Is there an oxidative cost of acute stress? Characterization, implication of glucocorticoids and modulation by prior stress experience

Acute rises in glucocorticoid hormones allow individuals to adaptively respond to environmental challenges but may also have negative consequences, including oxidative stress. While the effects of chronic glucocorticoid exposure on oxidative stress have been well characterized, those of acute stress or glucocorticoid exposure have mostly been overlooked. We examined the relationship between acute stress exposure, glucocorticoids and oxidative stress in Japanese quail (Coturnix japonica). We (i) characterized the pattern of oxidative stress during an acute stressor in two phenotypically distinct breeds; (ii) determined whether corticosterone ingestion, in the absence of acute stress, increased oxidative stress, which we call glucocorticoid-induced oxidative stress (GiOS); and (iii) explored how prior experience to stressful events affected GiOS. Both breeds exhibited an increase in oxidative stress in response to an acute stressor. Importantly, in the absence of acute stress, ingesting corticosterone caused an acute rise in plasma corticosterone and oxidative stress. Lastly, birds exposed to no previous acute stress or numerous stressful events had high levels of GiOS in response to acute stress, while birds with moderate prior exposure did not. Together, these findings suggest that an acute stress response results in GiOS, but prior experience to stressors may modulate that oxidative cost

Hyperglycaemia in pregnancy in Mediterranean women

New diagnostic criteria have recently been proposed that will result in a higher proportion of individuals being diagnosed as suffering from gestational diabetes mellitus (GDM) than previously. The present circum-Mediterranean study sets out to identify the relevance of the new criteria in this population. The study was a prospective, non-interventional, multicentre study in the Mediterranean region. A convenient sample of 1,368 pregnant women was recruited. All participants underwent a 75 g oGTT subdivided into five different glycaemic categories. The women's anthropomorphic and biological data, together with obstetric and infant outcomes, were collected. There was a threefold increase in diagnosis using the new criteria. Most of the biological characteristics generally associated with GDM showed high specificity and low sensitivity values. The biological characteristics, including maternal age, BMI and FBG, showed a progressive increase as a function of maternal glycaemia with moderate sensitivity and specificity values. Using these latter characteristics in combination ensures that 72.3 % of the GDM population would be correctly identified, while an oGTT would only be required in 18.7 % of the population. The progressive relationship of increasing glycaemia to adverse characteristics suggests that the new IADPSG criteria are reasonable provided that dietary advice is given to all pregnant women. In situations of economic restraints, it appears possible to screen Mediterranean women for GDM risk using a composite model using FBG >5.0 mmol/l combined with the performance of an oGTT in women with a low FBG but who are overweight and aged >30 years. © Springer-Verlag 2011

A composite risk assessment model to screen for gestational diabetes mellitus among Mediterranean women

Objective To determine whether clinical risk assessment for gestational diabetes mellitus (GDM) may preclude the need for universal screening with an oral glucose tolerance test (OGTT) in situations of economic restraint. Methods Women with either GDM (n = 119) or normal glucose tolerance (n = 1249) were recruited from centers among 11 Mediterranean countries between August 1, 2010, and May 31, 2011. Outcome measures included anthropomorphic and biological data, obstetric outcomes, and infant outcomes. Results Significant risk factors for GDM included maternal age of 30 years or more; elevated body mass index (BMI, calculated as weight in kilograms divided by the square of height in meters); elevated diastolic blood pressure; previous history of macrosomia; and family history of diabetes mellitus. These factors each had high specificity but low sensitivity for predicting GDM; however, when used in combination, sensitivity increased but specificity fell. Fasting blood glucose (FBG) level had high sensitivity (73.9%) and specificity (90.2%) for predicting GDM. Sensitivity was further increased by combining FBG measurement with maternal age and BMI (96.6%). Conclusion Use of a composite model to prescreen women for GDM risk may reduce the need for universal screening with the OGTT among centers facing health-cost pressures. © 2012 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved