Saeid B. Amini

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.

Perinatal risk factors for childhood obesity and metabolic dysregulation

BACKGROUND Childhood obesity has increased significantly in recent decades. OBJECTIVE The objective was to examine the perinatal risk factors related to childhood obesity. DESIGN In a prospective study, 89 women with normal glucose tolerance (NGT) or gestational diabetes mellitus (GDM) and their offspring were evaluated at birth and at 8.8 +/- 1.8 y. At birth, obstetrical data, parental anthropometric measures, and neonatal body composition were assessed; at follow-up, diet and activity were assessed and laboratory studies were conducted. Weight was classified by using weight for age and sex, and body composition was measured by using dual-energy X-ray absorptiometry. In childhood, data were analyzed as tertiles and prediction models were developed by using logistic and stepwise regression. RESULTS No significant differences in Centers for Disease Control and Prevention weight percentiles, body composition, and most metabolic measures were observed between children of mothers with NGT and GDM at follow-up. Children in the upper tertile for weight had greater energy intake (P = 0.02), skinfold thickness (P = 0.0001), and leptin concentrations (P < 0.0001) than did those in tertiles 1 and 2. Children in the upper tertile for percentage body fat had greater waist circumference (P = 0.0001), insulin resistance (P = 0.002), and triglyceride (P = 0.009) and leptin (P = 0.0001) concentrations than did children in tertiles 1 and 2. The correlation between body fat at birth and follow-up was r = 0.29 (P = 0.02). The strongest perinatal predictor for a child in the upper tertile for weight was maternal pregravid body mass index (BMI; kg/m(2)) >30 (odds ratio: 3.75; 95% CI: 1.39, 10.10; P = 0.009) and for percentage body fat was maternal pregravid BMI >30 (odds ratio: 5.45; 95% CI: 1.62, 18.41; P = 0.006). CONCLUSION Maternal pregravid BMI, independent of maternal glucose status or birth weight, was the strongest predictor of childhood obesity.

Maternal carbohydrate metabolism and its relationship fetal growth and body composition

OBJECTIVE Our purpose was to correlate maternal carbohydrate metabolism and parental morphometric measurements with neonatal birth weight, body composition, and placental weight. STUDY DESIGN Sixteen singleton (six control and 10 abnormal glucose tolerance) infants had placental weight, birth weight, and estimates of body composition performed within 24 hours of birth. Independent variables considered were (1) maternal and paternal demographic and morphometric measures, (2) neonatal sex and gestational age, and (3) estimates of maternal carbohydrate metabolism, including basal hepatic glucose production, insulin response, and insulin sensitivity. All metabolic measurements were performed before conception and in early (12 to 14 weeks) and late (34 to 36 weeks) gestation. Best-fit stepwise regression analysis was used to relate the independent variables with placental weight, neonatal birth weight, fat-free mass, and fat mass. RESULTS Insulin sensitivity in late gestation had the strongest correlation with placental weight (R2 = 0.28), neonatal birth weight (R2 = 0.28), and fat-free mass (R2 = 0.33). In contrast, insulin sensitivity before conception had the best correlation with neonatal fat mass (R2 = 0.15). Including all significant independent variables in the model improved the correlations for placental weight (R2 = 0.58), birth weight (R2 = 0.48), fat-free mass (R2 = 0.53), and fat mass (R2 = 0.46). CONCLUSION Maternal insulin sensitivity had stronger correlations with fetoplacental growth in comparison with maternal demographic or morphometric factors.

The Sensitivity of Medicare Claims Data for Case Ascertainment of Six Common Cancers

BACKGROUND Although Medicare claims data have been used to identify cases of cancer in older Americans, there are few data about their relative sensitivity. OBJECTIVES To investigate the sensitivity of diagnostic and procedural coding for case ascertainment of breast, colorectal, endometrial, lung, pancreatic, and prostate cancer. SUBJECTS Three hundred and eighty nine thousand and two hundred and thirty-six patients diagnosed with cancer between 1984 and 1993 resided in one of nine Surveillance Epidemiology and End Results (SEER) areas. MEASURES The sensitivity of inpatient and Part B diagnostic and cancer-specific procedural codes for case finding were compared with SEER. RESULTS The sensitivity of inpatient and inpatient plus Part B claims for the corresponding cancer diagnosis was 77.4% and 91.2%, respectively. The sensitivity of inpatient claims alone was highest for colorectal (86.1%) and endometrial (84.1%) cancer and lowest for prostate cancer (63.6%). However, when Part B claims were included, the sensitivity for diagnosis of breast cancer was greater than for other cancers (93.6%). Inpatient claim sensitivity was highest for earlier years of the study, and, because of more complete data and longer follow up, the highest sensitivity of combined inpatient and Part B claims was achieved in the late 1980s or early 1990s. CONCLUSIONS Medicare claims provide reasonably high sensitivity for the detection of cancer in the elderly, especially if inpatient and Part B claims are combined. Because the study did not measure other dimensions of accuracy, such as specificity and predictive value, the potential costs of including false positive cases need to be assessed.

