Randomized trial of diet versus diet plus cardiovascular conditioning on glucose levels in gestational diabetes

We studied the impact of a training program on glucose tolerance in gestational diabetes mellitus. Women with gestational diabetes mellitus (N = 19) were randomized into either group I, a 6-week diet alone group (24 to 30 kcal/kg/24 hours; 20% protein, 40% carbohydrate, 40% fat), or group II, which followed the same diet plus exercise (20 minutes three times a week for 6 weeks). An arm ergometer was used to maintain heart rate in the training range. Glycemic response was monitored by glycosylated hemoglobin, a 50 gm oral glucose challenge with a fasting and 1-hour plasma glucose, and blood glucose self-monitoring, fasting and 1 hour after meals. Week 1 glycemic parameters were the same for both groups. Week 6 data (mean +/- SD) were as follows: group I glycosylated hemoglobin, 4.7% + 0.2% versus group II, 4.2% +/- 0.2%; p less than 0.001. The group I glucose challenge fasting value was 87.6 +/- 6.2 versus 70.1 +/- 6.6 mg/dl, p less than 0.001 for group II. The group I 1-hour plasma glucose challenge result was 187.5 +/- 12.9 mg/dl versus 105.9 +/- 18.9 mg/dl for group II, p less than 0.001. The glycemic levels diverged between the groups at week 4. We conclude that arm ergometer training is feasible in women with gestational diabetes mellitus and results in lower glycosylated hemoglobin, fasting, and 1-hour plasma glucose concentrations than diet alone. Arm ergometer training may provide a useful treatment option for women with gestational diabetes mellitus and may obviate insulin treatment.     

C-peptide and insulin levels at 24-30 weeks' gestation: an increased risk of adverse pregnancy outcomes?

OBJECTIVE: The hypothesis was that fasting C-peptide and insulin values, during an oral glucose tolerance test (OGTT), might allow an estimation of the increased risk for gestational hypertension (GH) and fetal macrosomia. STUDY DESIGN: Two-hundred and six consecutive patients were submitted to an OGTT. Thirty-five developed gestational hypertension and 29 delivered large-for-gestational-age (LGA) newborns. Plasma glucose levels (mg/dl) and insulin levels (microU/ml) were measured fasting and after 60, 120 and 180 min C-peptide fasting levels (ng/ml) were also measured. RESULTS: Twenty-five patients were excluded, 181 were enrolled. According to the OGTT, 143 patients were classified as normal, 26 were found affected by gestational diabetes (GD) mellitus, and 12 had impaired gestational glucose tolerance (IGGT). Hypertensive women exhibited higher 60 and 120 min insulin values than the normotensive group (128.3+/-69.9 microU/ml versus 86.2+/-58.3 microU/ml, P<0.05; 104.9+/-66.4 microU/ml versus 78.7+/-56.5 microU/ml, P<0.05).C-peptide cut-off at 2.9 ng/ml resulted predictive for patients delivering large-for-gestational-age newborns (OR=3.42, 95% CI=1.59-7.39). CONCLUSIONS: C-peptide and insulin may be used as indicators of risk for the development of complications in late pregnancy.     

Recurrence of gestational diabetes mellitus.

OBJECTIVE: To assess the influence of several maternal and neonatal variables on the recurrence of gestational diabetes mellitus. METHODS: A retrospective review was conducted on 90 of our patients whose index pregnancy was complicated by gestational diabetes mellitus and whose subsequent pregnancy was also managed at our institution. RESULTS: Forty-seven women (52%) had a recurrence of gestational diabetes mellitus in their subsequent pregnancy. These 47 women had an increased body mass index (BMI) (32.8 +/- 8.2 versus 28.9 +/- 7.2 kg/m2; P < .03) and more large for gestational age (LGA) neonates (38 versus 14%; P < .05) and more of them required insulin during their index pregnancy (38 versus 19%; P < .05) than did those who did not have a recurrence of gestational diabetes mellitus. Women who developed a recurrence of gestational diabetes mellitus also had higher fasting (P < .05), 1-hour, 2-hour, and total glucose tolerance test values (P < or = .01) during their index pregnancy. CONCLUSION: Women with a history of gestational diabetes mellitus who have a BMI greater than 35 kg/m2, whose previous newborn was LGA, and who required insulin during their previous pregnancy are at increased risk for recurrence of gestational diabetes mellitus.     

