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When performing transmission polychromatic beam topography, the extensions to the line segments of the diffraction images of a straight dislocation are shown to intersect at a single point on the X-ray film. The location of this point, together with the diffraction pattern recorded on the film by synchrotron radiation, gives the crystallographic direction [hkl] of the dislocation unambiguously. The results of two synchrotron topography experiments are presented. Very long dislocations found in the center of a large 450â mm-diameter Czochralski silicon crystal align with the growth direction [001]. In the other silicon sample, the dislocations are of mixed type and along the [011] direction.
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AIM: Coffee consumption is inversely related to risk of type 2 diabetes (T2D). In contrast, an increased risk of latent autoimmune diabetes in adults (LADA) has been reported in heavy coffee consumers, primarily in a subgroup with stronger autoimmune characteristics. Our study aimed to investigate whether coffee consumption interacts with HLA genotypes in relation to risk of LADA. METHODS: This population-based study comprised incident cases of LADA (n=484) and T2D (n=1609), and also 885 healthy controls. Information on coffee consumption was collected by food frequency questionnaire. Odds ratios (ORs) with 95% CIs of diabetes were calculated and adjusted for age, gender, BMI, education level, smoking and alcohol intake. Potential interactions between coffee consumption and high-risk HLA genotypes were calculated by attributable proportion (AP) due to interaction. RESULTS: Coffee intake was positively associated with LADA in carriers of high-risk HLA genotypes (OR: 1.14 per cup/day, 95% CI: 1.02-1.28), whereas no association was observed in non-carriers (OR: 1.04, 95% CI: 0.93-1.17). Subjects with both heavy coffee consumption (≥4 cups/day) and high-risk HLA genotypes had an OR of 5.74 (95% CI: 3.34-9.88) with an estimated AP of 0.36 (95% CI: 0.01-0.71; P=0.04370). CONCLUSION: Our findings suggest that coffee consumption interacts with HLA to promote LADA.
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Café , Dieta/estadística & datos numéricos , Predisposición Genética a la Enfermedad/epidemiología , Diabetes Autoinmune Latente del Adulto/epidemiología , Anciano , Estudios de Casos y Controles , Femenino , Predisposición Genética a la Enfermedad/genética , Antígenos de Histocompatibilidad Clase I/genética , Humanos , Resistencia a la Insulina/genética , Diabetes Autoinmune Latente del Adulto/genética , Masculino , Persona de Mediana Edad , Estudios RetrospectivosRESUMEN
BACKGROUND: A family history of diabetes (FHD) is a strong predictor of diabetes risk, yet has rarely been investigated in latent autoimmune diabetes in adults (LADA). This study therefore investigated the risk of LADA and type 2 diabetes (T2D) in relation to FHD, taking into account the type of diabetes in relatives. METHODS: Data from a population-based study were used, including incident cases of LADA [glutamic acid decarboxylase antibody (GADA)-positive, n=378] and T2D (GADA-negative, n=1199), and their matched controls (n=1484). First-degree relatives with disease onset at age<40 years and taking insulin treatment were classified as type 1 diabetes (T1D) or, if otherwise, as T2D. Odds ratios (ORs) were adjusted for age, gender, BMI, education and smoking. Cases were genotyped for high- and low-risk HLA genotypes. RESULTS: Both FHD-T1D (OR: 5.8; 95% CI: 3.2-10.3) and FHD-T2D (OR: 1.9; 95% CI: 1.5-2.5) were associated with an increased risk of LADA, whereas the risk of T2D was associated with FHD-T2D (OR: 2.7; 95% CI: 2.2-3.3), but not FHD-T1D. In LADA patients, FHD-T1D vs FHD-T2D was associated with higher GADA but lower C-peptide levels, lower prevalence of low-risk HLA genotypes (5.0% vs 28.6%, respectively; P=0.038) and a tendency for higher prevalence of high-risk genotypes (90.0% vs 69.1%, respectively; P=0.0576). CONCLUSION: The risk of LADA is substantially increased with FHD-T1D but also, albeit significantly less so, with FHD-T2D. This supports the idea of LADA as a mix of both T1D and T2D, but suggests that the genes related to T1D have greater impact. LADA patients with FHD-T1D had more T1D-like features, emphasizing the heterogeneity of LADA.
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Diabetes Mellitus Tipo 1/epidemiología , Diabetes Mellitus Tipo 2/epidemiología , Diabetes Autoinmune Latente del Adulto/epidemiología , Anamnesis , Anciano , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Factores de RiesgoRESUMEN
AIM: It has been suggested that experiencing serious life events may promote Type 1 diabetes in children. Studies in adults are lacking, as are studies on the interaction of life events with genetic factors. We aimed to investigate life events and the risk of latent autoimmune diabetes in adults (LADA) and Type 2 diabetes while taking into account HLA genotype. METHODS: Analysis was based on 425 incident cases of LADA, 1417 incident cases of Type 2 diabetes and 1702 population-based controls recruited in Sweden between 2010 and 2016. Self-reported information on life events including conflicts, divorce, illness/accidents, death and financial problems experienced during the 5 years preceding diagnosis/index year was used. Odds ratios (ORs) and 95% confidence intervals (95% CI) were calculated by logistic regression and adjusted for age, sex, BMI, family history of diabetes, smoking, physical activity and education. RESULTS: Overall there was no association between experience of any life event and either LADA (OR 0.86, 95% CI 0.68-1.08) or Type 2 diabetes (OR 1.00, 95% CI 0.83-1.21). The results were similar for individual events as well as in separate analysis of men and women. Similar results were seen in more autoimmune LADA (glutamic acid decarboxylase antibodies > median) [OR (any life event) 0.88, 95% CI 0.64-1.21] and in LADA carriers of the high-risk HLADR4-DQ8 genotype (OR 0.89, 95% CI 0.61-1.29). CONCLUSIONS: Our findings indicate that experience of a serious life event, including the death of a family member, divorce or financial problems, is not associated with an increased risk of LADA, overall or in genetically susceptible individuals.
