High oleic/stearic fatty-acid desaturation index in cord plasma from infants of mothers with gestational diabetes

OBJECTIVE

Enhanced fatty-acid desaturation by stearoyl-CoA desaturase enzyme-1 (SCD1) is associated with obesity. This study determined desaturation in the cord plasma of newborns of mothers with and without gestational diabetes (GDM).

STUDY DESIGN

Newborns of mothers with GDM (n=21) and without (control, n=22) were recruited. Cord plasma fatty-acid desaturation indices (palmitoleic/palmitic, oleic/stearic ratios) were compared, and correlated with anthropometrics and biochemical measures. A subset of very low-density lipoprotein (VLDL) desaturation indices were determined to approximate the liver SCD1 activity.

RESULT

The total oleic/stearic index was higher in GDM, despite adjustment for cord glucose concentrations. Among GDM and controls, the oleic/stearic index correlated with cord glucose concentrations (rs=0.36, P=0.02). Both palmitoleic/palmitic and oleic/stearic indices correlated with waist circumference (r=0.47, P=0.001; r=0.37, P=0.01). The VLDL oleic/stearic index was higher in GDM.

CONCLUSION

The elevated total oleic/stearic index suggests increased lipogenesis in GDM newborns. Factors in addition to glucose supply may influence fetal SCD1 activity.

Attitudes and practices of healthcare providers regarding gestational diabetes: results of a survey conducted at the 2010 meeting of the International Association of Diabetes in Pregnancy Study Group (IADPSG)

OBJECTIVE

To investigate the attitudes and practices of healthcare providers regarding gestational diabetes mellitus and to identify differences between provider types and geographical locations.

RESEARCH DESIGN AND METHODS

A survey was distributed to participants at the 2010 GDM Pasadena II: International Conference regarding management of gestational diabetes.

RESULTS

Of 250 distributed surveys, there was a 60.8% (n = 152) response rate. Most responders believed it was cost beneficial to treat and screen for gestational diabetes. Approximately 2/3 accepted that the diagnosis of Type 2 diabetes could be made in pregnancy. For the diagnosis of gestational diabetes, c. 60% opted for a one-step screen while 30% opted for a two-step screen. Most responders were comfortable treating a non-pregnant woman with Type 2 diabetes. Ninety per cent of responders initiated antenatal testing at 32-34 weeks for medication-treated gestational diabetes, with a wider variation for diet-treated gestational diabetes. Obstetricians were less comfortable than other providers in treating a non-pregnant woman with Type 2 diabetes, but were more likely to prescribe glyburide. Providers in the USA, compared with those from other countries, were more likely to perform a Caesarean section based on fetal weight, use glibenclamide (glyburide), initiate exercise post-delivery and less likely to check 2-h postprandial glucose levels. At least 80% of responders routinely screened for Type 2 diabetes at 6-12 weeks post-delivery.

CONCLUSION

There are differences internationally and by provider types in attitudes and management regarding gestational diabetes. These findings may be useful in developing strategies for implementing the recent guidelines by the International Association of the Diabetes and Pregnancy Study Groups.

Cervilenz assessment of cervical length compared to fetal fibronectin in the prediction of preterm delivery in women with threatened preterm labor

OBJECTIVE

To determine whether cervical length (CL) measured by the Cervilenz™ measuring device is an effective screening tool for the prediction of preterm delivery (PTD) compared to fetal fibronectin (fFN).

METHODS

We evaluated fFN and CL among women who enrolled into a randomized control trial (RCT) comparing management algorithms for threatened preterm labor between 24 and 34 weeks' gestation. In all subjects, fFN was collected, with CL determined in blinded fashion. The sensitivity, specificity, and positive and negative predictive values (NPV) for fFN or Cervilenz in prediction of PTD within 7 days or prior to 37 weeks were determined.

RESULTS

Fifty-two subjects were evaluated. CL <30 mm correlated with PTD <7 days (r = 0.31, p = 0.04) and fFN positivity (r = 0.43, p = 0.006). CL <30 mm and fFN had excellent NPV for PTD <7 days (97.1 vs. 97.3%), and the area under the receiver operator characteristic curves were similar for prediction of PTD <7 days (76.6 vs. 75.2%, p = 0.71) or <37 weeks (56.7 vs. 55.2%, p = 0.71).

CONCLUSIONS

Measurement of CL with Cervilenz appears to be equivalent to fFN in screening symptomatic women for PTD within 7 days or prior to 37 weeks. Given cost and turnaround time with fFN testing, Cervilenz represents a promising new tool for real time, clinically useful results in the management of women with threatened preterm labor.

Detailed physiological characterization of the development of type 2 diabetes in Hispanic women with prior gestational diabetes mellitus

OBJECTIVE

To identify physiological and clinical variables associated with development of type 2 diabetes up to 12 years after pregnancies complicated by gestational diabetes.

RESEARCH DESIGN AND METHODS

Seventy-two islet cell antibody-negative nondiabetic Hispanic women had oral (oGTT) and intravenous (ivGTT) glucose tolerance tests, glucose clamps, and body composition assessed between 15 and 30 months after pregnancies complicated by gestational diabetes mellitus (GDM). They returned for oGTTs at 15-month intervals until they dropped out, developed diabetes, or reached 12 years postpartum. Cox regression analysis was used to identify baseline predictors and changes during follow-up that were associated with development of type 2 diabetes.

RESULTS

At baseline, relatively low insulin sensitivity, insulin response, and β-cell compensation for insulin resistance were independently associated with development of diabetes. During follow-up, weight and fat gain and rates of decline in β-cell compensation were significantly associated with diabetes, while additional pregnancy and use of progestin-only contraception were marginally associated with diabetes risk.

CONCLUSIONS

In Hispanic women, GDM represents detection of a chronic disease process characterized by falling β-cell compensation for chronic insulin resistance. Women who are farthest along at diagnosis and/or deteriorating most rapidly are most likely to develop type 2 diabetes within 12 years after the index pregnancy. Weight gain, additional pregnancy, and progestin-only contraception are potential modifiable factors that increase diabetes risk.

Declining beta-cell compensation for insulin resistance in Hispanic women with recent gestational diabetes mellitus: association with changes in weight, adiponectin, and C-reactive protein

OBJECTIVE

To identify factors associated with declining beta-cell compensation for insulin resistance.

RESEARCH DESIGN AND METHODS

In a cohort of Hispanic women with recent gestational diabetes mellitus, oral glucose tolerance tests (OGTTs), intravenous glucose tolerance tests (IVGTTs), and bioelectrical impedance measurements were performed at 15-month intervals for up to 5 years, or until fasting plasma glucose exceeded 140 mg/dl (7.8 mmol/l). Data were analyzed to identify predictors of declining beta-cell compensation for insulin resistance (the disposition index [DI]) and to examine the mechanism of weight gain and changes in circulating levels of selected adipokines and inflammatory markers on beta-cell compensation decline.

RESULTS

A total of 60 nondiabetic women had a median of four sets of OGTT + IVGTT during a median follow-up of 52 months. Fourteen of the women developed diabetes. None of the baseline characteristics were significantly predictive of a decline in DI. There were significant univariate associations between declining DI and weight gain (specifically fat gain), declining adiponectin and rising C-reactive protein. Multivariate analysis showed that the weight gain was the most significant factor associated with declining DI. The amount of association between weight gain and declining DI was explained 31% by changes in adiponectin and C-reactive protein and 40% by changes in insulin resistance.

CONCLUSIONS

These results identify weight gain as the strongest factor associated with declining beta-cell compensation for insulin resistance in Hispanic women at high risk for type 2 diabetes. Such effect may be mediated through at least two effects: alterations in adipokine levels and increasing insulin resistance.

How do we reduce the number of cases of missed postpartum diabetes in women with recent gestational diabetes mellitus?

OBJECTIVE

Up to 30% of women with recent gestational diabetes mellitus (GDM) remain glucose intolerant after delivery. However, the rate of postpartum oral glucose tolerance tests (ppOGTTs) is low. Our aim in this study was to develop a model for risk assessment to target women with high risk for postpartum diabetes.

RESEARCH DESIGN AND METHODS

In 605 Caucasian women with GDM, antenatal obstetrical and glucose data and the glucose data of the ppOGTTs performed 13 weeks (median) after delivery were prospectively collected.