One hour versus two hours postprandial glucose measurement in gestational diabetes: a prospective study.

OBJECTIVE: To compare the rate of adverse perinatal outcomes among women with gestational diabetes mellitus (GDM), monitored by 1 versus 2 hour-postprandial glucose (PPG) measurements. METHODS: A total of 112 women diagnosed with GDM, by the criteria of Carpenter-Coustan, were included in the study population. Women were recruited from two different treatment settings, but were managed by the same team of health-care professionals using a standardized protocol. Allocation to treatment group was based on treatment setting. Glucose levels were measured fasting, and either 1 hour (1-hour monitoring group-target values <140 mg/dl) or 2 hours (2-hour monitoring group-target values <120 mg/dl) postprandially. Demographic data and perinatal outcomes were collected from their medical records. RESULTS: In all, 66 women were assigned to 1-hour monitoring group (1 h-PPG) and 46 women to 2-hour monitoring group (2 h-PPG). There were no differences in parity, family history of diabetes, rate of GDM in previous pregnancies, weight gain, pregestational BMI and 50-g-glucose challenge test (GCT) and 100-g oral glucose challenge test (OGTT) results. As expected, there was a significant difference in mean blood glucose levels between the two groups (108.1+/-19.2 and 94.9+/-21.2 mg/dl, 1- and 2 hours, respectively, p<0.0001); however, HbA1C levels were similar in the two groups. Perinatal outcomes were defined as gestational week at delivery; fetal weight (3325+/-471 vs 3309+/-608 g, respectively) and percentile (47.2+/-27 vs 49.6+/-30, respectively), and were similar for both groups. Insulin therapy was initiated more frequently in 2-hour monitoring group (28 and 40% of women in groups 1 and 2, respectively; p<0.05). Rates of macrosomia (7.5 versus 10.6%), large for gestational age (7.4 versus 15.2%), and delivery by cesarean section (24 versus 30%) were increased in group 2 (2 h-PPG) but these differences did not reach statistical significance. CONCLUSION: These data suggest that diet control in women with GDM managed by 1-hour PPG measurements is associated with a decreased rate of insulin therapy. However, neonatal and obstetrical outcomes are not determined by the timing of their glucose determinations.     

Effects of new criteria for type 2 diabetes on the rate of postpartum glucose intolerance in women with gestational diabetes.

OBJECTIVE: Our purpose was to determine the impact of the 1997 American Diabetes Association diagnostic criteria for type 2 diabetes mellitus on the rate of postpartum glucose intolerance in women with gestational diabetes. STUDY DESIGN: Women identified as having gestational diabetes were instructed to undergo a 75-g, 2-hour glucose tolerance test 4 to 6 weeks after delivery. The results were retrospectively categorized with both the 1979 National Diabetes Data Group criteria and those recommended by the American Diabetes Association in 1997. RESULTS: Though the rate of overt diabetes mellitus did not increase when the 1997 American Diabetes Association criteria were used (7.8% vs 5.6%, P = not significant), the rate of impaired glucose metabolism was higher (20.1% vs 5%, P <.001). Most women (28/30, 93%) with a nondiagnostic glucose tolerance test result by the older criteria had abnormal results by the newer criteria. Fifty women had abnormalities of glucose metabolism under 1997 American Diabetes Association criteria; 34% of these women had fasting plasma glucose values in the normal range. Of the 25 women with impaired glucose tolerance, 16 (64%) had only an abnormal 2-hour value, with normal fasting glucose values. CONCLUSIONS: The rate of postpartum abnormalities in glucose metabolism more than doubles when the 1997 American Diabetes Association criteria are applied; more women are identified with lesser degrees of impairment. However, relying on fasting glucose levels alone, without glucose tolerance testing, may miss one third of women with such abnormalities.     