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Diabetes Mellitus Tipo 2/epidemiología , Diabetes Mellitus Tipo 2/etiología , Diabetes Autoinmune Latente del Adulto/epidemiología , Diabetes Autoinmune Latente del Adulto/etiología , Acontecimientos que Cambian la Vida , Adulto , Anciano , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Anamnesis/estadística & datos numéricos , Persona de Mediana Edad , Factores de Riesgo , Suecia/epidemiologíaRESUMEN
AIMS: It has been suggested that moist snuff (snus), a smokeless tobacco product that is high in nicotine and widespread in Scandinavia, increases the risk of Type 2 diabetes. Previous studies are however few, contradictory and, with regard to autoimmune diabetes, lacking. Our aim was to study the association between snus use and the risk of Type 2 diabetes and latent autoimmune diabetes of adulthood (LADA). METHOD: Analyses were based on incident cases (Type 2 diabetes, n = 724; LADA, n = 200) and population-based controls (n = 699) from a Swedish case-control study. Additional analyses were performed on cross-sectional data from the Norwegian HUNT study (n = 21 473) with 829 prevalent cases of Type 2 diabetes. Odds ratios (OR) were estimated adjusted for age, BMI family history of diabetes and smoking. Only men were included. RESULTS: No association between snus use and Type 2 diabetes or LADA was seen in the Swedish data. For Type 2 diabetes, the OR for > 10 box-years was 1.00 [95% confidence interval (CI), 0.47 to 2.11] and for LADA 1.01 (95% CI, 0.45 to 2.29). Similarly, in HUNT, the OR for Type 2 diabetes in ever-users was estimated at 0.91 (95% CI, 0.75 to 1.10) and in heavy users at 0.92 (95% CI, 0.46 to 1.83). CONCLUSION: The risk of Type 2 diabetes and LADA is unrelated to the use of snus, despite its high nicotine content. This opens the possibility of the increased risk of Type 2 diabetes seen in smokers may not be attributed to nicotine, but to other substances in tobacco smoke.
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Diabetes Mellitus Tipo 2/epidemiología , Diabetes Autoinmune Latente del Adulto/epidemiología , Uso de Tabaco/epidemiología , Tabaco sin Humo/estadística & datos numéricos , Anciano , Estudios Transversales , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Noruega/epidemiología , Oportunidad Relativa , Prevalencia , Suecia/epidemiologíaRESUMEN
BACKGROUND: Exposure to ambient air pollution may be associated with impaired mental health, including depression. However, evidence originates mainly from animal studies and epidemiological studies in specific subgroups. We investigated the association between air pollution and depressed mood in four European general population cohorts. METHODS: Data were obtained from LifeLines (the Netherlands), KORA (Germany), HUNT (Norway), and FINRISK (Finland). Residential exposure to particles (PM2.5, PM2.5absorbance, PM10) and nitrogen dioxide (NO2) was estimated using land use regression (LUR) models developed for the European Study of Cohorts for Air Pollution Effects (ESCAPE) and using European wide LUR models. Depressed mood was assessed with interviews and questionnaires. Logistic regression analyses were used to investigate the cohort specific associations between air pollution and depressed mood. RESULTS: A total of 70,928 participants were included in our analyses. Depressed mood ranged from 1.6% (KORA) to 11.3% (FINRISK). Cohort specific associations of the air pollutants and depressed mood showed heterogeneous results. For example, positive associations were found for NO2 in LifeLines (odds ratio [OR]=1.34; 95% CI: 1.17, 1.53 per 10 µg/m(3) increase in NO2), whereas negative associations were found in HUNT (OR=0.79; 95% CI: 0.66, 0.94 per 10 µg/m(3) increase in NO2). CONCLUSIONS: Our analyses of four European general population cohorts found no consistent evidence for an association between ambient air pollution and depressed mood.