RESULTS

A total of 132 (21.8%) women had an abnormal ppOGTT (2.8% impaired fasting glucose, 13.6% impaired glucose tolerance, and 5.5% diabetes). Independent risk factors were BMI >or=30 kg/m(2) (prevalence of abnormal ppOGTT 36.0 vs. 17.3%), gestational age at diagnosis <24 weeks (32.4 vs. 18.0%), 1-h antenatal value >200 mg/dl (11.1 mmol/l) (35.2 vs. 14.8%), and insulin therapy (30.3 vs. 14.5%). The prevalence of an abnormal ppOGTT was assessed according to the number of risk factors: 0, 9.2% (14 of 153); 1, 13.4% (25 of 186); 2, 28.5% (43 of 151); 3, 45.6% (26 of 57); and 4, 68.4% (13 of 19). Subjects were divided according to a significant increase of prevalence and risk for a ppOGTT: low risk (59.9% of subjects), <2 risk factors, 11.6%, odds ratio 1.3; intermediate risk, 2 risk factors, 28.5%, 4.0; and high risk, >2 risk factors, 51.3%, 10.5. The intermediate/high-risk group included 86.6% of those with diabetes and 67% of all those with abnormal ppOGTTs.

CONCLUSIONS

Women with >or=2 risk factors have a high risk for an abnormal ppOGTT, and 86% of postpartum diabetes is diagnosed within this group. Targeting women for ppOGTTs based on a risk assessment using available antenatal risk factors might reduce the number of missed cases of postpartum diabetes.

Independent predictors of Cesarean delivery in women with diabetes

OBJECTIVES

To identify independent risk factors for Cesarean delivery in women with pregnancy complicated by diabetes.

METHODS

Retrospective analysis of pregnancies from 5735 diabetic women delivering liveborn infants. Maternal demographic, medical, obstetric historical factors and index pregnancy obstetric, glycemic and neonatal outcome parameters were evaluated for association with Cesarean delivery after a trial of labor. Individual risk factors were analyzed for association by chi2 and ANOVA. Independent predictors of Cesarean delivery and adjusted relative risk (RR) were identified by stepwise logistic regression.

RESULTS

Trial of labor was permitted in 90.8% and 59.4% of women without (n = 4643) and with prior Cesarean delivery (n = 1092) and was successful in 85.2% and 56.9%, respectively. Eleven independent predictors were found. Five were related to obstetric history and maternal age: prior Cesarean delivery (RR 5.34, 95% CI 3.94-7.25), no prior live birth (RR 3.17, 95% CI 1.98-5.07), no prior vaginal delivery (RR 2.28, 95% CI 1.50-3.44), prior stillbirth (RR 1.71, 95% CI 1.09-2.68%) and maternal age > or = 35 years (RR 1.53, 95% CI 1.20-1.93). Two were related to the severity of diabetes at entry to diabetes care: requiring insulin (RR 1.53, 95% CI 1.20-1.93) and highest fasting plasma glucose level (RR 1.04, 95% CI 1.01-1.07). Two were related to obstetric factors: pre-eclampsia/hypertension (RR 2.56, 95% CI 2.00-3.27) and labor induction (RR 3.32, 95% CI 2.70-4.10). The remaining two were birth weight (per 250 g, RR 1.12, 95% CI 1.09-1.17) and pre-delivery body mass index (RR, 1.03, 95% CI 1.00-1.05).

CONCLUSION

The majority of predictors were not modifiable, relating to obstetric history, maternal age and diabetes severity. Possible modifiable interventions to avoid/improve labor induction, and decrease birth weight and maternal weight gain might decrease risk of Cesarean delivery. Future studies must address these multiple predictors.

Maternal lipids as strong determinants of fetal environment and growth in pregnancies with gestational diabetes mellitus

OBJECTIVE

To determine the contribution of maternal glucose and lipids to intrauterine metabolic environment and fetal growth in pregnancies with gestational diabetes mellitus (GDM).

RESEARCH DESIGN AND METHODS

In 150 pregnancies, serum triglycerides (TGs), cholesterol, free fatty acids (FFAs), glycerol, insulin, and glucose were determined in maternal serum and cord blood during the 3rd trimester. Maternal glucose values came from oral glucose tolerance testing and glucose profiles. Measurements of fetal abdominal circumference (AC) were performed simultaneously with maternal blood sampling and birth weight, and BMI and neonatal fat mass were obtained following delivery.

RESULTS

Maternal TGs and FFAs correlated with fetal AC size (at 28 weeks: triglycerides, P = 0.001; FFAs, P = 0.02), and at delivery they correlated with all neonatal anthropometric measures (FFA: birth weight, P = 0.002; BMI, P = 0.001; fat mass, P = 0.01). After adjustment for confounding variables, maternal FFAs and TGs at delivery remained the only parameters independently related to newborns large for gestational age (LGA) (P = 0.008 and P = 0.04, respectively). Maternal FFA levels were higher in mothers with LGA newborns than in those with appropriate for gestational age (AGA) newborns (362.8 +/- 101.7 vs. 252.4 +/- 10.1, P = 0.002). Maternal levels of TGs, FFAs, and glycerol at delivery correlated with those in cord blood (P = 0.003, P = 0.004, and P = 0.005, respectively). Fetal triglyceride and cholesterol levels were negatively correlated with newborn birth weight (P = 0.001), BMI (P = 0.004), and fat mass (P = 0.001). TGs were significantly higher in small for gestational age (SGA) newborns compared with AGA or LGA newborns, while insulin-to-glucose ratio and FFAs were the highest in LGA newborns.

CONCLUSIONS

In well-controlled GDM pregnancies, maternal lipids are strong predictors for fetal lipids and fetal growth. Infants with abnormal growth seem to be exposed to a distinct intrauterine environment compared with those with appropriate growth.

Evidence of interaction between PPARG2 and HNF4A contributing to variation in insulin sensitivity in Mexican Americans

OBJECTIVE

We hypothesized that interaction between PPARG2 Pro12Ala and variants in the promoter region of HNF4A are associated with type 2 diabetes-related quantitative traits in Mexican-American families of a proband with previous gestational diabetes.

RESEARCH DESIGN AND METHODS

The BetaGene project genotyped PPARG2 Pro12Ala and nine HNF4A single nucleotide polymorphisms (SNPs) in 473 individuals in 89 families. Members of the proband generation had fasting glucose <126 mg/dl and were phenotyped by oral and intravenous glucose tolerance tests.

RESULTS

Neither PPARG2 Pro12Ala nor any of the nine HNF4A SNPs were independently associated with type 2 diabetes-related quantitative traits. However, the interaction between PPARG2 Pro12Ala and HNF4A rs2144908 was significantly associated with both insulin sensitivity (S(I)) (Bonferroni P = 0.0006) and 2-h insulin (Bonferroni P = 0.039). Subjects with at least one PPARG2 Ala allele and homozygous for the HNF4A rs2144908 A allele had 40% higher S(I) compared with individuals with at least one G allele. S(I) did not vary by rs2144908 genotype among PPARG2 Pro/Pro. The interaction result for S(I) was replicated by the Insulin Resistance Atherosclerosis Family Study (P = 0.018) in their San Antonio sample (n = 484) where subjects with at least one PPARG2 Ala allele and homozygous for the HNF4A rs2144908 A allele had a 29% higher S(I) compared with individuals with at least one G allele. However, the interaction was not replicated in their San Luis Valley sample (n = 496; P = 0.401).

CONCLUSIONS

Together, these results suggest that variation in PPARG2 and HNF4A may interact to regulate insulin sensitivity in Mexican Americans at risk for type 2 diabetes.

Effect of pioglitazone on progression of subclinical atherosclerosis in non-diabetic premenopausal Hispanic women with prior gestational diabetes

The Pioglitazone in the Prevention of Diabetes (PIPOD) study was a single arm 3-year open-label pioglitazone treatment to determine the effects of pioglitazone in women with prior gestational diabetes mellitus (GDM) who had completed the troglitazone in the Prevention of Diabetes (TRIPOD) study. Here we report the results on progression of subclinical atherosclerosis, measured by carotid intima-media thickness (CIMT) in non-diabetic women. Data were analyzed to compare CIMT progression rates during pioglitazone treatment to rates that had been observed during either placebo or troglitazone treatment in the TRIPOD study. Sixty-one women met the entry criteria with mean age of 40 years. In the 30 women who came to PIPOD from the placebo arm of TRIPOD, the CIMT rate was 69% lower during pioglitazone treatment than it had been during placebo (0.0031 vs. 0.0100mm/yr, p=0.006). In the 31 women who came to PIPOD from the troglitazone arm of TRIPOD, CIMT rate was 38% lower during pioglitazone than it had been during troglitazone, a difference that was not statistically significant (0.0037 vs. 0.0060mm/year; p=0.26). Adjustment for differences in baseline characteristics and potential on-trial confounders did not alter the conclusion but did increase the CIMT rates differences slightly. We conclude that treatment with pioglitazone slowed CIMT progression in women who had been on placebo in the TRIPOD study and maintained a relatively low rate of progression in women who had been on troglitazone. Pioglitazone slows progression of subclinical atherosclerosis in young Hispanic women at increased risk for type 2 diabetes.