Anthropometric estimation of neonatal body composition

OBJECTIVE Estimation of neonatal body composition can be useful in the understanding of fetal growth. However, body composition methods such as total body water and total body electric conductivity are expensive and not readily available. Our primary purpose was to develop an anthropometric model to estimate neonatal body composition and prospectively validate the model against total body electric conductivity and secondarily to compare our anthropometric model and a previously published anthropometric formula with total body electric conductivity. STUDY DESIGN A total of 194 neonates had estimates of body composition according to total body electric conductivity (group 1). Parental morphometrics, gestational age, race, sex, parity, and neonatal measurements including birth weight, length, head circumference, and skinfolds (triceps, subscapular, flank, and thigh) were correlated with body fat by use of stepwise regression analysis. The model was validated in a second group of 65 neonates (group 2). RESULTS There were no significant differences in any of the parental or neonatal measurements between groups 1 and 2. In group 1, 78% of the variance in body fat with the use of total body electric conductivity was explained by birth weight, length, and flank skinfold (R2 = 0.78, p = 0.0001). When prospectively validated by the subjects in group 2, the model had significant and stronger correlation (R2 = 0.84, p = 0.0001) with body fat estimated by total body electric conductivity as compared with the other anthropometric model (R2 = 0.54, p = 0.0001). There was no significant (p = 0.11) difference between our anthropometric estimate of body fat and total body electric conductivity. CONCLUSIONS The anthropometric model developed can be used to reasonably predict neonatal body fat mass at birth.

Agreement of medicare claims and tumor registry data for assessment of cancer-related treatment

BACKGROUND Although health claims data are increasingly used in evaluating variations in patterns of cancer care and outcomes, little is known about the comparability of these data with tumor registry information. OBJECTIVES To evaluate the agreement between Medicare claims and tumor registry data in measuring patterns of diagnostic and therapeutic procedures for older cancer patients. RESEARCH DESIGN Analysis of a database linking Surveillance, Epidemiology and End Results (SEER) registry data and Medicare claims in patients aged > or =65 years with cancer. SUBJECTS 361,255 Medicare patients with invasive breast, colorectal, endometrial, lung, pancreatic, and prostate cancer diagnosed between 1984 and 1993. MEASURES Concordance of SEER files with corresponding Medicare claims. RESULTS Medicare claims generally identified patients who underwent resection and radical surgery according to SEER (ie, concordance > or =85%-90%) but less likely biopsy or local excision (ie, concordance < or =50%). In some instances, claims also categorized patients as having more invasive surgery than was listed in SEER and also provided incremental information about the use of surgical treatment after 4 months. SEER files and, to a lesser degree, Medicare claims identified radiation therapy not included in the other data source, and Medicare files also captured a significant number of patients with codes for chemotherapy. CONCLUSIONS Medicare files may be appropriate for studies of patterns of use of surgical treatment, but not for diagnostic procedures. The potential benefit of Medicare claims in identifying delayed surgical intervention and chemotherapy deserves further study.

Incidence and risk factors associated with abnormal postpartum glucose tolerance in women with gestational diabetes

To determine the incidence and risk factors associated with an abnormal postpartum glucose tolerance in women with gestational diabetes, 103 patients with gestational diabetes had a 2-hour, 75 gm oral glucose tolerance test 6 +/- 2 weeks (mean +/- SD) after delivery. Twenty-two percent (23/103) of results were abnormal: Three showed frank diabetes, four showed impaired glucose tolerance, and 16 were, nondiagnostic. There was a significant difference in gravidity, pregravid weight and body mass index, delivery weight, gestational age at diagnosis, fasting and 2- and 3-hour glucose level at the time of the oral glucose tolerance test during pregnancy, need for insulin therapy during gestation, and neonatal weight greater than 4000 gm in the abnormal group as compared with the normal group. Elevated fasting glucose level (p = 0.0001) and earlier gestational age at time of diagnosis of gestational diabetes (p = 0.013) were found to be most predictive of an abnormal postpartum glucose tolerance test result. These results support the importance of postpartum oral glucose tolerance testing in women with gestational diabetes.