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Contaminación del Aire/análisis , Depresión/epidemiología , Adulto , Contaminantes Atmosféricos/análisis , Estudios de Cohortes , Europa (Continente)/epidemiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Vehículos a Motor , Dióxido de Nitrógeno/análisis , Ruido , Oportunidad Relativa , Material Particulado/análisisRESUMEN
OBJECTIVE: It has been suggested that intake of fatty fish may protect against both type 1 and type 2 diabetes. Hypotheses rest on the high marine omega-3 fatty acid eicosapentaenoic acid+docosahexaenoic acid (EPA+DHA) and vitamin D contents, with possible beneficial effects on immune function and glucose metabolism. Our aim was to investigate, for the first time, fatty fish consumption in relation to the risk of latent autoimmune diabetes in adults (LADA). METHODS: Analyses were based on data from a Swedish case-control study with incident cases of LADA (n=89) and type 2 diabetes (n=462) and randomly selected diabetes-free controls (n=1007). Diabetes classification was based on the onset of age (⩾35), glutamic acid decarboxylase autoantibodies, and C-peptide. A validated food frequency questionnaire was used to derive information on previous intake of fish, polyunsaturated long-chain omega-3 fatty acids (n-3 PUFA) and supplementation of fish oil and vitamin D. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using logistic regression, adjusted for age, gender, body mass index (BMI), family history of diabetes, physical activity, smoking, education, and consumption of alcohol, fruit, vegetables and red meat. RESULTS: Weekly fatty fish consumption (⩾1 vs <1 serving per week), was associated with a reduced risk of LADA but not type 2 diabetes (OR 0.51, 95% CI 0.30-0.87, and 1.01, 95% CI 0.74-1.39, respectively). Similar associations were seen for estimated intake of n-3 PUFA (⩾0.3 g per day; LADA: OR 0.60, 95% CI 0.35-1.03, type 2 diabetes: OR 1.14, 95% CI 0.79-1.58) and fish oil supplementation (LADA: OR 0.47, 95% CI 0.19-1.12, type 2 diabetes: OR 1.58, 95% CI 1.08-2.31). CONCLUSIONS: Our findings suggest that fatty fish consumption may reduce the risk of LADA, possibly through effects of marine-originated omega-3 fatty acids.
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AIMS: Coffee consumption is associated with a reduced risk of Type 2 diabetes. Our aim was to investigate if coffee intake may also reduce the risk of latent autoimmune diabetes in adults, an autoimmune form of diabetes with features of Type 2 diabetes. METHODS: We used data from a population-based case-control study with incident cases of adult onset (≥ 35 years) diabetes, including 245 cases of latent autoimmune diabetes in adults (glutamic acid decarboxylase antibody positive), 759 cases of Type 2 diabetes (glutamic acid decarboxylase antibody negative), together with 990 control subjects without diabetes, randomly selected from the population. Using questionnaire information on coffee consumption, we estimated the odds ratio of latent autoimmune diabetes in adults and Type 2 diabetes adjusted for age, sex, BMI, smoking, physical activity, alcohol, education and family history of diabetes. RESULTS: Coffee intake was inversely associated with Type 2 diabetes (odds ratio 0.92, 95% CI 0.87-0.98 per cup/day). With regard to latent autoimmune diabetes in adults, the general trend was weak (odds ratio 1.04, 95% CI 0.96-1.13), but stratification by degree of autoimmunity (median glutamic acid decarboxylase antibody levels) suggested that coffee intake may be associated with an increased risk of high glutamic acid decarboxylase antibody latent autoimmune diabetes in adults (odds ratio 1.11, 95% CI 1.00-1.23 per cup/day). Furthermore, for every additional cup of coffee consumed per day, there was a 15.2% (P = 0.0268) increase in glutamic acid decarboxylase antibody levels. CONCLUSIONS: Our findings confirm that coffee consumption is associated with a reduced risk of Type 2 diabetes. Interestingly, the findings suggest that coffee may be associated with development of autoimmunity and possibly an increased risk of more Type 1-like latent autoimmune diabetes in adults.
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Autoinmunidad/efectos de los fármacos , Café , Diabetes Mellitus Tipo 1/epidemiología , Diabetes Mellitus Tipo 1/inmunología , Diabetes Mellitus Tipo 2/epidemiología , Diabetes Mellitus Tipo 2/prevención & control , Adulto , Factores de Edad , Índice de Masa Corporal , Estudios de Casos y Controles , Café/efectos adversos , Diabetes Mellitus Tipo 2/inmunología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Factores de Riesgo , Fumar , Encuestas y Cuestionarios , Suecia/epidemiologíaRESUMEN
AIMS: The aim was to evaluate the impact of family history of diabetes on the phenotype of patients diagnosed with Type 2 diabetes and the frequency of susceptibility genotypes. METHODS: Patients with Type 2 diabetes with family history for both Type 1 and Type 2 diabetes (FH(MIX, n) = 196) or Type 2 diabetes only (FH(T2), n = 139) matched for age, sex, BMI and age at diagnosis, underwent an oral glucose tolerance test and a combined glucagon test and insulin tolerance test. Glutamic acid decarboxylase (GAD) antibodies and major Type 1 and Type 2 diabetes susceptibility gene variants were analysed. Patients were stratified into groups according to family history or GAD antibody positivity (GADA+, GADA-) or a combination of these (GADA+/FH(MIX), GADA+/FH(T2), GADA-/FH(MIX), GADA-/FH(T2)). RESULTS: Compared with other patients, those with FH(MIX) more often had GAD antibodies (14.3 vs. 4.3%, P = 0.003), and those with both FH(MIX) and GAD antibodies had the highest frequency of insulin deficiency (stimulated serum C-peptide < 0.7 nmol/l, GADA+/FH(MIX) 46.4% vs. GADA-/FH(MIX) 9.5% (P < 0.00001), GADA-/FH(T2) 4.5% (P < 0.00001), GADA+/FH(T2) 0%). Patients with GADA+/FH(MIX) more often had HLA-DQB1 risk genotypes compared with patients with GADA-/FH(MIX) or GADA-/FH(T2D) (47 vs. 23 or 14%, P = 0.05 and P < 0.00001, respectively). In logistic regression analyses, FH(MIX), GAD antibody positivity and HLA risk genotypes were independently associated with insulin deficiency. CONCLUSION: A family history for both type 1 and type 2 diabetes was associated with higher prevalence of GAD antibodies and HLA-DQB1 risk genotypes than a family history of type 2 diabetes only, and was associated with earlier and more severe development of insulin deficiency, which was only partially explained by GAD antibodies and HLA.
