Risk factors associated with the development of postpartum diabetes in Japanese women with gestational diabetes.

BACKGROUND: Although the onset of gestational diabetes (GDM) is known to be a significant risk factor for the future development of type 2 diabetes, this risk specifically in women with GDM diagnosed by the International Association of Diabetes and Pregnancy Study Group (IADPSG) criteria has not yet been thoroughly investigated. This study was performed to investigate the risk factors associated with the development of postpartum diabetes in Japanese women with a history of GDM, and the effects of the differences in the previous Japanese criteria and the IADPSG criteria. METHODS: This retrospective cohort study included Japanese women with GDM who underwent at least one postpartum oral glucose tolerance test (OGTT) between 2003 and 2014. Cases with overt diabetes in pregnancy were excluded. We investigated the risk factors including maternal baseline and pregnancy characteristics associated with the development of postpartum diabetes. RESULTS: Among 354 women diagnosed with GDM during the study period, 306 (86%) (116/136 [85.3%] and 190/218 [87.2%] under the previous criteria and the IADPSG criteria, respectively) who underwent at least 1 follow-up OGTT were included in the study. Thirty-two women (10.1%) developed diabetes within a median follow-up period of 57 weeks (range, 6-292 weeks). Eleven (9.5%) and 21 (11.1%) were diagnosed as GDM during pregnancy based on the previous Japanese criteria and the IADPSG criteria, respectively, which did not significantly differ between those criteria. A multivariate logistic regression analysis revealed that HbA1c and 2-h plasma glucose (PG) at the time of the diagnostic OGTT during pregnancy were independent predictors of the development of diabetes after adjusting for confounders. The adjusted relative risk of HbA1c ≥5.6% for the development of diabetes was 4.67 (95% confidence interval, 1.53-16.73), while that of 2-h PG ≥183 mg/dl was 7.02 (2.51-20.72). CONCLUSIONS: A modest elevation of the HbA1c and 2-h PG values at the time of the diagnosis of GDM during pregnancy are independent predictors of the development of diabetes during the postpartum period in Japanese women with a history of GDM. The diagnostic criteria did not affect the incidence of postpartum diabetes.

Factors associated with patients with gestational diabetes in Japan being at increased risk of requiring intensive care.

OBJECTIVE: To investigate factors associated with high-risk gestational diabetes (GDM) among patients with GDM. METHODS: The present retrospective study included women with singleton pregnancies diagnosed with GDM using International Association of Diabetes and Pregnancy Study Group criteria at a single tertiary perinatal care center in Japan between July 1, 2010, and October 31, 2014. High-risk GDM was defined as patients who required at least 20 units of insulin therapy a day, delivering a large-for-gestational age neonate regardless of insulin therapy, or both. Maternal characteristics and diagnostic test results were investigated to identify associations with the high-risk criteria, and odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. RESULTS: Among 217 patients, 95 (43.8%) were categorized as high risk. After adjusting for confounders, a fasting plasma glucose level at diagnosis of at least 4.66 mmol/L (adjusted OR 2.88, 95% CI 1.51-5.58) and pre-pregnancy body mass index (calculated as weight in kilograms divided by the square of height in meters) of at least 24 (adjusted OR 3.27, 95% CI 1.60-6.90) were independently associated with meeting the high-risk criteria. CONCLUSION: Among Japanese patients with GDM, pre-pregnancy body mass index and fasting plasma glucose levels could be used to identify high-risk patients requiring intensive care during pregnancy.

The effect of high-intensity breastfeeding on postpartum glucose tolerance in women with recent gestational diabetes.

BACKGROUND: Although breastfeeding is expected to reduce the incidence of diabetes in women with gestational diabetes, the effect has not been clearly confirmed. We examined whether or not high-intensity breastfeeding reduces the incidence of abnormal glucose tolerance and investigated the effect of high-intensity breastfeeding on insulin resistance during the first year postpartum in Japanese women with current gestational diabetes. METHODS: In this retrospective study, we included women with gestational diabetes who underwent postpartum 75 g oral glucose tolerance test during the first year (12-14 months) postpartum from 2009 to 2011 at a single tertiary perinatal care center in Japan. High-intensity breastfeeding was defined as the condition in which infants were fed by breastfeeding alone or 80% or more of the volume. We investigated the effect of high-intensity breastfeeding on the prevalence of postpartum abnormal glucose tolerance and the postpartum homeostasis model of assessment of insulin resistance (HOMA-IR), after controlling for confounders, including prepregnancy obesity and weight changes during pregnancy and postpartum. RESULTS: Among 88 women with gestational diabetes, 46 (52%) had abnormal glucose tolerance during the postpartum period. High-intensity breastfeeding women (n = 70) were significantly less likely to have abnormal glucose tolerance than non-high-intensity breastfeeding women (n = 18) (46% vs. 78%, p = 0.015). High-intensity breastfeeding was also associated with a lower HOMA-IR at 12-14 months postpartum than non-high-intensity breastfeeding (1.41 ± 1.02 vs. 2.28 ± 1.05, p = 0.035). Those associations remained significant after controlling for confounders. At least six months of high-intensity breastfeeding had a significant effect on lowering both the abnormal glucose tolerance prevalence and HOMA-IR compared with non-high-intensity breastfeeding. CONCLUSIONS: In Japanese women with gestational diabetes, high-intensity breastfeeding ≥6 months had a protective effect against the development of abnormal glucose tolerance during the first year postpartum through improving insulin resistance, independent of obesity and postpartum weight change.

