including BMI and waist-to-hip ratio. CONCLUSIONS/INTERPRETATION: The present study, the first reported analysis of this gene, indicates that the SCD variants typed do not explain chromosome-10-encoded susceptibility to type 2 diabetes. Although this study provided no evidence that SCD sequence variation influences diabetes susceptibility or related traits, SCD remains a major target for pharmaceutical and/or environmental manipulation.

Adult↗
PubMed2004

Heritability estimates for beta cell function and features of the insulin resistance syndrome in UK families with an increased susceptibility to type 2 diabetes.

AIMS/HYPOTHESIS: The aim of this study was to measure the heritability estimates for metabolic traits and the features of the insulin resistance syndrome in families with an increased genetic susceptibility to Type 2 diabetes. METHODS: A total of 811 non-diabetic relatives from 278 pedigrees of northern European extraction in which there was a sib-pair with Type 2 diabetes were recruited and studied at the six Diabetes UK Warren Type 2 diabetes centres. Heritability estimates were calculated, allowing for key covariates (age, sex, BMI and recruitment centre). Values greater than 0.10 were considered statistically significant in comparison to zero. RESULTS: Fasting glucose concentration and homeostasis model assessment of pancreatic beta cell function (HOMA %B) had the highest heritability estimates of 0.72 and 0.78 respectively. Heritability estimates for the features of the insulin resistance syndrome (BMI, WHR, systolic and diastolic blood pressure, serum lipids and homeostasis model assessment of insulin sensitivity [HOMA %S]) were also high. The heritability estimate for fasting glucose was markedly higher in the present study (0.77 vs 0.21 adjusted for age and sex; p<0.001) than in a comparable study of families from the same background population but with no increased susceptibility to diabetes. However, the estimates for the features of the insulin resistance syndrome were similar in the two studies. CONCLUSIONS/INTERPRETATION: In families with a high risk of Type 2 diabetes, the heritability estimates for fasting glucose, pancreatic beta cell function and the features of the insulin resistance syndrome were all high. The higher heritability estimate for pancreatic beta cell function suggests that this resource may be most effective when investigating genetic susceptibility to beta cell dysfunction.

Adult↗
PubMed2004

An increase in insulin sensitivity and basal beta-cell function in diabetic subjects treated with pioglitazone in a placebo-controlled randomized study.

AIMS: To investigate the effect of treatment with pioglitazone on beta-cell function and insulin sensitivity in Type 2 diabetes. METHODS: Thirty subjects with diet-controlled Type 2 diabetes were randomized to 3 months treatment with pioglitazone (n = 19) or placebo (n = 11). All subjects underwent basal sampling for homeostatic model assessment (HOMA), followed by an intravenous glucose tolerance test and hyperglycaemic clamp, followed by an euglycaemic hyperinsulinaemic clamp; at baseline and after treatment. RESULTS: All results are expressed as mean (sem). Pioglitazone increased basal insulin sensitivity by 24.7% (7.8) HOMA-%S vs. 2.1% (5.9) in the placebo group (P = 0.02). Stimulated insulin sensitivity, M/I, increased in the pioglitazone group compared with placebo: +15.1 (2.8) l kg(-1) min(-1) vs. +3.2 (2.9) l kg(-1) min(-1), respectively (P = 0.009). Pioglitazone increased adiponectin by 39.3 (6.3), ng/ml compared with a decrease of 0.8 (1.3) ng/ml with placebo (P = 0.00004). HOMA-%B increased with pioglitazone, +11.5% (4.8) vs. -2.0% (4.8) with placebo (P = 0.049), but there was no change in stimulated beta-cell function as determined by hyperglycaemic clamps. There was a significant reduction in the proinsulin/insulin ratio in the pioglitazone group, -0.057 (0.02) compared with placebo, +0.004 (0.02) (P = 0.03). There was a significant reduction in HbA(1c) of 0.6% (0.1) in the pioglitazone group compared with placebo (P = 0.003). There was no significant weight gain associated with pioglitazone therapy: +0.7 (sem 0.6) kg vs. +1.1 (sem 0.5) kg in placebo group (P = NS). CONCLUSIONS: Basal beta-cell function and insulin sensitivity improved following pioglitazone therapy. The improvement in proinsulin to insulin ratio suggests that beta-cells are under less stress.

Aged↗
PubMed2003

Apolipoprotein E genotype, islet amyloid deposition and severity of Type 2 diabetes.

