Obesity during pregnancy on vagal tone, hemoglobin A1c, oxygenation, and perinatal outcomes

Purpose: To examine the effect of obesity and gestational weight gain on heart rate variability (HRV), oxygenation (HbO 2 and SpO2), hemoglobin A1c (HbA1c) and the frequency of pregnancy complications in obese (O) and non-obese (NO) women.^ Design: The study was an observational comparison study with a repeated measures design. ^ Setting: The setting was a low risk prenatal, university clinic located in a large southeastern metropolitan city. ^ Sample: The sample consisted of a volunteer group of 41 pregnant women who were observed at the three time points of 20, 28, and 36 weeks gestation. ^ Analysis: Analysis included general linear modeling with repeated measures to test for group differences with changes over time on vagal response, HbA1c, and oxygenation. Odds ratios were computed to compare the frequency of birth outcomes. ^ Findings: The interaction effect of time between O and NO women on HbO2 was significant. The mean HP, RSA, and HbO2 changed significantly over time within the NO women. The mean HbA 1c increased significantly over time within the O women. Women with excess gestational weight gain had significantly lower heart period than women with weight gain within the IOM recommendations. Obese women were more likely to have Group B streptococcal infections, gestational hypertension, give birth by cesarean or instrument assistance, and have at least one postnatal event. ^ Conclusions: Monitoring HRV, oxygenation, and HbA1c using minimally invasive measures may permit early identification of alterations in autonomic response. Implementation of interventions to promote vagal tone may help to reduce risks for adverse perinatal outcomes related to obesity. Future studies should examine the effect of obesity on the vagal response and perinatal outcomes. ^

A GENETIC MARKER STUDY OF NON - INSULIN DEPENDENT DIABETICS IN THE MEXICAN-AMERICAN COMMUNITY FROM STARR COUNTY, TEXAS (PLASMA GLUCOSE, HEMOGLOBIN ANALYSIS)

Diabetes mellitus occurs in two forms, insulin-dependent (IDDM, formerly called juvenile type) and non-insulin dependent (NIDDM, formerly called adult type). Prevalence figures from around the world for NIDDM, show that all societies and all races are affected; although uncommon in some populations (.4%), it is common (10%) or very common (40%) in others (Tables 1 and 2).^ In Mexican-Americans in particular, the prevalence rates (7-10%) are intermediate to those in Caucasians (1-2%) and Amerindians (35%). Information about the distribution of the disease and identification of high risk groups for developing glucose intolerance or its vascular manifestations by the study of genetic markers will help to clarify and solve some of the problems from the public health and the genetic point of view.^ This research was designed to examine two general areas in relation to NIDDM. The first aims to determine the prevalence of polymorphic genetic markers in two groups distinguished by the presence or absence of diabetes and to observe if there are any genetic marker-disease association (univariate analysis using two by two tables and logistic regression to study the individual and joint effects of the different variables). The second deals with the effect of genetic differences on the variation in fasting plasma glucose and percent glycosylated hemoglobin (HbAl) (analysis of Covariance for each marker, using age and sex as covariates).^ The results from the first analysis were not statistically significant at the corrected p value of 0.003 given the number of tests that were performed. From the analysis of covariance of all the markers studied, only Duffy and Phosphoglucomutase were statistically significant but poor predictors, given that the amount they explain in terms of variation in glycosylated hemoglobin is very small.^ Trying to determine the polygenic component of chronic disease is not an easy task. This study confirms the fact that a larger and random or representative sample is needed to be able to detect differences in the prevalence of a marker for association studies and in the genetic contribution to the variation in glucose and glycosylated hemoglobin. The importance that ethnic homogeneity in the groups studied and standardization in the methodology will have on the results has been stressed. ^

HEMATOCRIT AND HEMOGLOBIN, ATP AND DPG CONCENTRATIONS IN ANDEAN MAN: VARIABILITY BY SEX, AGE, VILLAGE, ALTITUDE, WEIGHT, SMOKING HABITS AND GENETIC CONSTITUTION