Present status of clinical care for postpartum patients with hypertensive disorders of pregnancy in Japan: findings from a nationwide questionnaire survey.

OBJECTIVE: To assess the present status of clinical care for postpartum patients with hypertensive disorders of pregnancy (HDP) in Japan. METHODS: We conducted a nationwide questionnaire survey of obstetricians, internists and hypertension specialists and analyzed 686 valid responses. RESULTS: Though HDP is widely known as a risk factor for subsequent hypertension and cardiovascular disease, over one-third of obstetricians terminated their postpartum follow-up of HDP patients without referring them to other departments. CONCLUSION: It is important to establish an effective referral system, whereby patients with HDP can be smoothly transferred to primary care or a specialist physician after childbirth for long-term monitoring and management of blood pressure.

Risk factors associated with abnormal glucose tolerance in the early postpartum period among Japanese women with gestational diabetes.

OBJECTIVE: To identify the risk factors associated with abnormal glucose tolerance (AGT) on the first postpartum oral glucose tolerance test (OGTT) among Japanese women with gestational diabetes (GDM). METHODS: In a retrospective study, data were analyzed from women with GDM who underwent their first postpartum OGTT 6-8weeks post partum at a center in Omura, Japan, between January 1, 2007, and December 31, 2011. Women with diabetes or impaired glucose tolerance were deemed to have postpartum AGT. The association between postpartum AGT and various risk factors was analyzed. RESULTS: Among 169 women who underwent a postpartum OGTT, 58 (34.3%) had AGT. The significant risk factors associated with postpartum AGT in univariate analysis were pre-pregnancy body mass index (P=0.096), 1-hour plasma glucose (P=0.006), hemoglobin A1c (P<0.001), insulinogenic index (P=0.05), an insulinogenic index of less than 0.4 (P=0.006), and insulin therapy during pregnancy (P<0.001). Independent risk factors identified by multivariate logistic regression models were insulinogenic index (odds ratio [OR] 0.10, 95% confidence interval [CI] 0.01-0.74; P=0.002), an insulinogenic index of less than 0.4 (OR 5.70, 95% CI 1.69-21.66; P=0.005), and insulin therapy during pregnancy (OR 3.43, 95% CI 1.03-12.55; P=0.044). CONCLUSION: Among Japanese women with GDM, a lower insulinogenic index and use of insulin therapy during pregnancy are associated with early postpartum AGT.

The association between maternal insulin resistance in mid-pregnancy and neonatal birthweight in uncomplicated pregnancies.

There have been few studies performed to address the association between the degree of physiological increase in maternal insulin resistance during pregnancy and neonatal birthweight in non-diabetic pregnancy. We attempted to determine whether maternal insulin resistance, as measured by homeostasis model assessment-insulin resistance (HOMA-IR), in mid-pregnancy is associated with neonatal birthweight in normal pregnancies. In this retrospective observational study, we measured HOMA-IR in singleton healthy pregnant women who underwent a 75 g oral glucose tolerance test (OGTT) in mid-pregnancy because of a positive diabetes screen. Using multivariate analyses to adjust for maternal parity, pre-gestational obesity, gestational weight gain, plasma glucose levels, and gestational age at delivery, we tested the association between HOMA-IR and birthweight in their offspring. We also tested the association HOMA-IR and a risk of large-for-gestational-age (LGA) infants. In 655 Japanese women, HOMA-IR was positively associated with birthweight after adjusting for these confounders (p<0.05). A higher HOMA-IR was significantly associated with an increased incidence of LGA infants with an adjusted odds ratio of 1.53 (95% confidence interval, 1.10-2.15) per 1 unit of HOMA-IR. The degree of maternal insulin resistance in mid-pregnancy was associated with birthweight and the risk of giving birth to an LGA infant in normal pregnancies, independent of maternal obesity and glucose levels.