Effect of varying degrees of "normal" glucose metabolism on maternal and perinatal outcome

Prior studies concerning effects of varying degrees of normal glucose metabolism on pregnancy have reported an increase in the incidence of a variety of pregnancy complications in women with normal oral glucose tolerance test results as the glucose concentration after a standardized meal rose. However, these investigations have neglected to include a control group of women with gestational diabetes for comparison. We theorized that if the adverse outcomes noted were indeed a reflection of glucose concentration, women with gestational diabetes should have an even higher incidence of these complications. Mother and infant charts of 312 consecutive women undergoing an oral glucose tolerance test were reviewed. A glucose challenge test preceded the oral glucose tolerance test in 310. The glucose challenge test value was less than 140 mg/dl in 64 and greater than or equal to 140 mg/dl in 246. There were 63 abnormal oral glucose tolerance test results (2.7% of the population studied). Among all patients, the relationship between glucose challenge test and oral glucose tolerance test values followed a gradient with a progressive rise in mean oral glucose tolerance test values when the glucose challenge test result was greater than or equal to 160 mg/dl. However, the incidence of an abnormal oral glucose tolerance test result did not rise significantly until the glucose challenge test result exceeded 180 mg/dl. A wide variety of outcome parameters were studied; none were related to the glucose challenge test value. Similar analysis of the 2-hour oral glucose tolerance test value revealed an increase in the incidence of nonelective operative deliveries and a decrease in the percentage of infants discharged home with their mother where values were greater than 180 mg/dl. However, when women with gestational diabetes were excluded from analysis, neither the glucose challenge test nor the 2-hour glucose tolerance test measurements were related to adverse outcome. When analysis was limited to women with gestational diabetes, there was no clinically significant relationship between either glucose challenge test or 2-hour glucose tolerance test and the outcome parameters. Finally, when analysis was repeated according to diagnosis, women with gestational diabetes had a significantly higher risk of having nonelective operative delivery, premature delivery, growth-retarded neonate, 1-minute Apgar score less than 7, and neonatal hypoglycemia than women with normal oral glucose tolerance test results.(ABSTRACT TRUNCATED AT 400 WORDS)     

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.     

Clinical usefulness of estimation of serum fructosamine concentration as screening test for gestational diabetes

Serum fructosamine levels and fructosamine/protein ratios were measured in 100 pregnant women who underwent glucose tolerance tests because of clinical risk. Compared with normal pregnant women, the 13 study participants with gestational diabetes had higher fructosamine/protein levels (39 +/- 3.9 mumol/gm versus 37 +/- 3.2 mumol/gm, p less than 0.05), fasting serum glucose levels (107 +/- 13.7 mg/dl versus 82 +/- 8.6 mg/dl, p less than 0.001), and area under curve of glucose tolerance test (36 +/- 5 gm x min x dl-1 versus 22 +/- 3.6 gm x min x dl-1, p less than 0.001). The serum fructosamine levels were not significantly different between the two groups of participants (2.3 +/- 0.26 mmol/L versus 2.2 +/- 0.17 mmol/L); 10 of the 13 women with diabetes had a fructosamine/protein ratio within 2 SD of the mean of the groups of normal pregnant women. Spontaneous caloric intakes (r = 0.72, p less than 0.005) and the hospital mean daily capillary glucose levels during diabetic diet (r = 0.72, p less than 0.005) correlated better with the fructosamine/protein ratio than with fasting serum glucose levels (r = 0.58, p less than 0.05) and area under curve (r = 0.57, p less than 0.05). Consequently, serum fructosamine and fructosamine/protein ratio levels should be considered insensitive as a screening test in pregnant patients with clinical risk of gestational diabetes.     

Should the fifty-gram, one-hour plasma glucose screening test for gestational diabetes be administered in the fasting or fed state?

To determine whether the 50 gm, 1-hour plasma glucose screening test for gestational diabetes should be administered in the fasted or fed state, 50 presumed normal and 20 gestational diabetic pregnant women in the early third trimester underwent this test twice, once under each condition, within a 1-week interval. There was no difference in test results under the two conditions among the normal individuals (fasted 118.4 +/- 24.7 mg/dl; fed 115.8 +/- 23.4 mg/dl). However, when the test was administered to women with known gestational diabetes, the result was significantly (p = 0.011) higher if patients were fasted (173.9 +/- 28.8 mg/dl) than if they had been given a standard 600 kcal meal 1 hour previously (154.8 +/- 24.1 mg/dl). The effect of these two conditions on the sensitivity and specificity of the screening test is described, and it is suggested that the threshold for glucose tolerance testing be 130 mg/dl if the test is administered in the fed state.     

Low values on 50 gram glucose challenge test or oral 100 gram glucose tolerance test are associated with good perinatal outcome.

