Parity increases diabetes risk in young Danish women
MedWire News: Study findings show that young women who have given birth to more than one child have an increased risk for diabetes compared with those who have experienced just one birth.
In older women, this association was only significant in those who had given birth to more than four children compared with one, in agreement with previous study results reported by MedWire News.
Klara Vinsand Naver (Copenhagen University Hospital, Hvidovre, Denmark) and colleagues analyzed data from a study population consisting of 100,699 Danish women who gave birth (singleton only) during 1982-1983 and went on to have 74,966 deliveries in the period leading up to the end of 2006.
The participants were followed up for a diagnosis of diabetes between baseline in 1982-1983 and 2006.
In women below the age of 33 years, those with parity of two, three, or four or more had a significant 1.61-, 2.78-, and 2.46-fold increased relative risk for diabetes, respectively, compared with women who gave birth just once, following adjustment for fetal weight (Z-score) and duration of gestation at initial pregnancy.
In contrast, in women over the age of 33 years, only those who had a parity of four or more had a significant 1.64-fold increased risk for diabetes compared with those with a parity of one. Indeed, older women with a parity of two or three seemed to have a small reduction in risk for diabetes compared with those with a parity of one.
"Possible biological explanations for an association between parity and risk of diabetes, as was seen for younger women in the present study, could be a persistently increased insulin resistance in the peripheral tissue, with progressive aggravation in each pregnancy," suggest the authors.
"In pregnancy, gestational hormones such as placental growth hormone, placental lactogen and circulating insulin-like growth factor-I promote insulin resistance and pancreatic β cell proliferation," add Naver et al in the journal Diabetic Medicine.
"The β-cell mass expands in response to pregnancy, and as pregnancy progresses the insulin secretion must increase 1.5-fold in order to maintain maternal euglycemia. This extra demand during pregnancy could exhaust the β cells, resulting in a permanent derangement of insulin secretion."
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By Helen Albert