Prediction of postpartum diabetes in women with gestational diabetes mellitus

Aims/hypothesis  

We studied the incidence of postpartum diabetes after gestational diabetes mellitus and investigated biochemical and clinical predictors of postpartum diabetes.     

Transforming growth factor-beta 1 levels in women with prior history of gestational diabetes mellitus

It is known that women with prior history of gestational diabetes mellitus (pGDM) feature obesity, insulin resistance and endothelial dysfunction which cause premature atherosclerosis. Transforming growth factor-beta 1 (TGF-beta1) is a key cytokine in obesity and insulin resistance and also play important roles in the development of atherosclerosis. This study was conducted to demonstrate the serum TGF-beta1 levels of people with pGDM. Thirty women with pGDM, 20 women with type 2 diabetes mellitus (T2DM) and 20 healthy women were enrolled. Serum TGF-beta1 levels of people with pGDM were found to be significantly higher than healthy controls and significantly lower than women with T2DM. TGF-beta1 levels were found to be correlated with postprandial glucose and age and inversely correlated with body mass index (BMI) and waist circumference. On multiple regression analysis postprandial glucose level, age and BMI were determined as the most important factors affecting TGF-beta1 levels. This study demonstrates elevated TGF-beta1 levels in pGDM. The inflammatory response to hyperglycemia and insulin resistance could be the major factors for the increased expression of TGF-beta1.     

Renal antioxidant enzyme mRNA levels are increased in rats with experimental diabetes mellitus

Summary Exposure to high glucose concentrations increases the mRNA levels of oxygen radical scavenging enzymes in cultured endothelial cells, suggesting a compensatory response to increased free radical production. To test the hypothesis that this response also occurs in vivo, Cu,Zn-superoxide dismutase (Cu,Zn-SOD) and catalase mRNA levels, were measured in the kidneys of Sprague-Dawley rats 17 days after intravenous injection of streptozotocin (60 mg/kg body weight) and compared with those of control rats. Diabetic rats were either left untreated or given differing insulin regimens (2, 3–8, 6–10 IU/day) in two different experiments that were designed to achieve varying degrees of metabolic control. Cu,Zn-SOD and catalase mRNA levels were measured by Northern blot hybridization and standardized by 28S ribosomal RNA determination. Renal Cu,Zn-SOD and catalase mRNA levels were significantly greater in untreated diabetic and in low-dose (2 IU/day) insulin-treated rats than in controls. Treatment with a moderate dose (3–8 IU/day) of insulin normalized catalase but not Cu,Zn-SOD mRNA levels. The highest insulin regimen (6–10 IU/day), in addition to achieving complete metabolic control as evidenced by normal growth and plasma glucose levels, normalized both catalase and Cu,Zn-SOD mRNA levels. Thus, in rats with streptozotocin-induced diabetes Cu,Zn-SOD and catalase renal mRNA levels are greater than in normal rats. This difference is prevented by sufficient insulin dosage to normalize plasma glucose and might be due to an increased production of free radicals. [Diabetologia (1997) 40: 23–29] Received: 15 May 1996 and in revised form: 16 October 1996     

Increased cholesterol intake in women with gestational diabetes mellitus

AIM: Cholesterol intake is associated with the risk for type 2 diabetes mellitus, but no previous studies have evaluated its role regarding the risk of gestational diabetes mellitus (GDM). We investigate the relation between cholesterol intake and GDM. METHODS: At screening for GDM, 335 pregnant women were evaluated for dietary intake (including cholesterol) during the previous year (validated food-frequency questionnaire). RESULTS: Forty-one women were diagnosed with GDM and 294 did not meet the GDM criteria. Women with GDM were older (32.8+/-0.7 vs. 30.2+/-0.3 years; P=0.01) and had a higher body mass index (27.3+/-0.7 vs. 24.3+/-0.3 kg/m2; P=0.01) than women without GDM. They also had more frequently a family history of type 2 diabetes mellitus (51.2% vs. 40.0%; P=0.02) and history of previous GDM (14.6% vs. 1.7%; P=0.01), and were evaluated earlier in pregnancy (22.1+/-1.2 vs. 24.9+/-0.5 weeks; P=0.03). There were no significant differences between groups in smoking habit, and alcohol, total energy, protein, carbohydrate, fats and fiber intake. Women with GDM had a higher cholesterol intake than women without GDM (145.3+/-4.5 mg/1000 kcal vs. 134.5+/-1.6 mg/1000 kcal; P=0.03). In a multiple logistic regression model, previous GDM, BMI, age and cholesterol intake (OR=1.88; 95% CI: 1.09-3.23 for each increase of 50 mg/1000 kcal) were independently and positively associated with GDM. CONCLUSION: We conclude that cholesterol intake is independently associated with GDM and that it could be involved in the pathogenesis of GDM.     