We set out to reevaluate the hypothesis that high normal (negative) results of 50 g oral glucose challenge test or high normal glucose level on 100 g oral glucose tolerance test are associated with complications of pregnancy and delivery. This was a prospective study involving 735 nondiabetic women. The first group (n=352) was made up of pregnant women with normal 50 g oral glucose challenge test without previous history of diabetes mellitus or gestational diabetes. The second group (n=383) was made up of pregnant women without previous history of diabetes mellitus or gestational diabetes with an abnormal 50 g oral glucose challenge test and with normal 100 g oral glucose tolerance test and not more than one previous delivery. In nondiabetic women, we demonstrated a positive correlation between high normal 50 g glucose challenge test values and the incidence of preeclampsia, caesarean section rate, macrosomia, neonatal hyperlipidaemia and minor congenital abnormalities. We failed to confirm any relationship to any pregnancy complication in pregnant women with 2-hour glucose levels in the range 6.7-9.1 mmol/l on the 100 g oral glucose tolerance test. We have demonstrated a positive relationship between the incidence of premature rupture of membranes and 1-hour glucose level, caesarean section rate and maternal 1-hour glucose level or 1-hour glucose level minus fasting glucose level of 4.2 mmol/l, instrumental delivery rate and maternal 3-hour glucose level, incidence of neonatal macrosomia and 1-hour glucose level, and incidence of neonatal hyperlipidaemia and at least one high but normal glucose level on the 100 g oral glucose tolerance test. With regard to pregnancy and delivery complications there were no significant difference if the high normal value is on the 50 g glucose challenge test or on the 100 g oral glucose tolerance test. It is concluded that one high normal 100 g oral glucose tolerance test or high normal 50 g glucose challenge test are associated with adverse pregnancy and delivery outcome. Nondiabetic women with 50 g glucose challenge test value of 6.1 mmol/l and/or 100 g oral glucose tolerance test values of 5 mmol/l have a favourable pregnancy and delivery outcome.     

Longitudinal changes in plasma glucose values of the 75-g glucose tolerance test in triplet pregnancies

We evaluated longitudinal changing patterns of 75 g glucose tolerance test (GTT) in triplet pregnancies. Eight triplet pregnancies were prospectively studied. All triplet pregnancies were fertilized with artificial reproductive techniques; patients showed no glucosuria or fasting hyperglycemia > 100 mg/dL before pregnancy. The 75-g GTT was performed at first, second, and third trimester, as well as at postpartum. Longitudinal changes in glucose levels at fasting, 1 hour, and 2 hours were compared by one-way repeated-measure analysis of variance (ANOVA) and Bonferroni/Dunn test ( p < 0.05). Values were expressed as mean +/- standard deviation. Each of the 3-point values of 75-g GTT decreased after 28 weeks of gestation in triplet pregnancies. During the third trimester, fasting values were significantly decreased compared with postpartum values (65.5 +/- 13.4 versus 74.6 +/- 4.0 mg/dL), and 2-hour values were significantly decreased from those of second-trimester 75-g GTT (116.3 +/- 19.5 versus 99.6 +/- 17.1 mg/dL). Longitudinal glucose values of 75-g GTT improve during third trimester in triplet pregnancies, suggesting that fetoplacental fuel drain may counterbalance maternal insulin resistance.     

Urinary C-peptide in the neonate correlates both to maternal glucose tolerance and to fetal size at birth

In 18 women with gestational diabetes the variables of an oral glucose tolerance test (fasting and 2-hour blood glucose values and area under the blood glucose curve) performed in the last trimester of pregnancy correlated significantly with the urinary C-peptide excretion during the first 12 hours of the life (r = 0.47, 0.71, and 0.60, respectively). In a combined group with 28 type II pregnant diabetic women there was also a significant correlation between the urinary C-peptide excretion of the infants and their skinfold. Assay of the urinary C-peptide excretion of the neonate, reflecting its insulin production, seems to be a sensitive parameter to study the influence of the maternal carbohydrate metabolism in the offspring.     

