Markers In Adolescents Research Articles

Inhalant Use in Florida Youth

Purpose: To determine (1) the prevalence of use, (2) risk and protective factors for use of inhalants in Florida youth. Methods: The Florida Youth Substance Abuse Survey 2004 is a comprehensive assessment of youth substance abuse attitudes and practices obtained by sampling youth from sixty-five counties. Results: The sample consisted of 60,345 students from 6th to 12th grade; ages 10 to 19 + years (mean 14.5 years ±4), 53% were female with 59% White, 19% African-American, 16% Hispanic, 5% Native American, 2% Asian and 7% other. Lifetime use was highest among 14 year olds (16.5%), and current use among 13 year olds (16.7%). Females had significantly (p < .000) higher rates than males for lifetime (14.2% vs. 12.7%) and current use (5.1% vs. 4.1%). Native Americans had the highest rates of lifetime use (17%) followed by Whites (15%), mixed/other (15%), Hispanics (14%), Asians (13%), and Blacks (9%). The younger the age of first use of alcohol, cigarettes and marijuana, the higher the lifetime and current prevalence of use of inhalants. Inhalant users were more likely to be depressed, acknowledge deviant behavior and skipping school, have lower grades, have siblings and friends who used illegal substances and parents with a history of antisocial behavior (p < .000). Conclusion: Inhalant use may be a marker for adolescents with a high-risk profile for subsequent illegal drug use. Prevention efforts should be directed to these students at an early age.

Coronary artery calcification, serum lipids, lipoproteins, and peripheral inflammatory markers in adolescents and young adults with type 1 diabetes

To determine whether coronary artery calcification (CAC), elevated fasting lipids, and lipoproteins and peripheral inflammatory markers are present in insulin-dependent diabetic adolescents and young adults several years after diagnosis. Hispanic insulin-dependent diabetics (n = 32) diagnosed a mean of 7.8 +/- 4.5 years ago (range, 3 to 16 years), with a mean glycosylated hemoglobin concentration at the time of the study of 8.8% +/- 2.3% and a mean chronological age of 16.1 +/- 4.4 years, were evaluated. Healthy patients (n = 15) with a chronological age (CA) of 15.2 +/- 2.2 years served as control subjects. CAC was assessed by multiple slice computed tomography, and total CAC score in Agatston units was calculated. Fasting lipids, C-reactive protein, apolipoprotein (Apo) A, Apo B, and metalloproteinase-9 (MMP-9) concentrations were measured in all subjects. Neither adolescents with type 1 diabetes nor healthy control subjects presented with evidence of CAC. Fasting lipids, Apo A, Apo B, CRP, and MMP-9 concentrations were similar between diabetic subjects and control subjects. However, 34.4% and 25.0% of our type 1 diabetic subjects had elevated total and LDL cholesterol levels (>200 and >130 mg/dL, respectively), whereas 15.6% and 28.1% had elevated triglyceride and Apo B concentrations (>150 mg/dL and >100 mg/dL, respectively). In addition, 28.1% and 34.4% presented with elevated CRP and MMP-9 levels (>2 mg/L and >80 ng/mL, respectively). Total, LDL and HDL cholesterol, triglycerides, Apo B, CRP, and MMP-9 concentrations correlated positively with duration of the disease and with glycosylated hemoglobin levels. Although the study adolescents with type 1 diabetes did not present any radiologic evidence of CAC at this stage of the disease, they remain a high-risk group for the development of microvascular and macrovascular artery disease, as risk factors such as elevated lipoproteins and proinflammatory markers are already present in a significant percentage of patients studied.

Peripheral inflammatory and fibrinolytic markers in adolescents with growth hormone deficiency: Relation to postprandial dyslipidemia

To determine whether peripheral inflammatory and fibrinolytic markers are elevated in growth hormone-deficient (GHD) adolescents and associated with increased postprandial lipoproteins. Fifteen GHD children on GH treatment with a chronologic age of 12.7 +/- 2.5 years and 10 untreated GHD adolescents with a chronologic age of 13.0 +/- 2.6 years were studied. Triglycerides (TG), C-reactive protein (CRP), fibrinogen, interleukin 6 (IL-6), and tumor necrosis factor alpha (TNF-alpha) were measured in the fasting state and 4 hours after ingesting a high-fat meal; 15 healthy adolescents served as controls. Fasting and postprandial TG of untreated GHD children were higher than those in treated subjects and healthy controls. Fasting TNF-alpha, CRP, and fibrinogen concentrations of untreated GHD adolescents were higher than those in healthy controls, but similar to those of GH-treated GHD adolescents. Although fibrinogen levels increased after a high-fat meal in GHD adolescents, CRP, TNF-alpha, and IL-6 concentrations did not increase further. Fasting and postprandial TG of untreated GHD adolescents were positively associated with fasting and postprandial CRP, and with postprandial TNF-alpha and IL-6 concentrations. Fasting TG also correlated positively with fasting fibrinogen concentrations in untreated and treated GHD adolescents. The pronounced inflammatory response seen in GHD adolescents seems to be associated with the presence of elevated levels of fasting and postprandial TG, which may result in an increased susceptibility for premature atherosclerosis.