Islet amyloid is found in 90% of patients with Type 2 (non-insulin-dependent) diabetes at post-mortem. More extensive amyloidosis is associated with decreased islet function and requirement for insulin therapy. Severity of cerebral amyloidosis in Alzheimer's disease (AD) is increased in subjects with the apolipoprotein E (ApoE) epsilon 4 allele. To determine if ApoE genotype was associated with severity of islet amyloidosis and diabetes, samples were genotyped from 32 specimens of post-mortem pancreas and from patients classified by disease progression. DNA was extracted from blood samples from Caucasian patients diagnosed with Type 2 diabetes, at age >40 years, classified according to disease progression: group 1 on oral therapy for at least 10 years from diagnosis, (n=147) and group 2, requiring insulin within 6 years from diagnosis, (n=187). ApoE genotype was determined by restriction-fragment length polymorphism analysis. DNA in pancreatic extracts (23 diabetic; 9 non-diabetic subjects) showed no association of ApoE polymorphisms with either degree of islet amyloidosis or disease severity. The distributions of ApoE epsilon 2, epsilon 3 and epsilon 4 were similar in both clinical patient groups and in the non-diabetic group and unrelated to progression of disease. It is unlikely that the common polymorphisms for the ApoE gene are linked to amyloid formation or progression of islet dysfunction in Type 2 diabetes.

Adult↗
PubMed2003

Cannabis use as described by people with multiple sclerosis.

BACKGROUND: Multiple sclerosis (MS) is one of the most common neurological diseases affecting young adults. The prevalence of MS in Alberta has been described as among the highest reported in the world, estimated at 217 per 100,000. Numerous anecdotal reports, and a few small empirical investigations have suggested that cannabis use may relieve the symptom experience of those with MS. The present study was undertaken to describe cannabis use by this patient group. Information on peoples' beliefs, practices and experiences related to use were investigated. METHODS: A questionnaire was mailed to a sample of 780 adults with MS in southern Alberta, Canada. RESULTS: Completed questionnaires were returned by 420/673 eligible subjects (response rate 62%). Mean sample age was 48 years and 75% were women. Respondents ranged from mildly to severely impaired. The majority of respondents (96%) was aware cannabis was potentially therapeutically useful for MS and most (72%) supported legalization for medicinal purposes. Forty-three percent had tried cannabis at some point in their lives, 16% for medicinal purposes. Symptoms reported to be ameliorated included anxiety/depression, spasticity and chronic pain. Reasons given for not trying cannabis were the fact that it is an illegal substance, concern about side effects and lack of knowledge on how to obtain it. CONCLUSIONS: Subjective improvements in symptom experience were reported by the majority of people with MS who currently use cannabis. Further evaluation of this substance is warranted.

Adult↗
PubMed2003

The impact of screening for Type 2 diabetes in siblings of patients with established diabetes.

BACKGROUND: Targeted screening for Type 2 diabetes has been proposed as a method of identifying people with, or at risk of, the disease in order to implement preventive care. AIM: To assess the changes in anxiety, well-being, and cognitions associated with screening for Type 2 diabetes in people at increased risk of diabetes after 1 year; and to identify potential predictors of increased anxiety and lower well being over this period. DESIGN AND SETTING: One-year follow up of a cohort of non-diabetic siblings of those with Type 2 diabetes registered with general practitioners in Oxfordshire and Northamptonshire who were identified for participation in a programme to undertake sib-pair genetic analysis. METHODS: Potential families were selected through identification of people with Type 2 diabetes. Family members aged 35-74 years, who did not have diabetes and who were willing to participate in the study, completed measures before receiving the results of a fasting plasma glucose test, and 1 year later. Measures included the Spielberger State Anxiety Scale-short form (SSAI-SF), the Well-Being Questionnaire 12 item scale (WBQ-12), and measures of cognitions about developing diabetes. The Health Anxiety Inventory (HAI) was completed before receiving the results of the tests to assess its relationship with anxiety at 1 year. RESULTS: A cohort of 431 individuals was identified, of whom 328 (76%) returned fully completed WBQ scales both initially and at 1 year. State anxiety measured with the SSAI-SF fell from 34.5 (95% CI 33.4-35.6) to 32.3 (31.2-33.4) at 1 year (P < 0.0001). Mean WBQ-12 scores rose (i.e. improved) from 26.8 (26.0-27.4) to 27.4 (26.7-28.1) (P = 0.008). SSAI-SF and WBQ-12 mean scores over 1 year did not differ between participants receiving a normal or an at-risk test result. However, those receiving an at-risk test result were more likely, at 1 year, to consider themselves at increased likelihood of developing diabetes (P < 0.001) and to report thinking about what it would be like to develop diabetes (P = 0.006). A score in the upper tertile of the initial HAI was associated with an increased level of anxiety at 1 year (adjusted odds ratio 2.0, 95% CI 1.2-3.4, P = 0.006). CONCLUSIONS: There is no evidence that an 'at-risk' test result leads to sustained anxiety or reduced well being at 1 year compared with those receiving a normal test result. However, further studies are required to clarify levels of anxiety prior to screening to assess the overall impact of the process.