The Departmento de Arica in northern Chile was chosen as the investigation site for a study of the role of certain hematologic and glycolytic variables in the physiological and genetic adaptation to hypoxia.^ The population studied comprised 876 individuals, residents of seven villages at three altitudes: coast (0-500m), sierra (2,500-3,500m) and altiplano (> 4,000m). There was an equal number of males and females ranging in ages from six to 90 years. Although predominantly Aymara, those of mixed or Spanish origin were also examined. The specimens were collected in heparinized vacutainers precipitated with cold trichloroacetic acid (TCA) and immediately frozen to -196(DEGREES)C. Six variables were measured. Three were hematologic: hemoglobin, hematocrit and mean cell hemoglobin concentration. The three others were glycolytic: erythrocyte 2,3-diphosphoglycerate (DPG), adenosine triphosphate (ATP) and the percentage of phosphates (DPG + ATP) in the form of DPG.^ Hemoglobin and hematocrit were measured on site. The DPG and ATP content was assayed in specimens which had been frozen at -196(DEGREES)C and transported to Houston. Structured interviews on site provided information as to lifestyle and family pedigrees.^ The following results were obtained: (1) The actual village, rather than the altitude, of examination accounted for the greatest proportion of the variance in all variables. In the coast, a large difference in levels of ionic lithium in the drinking water exists. The chemical environment of food and drink is postulated to account, in part, for the importance of geographic location in explaining the observed variance. (2) Measurements of individuals from the two extreme altitudes, coast and altiplano, did not exhibit the same relationship with age and body mass. The hematologic variables were significantly related to both age and body build in the coast. The glycolytic variables were significantly related to age and body mass in the altiplano. (3) The environment modified male values more than female values in all variables. The two sexes responded quite differently to age and changes in body mass as well. The question of differing adaptability of the two sexes is discussed. (4) Environmental factors explained a significantly higher proportion of total variability in the altiplano than in the coast for hemoglobin, hematocrit and DPG. Most of the ATP variability at both altitudes is explained by genetic factors. ^

Notification of abnormal lab test results in an electronic medical record: do any safety concerns remain?

BACKGROUND: Follow-up of abnormal outpatient laboratory test results is a major patient safety concern. Electronic medical records can potentially address this concern through automated notification. We examined whether automated notifications of abnormal laboratory results (alerts) in an integrated electronic medical record resulted in timely follow-up actions. METHODS: We studied 4 alerts: hemoglobin A1c > or =15%, positive hepatitis C antibody, prostate-specific antigen > or =15 ng/mL, and thyroid-stimulating hormone > or =15 mIU/L. An alert tracking system determined whether the alert was acknowledged (ie, provider clicked on and opened the message) within 2 weeks of transmission; acknowledged alerts were considered read. Within 30 days of result transmission, record review and provider contact determined follow-up actions (eg, patient contact, treatment). Multivariable logistic regression models analyzed predictors for lack of timely follow-up. RESULTS: Between May and December 2008, 78,158 tests (hemoglobin A1c, hepatitis C antibody, thyroid-stimulating hormone, and prostate-specific antigen) were performed, of which 1163 (1.48%) were transmitted as alerts; 10.2% of these (119/1163) were unacknowledged. Timely follow-up was lacking in 79 (6.8%), and was statistically not different for acknowledged and unacknowledged alerts (6.4% vs 10.1%; P =.13). Of 1163 alerts, 202 (17.4%) arose from unnecessarily ordered (redundant) tests. Alerts for a new versus known diagnosis were more likely to lack timely follow-up (odds ratio 7.35; 95% confidence interval, 4.16-12.97), whereas alerts related to redundant tests were less likely to lack timely follow-up (odds ratio 0.24; 95% confidence interval, 0.07-0.84). CONCLUSIONS: Safety concerns related to timely patient follow-up remain despite automated notification of non-life-threatening abnormal laboratory results in the outpatient setting.

Uptake And Metabolism Of 5’-AMP In The Erythrocyte Play Key Roles In The 5’-AMP Induced Model Of Deep Hypometabolism

UPTAKE AND METABOLISM OF 5’-AMP IN THE ERYTHROCYTE PLAY KEY ROLES IN THE 5’-AMP INDUCED MODEL OF DEEP HYPOMETABOLISM Publication No. ________ Isadora Susan Daniels, B.A. Supervisory Professor: Cheng Chi Lee, Ph.D. Mechanisms that initiate and control the natural hypometabolic states of mammals are poorly understood. The laboratory developed a model of deep hypometabolism (DH) initiated by uptake of 5’-adenosine monophosphate (5’-AMP) into erythrocytes. Mice enter DH when given a high dose of 5’-AMP and the body cools readily. Influx of 5’-AMP appears to inhibit thermoregulatory control. In a 15°C environment, mice injected with 5’-AMP (0.5 mg/gw) enter a Phase I response in which oxygen consumption (VO2) drops rapidly to 1/3rd of euthermic levels. The Phase I response appears independent of body temperature (Tb). This is followed by gradual body temperature decline that correlates with VO2 decline, called Phase II response. Within 90 minutes, mouse Tb approaches 15°C, and VO2 is 1/10th of normal. Mice can remain several hours in this state, before gradually and safely recovering. The DH state translates to other mammalian species. Our studies show uptake and metabolism of 5’-AMP in erythrocytes causes biochemical changes that initiate DH. Increased AMP shifts the adenylate equilibrium toward ADP formation, consequently decreasing intracellular ATP. In turn, glycolysis slows, indicated by increased glucose and decreased lactate. 2,3-bisphosphoglycerate levels rise, allosterically reducing oxygen affinity for hemoglobin, and deoxyhemoglobin rises. Less oxygen transport to tissues likely triggers the DH model. The major intracellular pathway for AMP catabolism is catalyzed by AMP deaminase (AMPD). Multiple AMPD isozymes are expressed in various tissues, but erythrocytes only have AMPD3. Mice lacking AMPD3 were created to study control of the DH model, specifically in erythrocytes. Telemetric measurements demonstrate lower Tb and difficulty maintaining Tb under moderate metabolic stress. A more dramatic response to lower dose of 5’-AMP suggests AMPD activity in the erythrocyte plays an important role in control of the DH model. Analysis of adenylates in erythrocyte lysate shows 3-fold higher levels of ATP and ADP but similar AMP levels to wild-type. Taken together, results indicate alterations in energy status of erythrocytes can induce a hypometabolic state. AMPD3 control of AMP catabolism is important in controlling the DH model. Genetically reducing AMP catabolism in erythrocytes causes a phenotype of lower Tb and compromised ability to maintain temperature homeostasis.

Content of prenatal care and spontaneous preterm birth: Findings from the 1988 National Maternal and Infant Health Survey

The purposes of this study were to examine (1) the relationship between selected components of the content of prenatal care and spontaneous preterm birth; and (2) the degree of comparability between maternal and caregivers' responses regarding the number of prenatal care visits, selected components of the content of prenatal care, and gestational age, based on analyses of the 1988 National Maternal and Infant Health Survey conducted by the National Centers for Health Statistics. Spontaneous preterm birth was subcategorized into very preterm and moderately preterm births, with term birth as the controls. The study population was limited to non-Hispanic Anglo- and African-American mothers. The racial differences in terms of birth outcomes were also compared.^ This study concluded that: (1) there was not a high degree of comparability (less than 80%) between maternal and prenatal care provider's responses regarding the number of prenatal care visits and the content of prenatal care; (2) there was a low degree of comparability (less than 50%) between maternal and infant's hospital of delivery responses regarding gestational age at birth; (3) there were differences in selected components of the content of prenatal care between the cases and controls, overall and stratified by ethnicity (i.e., hemoglobin/hematocrit test, weight measurement, and breast-feeding counseling), but they were confounded with missing values and associated preterm delivery bias; (4) there were differences in selected components of the content of prenatal care between Anglo- and African-American cases (i.e., vitamin/mineral supplement advice, weight measurement, smoking cessation and drug abuse counseling), but they, too, were difficult to interpret definitively due to item nonresponse and preterm delivery biases; (5) no significant predictive association between selected components of the content of prenatal care and spontaneous preterm birth was found; and (6) inadequate/intermediate prenatal care and birth out of wedlock were found to be associated with moderately preterm birth.^ Future research is needed to examine the validity of maternal and prenatal care providers' responses and identify the sources of disagreement between their responses. In addition, further studies are needed to examine the relationship between the quality of prenatal care and preterm birth. Finally, the completeness and quality of patient and provider data on the utilization and content of prenatal care needs to be strengthened in subsequent studies. ^

An investigation of the pica practices of pregnant women in Houston and Prairie View, Texas

Pregnant African American women are at higher risk of having a preterm delivery and/or a low birthweight infant. Many factors are associated with adverse pregnancy outcomes but a food habit that deserves further study in the causal process is pica, a craving for, and ingestion of, nonnutritive substances such as laundry starch, clay, dirt, or ice. This food habit is more common in the African American population but has not been adequately studied in relation to preterm and/or low birth weight infants.^ Mothers (n = 281) with infants less than one year of age who participated in the Special Supplementary Food Program for Women, Infants, and Children (WIC) at clinics in Houston and Prairie View, Texas were interviewed regarding pica practices during pregnancy, dietary practices, and some demographic indices. Hospital records were abstracted for health information on the mothers and infants, including birthweight and gestational age at birth of the infant.^ The subjects were 88.6% African American, 6.8% Hispanic, and 4.6% Caucasian. Overall prevalence of pica was 76.5%. Pica prevalence by substance(s) was as follows: ice 53.7%; ice and freezer frost 14.6%; other substances such as baking soda, baking powder, cornstarch, laundry starch, and clay or dirt 8.2%; and 23.5% reported no pica. The women who reported ice/freezer frost pica had a higher percentage of illegal drug use and alcohol use during pregnancy. The women who reported other pica substances had the lowest mean educational level, highest gravidity, and a higher percentage smoked during pregnancy.^ There were no significant differences in nutrient intakes measured by the mean 24-hour dietary recalls between women who reported ice pica (n = 103) and women who denied pica (n = 50). The women who reported ice/freezer frost pica or other pica substances had more food cravings and food dislikes during pregnancy than those who reported ice pica or no pica.^ There were no differences in mean birthweight or mean gestational age at birth of infants born to mothers from the three pica groups and the no pica group but regression analyses revealed a possible relationship between pica, low maternal hemoglobin at delivery, and preterm birth. ^