Socioeconomic Status, Stress, and Immune Markers in Adolescents With Asthma

Previous research has demonstrated links between low socioeconomic status (SES) and clinical asthma outcomes, as well as links between stress and asthma. The objective of this study was to test whether adolescents with asthma from different SES backgrounds differed in biological profiles relevant to asthma, including immune and cortisol measures. The second objective was to test whether psychological stress and control beliefs could explain these differences. Adolescents with persistent asthma from either low (N= 18) or high (N= 12) SES neighborhoods were interviewed about their stress experiences (chronic stress, acute life events, interpretations of ambiguous life events) and control beliefs. Blood was drawn to assess immune (cytokines, eosinophils, IgE) and neuroendocrine (cortisol) markers associated with asthma. Adolescents in the low SES group had significantly higher levels of a stimulated cytokine associated with a Th-2 immune response (IL-5), higher levels of a stimulated cytokine associated with a Th-1 immune response (IFN-gamma), and marginally lower morning cortisol values compared with the high SES group. Low SES adolescents also had greater stress experiences and lower beliefs about control over their health. Statistical mediational analyses revealed that stress and control beliefs partially explained the relationship between SES and IL-5/IFN-gamma. Our finding that low SES was associated with elevations in certain immune responses (IL-5/IFN-gamma) in adolescents with asthma suggests the importance of further exploration into relationships between SES and Th-2/Th-1 responses in asthma. Our findings also suggest that psychological stress and control beliefs may provide one explanation for links between SES and immune responses in childhood asthma.

Developmental Markers in Adolescence: Implications for Studies of Pubertal Processes

There is inconsistency in the outcome measures of biological and psychosocial studies using measures of puberty as a predictor. For example, some studies show that maturational timing may have differential influences (positive, negative, or no effect) depending on the specific disorder, dimension of measure, and gender. Other studies have suggested that some effects may be more directly linked to pubertal stage or hormone concentrations rather than timing per se. This study outlines several conceptual and methodological issues that may be relevant to addressing these inconsistencies, in the context of examining data from a study of maturational hormones obtained from a unique longitudinal cohort of 24 girls (age 10.0 ± 1.6 years) and 36 boys (age 10.4 ± 1.6 years) in the early part of puberty, where the developmental trajectory of these hormones were tracked annually in 65% of the sample. We explored the contributions of measures of pubertal growth and sociodemographic factors on hormone concentrations. In brief, it appears that no single measure best captures the maturational processes during puberty and suggests that multiple processes are occurring in parallel. Several conceptual and methodological implications are discussed that may guide investigators in interpreting existing studies of pubertal timing and behavior as well as in conducting future studies.

A prospective longitudinal study of urinary excretion of a bone resorption marker in adolescents

In growing subjects, the rates of bone resorption and bone deposition are substantially larger than in non-growing individuals. The purpose of this study was to measure the urinary excretion of a specific bone resorption marker in function of adolescent growth stages in a prospective longitudinal study. A cohort of 60 adolescents (28 male and 32 female) was followed for 3.4 years (range 1.7-4.6 years). Monthly measurements of height, weight and urinary excretion of a bone resorption marker, collagen type I N-telopeptides (NTx), were made. Changes in standing height were used to classify the adolescents into one or more of six adolescent growth stages: pre-pubertal growth (continuous moderate growth rate), ascending growth spurt (increasing growth rate), peak growth spurt (growth rate higher than 7cm/year for at least 6 months), descending growth spurt (continuous decrease in growth rate), end of growth (growth rate between 0 and 2cm/year), and no growth. An increase in NTx excretion from the pre-pubertal to peak growth spurt of about 33% was found (44% and 27% for females and males respectively). The decreasing growth rate after the pubertal growth spurt coincided with a clear decrease in NTx excretion. These differences were statistically significant, except between the prepubertal and ascending growth stage. Individual mean NTx excretion during each growth stage was correlated with the individual's growth rate during that time (r = 0.81). There was large inter-and intra individual variability. In non-growing adolescents (growth rate 0cm/y) NTx excretion levels were 4-7 times greater than in adults. In all females, menarche was followed by a decrease in NTx excretion. In conclusion, the excretion of a specific bone resorption marker, NTx, was correlated with the changes in growth rate during adolescence, both for males and females. There were large inter and intra-individual differences in NTx excretion during the different growth stages. In adolescents who reached their adult height at the end of the pubertal growth spurt, bone resorption decreased dramatically but remained 4-7 fold higher than in adults.