Capillary blood glucose screening for gestational diabetes: a preliminary investigation

Home glucose monitoring with the use of reflectance meters is an important adjunct in the care of pregnant women with insulin-dependent diabetes. The accuracy of reflectance meters for the assay of capillary glucose specimens has been well documented. The present preliminary study was undertaken to determine the utility of outpatient screening for gestational diabetes mellitus with the use of a reflectance meter (Accu-Chek, Boehringer Mannheim Co.). One hundred twenty-five patients in our high-risk practice had a standard 50 gm glucose load at 26 to 28 weeks' gestation. Capillary glucose values were measured on site with the Accu-Chek. Venous plasma glucose levels were measured by the central laboratory chemistry analyzer. While the laboratory (x) and meter (y) glucose determinations between the two sets of values were highly correlated (R = 0.89, p less than 0.001), there was a significant difference in their average values (x = 111.74, y = 136.35, p less than 0.0001). With the use of a receiver operator characteristic curve, a meter value of 160 mg/dl was determined as the optimal threshold for performing a 3-hour glucose tolerance test. The sensitivity and specificity with the use of a meter value of 160 mg/dl were 93% and 96%, respectively, for detecting an abnormal screening test in venous plasma (greater than or equal to 135 mg/dl). A total of 32 glucose tolerance tests were performed, with four patients included who had venous values less than 135 mg/dl. All eight patients with gestational diabetes mellitus were correctly identified. These data suggest that a glucose reflectance meter can be used for accurate outpatient screening of gestational diabetes mellitus. The potential advantages of capillary blood glucose screening include both cost and efficiency. Patients with abnormal screening values can be promptly identified and scheduled for a follow-up 3-hour glucose tolerance test.     

Does a High Carbohydrate Preparatory Diet Affect the 3-Hour Oral Glucose Tolerance Test in Pregnancy?

The aim of this study was to determine the effect of a high carbohydrate preparatory diet on the performance of the 3-hour oral glucose tolerance test (OTT) in pregnancy. This prospective clinical trial was performed at a university hospital outpatient obstetric clinic. Gravidas who had an abnormal blood sugar screening test were asked to ingest one of two preparatory diets: ≥ 150g/day of carbohydrate for 3 days (Carbo) or six Snickers? candy bars per day for 3 days (Candy), or to remain on their usual diet (Ad lib) prior to the GTT. A 100g oral OTT was performed after an overnight fast, and blood glucose values were determined at 1, 2, and 3 hours. Patients with either a fasting whole blood glucose > 120 mg/dl or ≥ two abnormal values on the GTT were considered to have gestational diabetes mellitus and received diet therapy. Women who failed diet therapy also received insulin. Our primary outcome parameter was the intergroup incidence of gestational diabetes mellitus. Other parameters included the mean 1-, 2-, and 3-hour glucose values and the rates of both cesarean delivery and large-for-gestational age infants. Of the 354 women studied, 108 entered the Carbo group, 105 entered the Candy group, and 141 comprised the Ad Lib group. The three groups were comparable with regard to historic and demographic risk factors for gestational diabetes mellitus. After the OTT, 29% of the Carbo group were considered to have gestational diabetes mellitus vs. 28% in both the Ad lib and Candy groups (P = 0.98). Additionally, both the mean intergroup fasting, 1-hour, 2-hour, and 3-hour whole blood glucose values and selected clinical outcomes were similar (P = 0.35–0.99). Compared to usual dietary intake, recommending a high carbohydrate diet had a negligible effect on the 100g oral OTT in pregnancy.     

Increased fetal adiposity: a very sensitive marker of abnormal in utero development

OBJECTIVE: Because offspring of women with gestational diabetes mellitus have an increased risk of obesity and diabetes mellitus as young adults, our purpose was to characterize body composition at birth in infants of women with gestational diabetes mellitus and normal glucose tolerance. STUDY DESIGN: One hundred ninety-five infants of women with gestational diabetes mellitus and 220 infants of women with normal glucose tolerance had anthropometric measurements and total body electrical conductivity body composition evaluations at birth. Parental demographic, anthropometric, medical and family history data, and diagnostic glucose values were used to develop a stepwise regression model that related to fetal growth and body composition. RESULTS: There was no significant difference in birth weight (gestational diabetes mellitus [3398+/-550 g] vs normal glucose tolerance [3337+/-549 g], P=.26) or fat-free mass (gestational diabetes mellitus [2962+/-405 g] vs normal glucose tolerance [2975+/-408 g], P=.74) between groups. However, infants of women with gestational diabetes mellitus had significantly greater skinfold measures (P=.0001) and fat mass (gestational diabetes mellitus [436+/-206 g] vs normal glucose tolerance [362+/-198 g], P=.0002) compared with infants of women with normal glucose tolerance. In the gestational diabetes mellitus group, although gestational age had the strongest correlation with birth weight and fat-free mass, fasting glucose level had the strongest correlation with neonatal adiposity. CONCLUSION: Infants of women with gestational diabetes mellitus, even when they are average weight for gestational age, have increased body fat compared with infants of women with normal glucose tolerance. Maternal fasting glucose level was the strongest predictor of fat mass in infants of women with gestational diabetes mellitus. This increase in body fat may be a significant risk factor for obesity in early childhood and possibly in later life.     