Adult↗
PubMed2002

Interaction between specific fatty acids, GLP-1 and insulin secretion in humans.

AIMS/HYPOTHESIS: Fatty acids affect insulin secretion in vivo, but little is known about the effects of specific fatty acids. Our aim was to investigate differential effects of acutely increased plasma monounsaturated, polyunsaturated and saturated fatty acids on glucose-stimulated insulin secretion in healthy humans. METHODS: A new experimental protocol was used to increase plasma monounsaturated (MUFA test), polyunsaturated (PUFA test) or saturated (SFA test) non-esterified fatty acids for 2 h by repeated oral fat feeding and continuous intravenous heparin infusion. This was followed by a hyperglycaemic clamp (10 mmol/l) to test insulin secretion in response to a prior plasma NEFA increase. RESULTS: Total plasma NEFA concentrations were increased during the fat tests compared to the control visit (1.7-fold increase for MUFA and SFA tests and 1.4-fold increase for PUFA test; p<0.001). Exaggerated responses in plasma insulin, C-peptide and proinsulin concentrations were seen during the hyperglycaemic clamp after increasing plasma NEFA concentrations compared with the control (p<0.01). The effects were greatest for the MUFA test followed by the PUFA test and SFA test (p<0.01). Plasma GLP-1 concentrations increased during fat feeding, with a higher response during the MUFA test compared to PUFA and SFA tests (p<0.01). CONCLUSION/INTERPRETATION: Increasing plasma NEFA concentrations by oral fat feeding with heparin infusion augments glucose-stimulated insulin secretion with the greatest effect for monounsaturated fatty acids and the lowest effect for saturated fatty acids. Monounsaturated fatty acids also increase GLP-1 more than saturated fatty acids. Therefore, the exaggerated insulin concentrations could be due to both NEFA and GLP-1.

Adult↗
PubMed2002

Hyperglycaemic siblings of Type II (non-insulin-dependent) diabetic patients have increased PAI-1, central obesity and insulin resistance compared with their paired normoglycaemic sibling.

AIMS/HYPOTHESIS: First-degree relatives of Type II (non-insulin-dependent) diabetic patients in cross-sectional studies have increased insulin resistance, associated cardiovascular risk factors and abnormalities of fibrinolysis and coagulation. To minimise between-family genetic and environmental confounders, we investigated within-family relationships between early hyperglycaemia and risk factors. METHODS: Thirteen age and gender matched sibling pairs of Type II (non-insulin-dependent) diabetic patients, one hyperglycaemic, one normoglycaemic (fasting plasma glucose at screening 6.0-7.7 mmol.l(-1) and < 6.0 mmol.l(-1), respectively) were assessed for plasminogen activator inhibitor antigen (PAI-1), tissue plasminogen activator antigen (t-PA), fibrinogen, Factor VII and Factor VIII/von Willebrand factor antigen. Fasting lipid profiles, blood pressure and HOMA insulin sensitivity (%S) were also measured in siblings and in matched subjects without family history of diabetes. RESULTS: Hyperglycaemic and normoglycaemic siblings (7 female, 6 male) were aged, mean (SD) 56.8 (8.7) and 55.8 (8.4) years. Hyperglycaemic siblings had increased PAI-1 antigen, geometric mean (i.q.r.): 26.3 (15.1-45.6) vs 11.1 (2.1-23.3) ng/ml, p=0.0002, similar t-PA antigen, mean (SD) 9.5 (4.3) vs 7.4 (2.5) ng/ml, p=0.2 and fibrinogen 2.2 (0.3) vs 2.3 (0.6) g/l, p=0.5, and reduced %S 66.3 (30.5) vs 82.9 (25), p=0.04. PAI-1 correlated negatively with %S ( r=-0.55, p=0.005). No significant differences were found in blood pressure or fasting lipids. CONCLUSION/INTERPRETATION: A minor increase in plasma glucose in non-diabetic sibling pairs of Type II (non-insulin-dependent) diabetic patients was associated with reduced insulin sensitivity, increased central adiposity and a doubling of PAI-1 antigen concentration, suggesting impaired fibrinolysis. It is possible that this could contribute to increased cardiovascular risk in these subjects.

