Cigarette Smoking and the Risk of Gestational and Pregestational Diabetes in Two Consecutive Pregnancies

Abstract

OBJECTIVE -Cigarette smoking during pregnancy may increase the risk of gestational diabetes mellitus (GDM) or pregestational diabetes mellitus (PDM). Smoking has been associated positively with hyperinsulinemia and insulin resistance in experimental studies, although the association with diabetes remains unclear. To further explore this issue, we examined the association with smoking in the largest prospective cohort study of GDM and PDM to date. RESEARCH DESIGN AND METHODS-The study population comprised 212,190 women in the population-based Swedish Birth Registry who had their first and second deliveries between January 1987 and December 1995. Maternal characteristics were recorded in a standardized manner at the first prenatal visit, followed by a clinical examination and a standardized in-person interview to assess lifestyle habits. Women were categorized as nonsmokers, light smokers (one to nine cigarettes per day), or moderate-to-heavy smokers (at least 10 cigarettes per day).RESULTS -Women with GDM in their first pregnancy experienced an eight-to ninefold increased risk of GDM or PDM in their second pregnancy. Cigarette smoking was not associated with increased risk of these conditions. Neither women who smoked during their first and second pregnancies nor those who commenced smoking between pregnancies had a higher risk of GDM or PDM than nonsmokers.CONCLUSIONS -Our findings do not support an association between cigarette smoking and risk of GDM or PDM in young women of childbearing age. Diabetes Care 26:2994 -2998, 2003G estational diabetes mellitus (GDM) is defined as the onset or recognition of glucose intolerance during pregnancy (1). GDM has been associated with pre-eclampsia and perinatal conditions such as macrosomia, fetal hyperinsulinemia, and perinatal mortality (1,2). Women with GDM also have an increased risk of developing overt diabetes later in life (2). Thus, glucose control in pregnancy is an important way of reducing the risk of maternal and fetal complications.Cigarette smoking has been associated positively with HbA 1c levels, which reflect long-term glucose levels in some (3-5) but not all (6,7) studies to date. Cigarette smoking also has been associated positively with hyperinsulinemia and insulin resistance in some (but not all) studies (8), including those that have compared the glucose response of smokers and nonsmokers in glucose tolerance tests. Nevertheless, the association between smoking and GDM itself remains unclear (8). The Nurses' Health Study (9), which is the only cohort study that has examined this association previously, found a statistically significant 40% increased risk of GDM among 1,433 current smokers compared with 10,288 never smokers. Supporting these findings, recent cross-sectional data among pregnant women in Scandinavia suggest that smoking Ն10 cigarettes per day affects glucose homeostasis in the direction of GDM (10). In contrast, no association between cigarette smoking and GDM was observed in a cross-sectional study of 10,000 maternity patients in New...

Gestational diabetes and pre-eclampsia: common antecedents?

“…Smoking as a risk factor for gestational diabetes has been less studied, with mixed findings. A study (62), different from ours, found increased risk with smoking, while others found no statistically significant association (63)(64)(65). Fatness has been associated with a greater frequency of gestational diabetes (66.67) and is inversely associated with smoking habits (68.69).…”

Non classical risk factors for gestational diabetes mellitus: a systematic review of the literature

“…The wide confidence interval in the study by Yang et al suggests a lack of precision in the estimate, since only two of the diabetic pregnant women were smokers 29,42 . Other studies have not found this association 21,35,44 . Berkowitz et al 35 did not include cigarette smoking in the multivariate analysis and, therefore, had not adjusted its effect for the effects of other variables; and Innes et al 21 and Terry et al 44 carried out studies with young pregnant women, with average ages of 21 and 24 respectively, probably with less time of exposure to smoking.…”

“…Other studies have not found this association 21,35,44 . Berkowitz et al 35 did not include cigarette smoking in the multivariate analysis and, therefore, had not adjusted its effect for the effects of other variables; and Innes et al 21 and Terry et al 44 carried out studies with young pregnant women, with average ages of 21 and 24 respectively, probably with less time of exposure to smoking. One methodological problem of the studies was that some studies 21,29,35 classified women as smokers (at least one cigarette per day) or non-smokers, without considering the exposure period.…”

Association of diabetes and cigarette smoke exposure on the glycemia and liver glycogen of pregnant Wistar rats

“…These results disagree with Bertolini et al 18 , which demonstrated that smoke-exposed rats during pregnancy presented no alterations on the litter weight and reduced maternal weight gain. Studies with women pregnant smokers showed contradictory results about maternal weight gain 19,20,21 . The association of diabetes and cigarette smoke impaired maternal weight gain and litter gain, fetal weight and number of fetus (data not shown).…”