Association of exposure to air pollutants with gestational diabetes mellitus in Chiayi City, Taiwan

IntroductionWe investigated the associations of exposure to particulate matter with an aerodynamic diameter less than 2.5 μm (PM2.5) and several gaseous pollutants with risk of gestational diabetes mellitus (GDM) in Taiwan.MethodsWe retrospectively identified pregnant women who underwent a two-step approach to screen for GDM between 2006 and 2014. Information on concentrations of air pollutants (including PM2.5, sulfur dioxide [SO2], nitrogen oxides [NOx], and ozone [O3]) were collected from a single fixed-site monitoring station. We conducted logistic regression analyses to determine the associations between exposure to air pollutants and risk of GDM.ResultsA total of 11210 women were analyzed, and 705 were diagnosed with GDM. Exposure to PM2.5 during the second trimester was associated with a nearly 50% higher risk of GDM (odds ratio [OR] 1.47, 95% CI 0.96 to 2.24, p=0.077). The associations were consistent in the two-pollutant model (PM2.5 + SO2 [OR 1.73, p=0.038], PM2.5 + NOx [OR 1.52, p=0.064], PM2.5 + O3 [OR 1.96, p=0.015]), and were more prominent in women with age <30 years and body mass index <25 kg/m2 (interaction p values <0.01).DiscussionExposure to PM2.5 was associated with risk of GDM, especially in women who were younger or had a normal body mass index

Influence of the time of day and fasting duration on glucose level following a 1-hour, 50-gram glucose challenge test in pregnant women.

BACKGROUND: Previous studies have shown that the time of day (TD) of glucose measurement and the fasting duration (FD) influence the glucose levels in adults. Few studies have examined the effects of the TD and FD on the glucose level following a 1-hour, 50-gram glucose challenge test (GCT) in pregnant women in screening for or diagnosing gestational diabetes mellitus (GDM). The objective of this study was to investigate the influence of the TD (morning, afternoon, night) and the FD (the time of the last food ingestion as follows: ≤1 hour, 1-2 hours, and >2 hours) by examining their combined effects on the glucose levels following a 50-gram GCT in pregnant women. METHODS AND RESULTS: We analyzed the data of 1,454 non-diabetic pregnant Taiwanese women in a prospective study. Multiple linear regression and multiple logistic regression were used to estimate the relationships between the 9 TD-FD groups and the continuous and binary glucose levels (cut-off at 140 mg/dL) following a 50-gram GCT, after adjusting for maternal age, nulliparity, pre-pregnancy body mass index, and weight gain. Different TD and FD groups were associated with variable glucose responses to the 50-gram GCT, some of which were significant. The estimate coefficients (β) of the TD-FD groups "night, ≤1 hr" and "night, 1-2 hr" revealed significantly lower glucose concentrations [β (95% confidence interval [CI]): -6.46 (-12.53, -0.38) and -6.85 (-12.50, -1.20)] compared with the "morning, >2 hr" group. The TD-FD groups "afternoon, ≤1 hr" and "afternoon, 1-2 hr" showed significantly lower odds ratios (OR) of a positive GCT; the adjusted ORs (95% CI) were 0.54 (0.31-0.95) and 0.58 (0.35-0.96), respectively. CONCLUSIONS: Our findings demonstrate the importance of standardizing the TD and FD for the 1-hour, 50-gram GCT. In screening for and diagnosing GDM, the TD and FD are modifiable factors that should be considered in clinical practice and epidemiological studies

The association between TD-FD group and risk factors for the mean glucose level and a cut-off level of 140 mg/dL.

<p>TD-FD, time of day glucose was measured and fasting duration; GCT, glucose challenge test; BMI, body mass index.</p><p>*Data were analyzed using analysis of variance or Student's t test as appropriate.</p>†<p>Data were analyzed using the chi-square test.</p>‡<p>Percentage of gestational weight gain  =  [(weight at time of GCT − pre-pregnancy weight)/pre-pregnancy weight] * 100.</p><p>The association between TD-FD group and risk factors for the mean glucose level and a cut-off level of 140 mg/dL.</p

Multivariate analysis of the TD-FD groups and the GCT adjusted for risk factors (n = 1444).

<p>TD-FD, time of day glucose was measured and fasting duration; GCT, glucose challenge test; β, regression coefficient; BMI, body mass index.</p><p>*Percentage of gestational weight gain  =  [(weight at time of GCT − pre-pregnancy weight)/pre-pregnancy weight] * 100.</p><p>Multivariate analysis of the TD-FD groups and the GCT adjusted for risk factors (n = 1444).</p

Distribution of risk factors across the TD-FD groups.