A longitudinal study of lipids and blood pressure in relation to method of contraception in Latino women with prior gestational diabetes mellitus

OBJECTIVE

To investigate the effect of nonhormonal contraception (NHC), combination oral contraception (COC), and depo-medroxyprogesterone acetate (DMPA) on lipids and blood pressure in women with recent gestational diabetes mellitus (GDM).

RESEARCH DESIGN AND METHODS

An observational cohort of 972 nondiabetic, normotensive, postpartum Latino women who elected NHC (n = 448), COC (n = 430), or DMPA (n = 94) were followed for at least one subsequent metabolic evaluation on the same contraception. Baseline and follow-up measures included glucose tolerance testing, fasting serum LDL and HDL cholesterol, triglycerides, and systolic (SBP) and diastolic (DBP) blood pressure. Patterns of changes in lipids and blood pressure were evaluated by comparing slopes over follow-up time using random coefficient linear mixed-effects models.

RESULTS

Median follow-up times were 20, 12, and 11 months in the NHC, COC, and DMPA groups. The DMPA users gained significantly more weight (4.3 +/- 6.9 kg/year) compared with NHC and COC users (1.2 +/- 4.7 and 0.7 +/- 6.0 kg/year, respectively; P < 0.0001). Patterns of change in LDL cholesterol, triglycerides, and DBP were not significantly different among groups. HDL cholesterol change differed only between COC and NHC groups (adjusted slopes: 1.0 vs. -1.6 mg x dl(-1) x year(-1), respectively; P < 0.0001). SBP change differed only between COC and DMPA groups (adjusted slopes: 1.3 vs. -1.7 mmHg/year, respectively; P = 0.01).

CONCLUSIONS

These results, derived predominantly from the initial 1-2 years of treatment in Hispanic women, demonstrate that DMPA was associated with greater weight gain than NHCs or COCs. Other differences in blood pressure and lipid effects were very small. These findings should be taken into account when advising women with recent GDM about their contraceptive choices.

After Pregnancy Complicated by Diabetes: Postpartum Care and Education

The postpartum period in women with pregestational or gestational diabetes allows the physician and mother to switch from intensive medical and obstetric management into a proactive and preventive mode, and to jointly develop a reproductive health plan. The woman's individual needs regarding contraception and breastfeeding, an appropriate diet to achieve healthy weight goals, the medical management of diabetes, daily exercise, and future pregnancy planning must be considered. Essential is the active participation of the woman, who, through education, gains an understanding of the far-reaching effects her active participation will have on her subsequent health, her newborn child's health, and possibly that of her future children.

Coordinate changes in plasma glucose and pancreatic beta-cell function in Latino women at high risk for type 2 diabetes

The purpose of this study was to examine longitudinally the relationship among glucose levels, pancreatic beta-cell function, and insulin resistance in women at high risk for type 2 diabetes. Oral glucose tolerance tests (OGTTs) and intravenous glucose tolerance tests (IVGTTs) were performed at 15-month intervals for up to 5 years or until fasting plasma glucose exceeded 140 mg/dl in Hispanic women with recent gestational diabetes. Data were analyzed 1) to compare changes in insulin sensitivity, beta-cell function, and glucose levels between women who had diabetes at one or more visits and women who remained diabetes free and 2) to determine longitudinal patterns of change in glucose levels and acute beta-cell compensation for insulin resistance. Seventy-one women provided data from a total of 280 paired OGTTs and IVGTTs during a median follow-up of 46 months. Compared with the 47 women who remained free of diabetes, the 24 who either had diabetes (n = 9) or developed it during follow-up (n = 15) had higher baseline glucose levels and lower acute beta-cell compensation for insulin resistance. Baseline insulin sensitivity was low in both groups and did not change significantly during follow-up. Fasting and 2-h glucose levels increased more rapidly in the diabetic group despite a decline in acute beta-cell compensation that was significantly slower than the decline in women who did not develop diabetes. This paradox was explained by an accelerated rise in glucose levels for any decline in beta-cell compensation when beta-cell compensation reached approximately 10% of normal, a level that was reached in the women who had or developed diabetes but not in the women who remained diabetes free. These findings define a pathogenesis for type 2 diabetes in one high-risk group that is characterized by a relatively long-term decline in acute beta-cell compensation for chronic insulin resistance that is attended by slowly rising glucose levels. Only relatively late in this process do glucose levels rise rapidly and into the diabetic range.

Long-acting injectable progestin contraception and risk of type 2 diabetes in Latino women with prior gestational diabetes mellitus

OBJECTIVE

To investigate the impact of a long-acting injectable progestin, depo-medroxyprogesterone acetate (DMPA), compared with combination oral contraceptives (COCs) on the risk of diabetes in Latino women with prior gestational diabetes mellitus (GDM).

RESEARCH DESIGN AND METHODS

An observational cohort study of 526 Hispanic women with prior GDM who were not diabetic in their postpartum visit during January 1987 to October 1997 and who elected DMPA (n = 96) or COCs (n = 430) as initial contraception were followed for a maximum of 9.2 years with a median follow-up of approximately 12 months. Oral glucose tolerance tests were performed and choice of contraception method was recorded at each visit as part of routine clinical care.

RESULTS

Annual diabetes incidence rates were 19% in the DMPA group and 12% in the COC group, with an unadjusted hazard ratio (HR) of 1.58 (95% CI 1.00-2.50; P = 0.05) for DMPA compared with COCs. Adjustment for baseline imbalances reduced the HR to 1.18 (0.67-2.28; P = 0.57). Additional adjustment for weight gain during follow-up, which was on average 1.8 kg higher in the DMPA group (P < 0.0001), reduced the HR to 1.07. DMPA interacted with baseline serum triglyceride levels and, separately, with breast-feeding to increase the diabetes risk.

CONCLUSIONS

DMPA use was associated with an increased risk of diabetes that appeared to be explained by three factors: 1) use in women with increased baseline diabetes risk, 2) weight gain during use, and 3) use with high baseline triglycerides and/or during breast-feeding.

Effect of pioglitazone on pancreatic beta-cell function and diabetes risk in Hispanic women with prior gestational diabetes

The Pioglitazone In Prevention Of Diabetes (PIPOD) study was conducted to evaluate beta-cell function, insulin resistance, and the incidence of diabetes during treatment with pioglitazone in Hispanic women with prior gestational diabetes who had completed participation in the Troglitazone In Prevention Of Diabetes (TRIPOD) study. Women who completed the TRIPOD study were offered participation in the PIPOD study for a planned 3 years of drug treatment and 6 months of postdrug washout. Oral glucose tolerance tests were performed annually on pioglitazone and at the end of the postdrug washout. Intravenous glucose tolerance tests (IVGTTs) for assessment of insulin sensitivity and beta-cell function were conducted at baseline, after 1 year on pioglitazone, and at the end of the postdrug washout. Of 95 women who were not diabetic at the end of the TRIPOD study, 89 enrolled in the PIPOD study, 86 completed at least one follow-up visit, and 65 completed all study visits, including the postdrug tests. Comparison of changes in beta-cell compensation for insulin resistance across the TRIPOD and PIPOD studies revealed that pioglitazone stopped the decline in beta-cell function that occurred during placebo treatment in the TRIPOD study and maintained the stability of beta-cell function that had occurred during troglitazone treatment in the TRIPOD study. The risk of diabetes, which occurred at an average rate of 4.6% per year, was lowest in women with the largest reduction in total IVGTT insulin area after 1 year of treatment. The similarity of findings between the PIPOD and TRIPOD studies support a class effect of thiazolidinedione drugs to enhance insulin sensitivity, reduce insulin secretory demands, and preserve pancreatic beta-cell function, all in association with a relatively low rate of type 2 diabetes, in Hispanic women with prior gestational diabetes.

Insulin resistance and preeclampsia in gestational diabetes mellitus

OBJECTIVE

To compare the degree of insulin resistance in women with gestational diabetes mellitus (GDM) who do and do not develop preeclampsia.

RESEARCH DESIGN AND METHODS

We conducted a prospective cohort study of initially normotensive women with GDM who underwent oral glucose tolerance tests (OGTTs), intravenous glucose tolerance tests (IVGTTs), and glucose clamp studies in the early third trimester (n = 150) and 15 months postpartum (n = 89). After delivery, the women were categorized as nonpreeclamptic or preeclamptic (systolic blood pressure [SBP] > or = 140 mmHg, diastolic blood pressure [DBP] > or = 90 mmHg, and at least >1+ proteinuria or >300 mg/24 h). Metabolic parameters between the groups were compared by chi2 or Fisher's exact tests and ANOVA with P < 0.05 as significant.

