Biomedical subjects

Daniel Rodriguez

Publications and source records attributed to Daniel Rodriguez.

18 recordsLinked to original sources

PubMed2006

The role of CYP2A6 in the emergence of nicotine dependence in adolescents.

OBJECTIVES: The objectives of our study were to evaluate whether genetic variation in nicotine metabolic inactivation accounted for the emergence of nicotine dependence from mid- to late adolescence and whether initial smoking experiences mediated this effect. METHODS: Participants were 222 adolescents of European ancestry who participated in a longitudinal cohort study of the biobehavioral determinants of adolescent smoking. Survey data were collected annually from grade 9 to the end of grade 12. Self-report measures included nicotine dependence, smoking, age first smoked, initial smoking experiences, peer and household member smoking, and alcohol and marijuana use. DNA collected via buccal swabs was assessed for CYP2A6 alleles that are common in white people and are demonstrated to decrease enzymatic function (CYP2A6*2, *4, *9, *12). RESULTS: Latent growth-curve modeling indicated that normal metabolizers (individuals with no detected CYP2A6 variants) progressed in nicotine dependence at a faster rate and that these increases in nicotine dependence leveled off more slowly compared with slower metabolizers (individuals with CYP2A6 variants). Initial smoking experiences did not account for how CYP2A6 genetic variation impacts nicotine dependence. CONCLUSIONS: These findings may help to promote a better understanding of the biology of smoking behavior and the emergence of nicotine dependence in adolescents and inform future work aimed at understanding the complex interplay between genetic, social, and psychological factors in adolescent smoking behavior.

Adolescent↗

PubMed2006

Cost-effectiveness of B-type natriuretic peptide testing in patients with acute dyspnea.

BACKGROUND: B-type natriuretic peptide (BNP) is a quantitative marker of heart failure that seems to be helpful in its diagnosis. METHODS: We performed a prospective randomized study (B-Type Natriuretic Peptide for Acute Shortness of Breath Evaluation) including 452 patients who presented to the emergency department with acute dyspnea to estimate the long-term cost-effectiveness of BNP guidance. Participants were randomly assigned to a diagnostic strategy involving the measurement of BNP levels (n = 225) or assessment in a standard manner (n = 227). Nonparametric bootstrapping was used to estimate the distribution of incremental costs and effects on the cost-effectiveness plane during 180 days of follow-up. RESULTS: Testing of BNP induced several important changes in management of dyspnea, including a reduction in the initial hospital admission rate, the use of intensive care, and total days in the hospital at 180 days (median, 10 days [interquartile range, 2-24 days] in the BNP group vs 14 days [interquartile range, 6-27 days] in the control group; P = .005). At 180 days, all-cause mortality was 20% in the BNP group and 23% in the control group (P = .42). Total treatment cost was significantly reduced in the BNP group (7930 dollars vs 10,503 dollars in the control group; P = .004). Analysis of incremental 180-day cost-effectiveness showed that BNP guidance resulted in lower mortality and lower cost in 80.6%, in higher mortality and lower cost in 19.3%, and in higher or lower mortality and higher cost in less than 0.1% each. Results were robust to changes in most variables but sensitive to changes in rehospitalization with BNP guidance. CONCLUSION: Testing of BNP is cost-effective in patients with acute dyspnea.

Acute Disease↗

PubMed2006

Effect of team sport participation on genetic predisposition to adolescent smoking progression.

CONTEXT: There is much to be learned about why some adolescents progress to a regular smoking habit and others do not. OBJECTIVE: To evaluate whether (1) team sport participation buffers the effect of having 2 smoking risk genotypes (the dopamine reuptake transporter [SLC6A3] and the dopamine D(2) receptor [DRD2]) or 1 of these risk genotypes vs having none on adolescent smoking progression and (2) the buffering effects of team sports were due to physical activity associated with team sport participation. DESIGN: Longitudinal cohort study. Survey data were collected annually from grade 9 to the end of grade 12. Self-report measures included smoking, team sport participation, physical activity, depression, smoking exposure, and alcohol and marijuana use. DNA was collected via buccal swabs. Data were analyzed using latent growth modeling. SETTING: Five public high schools in Virginia. PARTICIPANTS: A total of 361 students of European ancestry. Main Outcome Measure Smoking progression. RESULTS: For adolescents participating in at least 1 team sport, but not for adolescents with no team sport participation, physical activity had a significant negative effect on smoking progression (z = -3.85, P<.001; chi(2)(1,N = 361) = 6.73, P = .009). In addition, having 1 (z = 2.69; P = .007) and 2 (z = 2.22; P = .03) smoking risk genotypes had a positive effect on physical activity. These represented significant between-group effects (chi(2)(1,N = 361) = 6.29, P = .01; chi(2)(1,N = 361) = 3.81, P = .05, respectively). Thus, having 1 or more smoking risk genotypes was related to higher levels of physical activity, which, in turn, was related to lower levels of smoking progression for adolescents participating in at least 1 team sport but not for adolescents with no team sport participation. CONCLUSIONS: This study provides the first evidence of an interaction between environmental influences and specific genes on adolescent smoking and may promote an understanding of important protective relationships in the environment.

