title: Effects of hyperinsulinemia and obesity on risk of neural tube defects among Mexican Americans.
abstract: Although both maternal obesity and diabetes mellitus increase the risk for neural tube defects, it is unknown whether they are independent risk factors or manifestations of an underlying prediabetic state such as hyperinsulinemia. We investigated whether hyperinsulinemia was a risk factor for neural tube defects independent of obesity and hyperglycemia in Mexican-American women. We identified case and control women from residents delivering or terminating pregnancies in hospitals or birthing centers in any of the 14 Texas-Mexico border counties during 1995-2000. Case women had a pregnancy affected by anencephaly, spina bifida, or encephalocele; randomly selected control women had normal births, frequency matched by year and birth facility. Questionnaire and laboratory values obtained 5-6 weeks postpartum were available for 149 case and 178 control women. Both hyperinsulinemia and obesity were related to increased neural tube defect risk [odds ratio (OR) = 1.91, 95% confidence interval (CI) = 1.21-3.01 and OR = 1.73, 95% CI = 1.03-2.92, respectively]. Adjustment for obesity only slightly reduced the effect of hyperinsulinemia (OR = 1.75, 95% CI = 1.09-2.82). Alternatively, a modest effect remained for obesity after adjustment for hyperinsulinemia (OR = 1.45, 95% CI = 0.84-2.51). Hyperinsulinemia is a strong risk factor for neural tube defects and may be the driving force for the observed risk in obese women.
authors.affiliation: Division of Infectious Disease Epidemiology and Surveillance, Texas Department of Health, Austin 78756, USA.
authors.forename: K A
authors.initials: KA
authors.lastname: Hendricks
authors.forename: O M
authors.initials: OM
authors.lastname: Nuno
authors.forename: L
authors.initials: L
authors.lastname: Suarez
authors.forename: R
authors.initials: R
authors.lastname: Larsen
mesh_terms: D000328:Adult; D015992:Body Mass Index; D016022:Case-Control Studies; D003920:Diabetes Mellitus / Q000208:ethnology*; D005260:Female; D005947:Glucose / Q000737:chemistry; D006801:Humans; D006946:Hyperinsulinism / Q000208:ethnology*; D007328:Insulin / Q000097:blood; D016015:Logistic Models; D017058:Mexican Americans; D009436:Neural Tube Defects / Q000208:ethnology*; D009765:Obesity / Q000208:ethnology*; D016017:Odds Ratio; D011159:Population Surveillance / Q000379:methods; D011247:Pregnancy; D013781:Texas / Q000208:ethnology
chemical_list: D007328:Insulin; D005947:Glucose