RESULTS

A total of 29 women (19%) developed preeclampsia, which was mild in 21 and severe in 8 women. At entry, there were no differences in age, weight indexes, and glycemic measures between the nonpreeclamptic and preeclamptic groups. Those with preeclampsia were significantly taller (61.5 +/- 2.4 vs. 60.1 +/- 2.3 in, P = 0.003), were more often nulliparous (38 vs. 16%, P = 0.01), and had higher entry SBP (112 +/- 10 vs. 103 +/- 6.9 mmHg, P < 0.0001) and DBP (64 +/- 9 vs. 59 +/- 5 mmHg, P = 0.002). No significant differences between the groups were found in any measures of the OGTT glucose levels, insulin sensitivity index, glucose effectiveness, acute response to glucose, or disposition index, nor were there any differences found in the euglycemic clamp measures of basal or steady-state levels of glucose, insulin, free fatty acid, hepatic glucose output, peripheral glucose clearance, C-peptide, or glucagon. At 15 months postpartum, blood pressure levels remained significantly higher in the preeclamptic group (n = 19) compared with the nonpreeclamptic group (n = 70). No differences in any glycemic or insulin resistance measures were found.

CONCLUSIONS

Women with GDM were uniformly insulin resistant. Those who developed preeclampsia, when compared with those who remained nonpreeclamptic, were not more insulin resistant in either the third trimester or 15 months postpartum. However, women who developed preeclampsia had blood pressure levels that were significantly higher, although still in the normal range, than those of women who remained nonpreeclamptic.

Effect of thiazolidinedione treatment on progression of subclinical atherosclerosis in premenopausal women at high risk for type 2 diabetes

We tested the effects of treatment with a thiazolidinedione drug on rates of progression of carotid intima-media thickness (CIMT) and some putative determinants of CIMT in young women at high risk for type 2 diabetes. A total of 266 nondiabetic, Hispanic women with recent gestational diabetes were randomized to placebo or troglitazone. CIMT measurements were made at baseline, annually, and at study end, together with measurements of obesity, serum lipids, and glucose and insulin levels during oral glucose tolerance tests. Insulin sensitivity (minimal model analysis) was measured at baseline and 3 months later. Data were analyzed to compare CIMT progression rates between treatment groups and investigate potential determinants of differences in CIMT progression. One hundred ninety-two women had a CIMT measurement at baseline and at least one follow-up visit. The mean rate of CIMT change was 31% lower in women assigned to troglitazone (P = 0.048). This intergroup difference was not explained by baseline or on-trial differences in obesity, lipids, glucose, or insulin. The reduction in CIMT progression developed gradually, occurred only in women who had an increase in insulin sensitivity, and was unrelated to the presence of the metabolic syndrome at baseline. Troglitazone reduced the progression of subclinical atherosclerosis via a mechanism that involved unmeasured mediators of atherosclerosis, either in the circulation or directly in the arterial wall.

Pharmacological treatment of insulin resistance at two different stages in the evolution of type 2 diabetes: impact on glucose tolerance and beta-cell function

The purpose of this study was to compare the impact of treating insulin resistance with a thiazolidinedione drug before vs. at the onset of diabetes on glucose levels and beta-cell function. Nondiabetic Hispanic women of Mexican or Central American descent with prior gestational diabetes mellitus (GDM) were randomized to troglitazone (early intervention), 400 mg/d, or placebo (later intervention). Women who developed diabetes were placed on open-label troglitazone. Glucose tolerance, insulin resistance, and beta-cell function were measured at randomization, at the diagnosis of diabetes, and 8 months post trial to determine the long-term impact of the two treatment strategies on glucose levels and beta-cell function. During a mean follow-up of 4.3 yr between baseline and posttrial tests, glucose tolerance (oral glucose tolerance test glucose area, P = 0.04) and insulin resistance (MINMOD SI, P = 0.02) worsened more in women randomized to late intervention (n = 69) than to early intervention (n = 57). Insulin secretion (acute insulin response in the iv glucose tolerance test, P = 0.09) and beta-cell compensation for insulin resistance (disposition index, P = 0.07) also tended to worsen more in the late intervention group. Among women in the late intervention group who developed diabetes, oral glucose tolerance test glucose area (P = 0.0001) and beta-cell function (P < or = 0.04) deteriorated significantly during development of diabetes on placebo and then did not change significantly (P > 0.50) during treatment with troglitazone and posttreatment washout. In high-risk Hispanic women, amelioration of insulin resistance can stabilize glycemia at the time diabetes develops. These findings highlight the role of insulin resistance in the genesis of progressive beta-cell dysfunction during the evolution of type 2 diabetes.

A randomized trial evaluating a predominantly fetal growth-based strategy to guide management of gestational diabetes in Caucasian women

OBJECTIVE

To compare the management of Caucasian women with gestational diabetes (GDM) based predominantly on monthly fetal growth ultrasound examinations with an approach based solely on maternal glycemia.

RESEARCH DESIGN AND METHODS

Women with GDM who attained fasting capillary glucose (FCG) <120 mg/dl and 2-h postprandial capillary glucose (2h-CG) <200 mg/dl after 1 week of diet were randomized to management based on maternal glycemia alone (standard) or glycemia plus ultrasound. In the standard group, insulin was initiated if FCG was repeatedly >90 mg/dl or 2h-CG was >120 mg/dl. In the ultrasound group, thresholds were 120 and 200 mg/dl, respectively, or a fetal abdominal circumference >75th percentile (AC>p75). Outcome criteria were rates of C-section, small-for-gestational-age (SGA) or large-for-gestational-age (LGA) infants, neonatal hypoglycemia (<40 mg/dl), and neonatal care admission.

RESULTS

Maternal characteristics and fetal AC>p75 (36.0 vs. 38.4%) at entry did not differ between the standard (n = 100) and ultrasound groups (n = 99). Assignment to (30.0 vs. 40.4%) and mean duration of insulin treatment (8.3 vs. 8.1 weeks) did not differ between groups. In the ultrasound group, AC>p75 was the sole indication for insulin. The ultrasound-based strategy, as compared with the maternal glycemia-only strategy, resulted in a different treatment assignment in 34% of women. Rates of C-section (19.0 vs. 18.2%), LGA (10.0 vs. 12.1%), SGA (13.0 vs. 12.1%), hypoglycemia (16.0 vs. 17.0%), and admission (15.0 vs. 14.1%) did not differ significantly.

CONCLUSIONS

GDM management based on fetal growth combined with high glycemic criteria provides outcomes equivalent to management based on strict glycemic criteria alone. Inclusion of fetal growth might provide the opportunity to reduce glucose testing in low-risk pregnancies.

Comparison of point-of-care-testing glucose meters with standard laboratory measurement of the 50g-glucose-challenge test (GCT) during pregnancy

OBJECTIVES

Although glucose meters are well-established instruments for self-monitoring blood glucose levels, diagnostic and screening procedures should be performed using standard laboratory methods. In addition to standard laboratory methods, HemoCue is authorized for screening and diagnostic purposes in Germany. The rapid development of other glucose meters makes it necessary to re-evaluate this recommendation. Our objective was to test the usefulness of glucose meters in screening pregnant patients for gestational diabetes.

METHODS

The 50-g glucose challenge test was administered to one hundred and ninety-three pregnant patients whose blood glucose levels were then simultaneously measured with five portable meters and the HemoCue. The results were compared to our standard method (Hexokinase). A cut-off of 7.8 mmol/L was used and sensitivity, specificity, accuracy, the Youden index, and the Kappa index were calculated. The tests were performed by well-trained personnel (C.D. and U.S.).

RESULTS

1212 measurements were performed on 193 patients. All glucose meters showed a very good correlation (r > 0.90). None of the measurements showed an extreme deviation necessitating the error grid analysis. The GlucoTouch (5.93% +/- 7.4) and the HemoCue (-9.04% +/- 5.9) showed a mean deviation greater than 5%. None of the meters had a mean deviation greater than 10%. The accuracy fluctuated between 0.85 and 0.94. The Kappa index was between 66 to 85. In our clinical trial, the Accu-Chek, Glucotouch, OneTouch, and Precision demonstrated greater accuracy and a higher Kappa index than the HemoCue.

CONCLUSIONS

Our data showed good concordance in statistical and clinical parameters for most of the six glucose meters. The HemoCue, recommended as a standard method in several countries, did not show better concordance than most of the tested glucose meters. When used by well-trained personnel, the accuracy of the Accu-Chek, Glucotouch, One-Touch, and Precision was acceptable for use in gestational diabetes screening.

Amniotic fluid insulin levels and fetal abdominal circumference at time of amniocentesis in pregnancies with diabetes

AIMS

Fetal hyperinsulinism is a strong predictor for excessive growth and fetopathy in pregnancies complicated by diabetes. We examined (i). the relationship between measurements of amniotic fluid insulin (AF insulin) and fetal abdominal circumference (AC) at the time of amniocentesis, and (ii). whether there is a threshold for fetal AC percentiles which can identify low vs. high-risk levels of AF insulin without performing an amniocentesis.