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Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 2/genética , Glutamato Descarboxilasa/sangre , Antígenos HLA/sangre , Insulina/metabolismo , Adolescente , Adulto , Péptido C/sangre , Péptido C/genética , Estudios Transversales , Diabetes Mellitus Tipo 1/sangre , Diabetes Mellitus Tipo 1/enzimología , Diabetes Mellitus Tipo 1/epidemiología , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/enzimología , Diabetes Mellitus Tipo 2/epidemiología , Femenino , Finlandia/epidemiología , Predisposición Genética a la Enfermedad , Genotipo , Prueba de Tolerancia a la Glucosa , Glutamato Descarboxilasa/inmunología , Antígenos HLA/genética , Humanos , Insulina/genética , Secreción de Insulina , Masculino , Tamizaje Masivo , Persona de Mediana Edad , FenotipoRESUMEN
AIMS/HYPOTHESIS: Voltage-gated calcium channels of the L-type have been shown to be essential for rodent pancreatic beta cell function, but data about their presence and regulation in humans are incomplete. We therefore sought to elucidate which L-type channel isoform is functionally important and its association with inherited diabetes-related phenotypes. METHODS: Beta cells of human islets from cadaver donors were enriched using FACS to study the expression of the genes encoding voltage-gated calcium channel (Cav)1.2 and Cav1.3 by absolute quantitative PCR in whole human and rat islets, as well as in clonal cells. Single-cell exocytosis was monitored as increases in cell capacitance after treatment with small interfering (si)RNA against CACNA1D (which encodes Cav1.3). Three single nucleotide polymorphisms (SNPs) were genotyped in 8,987 non-diabetic and 2,830 type 2 diabetic individuals from Finland and Sweden and analysed for associations with type 2 diabetes and insulin phenotypes. RESULTS: In FACS-enriched human beta cells, CACNA1D mRNA expression exceeded that of CACNA1C (which encodes Cav1.2) by approximately 60-fold and was decreased in islets from type 2 diabetes patients. The latter coincided with diminished secretion of insulin in vitro. CACNA1D siRNA reduced glucose-stimulated insulin release in INS-1 832/13 cells and exocytosis in human beta cells. Phenotype/genotype associations of three SNPs in the CACNA1D gene revealed an association between the C allele of the SNP rs312480 and reduced mRNA expression, as well as decreased insulin secretion in vivo, whereas both rs312486/G and rs9841978/G were associated with type 2 diabetes. CONCLUSION/INTERPRETATION: We conclude that the L-type calcium channel Cav1.3 is important in human glucose-induced insulin secretion, and common variants in CACNA1D might contribute to type 2 diabetes.
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Canales de Calcio Tipo L/genética , Canales de Calcio Tipo L/metabolismo , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Polimorfismo de Nucleótido Simple/genética , Adulto , Células Cultivadas , Femenino , Citometría de Flujo , Humanos , Masculino , Persona de Mediana Edad , Análisis de Secuencia por Matrices de OligonucleótidosRESUMEN
CONTEXT: Titanium dioxide (TiO2) factory workers' source specific exposure and dose to airborne particles was studied extensively for particles between 5 nm and 10 µm in size. OBJECTIVE: We defined TiO2 industry workers' quantitative inhalation exposure levels during the packing of pigment TiO2 (pTiO2) and nanoscale TiO2 (nTiO2) material from concentrations measured at work area. METHODS: Particle emissions from different work events were identified by linking work activity with the measured number size distributions and mass concentrations of particles. A lung deposit model was used to calculate regional inhalation dose rates in units of particles min⻹ and µg min⻹ without use of respirators. RESULTS: Workers' average exposure varied from 225 to 700 µg m⻳ and from 1.15 × 104 to 20.1 × 104 cmâ»4. Over 90% of the particles were smaller than 100 nm. These were mainly soot and particles formed from process chemicals. Mass concentration originated primarily from the packing of pTiO2 and nTiO2 agglomerates. The nTiO2 exposure resulted in a calculated dose rate of 3.6 × 106 min⻹ and 32 µg min⻹ where 70% of the particles and 85% of the mass was deposited in head airways. CONCLUSIONS: The recommended TiO2 exposure limits in mass by NIOSH and in particle number by IFA were not exceeded. We recommend source-specific exposure assessment in order to evaluate the workers' risks. In nTiO2 packing, mass concentration best describes the workers' exposure to nTiO2 agglomerates. Minute dose rates enable the simulation of workers' risks in different exposure scenarios.
