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Biomedical subjects

G Dahlquist

Publications and source records attributed to G Dahlquist.

At least 55 records · Page 3Linked to original sources
PubMed1997

Cumulative incidence of childhood-onset IDDM is unaffected by pertussis immunization.

OBJECTIVE: To identify a possible effect of pertussis vaccination in infancy on the risk for developing human IDDM. RESEARCH DESIGN AND METHODS: A comparison was made of the cumulative incidence of IDDM in children age 0-12 years between two birth cohorts born before pertussis vaccination and two birth cohorts born after pertussis vaccination had been excluded from the Swedish national immunization program. The Swedish Childhood Diabetes registry was used to identify cases of IDDM. Yearly nurse reports on administered vaccines were used to determine coverage for diphtheria/tetanus/pertussis (DTP) and diphtheria/tetanus (DT) vaccines. Pertussis vaccine coverage was estimated based on number of doses of vaccine made available on license. RESULTS: No difference in cumulative incidence rate of IDDM up to the age of 12 years was found when the birth cohorts for 1978 and 1979 with high DTP vaccination coverage were compared with the cohorts of 1980 and 1981 with low pertussis vaccination coverage. CONCLUSIONS: The comparison of the cumulative incidence of IDDM, up to the age of 12 years, in birth cohorts with high and low exposure to pertussis vaccine does not support the hypothesis that pertussis could induce autoimmunity to the beta-cell that may lead to IDDM.

Age Factors↗
PubMed1997

Predictors of renal morphological changes in the early stage of microalbuminuria in adolescents with IDDM.

OBJECTIVE: To evaluate the impact of glycemic control, blood pressure, lipid levels, glomerular filtration rate (GFR), age, and duration of IDDM on the degree of structural glomerular changes in the transitional stage of microalbuminuria. RESEARCH DESIGN AND METHODS: Fifteen adolescents (seven boys and eight girls) with > 5 years of duration of IDDM and with low-grade microalbuminuria (15-30 micrograms/min) participated. Seventeen living kidney donors served as healthy control subjects. Five-year mean HbA1c; 5-year mean systolic and diastolic blood pressure; GFR, cholesterol, and triglycerides 2-5 years before renal biopsy; age; and duration of IDDM were investigated and related to basement membrane thickness (BMT), mesangial and matrix volume fractions, and the overall glomerulopathy index [(BMT/10 + mat/glom, %) + matrix star volume]. RESULTS: BMT and the overall diabetic glomerulopathy were increased in diabetic patients as compared with control subjects (P < 0.001), whereas matrix volume fraction, but not mesangial volume fraction, tended to be increased (P = 0.11). In multivariate analysis, BMT was predicted by 5-year mean HbA1c, diabetes duration, and previous GFR (R2 = 0.71, P = 0.003). With matrix volume fraction as the dependent variable, BMT and diabetes duration were the only significant determinants (R2 = 0.63, P = 0.003). Diabetes duration, 5-year mean HbA1c, and GFR were the variables with an independent influence on the overall diabetic glomerulopathy index (R2 = 0.72, P = 0.003). Preceding blood pressure and lipid levels or age had no significant independent influence on these morphometric measures. CONCLUSIONS: In the very early stage of microalbuminuria in IDDM adolescents, a high percentage of the variation in BMT and overall severity of glomerulopathy is explained by prolonged hyperglycemia and diabetes duration. Previous glomerular hyperfiltration may also add to the prediction of these morphological changes.

Adolescent↗
PubMed1996

Intrauterine growth pattern and risk of childhood onset insulin dependent (type I) diabetes: population based case-control study.

OBJECTIVE: To investigate whether prenatal growth affects the risk of development of childhood onset insulin dependent (type I) diabetes mellitus. DESIGN: Population based case-control study. SETTING: Data from a nationwide childhood diabetes case register were linked with data from the nationwide Swedish Medical Birth Registry. SUBJECTS: Data from a total of 4584 diabetic children born after 1973 and diagnosed with diabetes from 1978 to 1992 were studied. For each child with insulin dependent diabetes three control children were randomly selected from among all infants born in the same year and at the same hospital as the proband. MAIN OUTCOME MEASURES: Birth weight, gestation, maternal age and parity, number of previous spontaneous abortions, and sex specific birth weight by gestational week expressed as multiples of the standard deviation (SD). RESULTS: There was a clear trend in the odds ratio for childhood onset diabetes according to SD of birth weight. The odds ratio (95% confidence interval) for small for gestational age after stratification for maternal age, parity, smoking habits, and maternal diabetes was 0.81 (0.65 to 0.99) and for large for gestational age after similar stratification was 1.20 (1.02 to 1.42). CONCLUSIONS: Intrauterine conditions that affect prenatal growth seem also to affect the risk of development of childhood diabetes in the way previously described for postnatal growth: a poor growth decreases and an excess growth increases the risk. The mechanism for this association is unclear.