METHODS

In a retrospective study, AF insulin from 121 pregnant diabetic women (32 pregestational; 89 gestational) was measured during the 3rd trimester as part of a diabetes management protocol. AC measurements were transformed into a continuous variable of percentile growth for gestational age (Hadlock). Division of the cohort according to deciles or quartiles of AC percentiles was performed to identify a threshold AC with a significant increase in elevated AF insulin, previously defined as AF insulin >or= 7 microU/ml. A receiver operator characteristic (ROC) curve was created and the negative predictive value (NPV) of the determined threshold was calculated.

RESULTS

AF insulin levels were significantly correlated with the AC percentiles (r = 0.3, P = 0.0005) by linear regression. No AC threshold could reliably identify a moderate elevated AF insulin >or= 7 microU/ml (NPV 77.2%), but an AC threshold >or= 75th percentile could identify with fetal hyperinsulinism with an AF insulin >or= 16 microU/ml. All 10 cases of AF insulin >or= 16 microU/ml were identified with a NPV of 100% (74/74).

CONCLUSIONS

Our data indicate that an AC >or= 75th percentile determined by a 3rd trimester ultrasound examination may discriminate between pregnancies at low vs. high risk for AF insulin >or= 16 microU/ml. This AF insulin concentration corresponds to a level of hyperinsulinism reported to be associated with considerable neonatal and long term morbidity.

Determinants of fetal growth at different periods of pregnancies complicated by gestational diabetes mellitus or impaired glucose tolerance

OBJECTIVE

To determine maternal parameters with the strongest influence on fetal growth in different periods of pregnancies complicated by an abnormal glucose tolerance test (GTT).

RESEARCH DESIGN AND METHODS

Retrospective study of 368 women with gestational diabetes mellitus (GDM; > or = 2 abnormal GTT values, n = 280) and impaired glucose tolerance (IGT; one abnormal value, n = 88) with 869 ultrasound examinations at entry to and during diabetic care. Both groups were managed comparably. Abdominal circumference (AC) > or = 90th percentile defined fetal macrosomia. Maternal historical and clinical parameters, and diagnostic and glycemic values of glucose profiles divided into five categories of 4 weeks of gestational age (GA; <24 weeks, 24 weeks/0 days to 27 weeks/6 days, 28/0-31/6, 32/0-35/6, and 36/0-40/0 [referred to as <24 GA, 24 GA, 28 GA, 32 GA, and 36 GA categories, respectively]) were tested by univariate and multiple logistic regression analysis for their ability to predict an AC > or = 90th percentile at each GA group and large-for-gestational-age (LGA) newborn. Data obtained at entry were also analyzed separately irrespective of the GA.

RESULTS

Maternal weight, glycemia after therapy, rates of fetal macrosomia, and LGA were not significantly different between GDM and IGT; thus, both groups were analyzed together. LGA in a previous pregnancy, (odds ratio [OR] 3.6; 95% CI 1.8-7.3) and prepregnancy obesity (BMI > or = 30 kg/m(2); 2.1; 1.2-3.7) independently predicted AC > or = 90th percentile at entry. When data for each GA category were analyzed, no predictors were found for <24 GA. Independent predictors for each subsequent GA category were as follows: at 24 GA, LGA history (OR 9.8); at 28 GA, LGA history (OR 4.2), and obesity (OR 3.3); at 32 GA, fasting glucose of 32 GA (OR 1.6 per 5-mg/dl increase); at 36 GA, fasting glucose of 32 GA (OR 1.6); and for LGA at birth, LGA history (OR 2.7), and obesity (OR 2.4).

CONCLUSIONS

In the late second and early third trimester, maternal BMI and LGA in a previous pregnancy appear to have the strongest influence on fetal growth, while later in the third trimester coincident with the period of maximum growth described in diabetic pregnancies, maternal glycemia predominates.

Prospective delivery of reliably dated term infants of diabetic mothers without determination of fetal lung maturity: comparison to historical control

OBJECTIVE

To determine whether omitting fetal lung maturity (FLM) testing prior to delivery in term pregnancies complicated by gestational (GDM) and pregestational diabetes mellitus would increase the risk of neonatal respiratory distress syndrome (RDS).

METHODS

In a 2-year study (1990-91), 1,457 pregnant women with accurately dated pregnancies were enrolled after 37 completed weeks and prospectively followed through delivery without FLM testing (study group). The prevalence of RDS and other neonatal outcomes was compared with a historical control group (n = 713, 1988-89) who had undergone determination of lecithin/sphingomyclin ratio prior to delivery at term. Logistic regression analysis was performed to determine independent predictors of RDS.

RESULTS

The study group compared to the control group had less severe diabetes: diet-controlled GDM, 35% vs. 18%, respectively; insulin-requiring GDM, 42% vs. 42%, respectively; undiagnosed type-2 diabetes, 14% vs. 31%, respectively; and pre-existing diabetes, 9.6% vs. 8.8%, respectively, p < 0.001. RDS rates in the study group (0.8%) and control group (1.0%) were not significantly different, nor were rates of resuscitation at delivery, neonatal intensive care admission or hospitalization days. Logistic regression analysis found only Cesarean delivery to be independently predictive (adjusted OR 2.21, 95% CI 2.04-2.27) of RDS. Non-predictive variables included FLM testing, diabetic classification, insulin use, poor third-trimester glycemic control, chronic hypertension, pre-eclampsia, labor, neonatal gender, gestational age or large-for-gestational-age fetuses.

CONCLUSIONS

Routine FLM testing did not change the RDS prevalence in reliably dated, term infants of diabetic mothers and should be abandoned. Delivery by Cesarean section was associated with increased RDS.

Rate and risk factors of hypoglycemia in large-for-gestational-age newborn infants of nondiabetic mothers

OBJECTIVE

The purpose of this study was to investigate the rate of hypoglycemia in large-for-gestational-age infants of nondiabetic mothers in relation to maternal or neonatal risk factors.

STUDY DESIGN

Hospital charts of all term large-for-gestational-age infants born between 1994 and 1998 (n = 1136) were analyzed for the rate of neonatal hypoglycemia (capillary glucose level, < or =30 mg/dL) during the first 24 hours of life. Infants of women with preexisting or gestational diabetes mellitus were excluded (n = 180). Neonatal glucose testing was performed at 1 or 2 hours of life, with subsequent measurements every 4 to 6 hours. Maternal and neonatal parameters were compared between neonates with and without hypoglycemia, including recent oral glucose tolerance test values in those women who were tested (n = 358).

RESULTS

Of 956 infants, 69 infants (7.2%) were not tested for hypoglycemia. In the remaining 887 infants, hypoglycemia occurred in 142 infants (16%) within the first 24 hours of life. The incidence of hypoglycemia decreased sharply during the first few hours of life, from 9.2% within the first hour of life, to 3.5% between 2 to 5 hours (cumulative) of life, and 2.4% between 6 and 24 hours of life. Gestational age at delivery was the only neonatal parameter that differed significantly between infants with and without hypoglycemia (39.5 vs 39.3 weeks, P =.01). The antenatal 1-hour oral glucose tolerance test value was the only predictive maternal parameter (141.5 vs 163.0 mg/dL, P <.006). There was an incremental risk of hypoglycemia with increasing 1-hour oral glucose tolerance test values, with hypoglycemia rates of 2.5%, 9.3%, 22.0%, and 50.0% that were associated with maternal 1-hour glucose values of <120, 120-179, 180-239, and > or =240 mg/dL, respectively (P <.05, for all comparisons).

CONCLUSION

Routine glucose testing is indicated in large-for-gestational-age newborn infants of nondiabetic mothers. The 1-hour glucose value of the maternal oral glucose tolerance test is a fairly good predictor of subsequent neonatal hypoglycemia. A single elevated 1-hour value of > or =180 mg/dL markedly increases the risk of neonatal hypoglycemia.

Preservation of pancreatic beta-cell function and prevention of type 2 diabetes by pharmacological treatment of insulin resistance in high-risk hispanic women

Type 2 diabetes frequently results from progressive failure of pancreatic beta-cell function in the presence of chronic insulin resistance. We tested whether chronic amelioration of insulin resistance would preserve pancreatic beta-cell function and delay or prevent the onset of type 2 diabetes in high-risk Hispanic women. Women with previous gestational diabetes were randomized to placebo (n = 133) or the insulin-sensitizing drug troglitazone (400 mg/day; n = 133) administered in double-blind fashion. Fasting plasma glucose was measured every 3 months, and oral glucose tolerance tests (OGTTs) were performed annually to detect diabetes. Intravenous glucose tolerance tests (IVGTTs) were performed at baseline and 3 months later to identify early metabolic changes associated with any protection from diabetes. Women who did not develop diabetes during the trial returned for OGTTs and IVGTTs 8 months after study medications were stopped. During a median follow-up of 30 months on blinded medication, average annual diabetes incidence rates in the 236 women who returned for at least one follow-up visit were 12.1 and 5.4% in women assigned to placebo and troglitazone, respectively (P < 0.01). Protection from diabetes in the troglitazone group 1) was closely related to the degree of reduction in endogenous insulin requirements 3 months after randomization, 2) persisted 8 months after study medications were stopped, and 3) was associated with preservation of beta-cell compensation for insulin resistance. Treatment with troglitazone delayed or prevented the onset of type 2 diabetes in high-risk Hispanic women. The protective effect was associated with the preservation of pancreatic beta-cell function and appeared to be mediated by a reduction in the secretory demands placed on beta-cells by chronic insulin resistance.