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Contaminantes Ocupacionales del Aire/análisis , Industria Química , Colorantes/administración & dosificación , Nanopartículas del Metal/administración & dosificación , Modelos Biológicos , Exposición Profesional/efectos adversos , Titanio/administración & dosificación , Contaminantes Ocupacionales del Aire/farmacocinética , Contaminantes Ocupacionales del Aire/toxicidad , Automatización , Industria Química/métodos , Colorantes/análisis , Colorantes/farmacocinética , Colorantes/toxicidad , Relación Dosis-Respuesta a Droga , Finlandia , Humanos , Exposición por Inhalación/efectos adversos , Pulmón/química , Pulmón/efectos de los fármacos , Pulmón/metabolismo , Nanopartículas del Metal/análisis , Nanopartículas del Metal/toxicidad , Tamaño de la Partícula , Material Particulado/administración & dosificación , Material Particulado/análisis , Material Particulado/farmacocinética , Material Particulado/toxicidad , Embalaje de Productos , Mucosa Respiratoria/química , Mucosa Respiratoria/efectos de los fármacos , Mucosa Respiratoria/metabolismo , Medición de Riesgo/métodos , Hollín/administración & dosificación , Hollín/análisis , Hollín/farmacocinética , Hollín/toxicidad , Distribución Tisular , Titanio/análisis , Titanio/farmacocinética , Titanio/toxicidad , Recursos HumanosRESUMEN
AIM/HYPOTHESIS: Individuals at risk of developing type 2 diabetes show a progressive decline in insulin secretion and increased insulin resistance over time. However, inability of the beta cells to compensate for the increased insulin resistance represents a key defect leading to overt type 2 diabetes. The aims of the present study were to replicate the association between genetic variants of the PCSK2 gene and insulin secretion, and to explore the effect on risk of type 2 diabetes. METHODS: Replication of PCSK2 variants against insulin secretion included 7,682 non-diabetic Scandinavian individuals. Insulin secretion was measured as the corrected insulin response or disposition index, i.e. insulin secretion adjusted for the degree of insulin resistance. Risk of type 2 diabetes was studied in 28,287 Scandinavian individuals. RESULTS: The C-allele of PCSK2 rs2208203 was associated with reduced insulin secretion measured as the corrected insulin response (n = 8,151; ß = -0.112, p = 1.3 × 10(-6)) as well as disposition index (n = 8,078, ß = -0.128, p = 1.6 × 10(-7)). The variant was also associated with lower fasting glucagon levels (ß = -0.084, p = 0.005) in non-diabetic individuals with a fasting plasma glucose of over 5.5 mmol/l. In human pancreatic islets, PCSK2 expression correlated negatively with HbA(1c) (n = 133, r = -0.196, p = 0.038), and showed a tendency to be lower in hyperglycaemic (HbA(1c) ≥6.0% or type 2 diabetes; n = 47, p = 0.13) than normoglycaemic (HbA(1c) >6.0%; n = 66) donors. The presence of the PCSK2 rs2208203 risk allele did not influence gene expression, nor did it show an apparent risk in terms of type 2 diabetes. CONCLUSIONS/INTERPRETATION: A variant of the PCSK2 gene was associated with reduced glucose-stimulated insulin secretion, but also with lower glucagon levels, which could potentially counteract the effects of decreased insulin secretion on the risk of type 2 diabetes.
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Glucemia/metabolismo , Variación Genética , Resistencia a la Insulina/genética , Insulina/genética , Insulina/metabolismo , Islotes Pancreáticos/metabolismo , Proproteína Convertasa 2/genética , Anciano , Ayuno , Femenino , Finlandia/epidemiología , Estudios de Seguimiento , Genotipo , Humanos , Secreción de Insulina , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Estudios Prospectivos , Medición de Riesgo , Suecia/epidemiologíaRESUMEN
AIMS/HYPOTHESIS: Impaired glucose tolerance and impaired insulin secretion have been reported in families with PAX6 mutations and it is suggested that they result from defective proinsulin processing due to lack of prohormone convertase 1/3, encoded by PCSK1. We investigated whether a common PAX6 variant would mimic these findings and explored in detail its effect on islet function in man. METHODS: A PAX6 candidate single nucleotide polymorphism (rs685428) was associated with fasting insulin levels in the Diabetes Genetics Initiative genome-wide association study. We explored its potential association with glucose tolerance and insulin processing and secretion in three Scandinavian cohorts (N = 8,897 individuals). In addition, insulin secretion and the expression of PAX6 and transcriptional target genes were studied in human pancreatic islets. RESULTS: rs685428 G allele carriers had lower islet mRNA expression of PAX6 (p = 0.01) and PCSK1 (p = 0.001) than AA homozygotes. The G allele was associated with increased fasting insulin (p (replication) = 0.02, p (all) = 0.0008) and HOMA-insulin resistance (p (replication) = 0.02, p (all) = 0.001) as well as a lower fasting proinsulin/insulin ratio (p (all) = 0.008) and lower fasting glucagon (p = 0.04) and gastric inhibitory peptide (GIP) (p = 0.05) concentrations. Arginine-stimulated (p = 0.02) insulin secretion was reduced in vivo, which was further reflected by a reduction of glucose- and potassium-stimulated insulin secretion (p = 0.002 and p = 0.04, respectively) in human islets in vitro. CONCLUSIONS/INTERPRETATION: A common variant in PAX6 is associated with reduced PAX6 and PCSK1 expression in human islets and reduced insulin response, as well as decreased glucagon and GIP concentrations and decreased insulin sensitivity. These findings emphasise the central role of PAX6 in the regulation of islet function and glucose metabolism in man.