Factors affecting fetal growth and body composition

OBJECTIVE Our purpose was to identify factors affecting fetal growth with birth weight and body composition. STUDY DESIGN A total of 183 singleton infants had birth weights and estimates of body composition performed within 24 hours of birth. Independent variables included were (1) maternal height, weight, pregravid weight, weight gain, education, and parity, (2) paternal height and weight, and (3) neonatal sex and gestational age. Best-fit stepwise regression analysis was used to correlate the independent variables with birth weight, fat-free mass, and fat mass. RESULTS Compared with females, males had greater birth weight (p = 0.009) and fat-free mass (p = 0.0001) but not fat mass (p = 0.32). The strongest predictors were gestational age with birth weight (R2 = 0.10), neonatal sex with fat-free mass (R2 = 0.08), and parity with fat mass (R2 = 0.08). By use of the significant independent variables we explained 29% of the variation in birth weight, 30% in fat-free mass, and 17% in fat mass. CONCLUSION These data support the concept that various genetic and environmental factors may modify fetal growth by differentially affecting growth of fetal fat and fat-free mass.

Longitudinal changes in body composition and energy balance in lean women with normal and abnormal glucose tolerance during pregnancy

OBJECTIVE The objective of this study was to evaluate the longitudinal changes in energy expenditure and body composition in relationship to alterations in carbohydrate metabolism in women with normal and abnormal glucose metabolism. We hypothesized that women with decreased insulin sensitivity before conception would have less fat accretion and smaller increases in energy expenditure. STUDY DESIGN Six women with normal glucose tolerance and 10 women with abnormal glucose tolerance were evaluated before conception, and in early (12 to 14 weeks) and late (34 to 36 weeks) gestation. Body composition was estimated by hydrodensitometry, resting energy expenditure, and glucose and fat metabolism by indirect calorimetry, endogenous glucose production by infusion of [6-6 2H2] glucose, and insulin sensitivity using a hyperinsulinemic-euglycemic clamp (40 mU/m2/min). RESULTS There was a smaller increase in fat mass (1.3 kg [P = .04]) in early pregnancy in women with abnormal glucose tolerance before pregnancy. Indirect calorimetry measured gestational age-related increases in basal oxygen utilization, with or without correction for fat-free mass (VO2, P = .002), resting energy expenditure (expressed in kilocalories, P = .0001), and carbohydrate oxidation (P = .0003). The insulin-mediated elevation in VO2 increased in later gestation VO2 (P = .005), as did resting energy expenditure (P = .0001) and fat oxidation (P = 0.0001). However, there was a decrease in respiratory quotient (P = .0001), carbohydrate oxidation (P = .002), and nonoxidative carbohydrate metabolism (P = .0001) with advancing gestation during insulin infusion. In early pregnancy, changes in fat mass correlated inversely with changes in insulin sensitivity (r= -0.52, P = .04) and changes in basal VO2 correlated inversely with decreases in basal endogenous glucose production (r = -0.74, P = .01). CONCLUSION In early gestation, the changes in maternal fat mass and basal oxygen consumption are inversely related to the changes in insulin sensitivity. This response in lean women with decreased insulin sensitivity before conception may have survival value by providing a larger amount of available substrate to meet fetoplacental needs during gestation.

Births to teenagers: Trends and obstetric outcomes

Objective To compare the trends and obstetric outcomes of pregnancy in teenage women with those of adult women. Methods We analyzed a 19-year (1975–1993) computerized perinatal data base with on 69,096 births collected prospectively from a single inner-city tertiary medical center. Results Of all the births, 1875 (2.7%) were to teenagers 12–15 years old and 17,359 (25.3%) were to teenagers 16–19 years old. Over the study period, the number and proportion of births to teenagers of both age groups declined (P < .001 in both cases). The proportions of teenagers 12–15 and 16–19 years old were highest among blacks (4.1% and 28.1%, respectively), followed by Hispanics (2.4%, 24.7%) and whites (1.6%, 23.1%). More than 95% of teenagers had no private health insurance coverage (staff), significantly higher than the 81.6% of mothers aged 20 years of older (P < .001). More than 8.1% of teenagers 12–15 years old had two or fewer prenatal care visits, significantly higher than 6.8% for teenagers 16–19 years old and 7.1% for adults (P < .001. The average gestational age and birth weight were significantly lower for teenagers 12–15 years old compared with those 16–19 years old and adults. Patients 16–19 years of age had longer gestational age and higher birth weight than the adults. The proportion of primary cesarean deliveries among teenagers 12–15 years old was 11.6%, significantly higher than 9.4% for those 16–19 years old and 10.2% for adults (P < .001). Conclusion On average, females 16–19 years old had better obstetric outcomes than adults, whereas obstetric outcomes for those 12–158 years old were worse than for adults. Therefore, all teenagers should not be grouped together when their obstetric outcomes are compared with those of adults.