Does insulin secretion in patients with one abnormal glucose tolerance test value mimic gestational diabetes mellitus?

OBJECTIVE: The purpose of this study was to investigate the insulin response to a 3-hour oral glucose tolerance test and to compare the insulin levels in the gestational diabetes mellitus and single abnormal test value groups with a nondiabetic control group. STUDY DESIGN: One hundred ten Turkish women with uncomplicated pregnancy participated in this prospective controlled study between 24 to 28 weeks of gestation. A 100-g 3-hour oral glucose tolerance test was given, and glucose and insulin plasma levels were assayed. The subjects were classified according to established criteria. Early-phase insulin secretion was assessed by the insulinogenic index. Total insulin secretion was assessed by mean insulin level during the oral glucose tolerance test; insulin resistance was assessed by fasting insulin concentration and by the use of the homeostasis model. Data were analyzed by the Student t test and 1-way analysis of variance, with posthoc Bonferroni correction. RESULTS: The fasting insulin levels of patients with normal oral glucose tolerance test results were significantly lower than those of patients with gestational diabetes mellitus and a single value abnormality (P <.001 and P <.005, respectively). The insulinogenic index as a marker of early-phase insulin secretion was significantly lower in gestational diabetes mellitus, compared with that of patients with normal oral glucose tolerance test results (P <.05). The worsening of glycemic profile from normal oral glucose tolerance test results to gestational diabetes mellitus was associated with an increase in the homeostasis model; no significant difference was found between gestational diabetes mellitus and a single value abnormality group in terms of both the homeostasis model and the insulinogenic index. Values for total insulin secretion were highest in gestational diabetes mellitus, followed by the single value abnormality group, both significantly differing from the values of patients with normal oral glucose tolerance test results (P <.001 and P <.005, respectively). CONCLUSION: In this prospective study of Turkish subjects, we found a striking similarity in terms of patient characteristics between the gestational diabetes mellitus group and the single value abnormality group. Additionally, when we used fasting insulin level and insulin resistance as 2 separate criteria of analysis, patients with single value abnormality were indistinguishable from patients with gestational diabetes mellitus; both groups were significantly different from the normal oral glucose tolerance test group. Our findings suggest that a single abnormal test value on an oral glucose tolerance test should be regarded as a pathologic finding and that the patient with a single abnormal test value may be treated similarly to the patient with gestational diabetes mellitus.     

Low sensitivity of serum fructosamine as a screening parameter for gestational diabetes mellitus.

Oral glucose tolerance testing (OGTT) and quantification of serum fructosamine levels were performed in 190 asymptomatic women in weeks 24-28 of pregnancy. OGTT identified 10 of the 190 women as having gestational diabetes, but serum fructosamine quantification failed to do so because none of these 10 women exhibited levels exceeding the normal limit of 2.76 mmol/l. The mean fructosamine level in this group was 1.72 +/- 0.25 mmol/l compared to 1.60 +/- 0.15 mmol/l in the other 180 women without gestational diabetes. Fructosamine was found to correlate only with postload glucose values in excess of 180 mg/dl at 2 h (r = 0.87; p = 0.01), i.e. with the highest overall glucose values, but not with fasting glucose or milder postprandial hyperglycemia of under 180 mg/dl. We conclude that quantification of fructosamine detects only the rather severe cases of gestational hyperglycemia, but is too insensitive to uncover mild asymptomatic gestational diabetes mellitus, and we do not consider fructosamine to be a useful parameter for the diagnosis of this condition.     