<p>TD-FD, time of day glucose was measured and fasting duration; GCT, glucose challenge test; BMI, body mass index.</p><p>*Data are presented as n (%) and were analyzed using the chi-square test.</p>†<p>Percentage of gestational weight gain  =  [(weight at time of GCT − pre-pregnancy weight)/pre-pregnancy weight] * 100.</p><p>Distribution of risk factors across the TD-FD groups.</p

Flowchart of methods.

<p>Flowchart of methods.</p

Influence of medical nutrition therapy on borderline glucose intolerance in pregnant Taiwanese women

<p><i>Objective</i>: To investigate the influence of medical nutrition therapy (MNT) on borderline glucose intolerance (BGI) in pregnant Taiwanese women.</p> <p><i>Methods</i>: A total of 5194 singleton pregnant women were enrolled in this prospective, non-randomized study. The participants were subjected to the 50 g 1-h glucose challenge test (GCT) and 100 g 3-h oral glucose tolerance test (OGTT) to screening gestational diabetes mellitus (GDM). BGI was defined as a positive GCT and normal OGTT results. GDM was defined as a positive GCT and abnormal OGTT results. The women were categorized into the following groups: (1) GCT-negative, <i>n</i> = 3881; (2) BGI with MNT, <i>n</i> = 273; (3) BGI without MNT, <i>n</i> = 712; and (4) GDM, <i>n</i> = 328. Multiple logistic analyses were used to estimate the risks of pregnancy outcomes.</p> <p><i>Results</i>: The odds ratios (95% confidence interval) for total cesareans, third- or fourth-degree perineal lacerations, gestational hypertension or preeclampsia and macrosomia were 1.24 (1.04–1.49), 1.55 (1.06–1.28), 1.78 (1.21–2.61) and 2.50 (1.28–4.91) in the BGI without MNT group compared to the GCT-negative group. There was no difference between BGI with MNT and GCT-negative groups.</p> <p><i>Conclusions</i>: Women with BGI who did not receive MNT had increased risks of adverse pregnancy outcomes, whereas who received MNT had no different risk with GCT-negative women.</p

Associations of mid-pregnancy HbA1c with gestational diabetes and risk of adverse pregnancy outcomes in high-risk Taiwanese women

<div><p>Background</p><p>The objective of this study was to investigate the associations among the mid-pregnancy glycated hemoglobin A1c (HbA1c) level, gestational diabetes (GDM), and risk of adverse pregnancy outcomes in women without overt diabetes and with positive 50-g, 1-h glucose challenge test (GCT) results (140 mg/dL or greater).</p><p>Methods</p><p>This prospective study enrolled 1,989 pregnant Taiwanese women. A two-step approach, including a 50-g, 1-h GCT and 100-g, 3-h oral glucose tolerance test (OGTT), was employed for the diagnosis of GDM at weeks 23–32. The mid-pregnancy HbA1c level was measured at the time the OGTT was performed. A receiver operating characteristic (ROC) curve was used to determine the relationship between the mid-pregnancy HbA1c level and GDM. Multiple logistic regression models were implemented to assess the relationships between the mid-pregnancy HbA1c level and adverse pregnancy outcomes.</p><p>Results</p><p>An ROC curve demonstrated that the optimal mid-pregnancy HbA1c cut-off point to predict GDM, as diagnosed by the Carpenter-Coustan criteria using a two-step approach, was 5.7%. The area under the ROC curve of the mid-pregnancy HbA1c level for GDM was 0.70. Compared with the levels of 4.5–4.9%, higher mid-pregnancy HbA1c levels (5.0–5.4, 5.5–5.9, 6.0–6.4, 6.5–6.9, and >7.0%) were significantly associated with increased risks of gestational hypertension or preeclampsia, preterm delivery, admission to the neonatal intensive care unit, low birth weight, and macrosomia (the odds ratio [OR] ranges were 1.20–9.98, 1.31–5.16, 0.88–3.15, 0.89–4.10, and 2.22–27.86, respectively).</p><p>Conclusions</p><p>The mid-pregnancy HbA1c level was associated with various adverse pregnancy outcomes in high-risk Taiwanese women. However, it lacked adequate sensitivity and specificity to replace the two-step approach in the diagnosis of GDM. The current study comprised a single-center prospective study; thus, additional, randomized control design studies are required.</p></div