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- Cardwell, Chris R, et al.
(författare)
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Birth order and childhood type 1 diabetes risk: a pooled analysis of 31 observational studies
- 2011
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Ingår i: INTERNATIONAL JOURNAL OF EPIDEMIOLOGY. - : OXFORD UNIV PRESS, GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND. - 0300-5771 .- 1464-3685. ; 40:2, s. 363-374
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Tidskriftsartikel (refereegranskat)abstract
- Background The incidence rates of childhood onset type 1 diabetes are almost universally increasing across the globe but the aetiology of the disease remains largely unknown. We investigated whether birth order is associated with the risk of childhood diabetes by performing a pooled analysis of previous studies. Methods Relevant studies published before January 2010 were identified from MEDLINE, Web of Science and EMBASE. Authors of studies provided individual patient data or conducted pre-specified analyses. Meta-analysis techniques were used to derive combined odds ratios (ORs), before and after adjustment for confounders, and investigate heterogeneity. Results Data were available for 6 cohort and 25 case-control studies, including 11 955 cases of type 1 diabetes. Overall, there was no evidence of an association prior to adjustment for confounders. After adjustment for maternal age at birth and other confounders, a reduction in the risk of diabetes in second- or later born children became apparent [fully adjusted OR = 0.90 95% confidence interval (CI) 0.83-0.98; P = 0.02] but this association varied markedly between studies (I-2 = 67%). An a priori subgroup analysis showed that the association was stronger and more consistent in children andlt; 5 years of age (n = 25 studies, maternal age adjusted OR = 0.84 95% CI 0.75, 0.93; I-2 = 23%). Conclusion Although the association varied between studies, there was some evidence of a lower risk of childhood onset type 1 diabetes with increasing birth order, particularly in children aged andlt; 5 years. This finding could reflect increased exposure to infections in early life in later born children.
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| 2. |
- Cardwell, Chris R, et al.
(författare)
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Breast-Feeding and Childhood-Onset Type 1 Diabetes A pooled analysis of individual participant data from 43 observational studies
- 2012
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Ingår i: Diabetes Care. - : American Diabetes Association. - 0149-5992 .- 1935-5548. ; 35:11, s. 2215-2225
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE-To investigate if there is a reduced risk of type 1 diabetes in children breastfed or exclusively breastfed by performing a pooled analysis with adjustment for recognized confounders. less thanbrgreater than less thanbrgreater thanRESEARCH DESIGN AND METHODS-Relevant studies were identified from literature searches using MEDLINE, Web of Science, and EMBASE. Authors of relevant studies were asked to provide individual participant data or conduct prespecified analyses. Meta-analysis techniques were used to combine odds ratios (ORs) and investigate heterogeneity between studies. less thanbrgreater than less thanbrgreater thanRESULTS-Data were available from 43 studies including 9,874 patients with type 1 diabetes. Overall, there was a reduction in the risk of diabetes after exclusive breast-feeding for andgt;2 weeks (20 studies; OR = 0.75, 95% CI 0.64-0.88), the association after exclusive breast-feeding for andgt;3 months was weaker (30 studies; OR = 0.87, 95% CI 0.75-1.00), and no association was observed after (nonexclusive) breast-feeding for andgt;2 weeks (28 studies; OR = 0.93, 95% CI 0.81-1.07) or andgt;3 months (29 studies; OR = 0.88, 95% CI 0.78-1.00). These associations were all subject to marked heterogeneity (I-2 = 58, 76, 54, and 68%, respectively). In studies with lower risk of bias, the reduced risk after exclusive breast-feeding for andgt;2 weeks remained (12 studies; OR = 0.86, 95% CI 0.75-0.99), and heterogeneity was reduced (I-2 = 0%). Adjustments for potential confounders altered these estimates very little. less thanbrgreater than less thanbrgreater thanCONCLUSIONS-The pooled analysis suggests weak protective associations between exclusive breast-feeding and type 1 diabetes risk. However, these findings are difficult to interpret because of the marked variation in effect and possible biases (particularly recall bias) inherent in the included studies.
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| 3. |
- Cardwell, Chris R, et al.
(författare)
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Interbirth Interval Is Associated With Childhood Type 1 Diabetes Risk
- 2012
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 61:3, s. 702-707
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Tidskriftsartikel (refereegranskat)abstract
- Short interbirth interval has been associated with maternal complications and childhood autism and leukemia, possibly due to deficiencies in maternal micronutrients at conception or increased exposure to sibling infections. A possible association between interbirth interval and subsequent risk of childhood type 1 diabetes has not been investigated. A secondary analysis of 14 published observational studies of perinatal risk factors for type 1 diabetes was conducted. Risk estimates of diabetes by category of interbirth interval were calculated for each study. Random effects models were used to calculate pooled odds ratios (ORs) and investigate heterogeneity between studies. Overall, 2,787 children with type 1 diabetes were included. There was a reduction in the risk of childhood type 1 diabetes in children born to mothers after interbirth intervals andlt;3 years compared with longer interbirth intervals (OR 0.82 [95% CI 0.72-0.93]). Adjustments for various potential confounders little altered this estimate. In conclusion, there was evidence of a 20% reduction in the risk of childhood diabetes in children born to mothers after interbirth intervals andlt;3 years.
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| 4. |
- Cardwell, Chris R, et al.