Accelerated starvation in late pregnancy: a comparison between obese women with and without gestational diabetes mellitus

We compared the glucose, insulin, free fatty acid, and 3-hydroxybutyrate responses to a briefly extended overnight fast during the third trimester of pregnancy between two groups: obese women with normal glucose tolerance (n = 10) and age- and weight-matched women with gestational diabetes mellitus (n = 10). After a 12-hour overnight fast, plasma glucose (95 +/- 4 vs. 78 +/- 2 mg/dl; p less than 0.01), insulin (32 +/- 5 vs. 17 +/- 2 microU/ml; p less than 0.02), and free fatty acid (860 +/- 63 vs. 639 +/- 79 mmol/L; p less than 0.05) levels were higher in the patients with gestational diabetes mellitus. 3-Hydroxybutyrate levels were similar in the two groups at that time (0.23 +/- 0.04 vs. 0.18 +/- 0.03 mmol/L; p greater than 0.3). When the fast was extended to 18 hours by having the patients skip breakfast, glucose levels fell more rapidly in the group with gestational diabetes mellitus but remained elevated compared with the nondiabetic women. Insulin levels declined at a similar rate in the two groups. Free fatty acid levels did not increase significantly in the group with gestational diabetes mellitus during the extended fast. In contrast, free fatty acid levels increased by 44% in the normal pregnant women, reaching the level observed in the group with gestational diabetes mellitus after 18 hours. 3-Hydroxybutyrate levels remained virtually identical in the two groups throughout the brief fast. Thus, compared with that of normal pregnant women, the response of obese women with gestational diabetes mellitus to brief caloric deprivation during late pregnancy was characterized by a greater fall in plasma glucose values without a greater propensity to ketosis. Our findings may have important implications for the dietary management of obese patients with gestational diabetes mellitus.     

Continuous subcutaneous insulin infusion (CSII) in pregnant diabetic patients

The efficacy of the insulin infusion pump (CSII) in pregnancy was examined in 12 diabetic patients and compared with intermittent insulin therapy (IIT). In patients poorly controlled on IIT constant and rapid equilibrium was achieved with CSII (mean of glucose levels: CSII versus IIT = 84 versus 137 mg/dl; S.D. = 36 versus 63 mg/dl; mean amplitude of glycemic excursion (MAGE) = 65 versus 112 mg/dl. In patients well controlled on IIT, CSII led to a reduction in the variation of glucose excursions (S.D. = 29 versus 36 mg/dl; MAGE = 48 versus 76 mg/dl). CSII generally produced a reduction of 20-37 per cent of daily insulin dose (in three cases there was an increase of dose with the achievement of glycemic control). Furthermore in CSII treated-patients amniotic glucose, insulin and C-peptide concentrations were found to be in the normal range (22.1 +/- 10.1 mg/dl; 5.2 +/- 2.7 microU/ml; 1.25 +/- 0.71 ng/ml, respectively). All infants were born at or near-term, had no macrosomia or neonatal problems. It is concluded that CSII is a highly efficient way to achieve normal glucose levels in pregnancy, not only in type I, but also in type II or gestational diabetes.     

Perinatal complications in women with gestational diabetes mellitus

BACKGROUND: The aim of the study was to examine the outcome of the pregnancy and neonatal period in 1) women with gestational diabetes mellitus and non-diabetic pregnant women, and 2) in women with early and late diagnosis of gestational diabetes mellitus. METHODS: Included were 327 women with gestational diabetes mellitus and 295 non-diabetic women, who were screened with a 75 g oral glucose tolerance test because of risk factors for gestational diabetes. Women with gestational diabetes mellitus were treated with low-caloric diet and insulin when appropriate, while women in the control group received routine antenatal care. RESULTS: Gestational age at delivery was significantly lower in the group with gestational diabetes mellitus, both when considering all deliveries (39.1+/-1.7 weeks versus 39.8+/-2.0 weeks, p<0.05) and only those with spontaneous onset of labor (38.8+/-2.0 weeks versus 40.0+/-1.6 weeks, p<0.05). The frequency of macrosomia was increased, although not statistically significant (8% vs. 2%, p=0.07), and the rate of admission to the neonatal ward was significantly increased (18% vs. 9%, p<0.05) in the group with gestational diabetes. Women with early diagnosis of gestational diabetes mellitus had a significantly increased need for insulin treatment during pregnancy (36% vs. 9% p<0.05) and a significantly higher occurrence of diabetes mellitus at follow-up from two months until three years postpartum. CONCLUSIONS: This study of women with gestational diabetes mellitus and non-diabetic pregnant women showed that gestational diabetes mellitus was associated with a significantly lower gestational age at delivery and an increased rate of admission to the neonatal ward. Women diagnosed with GDM before 20 weeks of gestation had an increased need for insulin treatment during pregnancy and a high risk of subsequent overt DM, compared with women diagnosed with GDM later in pregnancy.