Clinical predictors for a high risk for the development of diabetes mellitus in the early puerperium in women with recent gestational diabetes mellitus

OBJECTIVE

The purpose of this study was to identify which maternal, antepartum, or neonatal clinical parameters were predictive for a high risk of diabetes mellitus in the puerperium in women with recent gestational diabetes mellitus and to calculate the associated diabetes mellitus rates and odds ratios.

STUDY DESIGN

One thousand six hundred thirty-six women underwent an oral glucose tolerance test within 1 to 4 months of delivery. Demographic, historic, and antenatal glycemic parameters and neonatal outcome parameters were tested by univariate and multivariate logistic regression for risk of postpartum diabetes mellitus. Continuous variables were divided into quartiles that compared the upper to lower quartile adjusted odds ratio and prevalence of diabetes mellitus.

RESULTS

Postpartum diabetes mellitus was diagnosed in 230 women (14.1%) according to the American Diabetes Association criteria (1997). No maternal demographic or neonatal parameters were significantly associated with diabetes mellitus. The final model of independent predictors in decreasing significance included the highest fasting plasma glucose level during pregnancy, any fasting plasma glucose level of > or = 105 mg/dL (class A(2)), the area under the curve of pregnancy oral glucose tolerance test, gestational age at diagnosis, previous gestational diabetes mellitus history, and 50-g glucose challenge test results. The fasting plasma glucose level was the best discriminator, with a 21-fold (95% CI, 4.6-96.3) increased odds ratio comparing the 4th quartile (fasting plasma glucose level, >121 mg/dL; diabetes mellitus rate, 36.7%) to 1st quartile (fasting plasma glucose level, < 95 mg/dL; diabetes mellitus rate, 0.5%). The presence of previous gestational diabetes mellitus or current class A(2) gestational diabetes mellitus approximately doubled the odds ratio for diabetes mellitus. The odds ratio increased 3- to 4-fold when the area under the curve was > or = 33.36 min small middle dot g/dL (4th quartile) or the glucose challenge test was > or = 155 mg/dL (2nd-4th quartiles) and decreased > 50% if gestational diabetes mellitus was diagnosed at > 27 weeks (3rd-4th quartile).

CONCLUSION

During pregnancy, the highest fasting glucose level, followed by the severity of glucose intolerance, and earlier gestational diabetes mellitus diagnosis were the best predictors for postpartum diabetes mellitus. Diabetic education should begin during pregnancy, especially for women who are identified to be at a high risk when they are highly motivated and under medical care.

A randomized controlled trial using glycemic plus fetal ultrasound parameters versus glycemic parameters to determine insulin therapy in gestational diabetes with fasting hyperglycemia

OBJECTIVE

To compare management based on maternal glycemic criteria with management based on relaxed glycemic criteria and fetal abdominal circumference (AC) measurements in order to select patients for insulin treatment of gestational diabetes mellitus (GDM) with fasting hyperglycemia.

RESEARCH DESIGN AND METHODS

In a pilot study, 98 women with fasting plasma glucose (FPG) concentrations of 105-120 mg/dl were randomized. The standard group received insulin treatment. The experimental group received insulin if the AC, measured monthly, was > or =70th percentile and/or if any venous FPG measurement was >120 mg/dl. Power was projected to detect a 250-g difference in birth weights.

RESULTS

Gestational ages, maternal glycemia, and AC percentiles were similar at randomization. After initiation of protocol, venous FPG (P = 0.003) and capillary blood glucose levels (P = 0.049) were significantly lower in the standard group. Birth weights (3,271 +/- 458 vs. 3,369 +/- 461 g), frequencies of birth weights >90th percentile (6.3 vs 8.3%), and neonatal morbidity (25 vs. 25%) did not differ significantly between the standard and experimental groups, respectively. The cesarean delivery rate was significantly lower (14.6 vs. 33.3%, P = 0.03) in the standard group; this difference was not explained by birth weights. In the experimental group, infants of women who did not receive insulin had lower birth weights than infants of mothers treated with insulin (3,180 +/- 425 vs. 3,482 +/- 451 g, P = 0.03).

CONCLUSIONS

In women with GDM and fasting hyperglycemia, glucose plus fetal AC measurements identified pregnancies at low risk for macrosomia and resulted in the avoidance of insulin therapy in 38% of patients without increasing rates of neonatal morbidity.

Vaginally administered misoprostol for outpatient cervical ripening in pregnancies complicated by diabetes mellitus

OBJECTIVE

To compare the use of vaginally administered misoprostol to placebo for outpatient labor induction in patients with diabetes.

STUDY DESIGN

In this double-masked, controlled clinical trial, pregnant women with diabetes and gestational age of >38(1/2) weeks were randomized to receive 25 microg misoprostol or placebo vaginally on days 1 and 4 of a 7-day outpatient cervical ripening period. If necessary, inpatient labor induction was managed by using a standard protocol.

RESULTS

Of 120 women included in the study, 57 received misoprostol and 63 received placebo. Most of the women had been diagnosed with gestational (Class A) diabetes. Similar numbers of misoprostol and placebo-treated women delivered within 7 days of the first dose (31/57 [54%] vs 36/63 [57%], P =.63). The mean (+/-SEM) interval from induction to delivery was similar (8530.5 minutes +/-1439.7 minutes vs 6712.5 minutes +/-606.4 minutes, P =.23).

CONCLUSION

Vaginally administered misoprostol was no more effective than placebo in reducing the need for inpatient labor induction or the induction-delivery interval. Outpatient cervical ripening with use of vaginally administered misoprostol was well tolerated.

Response of pancreatic beta-cells to improved insulin sensitivity in women at high risk for type 2 diabetes

The purpose of this study was to examine the response of pancreatic beta-cells to changes in insulin sensitivity in women at high risk for type 2 diabetes. Oral glucose tolerance tests (OGTTs) and frequently sampled intravenous glucose tolerance tests (FSIGTs) were conducted on Latino women with impaired glucose tolerance and a history of gestational diabetes before and after 12 weeks of treatment with 400 mg/day troglitazone (n = 13) or placebo (n = 12). Insulin sensitivity was assessed by minimal model analysis, and beta-cell insulin release was assessed as acute insulin responses to glucose (AIRg) and tolbutamide (AIRt) during FSIGTs and as the 30-min incremental insulin response (30-min dINS) during OGTTs. Beta-cell compensation for insulin resistance was assessed as the product (disposition index) of minimal model insulin sensitivity and each of the 3 measures of beta-cell insulin release. In the placebo group, there was no significant change in insulin sensitivity or in any measure of insulin release, beta-cell compensation for insulin resistance, or glucose tolerance. Troglitazone treatment resulted in a significant increase in insulin sensitivity, as reported previously. In response, AIRg did not change significantly, so that the disposition index for AIRg increased significantly from baseline (P = 0.004) and compared with placebo (P = 0.02). AIRt (P = 0.001) and 30-min dINS (P = 0.02) fell with improved insulin sensitivity during troglitazone treatment, so that the disposition index for each of these measures of beta-cell function did not change significantly from baseline (P > 0.20) or compared with placebo (P > 0.3). Minimal model analysis revealed that 89% of the change from baseline in insulin sensitivity during troglitazone treatment was accounted for by lowered plasma insulin concentrations. Neither oral nor intravenous glucose tolerance changed significantly from baseline or compared with placebo during troglitazone treatment. The predominant response of beta-cells to improved insulin sensitivity in women at high risk for type 2 diabetes was a reduction in insulin release to maintain nearly constant glucose tolerance.

Postpartum care of the woman with diabetes

The postpartum period in women with diabetes or GDM allows both the physician and mother to relax from the intensive medical and obstetric management that has permitted, in most cases, a successful and joyous outcome. The role of the physician, however, must switch to a proactive and preventive mode to formulate a reproductive health plan for women with diabetes and GDM. The plan should be individualized to address glycemic management and surveillance, nutritional management, contraception prescription, future pregnancy planning, and lifestyle changes. Essential to the development of a reproductive health plan is the active participation of the patient, who through education gains an understanding of the far-reaching effects her active participation will have on her subsequent health and possibly on that of her future children.