Total and segmental colonic transit time with radio-opaque markers in adolescents with functional constipation.

In most instances, constipation is considered idiopathic or functional. The total and segmental colonic transit time, traced by radio- opaque markers, makes possible the identification of the colon segment that has the motility alteration that causes constipation. A study was performed of 13 adolescents, aged 12 to 18, with functional chronic constipation and 13 without constipation. In all of them the total and segmental colonic transit times were measured with radio-opaque markers. The adolescents ingested 20 markers each on three successive days, and on the fourth day a plain abdominal radiograph was performed. In the nonconstipated adolescents the total colonic transit time (mean +/- SD) was 30.2 +/- 13.1 hours, in the right colon 5.7 +/- 3.9 hours, in the left colon 7.9 +/- 7.8 hours, and in the rectosigmoid 15.5 +/- 10.6 hours. In the constipated adolescents, the total colonic transit time was 58.3 +/- 17.4 hours, in the right colon 15.9 +/- 12.4 hours, in the left colon 14.7 +/- 13.4 hours, and in the rectosigmoid 17.2 +/- 16.2 hours. There was a statistically significant difference (p < 0.05) in the total colonic transit time, and in both the right and left colon transit times between constipated and nonconstipated adolescents. The measurement of total and segmental colonic transit times is a simple method that allows one to distinguish constipation due to colonic dysfunction (right colon and left colon) from constipation due to distal obstruction (rectosigmoid).

Sensitivity and Specificity of Coupled Dexamethasone Suppression and TRH Infusion Tests in 90 Postsuicide Hospitalized Adolescents with Depression

In order to reduce the possible confounding effect of suicidality on studies of biological markers in adolescents, we examined a sample consisting solely of adolescents hospitalized following a suicide attempt. Of 112 adolescents hospitalized after a suicide attempt, 90 met DSM-III-R criteria for a depressive disorder: major depression presented in 54% of these cases, dysthymia in 11%, and both (double depression) in 35%. The 22 adolescents who did not have depression formed the psychiatric control group. All patients were administered a dexamethasone suppression test and a TRH infusion test after several days in the hospital. There were no significant differences in DST or TRH responses among the adolescents with major depression, dysthymic disorder, or double depression. Among the depressed adolescents, cortisol nonsuppression was found in 42%, and blunted TSH response was noted in 51%; one of the two tests was abnormal in 74% of the depressed adolescents, and both tests were abnormal in 19%. Among the nondepressed adolescents, 18% manifested cortisol nonsuppression (a result which differs from the depressed group, p < 0.05) and 14% showed blunted TSH response (p < 0.01); one of the two tests was abnormal in 27% of the nondepressed adolescents (p < 0.0001), and both tests were abnormal in only one nondepressed patient (NS). For identifying depressed adolescents, the DST had a sensitivity of 42% and a specificity of 82%. The TRH test had a sensitivity of 51% and a specificity of 86%. An abnormality on one of the two tests had a sensitivity of 74% and a specificity of 73%. The sensitivity of the coupled tests was 19%, and the specificity was 95%. These figures do not provide a basis to support the use of these tests, singly or coupled, as a major clinical aid in the identification of depressed adolescents, even among postsuicide depressed adolescents.

Aggregation of plasma lipids and lipoproteins in families with and without coronary heart disease

Familial aggregation of total plasma cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C) was analyzed in 37 families with incidence cases of first myocardial infarction (MI), in 154 families of coronary heart disease (CHD) prevalence cases and in control families. Fasting plasma lipid levels were adjusted for age, sex, country of origin and season of year. Mean TC, LDL-C and TG levels were higher among cases, their spouses and among 17-year-old children of incidence cases than among control families. HDL-C was lower among cases and among wives of incidence cases than in their controls. No differences in HDL-C were noted among children. Mid parent-child correlations for TC and LDL-C were higher in 32 families of men who had a MI ( r = 0.43 and r = 0.49) than for control families ( r = 0.32 and r = 0.29, respectively). When the 5 families of mothers who had a first MI were included in the analysis, the case-child correlations for TC and LDL-C were 0.60 and 0.68, respectively. Father-child correlation for HDL-C was significantly lower ( r = −0.17) among the MI incidence case families than among the control families ( r = 0.22; P < 0.05). No substantial differences in familial correlations for lipid variables were noted in the CHD prevalence families and their controls. These findings suggest that total cholesterol and LDL-C levels, but not HDL-C levels, may be a risk marker in adolescents. The associations evident in adolescent children of families with MI incidence cases were not apparent in children whose parents had CHD on entering the study. This could be due to the probably greater misclassification of CHD prevalence cases than MI incidence cases, the awareness in patients with CHD and subsequent behavioural changes, to possible differences in patterns of survival in the two categories, or may reflect a chance finding.