Blood Glucose↗
PubMed2002

Human calcium/calmodulin-dependent protein kinase II gamma gene (CAMK2G): cloning, genomic structure and detection of variants in subjects with type II diabetes.

AIMS/HYPOTHESIS: Ca(2+)/calmodulin-dependent protein kinase II, is expressed in the pancreatic beta cells and is activated by glucose and other secretagogues in a manner correlating with insulin secretion. The activation of Ca(2+)/calmodulin-dependent protein kinase II mediates some of the actions of Ca(2+) on the exocytosis of insulin. We therefore investigated the gene encoding the gamma isoform ( CAMK2G) which has been shown to be expressed in human beta cells as a candidate gene for Type II (non-insulin-dependent) diabetes mellitus. METHODS: Human CAMK2G was cloned from a total human P1 artificial chromosome library using a partial Ca(2+)/calmodulin-dependent protein kinase gamma(E) cDNA probe. Positive PAC clones were localised to chromosome 10q22 by fluorescence in situ hybridisation. To obtain structural information and the sequences of the exon-intron boundaries, the published genomic structures of the rat and mouse genes allowed the putative exon-intron boundaries of human CAMK2G to be amplified by vectorette polymerase chain reaction and sequenced. Sequence variants in each exon were identified using single stranded conformational polymorphism analysis. RESULTS: The human CAMK2G gene comprises 22 exons which range in size between 43 to 230 bp. Screening of the exons and exon-intron boundaries identified two single nucleotide polymorphisms. These did not show association with diabetes in 122 patients and 144 control subjects. CONCLUSIONS/INTERPRETATION: We have identified the genomic structure of CAMK2G to enable further study of this potential candidate gene. Variation in this gene is not strongly associated with diabetes in Caucasians in the United Kingdom. We have identified two single nucleotide polymorphisms which, with appropriately large case control studies, can be used to assess the role of CAMK2G in the susceptibility to Type II diabetes.

Alleles↗
PubMed2002

Clinical usefulness of cystatin C for the estimation of glomerular filtration rate in type 1 diabetes: reproducibility and accuracy compared with standard measures and iohexol clearance.

OBJECTIVE-Assessment and follow-up of early renal dysfunction is important in diabetic nephropathy. Plasma creatinine is insensitive for a glomerular filtration rate (GFR) >50 ml/min and creatinine clearance is unwieldy and subject to collection inaccuracies. We aimed to assess the reproducibility, reliability, and accuracy of plasma cystatin C as a measure of GFR ranging from normal to moderate impairment due to type 1 diabetes in the presence of a normal plasma creatinine concentration. RESEARCH DESIGN AND METHODS-A sensitive immunoturbidimetric cystatin C assay was examined in 29 subjects with type 1 diabetes and 11 nondiabetic subjects. Duplicate measurements of the following were collected from each subject, 2 weeks apart: cystatin C, enzymatic plasma creatinine, 24-h creatinine clearance, GFR estimated from plasma creatinine by the Cockcroft-Gault equation, and iohexol clearance as a gold standard. RESULTS-Iohexol clearance ranged from 35 to 132 ml. min(-1). 1.73 m(-2). Plasma cystatin C compared well with the other clinically used tests. The reliability of cystatin C, as assessed by the discriminant ratio, was superior to creatinine clearance (3.4 vs. 1.5, P < 0.001) and the correlation of cystatin C with iohexol clearance (Rs -0.80) was similar to that of creatinine clearance (Rs -0.74) and superior to that of plasma creatinine and the Cockcroft-Gault estimate (Rs -0.54 and 0.66, respectively). Duplicate estimations were used to provide an unbiased equation to convert plasma cystatin C to GFR. CONCLUSIONS-Based on this study, cystatin C is a more reliable measure of GFR than creatinine clearance, is more highly correlated with iohexol clearance than plasma creatinine, and is worthy of further investigation as a clinical measure of GFR in type 1 diabetes.

Adult↗