Patterns of congenital anomalies and relationship to initial maternal fasting glucose levels in pregnancies complicated by type 2 and gestational diabetes

OBJECTIVES

We sought to determine the types of congenital anomalies affecting infants of women with gestational diabetes mellitus or type 2 diabetes and to examine the relationship between those malformation types and measures of initial glycemia of women at entry into prenatal care with type 2 diabetes or at time of diagnosis in women with gestational diabetes mellitus.

STUDY DESIGN

A total of 4,180 pregnancies complicated by gestational diabetes mellitus (n = 3764) or type 2 diabetes (n = 416) that were delivered after 20 weeks of gestation were reviewed for the presence of congenital malformations diagnosed before hospital discharge. Anomalies were categorized as being absent, minor, major, genetic syndromes, or aneuploidies. Major anomalies were further categorized by the number and type of affected organ systems. In addition to maternal clinical and historical parameters, the initial fasting serum glucose either from the diagnostic glucose tolerance test (gestational diabetes mellitus) or at entry to prenatal care (type 2 diabetes) and the initial glycosylated hemoglobin before insulin therapy were examined for a relationship to anomalies.

RESULTS

The initial fasting serum glucose and glycosylated hemoglobin levels were significantly higher in pregnancies with major (n = 143) and minor (n = 112) anomalies and genetic syndromes (n = 9) compared with pregnancies with no anomalies (n = 3895). Of those pregnancies with major anomalies, the most commonly affected organ systems were the cardiac (37.6%), musculoskeletal (14.7%), and central nervous systems (9.8%) and anomalies involving multiple organ systems (16%). There was no increased predominance of any specific organ system involvement seen with increasing fasting serum glucose levels in pregnancies with major congenital anomalies. Pregnancies with major anomalies affecting multiple organ systems had significantly higher initial fasting serum glucose levels (166 +/- 64 mg/dL) compared with pregnancies in which one organ system was affected (141 +/- 55 mg/dL, P <.04) or no organ systems were affected (115 +/- 38 mg/dL, P <.0001).

CONCLUSION

Congenital anomalies in offspring of women with gestational and type 2 diabetes affect the same organ systems that have been previously described in pregnancies complicated by type 1 diabetes. Increasing hyperglycemia at diagnosis or presentation for care was associated with an increasing risk of anomalies in general and with anomalies involving multiple organ systems without a preferential increase in involvement of specific organ system.

Antepartum predictors of the development of type 2 diabetes in Latino women 11-26 months after pregnancies complicated by gestational diabetes

In this study, we sought to identify antepartum characteristics that predict the de novo development of diabetes 11-26 months after the index pregnancy in a carefully characterized cohort of women with gestational diabetes mellitus (GDM). Oral and frequently sampled intravenous glucose tolerance tests (OGTTs and FSIGTs), hyperinsulinemic-euglycemic clamps with labeled glucose, and body composition studies were performed on 91 islet cell antibody-negative Latino women with GDM during the third trimester of pregnancy. The women were documented to be diabetes-free within 6 months postpartum. Their diabetes status was ascertained again between 11 and 26 months postpartum. Logistic regression analysis was used to identify independent predictors of the development of diabetes within that interval. Fourteen of the women developed diabetes by World Health Organization criteria 11-26 months after delivery of the index pregnancy. Three antepartum variables were independent predictors of diabetes: the 1-h postchallenge plasma glucose concentration from the 100-g OGTT at which GDM was diagnosed (higher = increased risk; P = 0.003); an index of pancreatic beta-cell compensation for insulin resistance, defined as the product of the 30-min incremental plasma insulin:glucose ratio on a 75-g OGTT and the insulin sensitivity index from a hyperinsulinemic-euglycemic clamp (lower = increased risk, P = 0.009); and the basal glucose production rate after an overnight fast (higher = increased risk; P = 0.04). We conclude that postchallenge hyperglycemia, poor pancreatic beta-cell compensation for insulin resistance, and elevated endogenous glucose production during pregnancy precede the development of type 2 diabetes in young Latino women by at least 1-2 years.

Gestational diabetes: risk or myth?

As currently defined (5), gestational diabetes is associated with important perinatal and long-term health risks. Many of the risks increase, in relation to the severity of maternal hyperglycemia. For perinatal risks to infants, the relationship seems to be continuous. Maternal fasting glucose levels can be used to identify subsets of patients with very low and very high risks. The majority of pregnancies lie between these two extremes; and nonglucose measures, such as fetal ultrasound, can be used to enhance risk assessment, thereby minimizing over- and undertreatment of patients. The major long-term maternal risk is development of type 1 or type 2 diabetes, predominantly the latter. The risk increases continuously, in relation to maternal glycemia during and, especially, after pregnancy. Patients seem to have a B-cell defect that is characterized by maladaptation to insulin resistance. The B-cell defect is predictive of future diabetes, supporting the testing and clinical application of interventions that minimize insulin resistance to delay or prevent diabetes. Women with impaired glucose tolerance in the first few months postpartum are at particularly high risk for diabetes and should receive the most intensive education, intervention, and follow-up. Offspring of women with GDM are at increased risk for obesity and have an unexpectedly high prevalence of elevated glucose levels during childhood and adolescence. Both genetic and intrauterine environmental influences are likely to contribute to these abnormalities. Optimal strategies to detect and prevent the long-term risks to offspring remain to be established.

Multiple metabolic defects during late pregnancy in women at high risk for type 2 diabetes

Detailed metabolic studies were carried out to compare major regulatory steps in glucose metabolism in vivo between 25 normal pregnant Latino women without and 150 pregnant Latino women with gestational diabetes mellitus (GDM). The two groups were frequency-matched for age, BMI, and gestational age at testing in the third trimester. After an overnight fast, women with GDM had higher fasting plasma glucose (P = 0.0001) and immunoreactive insulin (P = 0.0003) concentrations and higher glucose production rates (P = 0.01) but lower glucose clearance rates (P = 0.001) compared with normal pregnant women. During steady-state hyperinsulinemia (approximately 600 pmol/l) and euglycemia (approximately 4.9 mmol/l), women with GDM had lower glucose clearance rates (P = 0.0001) but higher glucose production rates (P = 0.0001) and plasma free fatty acid (FFA) concentrations (P = 0.0002) than the normal women. These intergroup differences persisted when a subgroup of 116 women with GDM who were not diabetic < or = 6 months after pregnancy were used in the analysis. When all subjects were considered, there was a very close correlation between glucose production rates and plasma FFA concentrations throughout the glucose clamps in control (r = 0.996) and GDM (r = 0.995) groups. Slopes and intercepts of the relationships were nearly identical, suggesting that blunted suppression of FFA concentrations contributed to blunted suppression of glucose production in the GDM group. In addition to these defects in insulin action, women with GDM had a 67% impairment of pancreatic beta-cell compensation for insulin resistance compared with normal pregnant women. These results demonstrate that women with GDM have multiple defects in insulin action together with impaired compensation for insulin resistance. Our findings suggest that defects in the regulation of glucose clearance, glucose production, and plasma FFA concentrations, together with defects in pancreatic beta-cell function, precede the development of type 2 diabetes in these high-risk women.

Contraception and the risk of type 2 diabetes mellitus in Latina women with prior gestational diabetes mellitus

CONTEXT

Effective contraception is essential in women with prior gestational diabetes mellitus (GDM) but should not increase their already substantial risk of developing type 2 diabetes.

OBJECTIVE

To determine whether exposure to low-dose oral contraceptives increases the risk of developing type 2 diabetes mellitus in women with recent GDM.

DESIGN

Retrospective cohort study of 904 Latinas with GDM who gave birth between January 1987 and March 1994, in whom postpartum diabetes was excluded at 4 to 16 weeks post partum.

INTERVENTIONS

At their initial postpartum visit, 443 women selected a nonhormonal form of contraception, 383 received a low-dose, estrogen-progestin combination oral contraceptive (OC), and 78 breast-feeding women received the progestin-only OC. When breast-feeding ended, patients initially taking progestin-only OCs were switched to combination OCs. Patients were followed up periodically with oral glucose tolerance tests for up to 7 1/2 years.

MAIN OUTCOME MEASURES

Person time was used to compute unadjusted average annual incidence rates of developing diabetes mellitus, as defined by the National Diabetes Data Group Criteria. Survival analysis was used to compute the unadjusted cumulative incidence rates and adjusted relative risks of diabetes mellitus.

RESULTS

The unadjusted average annual incidence rates of type 2 diabetes mellitus were 8.7%, 10.4%, and 26.5%, respectively, for patients using nonhormonal forms of contraception, combination OCs, and progestin-only OCs. Cumulative incidence rates were virtually identical for patients with uninterrupted use of combination OCs and nonhormonal forms of contraception, but patients using progestin-only OCs developed diabetes mellitus more rapidly during the first 2 years of use. After adjustment for potential confounding factors, the use of progestin-only OCs almost tripled the risk of type 2 diabetes mellitus compared with equivalent use of low-dose combination OCs (adjusted relative risk, 2.87; 95% confidence interval, 1.57-5.27). The magnitude of this risk increased with duration of uninterrupted use.