Vascular function in women with previous gestational diabetes mellitus

It is hypothesised that vascular dysfunction, which characterises type 2 diabetes, may predate development of hyperglycaemia. 17 women with previous gestational diabetes mellitus, and thus at risk of developing type 2 diabetes, were matched with normal controls for body mass index, menstrual phase, smoking, age, blood pressure, and lipid profiles. All had normal glucose tolerance. Tests of microvascular and macrovascular function, including endothelium-dependent and -independent vasodilatation, were performed. Laser Doppler fluximetry of maximum skin microvascular hyperaemia in response to local heating of the dorsum of the foot to 42 degrees C for 30 min was impaired in subjects compared to controls [subjects = 1.15 (0.73-1.73) V median (range) versus controls = 1.50 (0.95-2.29) V, p = 0.008]. There were no differences in laser Doppler perfusion imaging of responses to forearm skin iontophoresis of acetylcholine [subjects = 1.59 (0.32-2.55) V median (range) versus controls = 1.79 (0.72-2.06) V; p = 0.81] and sodium nitroprusside [subjects = 1.39 (0.8-3.14) V versus controls = 1.41 (0.34-2.19) V; p = 0.68], ultrasound estimation of brachial artery flow-mediated dilatation [subjects = 1.65 (-0.5-9.07)% versus controls = 2.77 (0.63-6.6)%; p = 0.42] and glyceryl trinitrate-induced dilatation [subjects = 15.20 (6.64-20.91)% versus controls = 15.92 (3.94-22.09)%; p = 0.48]. Microvascular maximum hyperaemia was impaired in the index group, suggesting the presence of a defect in vascular function. This defect was not explained by those aspects of endothelial function measured by the other techniques.     

Changes in visfatin levels after oral glucose tolerance test in women with gestational diabetes mellitus

Visfatin levels increased following an oral glucose tolerance test (OGTT) in normal pregnancy, and this increase correlated with metabolic indexes such as blood glucose, blood fat, and insulin resistance. Conversely, visfatin levels in women with gestational diabetes mellitus (GDM) increased to lesser extent than in normal pregnancy, which suggests a disorder in the relationship between visfatin, blood glucose and insulin.     

Circulating homocysteine levels in patients with type 2 diabetes mellitus

Background and aimPrevious studies have shown conflicting results regarding circulating homocysteine levels in patients with type 2 diabetes.Methods and resultsThis observational study included 2121 patients with angiographically proven coronary artery disease (507 patients with type 2 diabetes and 1614 patients without diabetes). Circulating homocysteine levels, methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphism, renal function, presence of coronary artery disease (CAD) diagnosed by coronary angiography, and circulating folate and vitamin B₁₂ status were assessed. Plasma homocysteine levels [median (25th; 75th percentile)] were significantly higher in patients with diabetes than in those without [12.4 μmol/L (9.9 μmol/L; 15.9 μmol/L) versus 11.7 μmol/L (9.6 μmol/L; 14.5 μmol/L), P = 0.011]. Diabetes affected homocysteine levels only in patients with a glomerular filtration rate <90 mL/min [13.0 μmol/L (10.5 μmol/L; 16.7 μmol/L) in patients with diabetes versus 12.2 μmol/L (10.1 μmol/L; 15.2 μmol/L) in patients without diabetes, P = 0.006] but not in those with a glomerular filtration rate ≥90 mL/min [10.1 μmol/L (8.1 μmol/L; 12.4 μmol/L) versus 10.2 μmol/L (8.8 μmol/L; 12.3 μmol/L), P = 0.267]. Multivariable analysis did not show an independent association between diabetes and homocysteine level (P = 0.342).ConclusionCirculating homocysteine levels are increased in patients with type 2 diabetes compared with non-diabetic patients due to a more diabetes-associated adverse risk profile rather than to diabetes itself.     

