Glucose response to an oral glucose tolerance test predicts weight change in non-diabetic subjects

Objective: Glucose exerts a dual action in the regulation of energy balance, consisting of inhibition of energy intake and stimulation of energy expenditure. Whether blood glucose affects long‐term regulation of body weight in humans remains to be established. We sought to test the hypothesis that the post‐challenge glucose response is a predictor of weight change. Research Methods and Procedures: We performed a prospective analysis of the impact of glucose response to an oral glucose tolerance test (OGTT) and a mixed‐meal test (MT) on subsequent changes in body weight (BW) on 253 Pima Indians (166 men and 87 women) with normal glucose regulation at baseline and follow‐up (follow‐up: 7 ± 4 years). Main outcome measures included BW change (total, percent, and annual), plasma glucose and insulin concentrations during OGTT and MT [total and incremental areas under the curve (AUCs)], resting metabolic rate (RMR; indirect calorimetry), and insulin action (euglycemic‐hyperinsulinemic clamp). Results: Total and incremental glucose AUCs during the OGTT (but not the MT) were negatively associated with BW change (total, percent, and annual), both before and after adjusting for sex, age, initial BW, follow‐up time, insulin action, RMR, fasting plasma glucose and insulin concentrations, and insulin response. Total and incremental glucose AUCs during the OGTT were independent determinants of final BW with age, initial BW, follow‐up time, fasting plasma insulin concentrations, and RMR. Discussion: Higher post‐challenge glucose response protects against BW gain in subjects with normal glucose regulation. We propose that this action may be because of the effect of glucose on food intake and/or thermogenesis.     

Do Psychosocial Variables Predict Weight Loss or Mental Health after Obesity Surgery? A Systematic Review

Objective: The objective of this study was to present a systematic review of psychological and psychosocial predictors of weight loss and mental health after bariatric surgery. This systematic review included all controlled and noncontrolled trials of the last 2 decades with either a retrospective or prospective design and a follow‐up period of at least 1 year. Research Methods and Procedures: The relevant literature was identified by a search of computerized databases. All articles published in English and German between 1980 and 2002 were reviewed. Results: Using the above inclusion/exclusion criteria, 29 articles were identified focusing on psychosocial predictors of weight loss and mental health after obesity surgery. Discussion: Personality traits have no predictive value for the postoperative course of weight or mental state. Apart from serious psychiatric disorders including personality disorders, psychiatric comorbidity seems to be of more predictive value for mental and physical well‐being as two essential aspects of quality of life than for weight loss postsurgery. However, depressive and anxiety symptoms as correlates of psychological stress with regard to obesity seem to be positive predictors of weight loss postsurgery. The severity of the symptoms or the disorder is more relevant for the outcome of obesity surgery than the specificity of the symptoms. It is also not solely the consumption of distinct “forbidden” foods, such as sweets or soft drinks, but rather a general hypercaloric eating behavior, either as an expression of the patient's inadequate compliance or a dysregulation in energy balance, which is associated with a poor weight loss postsurgery.     

Predictors for Seasonal and Nonseasonal Fractionally Integrated ARIMA Models

This paper derives easy-to-calculate preditors for seasonal and nonseasonal fractionally integrated autoregressive-moving average (ARIMA (p, d, q) × (P, D, Q)_s) models with both differencing parameters d and D assuming values on the real line. It is shown that these predictors are optimum. Special attention is given to the one-step-ahead predictors as they are constantly in demand in almost every practical situation.     

Fasting blood glucose as a predictor of mortality: Lost in translation

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Robustness of Shrunken Predictors in Stratified Populations

The effect of assuming an inadequate superpopulation model in stratified sampling is studied when a shrinkage technique is used. The robustness is close related with the balance of the strata samples. This theoretical problem is present in studies of ecology. The results obtained enable to estimate the abundance of plankton when salinity is the auxiliary variable and expert's advise, in coast experimental stations networks, is used for fixing the superpopulation model.     

Early Predictors of Gestational Diabetes Mellitus in IVF-Conceived Pregnancies

ObjectiveGestational diabetes mellitus (GDM) is associated with adverse maternal and fetal outcomes. This study aimed to identify early and reliable GDM predictors that would enable implementation of preventive and management measures.MethodsThe participants were a 28-week prospective cohort of in vitro fertilization (IVF)-conceived pregnant women (≤39 years, body mass index [BMI] 18.5-38 kg/m²) without a known history of diabetes mellitus. Fasting blood samples were analyzed at baseline (pre-IVF) and 12 weeks’ gestation for reproductive hormones, glucose, serum insulin, lipids, thyroid function, adiponectin, and lipopolysaccharide-binding protein. At 28 weeks, a 75-g oral glucose tolerance test was used to screen for GDM.ResultsFor the overall group at baseline, 22% had BMI ≥30 kg/m², 45% had polycystic ovary syndrome, 16% had hemoglobin A1C of 5.7% to 6.1%, and 14% had a past history of GDM. At 28 weeks of gestation (n = 158), 34 women had developed GDM and 124 had not. Significant baseline predictors of GDM onset included greater BMI (29.0 vs 25.8 kg/m²), older age (34 vs 32 years), higher levels of follicle-stimulating hormone/luteinizing hormone ratio (1.2 vs 1.0), hemoglobin A1C (5.5 vs 5.2%), insulin (10.6 vs 7.1 μIU/mL), homeostatic model assessment of insulin resistance (2.2 vs 1.7), total cholesterol (199 vs 171 mg/dL), and low-density lipoprotein cholesterol (123 vs 105 mg/dL), and lower triglyceride levels (74 vs 76 mg/dL). Significant 12-week GDM predictors included greater maternal weight gain (delta: 3.4 vs 1.5 kg) and higher levels of insulin (11.3 vs 7.6 μIU/mL), triglycerides (178 vs 120 mg/dL), and homeostatic model assessment of insulin resistance (2.3 vs 1.5). Twelve-week BMI is a predictor of GDM following adjustment for polycystic ovary syndrome status and maternal age.ConclusionWhile preconception maternal BMI, age, and follicle-stimulating hormone/luteinizing hormone ratio are predictors of subsequent development of GDM, early IVF-conceived gestational weight gain is the best predictor of GDM onset.