Adolescent↗
PubMed1996

Genetic and immunological findings in patients with newly diagnosed insulin-dependent diabetes mellitus. The Swedish Childhood Diabetes Study Group and The Diabetes Incidence in Sweden Study (DISS) Group.

Two large population-based case-control studies are reviewed. The aim is to determine the effects of HLA, other genetic factors and immune markers (ICA, IAA and GAD65Ab) on the age at onset of insulin-dependent diabetes mellitus (IDDM) in 0-34 year olds. The primary HLA risk gene sequence for IDDM was difficult to identify because of the low recombination frequency within the HLA region. The frequency of the DR3-DQA1*0501-DQB1*0201 haplotype and the DR3-DQA1*0501-DQB1*0201 (DQ2)/DR4-DQA1*0301-DQB1*0302 (DQ8) genotype were higher among patients diagnosed before the age of 10 compared with those diagnosed after the age of 30. The negatively associated haplotype, DR15-DQA1*0102-DQB1*0602 was absent before the age of 10, but the frequency increased with increasing age at onset. The IDDM2 gene representing the variable number of tandem repeat (VNTR) sequences and 5' of the insulin gene on chromosome 11 were associated with IDDM since homozygous short VNTR was positive but not homozygous, and heterozygous long VNTR was negatively associated with the disease. The diagnostic sensitivity and specificity of GAD65 (GA65Ab) and insulin (IAA) autoantibodies varied with the age at onset and gender. GAD65Ab had the highest sensitivity (> 80%) in patients older than 20 years of age with no difference in gender. The lowest sensitivity (54%) was in 0-10 year old boys, while age did not affect the sensitivity in girls. In contrast, the sensitivity of IAA was highest (46%) before the age of 15 but decreased thereafter as did the sensitivity for ICA. Classification of patients who develop IDDM above 20-25 years of age was inadequate since many patients classified with NIDDM either had GAD65Ab or ICA or developed these antibodies after 1-2 years of NIDDM. We conclude that not only age but also gender affect the risk for IDDM associated with HLA, other IDDM genes as well as commonly used immunological markers for IDDM.

Age Factors↗
PubMed1996

DR4 subtypes and their molecular properties in a population-based study of Swedish childhood diabetes.

The aim of this study was to determine the association between childhood insulin-dependent diabetes mellitus (IDDM) and HLA-DR4 subtypes and to test in a population-based investigation whether the DR4 association has an effect independent to that of DQ. First, HLA genotyping identified DR4 in 337/425 (79%) patients and 148/367 (40%) controls (Odds Ratio 5.67; p < 0.01). Second, a total of 14 DR4 subtypes were detected by PCR and sequence specific oligo probes. Only two DR4 subtypes, DRB1*0401 (62% patients and 25% controls; OR 4.95, p < 0.01) and *0404 (16% patients and 10% controls; OR 1.67, p < 0.05) were however positively associated with the disease. These two subtypes were positively associated only when linked to DQB1*0302-DQA1*0301 (DQ8) (56% patients and 14% controls; OR 7.69, p < 0.01; 15% patients and 10% controls; OR 1.55, p < 0.05, respectively). When DRB1*0401 was linked to DQB1*0301-DQA1*0301 (DQ7) (6% patients and 11% controls; OR 0.52, p < 0.05), this DR4 subtypes was negatively associated with IDDM. Third, tests of strongest association allowed the following ranking of alleles or haplotypes DQB1*0302-DQA1*0301 (DQ8) > DQB1*0302 > DRB1*0401 > DRB1*0404 and the association of DRB1*0401 has a significant effect in DQ8 positive IDDM patients. We conclude that the DR4 association with IDDM is secondary to DQ by linkage disequilibrium, which support the role of HLA-DQ as a primary genetic risk factor for IDDM.

Adolescent↗
PubMed1996

Psychological reactions at the onset of insulin-dependent diabetes mellitus in children and later adjustment and metabolic control.

The initial psychological reactions at the onset of insulin-dependent diabetes mellitus (IDDM) in a population-based sample of 76 children were studied with staff observations and a self-report questionnaire for children 12 years of age and more. Younger children reacted with more anger and less distress than the older children. High initial self-reported distress was associated with poorer subjective psychological IDDM adjustment at a follow-up 10 months later for the older children. The children's initial reactions as well as later adjustment were intimately associated with maternal initial reactions in the total group. The metabolic control, estimated as the mean level of the major fraction of glycosylated haemoglobin (Hb AIc) during the first 2 years, was poorer in the adolescent group. Initial anxiety over injections and protest but low general distress in mothers and children were associated with better metabolic control.

Adaptation, Psychological↗
PubMed1996

Determinants of progression of microalbuminuria in adolescents with IDDM.

OBJECTIVE: To evaluate the significance of microalbuminuria in adolescents with IDDM and to study the relative importance of blood pressure (BP), metabolic control, and albumin excretion rate (AER) on progression of microalbuminuria. RESEARCH DESIGN AND METHODS: A cohort of 155/156 children and adolescents followed from onset up to 18.3 years of IDDM participated. In a previous follow-up in July 1991 (up to 15 years of duration), 17 patients had developed persistent microalbuminuria (> or = 20 micrograms/min). In these adolescents, we analyzed whether microalbuminuria had progressed (in mean > or = 5% per year), had remained unchanged, or had normalized (< 20 micrograms/min) after another 3 years. The predictive values of mean HbA1c, diastolic blood pressure (dBP), systolic blood pressure (sBP), overnight AER, sex, age, and duration of diabetes for the progression of microalbuminuria were determined using multiple regression modeling. RESULTS: Seven of 17 patients with microalbuminuria in July 1991 had normalized, 6 of 17 patients had progressed, and 4 of 17 patients had remained unchanged after 3 years. Progressors had higher mean HbA1c during the first 5 years of IDDM and higher mean sBP in 1991 than nonprogressors. Patients with normalized microalbuminuria all had AER < 30 micrograms/min in 1991, were younger at onset of microalbuminuria, had lower mean HbA1c, and had lower dBP before normalized AER than nonregressors at the same duration of microalbuminuria. In multivariate analysis, independent significant predictors for progression were first 5-year mean HbA1c, mean AER, and mean sBP in 1991 (R2 = 0.76, P = 0.001). CONCLUSIONS: Progression of microalbuminuria in adolescents with IDDM is predicted by early sustained hyperglycemia, later elevated sBP, and increased AER per se. Microalbuminuria is frequently normalized in adolescents, and this is associated with better prevailing metabolic control, younger age, and lower dBP.

Adolescent↗
PubMed1996

Evidence of a relationship between childhood-onset type I diabetes and low groundwater concentration of zinc.

OBJECTIVE: Zinc deficiency has shown to increase the risk for diabetes in diabetes-prone experimental animals. Low concentrations of zinc have also been shown in serum of recent onset cases with IDDM. The present study examines the hypothesis that exposure to a low concentration of zinc in drinking water could increase the risk for future onset of IDDM. RESEARCH DESIGN AND METHODS: Using the Swedish childhood diabetes registry and data on residence 3 years before the onset of disease, a case-control study was designed comparing cases and control subjects with estimates of groundwater contents of zinc obtained in biogeochemical samples from areas of residence. RESULTS: A high groundwater concentration of zinc was associated with a significant decrease in risk (odds ration [OR] = 0.8; 95% CI = 0.7-0.9). The same OR was obtained when the model included information of other metals that might act as possible confounders (chromium, vanadium, cobalt selenium, cadmium, lead, and mercury). In small rural areas, in which drinking water is taken from local wells and thus is closely associated with the groundwater content within the area, an even stronger association between zinc and diabetes (OR = 0.6; 95% CI = 0.4-0.9) was found. CONCLUSIONS: It is concluded that this study for the first time provides evidence that a low groundwater content of zinc, which may reflect long-term exposure through drinking water, is associated with later development of childhood onset diabetes.

Adolescent↗
PubMed1995

Indications that maternal coxsackie B virus infection during pregnancy is a risk factor for childhood-onset IDDM.

In a population-based setting, we traced serum samples collected at time of birth from 55 mothers whose children later developed insulin-dependent diabetes (IDDM) and matched them pairwise to control subjects who gave birth at the same hospital during the same month. The sera were analysed for IgM antibodies to coxsackie B virus serotypes 2, 3 and 4 (CBV-2, 3 and 4) using a type-specific mu-antibody-capture radioimmunoassay. Despite a decreased power due to the close matching by time of birth we found a significantly higher frequency of CBV-3 IgM at delivery in mothers whose children later became diabetic compared to their matched control subjects. When using the presence of CBV-3 IgM as a risk factor the Mantel-Haenszel odds ratio estimate (95% confidence limits) was 2.57 (1.02; 7.31), p = 0.043. For CBV-2 and CBV-4, respectively no significant difference was found between mothers of patients and control subjects. According to the odds ratio estimate for CBV-3 and the proportion of exposed mothers among patients estimated in this study the aetiological fraction for this risk determinant would be 27%. In conclusion, this study indicates that children of mothers who expressed CBV IgM at delivery are at increased risk for developing childhood onset IDDM. A fetal infection with CBV similar to rubella virus may initiate autoimmunity or cause persistent infection that may lead to progressive beta-cell destruction.

Adolescent↗