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Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/fisiopatología , Proteínas del Ojo/genética , Proteínas de Homeodominio/genética , Resistencia a la Insulina , Islotes Pancreáticos/fisiopatología , Factores de Transcripción Paired Box/genética , Polimorfismo de Nucleótido Simple , Proteínas Represoras/genética , Adolescente , Adulto , Anciano , Estudios de Cohortes , Diabetes Mellitus Tipo 2/metabolismo , Regulación hacia Abajo , Proteínas del Ojo/metabolismo , Femenino , Finlandia , Estudios de Asociación Genética , Proteínas de Homeodominio/metabolismo , Humanos , Islotes Pancreáticos/metabolismo , Desequilibrio de Ligamiento , Masculino , Persona de Mediana Edad , Análisis de Secuencia por Matrices de Oligonucleótidos , Factor de Transcripción PAX6 , Factores de Transcripción Paired Box/metabolismo , Proproteína Convertasa 1/genética , Proproteína Convertasa 1/metabolismo , ARN Mensajero/metabolismo , Proteínas Represoras/metabolismo , Técnicas de Cultivo de Tejidos , Adulto JovenRESUMEN
AIMS/HYPOTHESIS: An accurate molecular diagnosis of diabetes subtype confers clinical benefits; however, many individuals with monogenic diabetes remain undiagnosed. Biomarkers could help to prioritise patients for genetic investigation. We recently demonstrated that high-sensitivity C-reactive protein (hsCRP) levels are lower in UK patients with hepatocyte nuclear factor 1 alpha (HNF1A)-MODY than in other diabetes subtypes. In this large multi-centre study we aimed to assess the clinical validity of hsCRP as a diagnostic biomarker, examine the genotype-phenotype relationship and compare different hsCRP assays. METHODS: High-sensitivity CRP levels were analysed in individuals with HNF1A-MODY (n = 457), glucokinase (GCK)-MODY (n = 404), hepatocyte nuclear factor 4 alpha (HNF4A)-MODY (n = 54) and type 2 diabetes (n = 582) from seven European centres. Three common assays for hsCRP analysis were evaluated. We excluded 121 participants (8.1%) with hsCRP values >10 mg/l. The discriminative power of hsCRP with respect to diabetes aetiology was assessed by receiver operating characteristic curve-derived C-statistic. RESULTS: In all centres and irrespective of the assay method, meta-analysis confirmed significantly lower hsCRP levels in those with HNF1A-MODY than in those with other aetiologies (z score -21.8, p < 5 × 10(-105)). HNF1A-MODY cases with missense mutations had lower hsCRP levels than those with truncating mutations (0.03 vs 0.08 mg/l, p < 5 × 10(-5)). High-sensitivity CRP values between assays were strongly correlated (r (2) ≥ 0.91, p ≤ 1 × 10(-5)). Across the seven centres, the C-statistic for distinguishing HNF1A-MODY from young adult-onset type 2 diabetes ranged from 0.79 to 0.97, indicating high discriminative accuracy. CONCLUSIONS/INTERPRETATION: In the largest study to date, we have established that hsCRP is a clinically valid biomarker for HNF1A-MODY in European populations. Given the modest costs and wide availability, hsCRP could translate rapidly into clinical practice, considerably improving diagnosis rates in monogenic diabetes.
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Proteína C-Reactiva/análisis , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/genética , Factor Nuclear 1-alfa del Hepatocito/genética , Técnicas de Diagnóstico Molecular , Adulto , Edad de Inicio , Biomarcadores/sangre , Diabetes Mellitus Tipo 2/diagnóstico , Europa (Continente) , Glucoquinasa/química , Glucoquinasa/genética , Factor Nuclear 1-alfa del Hepatocito/química , Factor Nuclear 4 del Hepatocito/química , Factor Nuclear 4 del Hepatocito/genética , Heterocigoto , Humanos , Metaanálisis como Asunto , Persona de Mediana Edad , Mutación , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Adulto JovenRESUMEN
AIMS/HYPOTHESIS: To study the heritability and familiality of type 2 diabetes and related quantitative traits in families from the Botnia Study in Finland. METHODS: Heritability estimates for type 2 diabetes adjusted for sex, age and BMI are provided for different age groups of type 2 diabetes and for 34 clinical and metabolic traits in 5,810 individuals from 942 families using a variance component model (SOLAR). In addition, family means of these traits and their distribution across families are calculated. RESULTS: The strongest heritability for type 2 diabetes was seen in patients with age at onset 35-60 years (h (2) = 0.69). However, including patients with onset up to 75 years dropped the h (2) estimates to 0.31. Among quantitative traits, the highest h (2) estimates in all individuals and in non-diabetic individuals were seen for lean body mass (h (2) = 0.53-0.65), HDL-cholesterol (0.52-0.61) and suppression of NEFA during OGTT (0.63-0.76) followed by measures of insulin secretion (insulinogenic index [IG(30)] = 0.41-0.50) and insulin action (insulin sensitivity index [ISI] = 0.37-0.40). In contrast, physical activity showed rather low heritability (0.16-0.18), whereas smoking showed strong heritability (0.57-0.59). Family means of these traits differed two- to fivefold between families belonging to the lowest and highest quartile of the trait (p < 0.00001). CONCLUSIONS/INTERPRETATION: To detect stronger genetic effects in type 2 diabetes, it seems reasonable to restrict inclusion of patients to those with age at onset 35-60 years. Sequencing of families with extreme quantitative traits could be an important next step in the dissection of the genetics of type 2 diabetes.