Iron status in women with and without gestational diabetes mellitus

ObjectiveGestational diabetes mellitus (GDM) affects approximately 7% of all pregnancies. Pregnancy, mostly because of the mitochondria-rich placenta, is a condition that favors oxidative stress. A transitional metal, especially iron, which is particularly abundant in the placenta, is important in the production of free radicals. Also, studies have shown that free radicals have a role in GDM. As there are little data about iron status in GDM, this study was performed to compare iron status in GDM and control group.Research Design and MethodsIn this case-control study, 34 women with diagnosed GDM were compared with 34 non-GDM women in the control group at 24–28 weeks of pregnancy in terms of iron status, including ferritin, serum iron, total iron-binding capacity (TIBC), hemoglobin (Hb), mean corpuscular volume (MCV), and mean corpuscular hemoglobin (MCH).ResultsIn this study, concentration of serum ferritin, iron, transferrin saturation and hemoglobin, MCV, and MCH was significantly higher in the GDM group and TIBC was significantly lower in this group (P<.05). No significant association was observed with the other variables including familial history of diabetes and GDM.ConclusionOur findings indicate an association between increased iron status and GDM. The role of iron excess from iron supplementation in the pathogenesis of GDM needs to be examined.     

Managing women with gestational diabetes mellitus in the postnatal period

Guidelines for management of women with a history of gestational diabetes mellitus (GDM) in the postpregnancy period have lagged behind the recognition that this is an important time for medical intervention. However, in the past decade, the evidence-base for screening algorithms, contraceptive management, diabetes prevention strategies and implications for offspring has expanded. In this review, we discuss current recommendations for managing women with GDM in the postnatal period, with particular attention to postpartum diabetes screening, prevention of future glucose intolerance and family planning.     

Relative hypoleptinaemia in women with mild gestational diabetes mellitus.

AIMS: There is increasing evidence suggesting that leptin plays a major role in the regulation of energy homeostasis, as well as in the neuroendocrine and reproductive systems. Leptin is synthesized in the human placenta. The aim of this study was to relate serum leptin levels during pregnancy to glucose tolerance, body mass index (BMI) and specific metabolic variables, such as specific insulin and proinsulin. METHODS: A 2-h 75 g oral glucose tolerance test was performed in 221 pregnant women at 22-29 weeks of gestation (median 25th week). Serum leptin was measured using a radioimmunoassay. In 49 women, sequential leptin measurements were performed (during pregnancy and post partum (median 5 months)). RESULTS: During pregnancy serum leptin was significantly related to body weight (r = 0.49), BMI (r = 0.51), fasting immunoreactive insulin (r = 0.46), specific insulin (r = 0.43) and proinsulin (r = 0.29) (all P-values <0.0001). In women with mild gestational diabetes (GDM, n = 55), leptin levels were lower compared to women with normal glucose tolerance (n = 166) after adjusting for BMI and fasting insulin (26.9 vs. 19.4 ng/ml, P = 0.0001). Leptin was significantly higher during pregnancy compared to post partum (mean +/- SE: 24.3+/-1.5 vs. 19.6+/-1.6 ng/ml, P = 0.0003), even after adjustment for changes in BMI and changes in fasting insulin (P = 0.013). CONCLUSIONS: Leptin levels are elevated in pregnancy. Women with mild GDM presented with relative hypoleptinaemia compared to women with normal glucose tolerance.