(författare)
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Maternal Age at Birth and Childhood Type 1 Diabetes: A Pooled Analysis of 30 Observational Studies
- 2010
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Ingår i: DIABETES. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 59:2, s. 486-494
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE-The aim if the study was to investigate whether children born to older mothers have an increased risk of type 1 diabetes by performing a pooled analysis of previous studies using individual patient data to adjust for recognized confounders. RESEARCH DESIGN AND METHODS-Relevant studies published before June 2009 were identified from MEDLINE, Web of Science, and EMBASE. Authors of studies were contacted and asked to provide individual patient data or conduct prespecified analyses. Risk estimates of type 1 diabetes by maternal age were calculated for each study, before and after adjustment for potential confounders. Meta-analysis techniques were used to derive combined odds ratios and to investigate heterogeneity among studies. RESULTS-Data were available for 5 cohort and 25 case-control studies, including 14,724 cases of type 1 diabetes. Overall, there was, on average, a 5% (95% CI 2-9) increase in childhood type 1 diabetes odds per 5-year increase in maternal age (P = 0.006), but there was heterogeneity among studies (heterogeneity I-2 = 70%). In studies with a low risk of bias, there was a more marked increase in diabetes odds of 10% per 5-year increase in maternal age. Adjustments for potential confounders little altered these estimates. CONCLUSIONS-There was evidence of a weak but significant linear increase in the risk of childhood type 1 diabetes across the range of maternal ages, but the magnitude of association varied between studies. A very small percentage of the increase in the incidence of childhood type 1 diabetes in recent years could be explained by increases in maternal age.
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| 5. |
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| 6. |
- Pundziute-Lyckå, Auste, 1968-
(författare)
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Incidence trends and environmental determinants of type 1 diabetes in Lithuania and Sweden
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Variation of diabetes incidence over time in countries with different incidence levels and socio-economic conditions, and in an age span beyond the childhood years, may give clues for diabetes causes.Materials: Data from prospective type 1 diabetes registers in Sweden and Lithuania in children (0-14 years) and young adults (15-34 and 15-39 years, respectively). Number of infections recorded in health care booklets (117 cases; 270 controls); interview about the dietary intake one-year before the diagnosis and routinely recorded growth data (99 cases; 180 controls).Results: The incidence of type 1 diabetes in Sweden and Lithuania differed most in the younger age groups, 28.9 and 7.5/100,000/year in 0-14-year group, respectively. During 1983-2000 incidence increased in 0-14-year old children in both countries, but the pattern of change differed. During 1983-1998 the incidence increased in Swedish children, but tended to decrease in young adults, with no increase in the age group below 35 years, indicating that the increase of childhood diabetes may be due to a shift towards a younger age at diagnosis. Within a low-incidence country Lithuania there was an urban-rural gradient of incidence, especially in the younger age groups, that seemed to follow poverty distribution: incidence in the 0-39-year group was 7.1, 9.0 and 8.8/100,000/year in rural areas, towns and cities, respectively, p<0.001.Exposure to one or more non-specific infection during the first half-year of life reduced diabetes risk: odds ratios (95%-CI) in 0-14 and 5-14-year groups were (0.60; 0.37-0.98) and (0.47; 0.26-0.87), respectively. Higher energy intake and weight-for-age were independent diabetes risk factors: odds ratios for medium and high levels of energy were 1.33 (0.52-3.42) and 5.23 (1.67-16.38), and for weight-for-age 3.20 (1.30-7.88) and 3.09 (1.16-8.22), respectively. High intake of carbohydrates, disaccharides and sucrose in particular, increased diabetes risk independently of the high intake of energy.Conclusion: Environmental factors associated with socio-economic conditions in childhood may be important for the occurrence of type 1 diabetes. Lack of exposure to microbial antigens early in life, higher intake of energy and more rapid growth may contribute to the increase of childhood-onset diabetes observed in many countries.
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| 7. |
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| 8. |
- Pundziūte-Lyckå, Auste, et al.
(författare)
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Time trend of childhood type 1 diabetes incidence in Lithuania and Sweden, 1983-2000
- 2004
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Ingår i: Acta Paediatrica. - : Wiley. - 0803-5253 .- 1651-2227. ; 93:11, s. 1519-1524
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Tidskriftsartikel (refereegranskat)abstract
- AIM: To compare the time trend of childhood type 1 diabetes over an 18-y period in Lithuania and Sweden--countries with different incidence levels and different socio-economic conditions. METHODS: Percent average incidence change per year between 1983 and 2000, based on 8031 Swedish and 1100 Lithuanian cases in the age group 0-14 y, was calculated using Poisson regression. RESULTS: Average age- and sex-standardized incidence/100 000/y was 28.9 (95% CI: 28.2-29.5) in Sweden and 7.5 (95% CI: 7.1-8.0) in Lithuania. Between 1983 and 2000, the average increase per year was 2.2% in Sweden (95% CI: 1.7-2.6) and 2.3% in Lithuania (95% CI: 1.1-3.5), but the latter trend depended on an increase during the last few years of the period, and only for girls. In Sweden, incidence increased significantly in all age groups, but more so in the younger groups (3.0%, 2.2% and 1.7% per year in 0-4, 5-9 and 10-14-y age groups, respectively), while in Lithuania a significant increase was found only in the 10-14-y age group (3.0%). In Sweden, a trend towards a younger age at diagnosis was indicated for both boys and girls when comparing 1983-1991 and 1992-2000, whereas in Lithuania, the changes in age distribution over time were small, with an opposite tendency for boys. CONCLUSION: Incidence variability over time differed considerably in the two countries in the region of the Baltic Sea, suggesting a complex effect of environmental risk factors, some of which may be associated with wealth and socio-economic conditions.
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