11 research outputs found
Maternal and neonatal risk factors for childhood type 1 diabetes: a matched case-control study
Peer reviewedPublisher PD
Maternal age at birth and childhood type 1 diabetes: a pooled analysis of 30 observational studies.
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 I2
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. Diabetes 59:486–494,
201
Birthweight and the risk of childhood-onset type 1 diabetes:a meta-analysis of observational studies using individual patient data
We investigated whether children who are heavier at birth have an increased risk of type 1 diabetes. Relevant studies published before February 2009 were identified from literature searches using MEDLINE, Web of Science and EMBASE. Authors of all studies containing relevant data were contacted and asked to provide individual patient data or conduct pre-specified analyses. Risk estimates of type 1 diabetes by category of birthweight were calculated for each study, before and after adjustment for potential confounders. Meta-analysis techniques were then used to derive combined ORs and investigate heterogeneity between studies. Data were available for 29 predominantly European studies (five cohort, 24 case-control studies), including 12,807 cases of type 1 diabetes. Overall, studies consistently demonstrated that children with birthweight from 3.5 to 4 kg had an increased risk of diabetes of 6% (OR 1.06 [95% CI 1.01-1.11]; p = 0.02) and children with birthweight over 4 kg had an increased risk of 10% (OR 1.10 [95% CI 1.04-1.19]; p = 0.003), compared with children weighing 3.0 to 3.5 kg at birth. This corresponded to a linear increase in diabetes risk of 3% per 500 g increase in birthweight (OR 1.03 [95% CI 1.00-1.06]; p = 0.03). Adjustments for potential confounders such as gestational age, maternal age, birth order, Caesarean section, breastfeeding and maternal diabetes had little effect on these findings. Children who are heavier at birth have a significant and consistent, but relatively small increase in risk of type 1 diabetes