Asunto(s)
Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/fisiopatología , Salud de la Familia , Predisposición Genética a la Enfermedad , Adolescente , Adulto , Edad de Inicio , Anciano , Índice de Masa Corporal , HDL-Colesterol/sangre , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/etiología , Ácidos Grasos no Esterificados/sangre , Femenino , Finlandia/epidemiología , Prueba de Tolerancia a la Glucosa , Humanos , Resistencia a la Insulina , Masculino , Persona de Mediana Edad , Modelos Genéticos , Actividad Motora , Riesgo , Fumar/genética , Adulto JovenRESUMEN
AIMS/HYPOTHESIS: We studied the impact of a family history of type 2 diabetes on physical fitness, lifestyle factors and diabetes-related metabolic factors. METHODS: The Prevalence, Prediction and Prevention of Diabetes (PPP)-Botnia study is a population-based study in Western Finland, which includes a random sample of 5,208 individuals aged 18 to 75 years identified through the national Finnish Population Registry. Physical activity, dietary habits and family history of type 2 diabetes were assessed by questionnaires and physical fitness by a validated 2 km walking test. Insulin secretion and action were assessed based upon OGTT measurements of insulin and glucose. RESULTS: A family history of type 2 diabetes was associated with a 2.4-fold risk of diabetes and lower physical fitness (maximal aerobic capacity 29.2 +/- 7.2 vs 32.1 +/- 7.0, p = 0.01) despite having similar reported physical activity to that of individuals with no family history. The same individuals also had reduced insulin secretion adjusted for insulin resistance, i.e. disposition index (p < 0.001) despite having higher BMI (27.4 +/- 4.6 vs 26.0 +/- 4.3 kg/m(2), p < 0.001). CONCLUSIONS/INTERPRETATION: Individuals with a family history of type 2 diabetes are characterised by lower physical fitness, which cannot solely be explained by lower physical activity. They also have an impaired capacity of beta cells to compensate for an increase in insulin resistance imposed by an increase in BMI. These defects should be important targets for interventions aiming at preventing type 2 diabetes in individuals with inherited susceptibility to the disease.
Asunto(s)
Diabetes Mellitus Tipo 2/epidemiología , Estilo de Vida , Aptitud Física/fisiología , Adolescente , Adulto , Anciano , Glucemia/metabolismo , Composición Corporal , Diabetes Mellitus Tipo 2/metabolismo , Familia , Femenino , Finlandia , Predisposición Genética a la Enfermedad , Humanos , Resistencia a la Insulina , Células Secretoras de Insulina/metabolismo , Masculino , Persona de Mediana Edad , Prevalencia , Sistema de Registros , Análisis de Regresión , Factores de Riesgo , Factores Sexuales , Encuestas y CuestionariosRESUMEN
OBJECTIVE: To investigate the fitness of serum apolipoprotein M (apoM) concentration as a marker for maturity-onset diabetes of the young 3 (MODY3). STUDY DESIGN AND SUBJECTS: This study consisted of two parts. A family study included 71 carriers of the P291fsinsC mutation in hepatocyte nuclear factor-1alpha (HNF-1alpha) from the Finnish Botnia study, 53 of whom were diabetic, and 75 matched family controls. A second, case-control study included 24 MODY3 patients, 17 healthy MODY3 mutation carriers, 11 MODY1 patients, 18 type 2 diabetes patients and 19 healthy control individuals. Subjects in the case-control study were recruited from the Botnia study or the Clinic of Endocrinology, Malmö University Hospital. Serum apoM levels were measured using a novel ELISA based on two monoclonal apoM antibodies. RESULTS: In the family study, mean serum apoM was 10% lower in female carriers of the P291fsinsC mutation compared to the family controls (P = 0.0058), a difference which remained significant after adjustment for diabetes status. There was no observed difference between groups for men. In the case-control study, no significant difference in apoM concentration was observed between MODY3 and type 2 diabetes patients, neither before nor after adjustment for total cholesterol. CONCLUSIONS: Female carriers of the P291fsinsC mutation in HNF-1alpha displayed slightly lower apoM serum levels. This difference is too small for apoM to be reliably employed as a biomarker for HNF-1alpha mutation status.