CONCLUSION

Progestin-only OCs were associated with an increased risk of diabetes in breast-feeding Latinas with recent GDM and probably should be prescribed with caution, if at all, in these women. Long-term use of low-dose combination OCs did not increase the risk of type 2 diabetes compared with use of nonhormonal contraception. Thus, combination OCs do not appear to increase the risk of diabetes in non-breast-feeding women with recent GDM.

Gestational diabetes: antepartum characteristics that predict postpartum glucose intolerance and type 2 diabetes in Latino women

We examined antepartum clinical characteristics along with measures of glucose tolerance, insulin sensitivity, pancreatic beta-cell function, and body composition in Latino women with gestational diabetes mellitus (GDM) for their ability to predict type 2 diabetes or impaired glucose tolerance (IGT) within 6 months after delivery. A total of 122 islet cell antibody-negative women underwent oral and intravenous glucose tolerance tests (OGTT; IVGTT), hyperinsulinemic-euglycemic clamps, and measurement of body fat between 29 and 36 weeks' gestation and returned between 1 and 6 months postpartum for a 75-g OGTT. Logistic regression analysis was used to examine the relationship between antepartum variables and glucose tolerance status postpartum. At postpartum testing, 40% of the cohort had normal glucose tolerance, 50% had IGT, and 10% had diabetes by American Diabetes Association criteria. Independent antepartum predictors of postpartum diabetes were the 30-min incremental insulin:glucose ratio during a 75-g OGTT (P = 0.0002) and the total area under the diagnostic 100-g glucose tolerance curve (P = 0.003). Independent predictors of postpartum IGT were a low first-phase IVGTT insulin response (P = 0.0001), a diagnosis of GDM before 22 weeks' gestation (P = 0.003), and weight gain between prepregnancy and the postpartum examination (P = 0.03). All subjects had low insulin sensitivity during late pregnancy, but neither glucose clamp nor minimal model measures of insulin sensitivity in the 3rd trimester were associated with the risk of IGT or diabetes within 6 months' postpartum. These results highlight the importance of pancreatic beta-cell dysfunction, detectable under conditions of marked insulin resistance in late pregnancy, to predict abnormalities of glucose tolerance soon after delivery in pregnancies complicated by GDM. Moreover, the association of postpartum IGT with weight gain and an early gestational age at diagnosis of GDM suggests a role for chronic insulin resistance in mediating hyperglycemia outside the 3rd trimester in women with such a beta-cell defect.

Hormonal choices after gestational diabetes. Subsequent pregnancy, contraception, and hormone replacement

The effects of subsequent states of excess hormone exposure, for example, subsequent pregnancy, hormonal contraception, and hormonal replacement therapy, on the development of diabetes in women with prior gestational diabetes were assessed. Current literature examining the effect of parity, hormonal contraception, and hormonal replacement therapy in healthy women and women with previous gestational diabetes and current diabetes was reviewed. Subsequent pregnancy in women with prior GDM appears to triple the risk of subsequent diabetes. Low-dose progestin and estrogen combination oral contraceptives do not appear to clinically increase the risk of diabetes. Hormonal replacement therapy appears to provide the greatest reduction in coronary artery disease to women at greatest risk, i.e., those who have developed diabetes. Careful follow-up and metabolic surveillance should be provided when prescribing hormonal contraception or replacement therapy. In women with prior gestational diabetes, exposure to repeat pregnancy poses a greater risk for subsequent diabetes than does either an exposure to low-dose progestin and estrogen combination oral contraceptives or to postmenopausal hormonal therapy, both of which do not appear to increase the risk of diabetes.

Utility of fetal measurements in the management of gestational diabetes mellitus

The metabolic management of gestational diabetes mellitus (GDM) during pregnancy traditionally has focused on maintenance of circulating maternal glucose concentrations in all patients within a range that is associated with a low rate of perinatal morbidity, especially morbidity related to excessive fetal growth and macrosomia. Clinical data reviewed elsewhere in this supplement provide guidelines for glycemic targets that appear to eliminate the excess risk to the fetus. However, because only a minority of infants are at risk for perinatal morbidity over the range of glycemia generally encountered in patients with GDM, attainment of those strict glycemic targets in all women with GDM requires implementation of self-monitoring of glucose and exogenous insulin therapy in many pregnancies that are not at risk. In this article, we review management approaches that take into account not only maternal glycemia, but also fetal growth and metabolic parameters in selecting GDM pregnancies for intensive metabolic therapy. The approaches can reduce the number of women with mild GDM who require self-monitoring of glucose and/or exogenous insulin therapy, thereby providing the potential to improve cost-effectiveness of antepartum management of GDM.

Hyperinsulinism, neonatal obesity and placental immaturity in infants born to women with one abnormal glucose tolerance test value

Several groups have reported a risk of fetal macrosomia in pregnancies with maternal glucose intolerance which is intermediate between gestational diabetes (GDM) and normal glucose tolerance. The present study was designed to determine whether these pregnancies are also at risk for fetal obesity, hyperinsulinism and placental villous immaturity. 325 women with risk factors for GDM underwent a 75 g OGTT interpreted according to the O'Sullivan criteria. All women who met the criteria for GDM were managed with diet therapy. Insulin therapy was added for women with a mean serum glucose value > 100 mg/dl on a 24 hour glucose profile. Patients not meeting the GDM criteria were managed without special intervention. Primary outcome variables were measures of neonatal weight and skinfold thickness, fetal and neonatal insulin and glucose concentration, and placental villous maturation. Outcome parameters were compared among three groups: pregnancies with normal OGTT (control, n = 95), 1 abnormal value in the OGTT (1 abnl, n = 76) and GDM (n = 154). The outcome of pregnancies with 1 abnormal value in the OGTT was different from those with normal OGTT. Regarding fetal growth, rates of LGA were approximately twice as high in groups with one abnormal value and GDM (21% and 24%) compared to women with normal OGTTs (11%: p < 0.05 vs GDM and p = 0.07 vs 1 abnormal value). The percent of infants with skinfold thickness > 90th percentile was also greater in the 1 abnormal value and GDM groups (31.1 and 31.6% respectively) compared to controls (19.2%; p < 0.05 for GDM vs control only). Regarding fetal hyperinsulinism, AFI concentrations were similar in control and GDM groups (3.1 +/- 0.4 and 3.4 +/- 0.8 microU/ml, respectively), but were higher in the group with one abnormal OGTT value (4.3 +/- 1.2 microU/ml, p < 0.05 vs controls). Cord blood insulin: glucose ratios were elevated in both the 1 abnormal value and GDM groups (0.22 +/- 0.05 and 0.20 +/- 0.02 microU/ml per mg/dl), compared to controls (0.12 +/- 0.01 microU/ml per mg/dl, p < 0.05 vs 1 abnormal value). Neonatal glycemia < 30 mg/dl was significantly more common in the one abnormal value than in the control group (49% vs 34% of infants) and intermediate in the GDM group (40%). Severe placental villous immaturity was more than twice as frequent in the 1 abnormal value group compared to controls (24% vs 9%, p < 0.05) and the most frequent in the GDM group (33%; p < 0.001 vs controls). Pregnancies with glucose intolerance below the thresholds for diagnosis of GDM have an increased risk for fetal obesity, hyperinsulinism, postpartum hypoglycemia and placental immaturity. These findings indicate the continuum of risk for fetal morbidity associated with increasing maternal glucose intolerance in pregnancy.

Fetal lung maturation. Comparison of biochemical indices in gestational diabetic and nondiabetic pregnancies

OBJECTIVE

To compare the biochemical maturation of the components of the lung profile according to gestational age between reliably dated gestational diabetic and nondiabetic pregnancies.

STUDY DESIGN

Lung maturation was compared in reliably dated pregnancies in 501 gestational diabetic women and 561 nondiabetic women. Lecithin/sphingomyelin ratio (L/S) and phosphatidylglycerol (PG) were evaluated by analysis of variance according to the presence or absence of diabetes and weeks of gestational age. The effect of gestational diabetes on fetal lung maturation was determined by analysis of variance.

RESULTS

The gestational diabetic group had no clinical or statistical differences in L/S ratios as compared to the nondiabetic patients at any gestational age. There were no differences in mean percent PG between the diabetic and nondiabetic groups at any gestational age. By 37 completed weeks, 86% of the L/S ratios and 78% of the PG values were mature in the diabetic group as compared to 80% of the L/S ratios and 78% of the PG values in the control group (P = .33 and .43, respectively).

CONCLUSION

In reliably dated gestational diabetic pregnancies, biochemical maturation of the fetal lung strongly correlates with gestational age and does not appear to be significantly delayed when compared to a nondiabetic control group.