The current retrospective cohort study was conducted between June 2002 and February 2003. The study sample included 53 adolescents ages 14-16 years old born with low birthweight (<2,500 g) and a matched group of 119 adolescents who were normal weight at birth (>2,500 g). First, women who gave birth at the Queen Elizabeth Hospital on the island of Barbados during the January 1,1986 through December 31, 1988 were recruited with the assistance of local physicians and nurses. A letter about the study was mailed to the homes of potential participants if a mailing address was available. The women were contacted and invited together with their eligible children to participate in the study. If a woman had multiple births during the reference period, only one child was randomly selected for inclusion in the study. Both the mothers and their adolescent child signed consent forms approved by the Biomedical Institutional Review Boards of the University of the West Indies and the University of Pittsburgh. Adolescents who were not of African descent, pregnant at the time of recruitment or unable to give informed consent were excluded from participation.
Demographic data and information about family history of diabetes were collected from the sample of mothers. The adolescents were administered questionnaires that collected information on INR, hostility, family history of diabetes (one or both parents with diabetes) and lifestyle behaviors, including fast-food consumption patterns and physical activity. INR was measured using the Racial and Stereotyping Scale (RASS), a modified version of the Nandolization (NAD) scale designed for children and adolescents. Like the NAD, the RASS assesses the degree to which the subjects agree with racist stereotypes that blacks are mentally and morally defective and physically gifted. The questions on this 20-item scale are in likert-type form with the responses graded from “agree with racist stereotypes 0-24% of the time” to “agree with racist stereotypes 75-100% of the time.” The possible range of scores of this scale are from 20 to 80, indicating low-to-high INR, respectively. The analysis for internal reliability of the RASS scale produced a Cronbach’s alpha (a) = 0.714. Hostility was assessed using the Cook-Medley Hostility Scale adapted for children which ranges in score from 27 to 108, indicating low-to-high levels of hostility, respectively. Information on fast-food consumption was collected by a question that ascertained how many times they ate at a fast food restaurant in a normal week. Physical activity was ascertained with the Modifiable Activity Questionnaire, which estimates energy expenditure as metabolic equivalent (MET) hours of time engaged in leisure time physical activity each week.
Weight (g) at birth was obtained by review of medical records. Anthropometric measurements were taken in duplicate and the average of these measurements used in analyses. Current weight (kg) of each adolescent participant was measured using a balance beam scale. Waist circumference (WC) was measured twice at the level of the umbilicus to the nearest centimeter using a standard tape measure. Height was measured using a wall-mounted stadiometer to the nearest centimeter. Body mass index (BMI), an estimate of overall obesity, was calculated using a ratio of weight in kilograms to height in meters (kg/m2).
Fasting blood glucose and insulin were measured from blood samples drawn from each adolescent participant after an overnight fast of 10-12 hours. Serum glucose (mg/dl) was quantitatively determined by a colorimetric enzymic determination read at 340/380 nm with a procedure similar to that described by Bondar and Mead (1974). Insulin (|nU/ml) was measured using an RIA procedure developed by Linco Research Inc. Cross-reactivity with proinsulin was under 2%. Insulin resistance was calculated using the homeostasis model assessment (HOMA). The HOMA model has been shown to be highly correlated with the standard clamp technique for measuring insulin resistance. canadian pharmacy cialis
Spearman correlation analyses were used to assess the univariate interrelationships between psychosocial and clinical variables. The differences between variable means were assessed using the t-test. The chi-square was used to compare the frequency of dichotomous variables. Odds Ratios (OR) and 95% confidence intervals (95% CI) from logistic regression analyses were used to estimate the odds of having abnormal body size and insulin resistance among adolescents with high levels of INR. In these analyses, INR was classified into low and high levels based on a median split. Since the distribution of HOMA scores are skewed the log transformed (Ln[HOMA]) values were used in analyses. Those with Ln[HOMA] values above the 75th percentile were classified as having high insulin resistance. Physical activity was dichotomized into “no activity” (<30th percentile for girls and boys) and “some activity.”
There were 12 participants removed from analysis due to incomplete blood analyses or abnormally high fasting insulin results. These individuals were not different with respect to age, sex and household income than those used for analysis in the study. All analyses were performed using the Statistical Package for Social Sciences. pharmacy united kingdom