Asunto(s)
Apolipoproteínas/sangre , Diabetes Mellitus Tipo 2/sangre , Adulto , Apolipoproteínas M , Biomarcadores/sangre , Estudios de Casos y Controles , Diabetes Mellitus Tipo 2/genética , Ensayo de Inmunoadsorción Enzimática , Femenino , Predisposición Genética a la Enfermedad , Factor Nuclear 1-alfa del Hepatocito/genética , Heterocigoto , Humanos , Lipocalinas , Masculino , Persona de Mediana Edad , Mutación , Valor Predictivo de las Pruebas , Factores SexualesRESUMEN
Studies on potential toxicity of engineered nanoparticle (ENP) in biological systems require a proper and accurate particle characterization to ensure the reproducibility of the results and to understand biological effects of ENP. A full characterization of ENP should include various measurements such as particle size and size distribution, shape and morphology, crystallinity, composition, surface chemistry, and surface area of ENP. It is also important to characterize the state of ENP dispersions. In this study, four different ENPs, rutile and anatase titanium dioxides and short single- and multi-walled carbon nanotubes, were characterized in two dispersion media: bronchial epithelial growth medium, used for bronchial epithelial BEAS cells, and RPMI-1640 culture media with 10% of fetal calf serum (FCS) for human mesothelial (MeT-5A) cells. The purpose of this study was to determine the characteristics of ENPs and their dispersions as well as to compare dispersion additives suitable for toxicity tests and thus establish an appropriate way to prepare dispersions that performs well with the selected ENP. Dispersion additives studied in the media were bovine serum albumin (BSA) as a protein resource, dipalmitoyl phosphatidylcholine (DPPC) as a model lung surfactant, and combination of BSA and DPPC. Dispersions were characterized using optical microscopy and transmission electron microscopy. Our results showed that protein addition, BSA or FCS, in cell culture media generated small agglomerates of primary particles with narrow size variations and improved the stability of the dispersions and thus also the relevance of the in-vitro genotoxicity tests to be done.
Asunto(s)
Nanopartículas , Bronquios/citología , Bronquios/efectos de los fármacos , Bronquios/metabolismo , Células Cultivadas , Medios de Cultivo , Células Epiteliales/efectos de los fármacos , Células Epiteliales/metabolismo , Humanos , Técnicas In Vitro , Microscopía Electrónica de Rastreo , Microscopía Electrónica de Transmisión , Tamaño de la Partícula , Reproducibilidad de los Resultados , Pruebas de ToxicidadRESUMEN
This study's database comprised results of volatile organic compound (VOC) measurements from 176 office buildings. In 23 of the 176 buildings, formaldehyde measurements were also conducted. It was suspected that the buildings had indoor air problems, but a walk-through inspection did not reveal any clear, abnormal contaminant sources. The 50 most abundant VOCs and their concentrations in 520 air samples were analyzed. The irritation potency was estimated for 33 out of the 50 common VOCs and their mixtures, as well as for formaldehyde. This information was used to calculate the recommended indoor air levels (RILs) for the VOCs. The RILs were considerably higher than the measured mean indoor air concentrations in the buildings. However, the RIL for formaldehyde was exceeded in most of the 23 buildings studied. According to the evaluation of irritation potency, formaldehyde was a more likely cause of sensory irritation than the mixture of common nonreactive VOCs at the concentrations that occurred in the buildings without abnormal indoor sources. Furthermore, environmental symptoms of office workers were characterized in 20 office buildings (including the database of 176 office buildings) with the aid of an indoor air questionnaire. The most frequent symptoms related to the indoor environment were involved the upper respiratory tract. However, no relationship could be shown between the reported symptoms and the occurrence of VOC and formaldehyde concentrations in these buildings. Generally, the study results indicated that formaldehyde was the more likely agent causing sensory irritation than the mixture of the common nonreactive VOCs at the concentrations occurring in the buildings without abnormal indoor sources.
Asunto(s)
Formaldehído/análisis , Irritantes/análisis , Exposición Profesional/análisis , Compuestos Orgánicos Volátiles/análisis , Contaminación del Aire Interior/análisis , Femenino , Finlandia , Formaldehído/toxicidad , Humanos , Irritantes/toxicidad , Masculino , Compuestos Orgánicos Volátiles/toxicidad , Lugar de TrabajoRESUMEN
In Finland, the new limit values for maximal allowable heavy metal concentrations for materials used as an earth construction agent came into force in July 2006. These limit values are applied if ash is utilized, e.g. in roads, cycling paths, pavements, car parks, sport fields, etc. In this study we have determined the most important chemical and physical properties of the cyclone fly ash originating from the grate-fired boiler incinerating forest residues (i.e. wood chips, sawdust and bark) at a small municipal district heating plant (6 MW), Northern Finland. This study clearly shows that elements are enriched in cyclone fly ash, since the total element concentrations in the cyclone fly ash were within 0.2-10 times higher than those in the bottom ash. The total concentrations of Cd (25 mg kg(-1); d.w.), Zn (3630 mg kg(-1); d.w.), Ba (4260 mg kg(-1); d.w.) and Hg (1.7 mg kg(-1); d.w.) exceeded the limit values, and therefore the cyclone fly ash cannot be used as an earth construction agent. According to the leached amounts of Cr (38 mg kg(-1); d.w.), Zn (51 mg kg(-1); d.w.) and sulphate (50,000 mg kg(-1); d.w.), the cyclone fly ash is classified as a hazardous waste, and it has to be deposited in a hazardous waste landfill.