Adolescent↗

PubMed2006

Use of B-type natriuretic peptide in the management of acute dyspnea in patients with pulmonary disease.

BACKGROUND: In patients with pulmonary disease, it is often challenging to distinguish exacerbated pulmonary disease from congestive heart failure (CHF). The impact of B-type natriuretic peptide (BNP) measurements on the management of patients with pulmonary disease and acute dyspnea remains to be defined. METHODS: This study evaluated the subgroup of 226 patients with a history of pulmonary disease included in the BASEL Study. Patients were randomly assigned to a diagnostic strategy with (n = 119, BNP group) or without (n = 107, clinical group) the use of BNP levels provided by a rapid bedside assay. Time to discharge and total cost of treatment were recorded as the primary end points. RESULTS: Baseline characteristics were similar in patients assigned to the BNP and control groups. Comorbidity was extensive, including coronary artery disease and hypertension in half of patients. The primary discharge diagnosis was CHF and exacerbated obstructive pulmonary disease in 39% and 33%, respectively. The use of BNP levels significantly reduced the need for hospital admission (81% vs 91%, P = .034). Median time to discharge was 9.0 days in the BNP group as compared with 12.0 days (P = .001) in the clinical group. Median total cost of treatment was $4841 in the BNP group as compared with $5671 in the clinical group (P = .008). Inhospital mortality was 8% in both groups. CONCLUSIONS: CHF is a major cause of acute dyspnea in patients with a history of pulmonary disease. Used in conjunction with other clinical information, rapid measurement of BNP reduced time to discharge and total treatment cost of these patients.

Acute Disease↗

PubMed2006

How do psychological factors influence adolescent smoking progression? The evidence for indirect effects through tobacco advertising receptivity.

OBJECTIVES: To determine whether novelty seeking and depressive symptoms had mediated or indirect effects on adolescent smoking progression through tobacco advertising receptivity. METHODS: More than 1000 adolescents were monitored from 9th grade to 12th grade and completed annual surveys that measured demographic characteristics, smoking behavior, tobacco advertising receptivity, novelty-seeking personality, depressive symptoms, family and peer smoking, alcohol use, and marijuana use. RESULTS: Latent growth modeling indicated that novelty seeking had a significant indirect effect on smoking progression through baseline tobacco advertising receptivity. For each 1-SD increase in novelty seeking, the odds of being more receptive to tobacco advertising increased by 12% (ie, being in a specific category or higher), which in turn resulted in an 11% increase in the odds of smoking progression from 9th grade to 12th grade. The indirect effect from depressive symptoms to smoking progression did not reach significance. CONCLUSIONS: These findings may inform future research on other factors that influence tobacco advertising receptivity, as well as programs aimed at preventing adolescent smoking initiation and progression.

Adolescent↗

PubMed2005

The impact of self-control indices on peer smoking and adolescent smoking progression.

OBJECTIVE: To determine the direct impact of self-control variables on baseline smoking and smoking progression and determine whether self-control had indirect effects on smoking practices through effects on peer smoking. METHODS: Study participants were 918 adolescents who were followed from 9th through the 12th grade and completed self-report measures of peer smoking, self-control, and cigarette smoking. An exploratory factor analysis (EFA) was conducted to assess the factor structure of a 41-item self-control measure. The EFA indicated a six-factor structure comprising of impulsive control, planning, hostile blaming, attentional disregulation, conscientiousness, and physical aggression. RESULTS: The results of a latent growth model indicated that conscientiousness (OR = 0.81, CI = 0.73-0.90), hostile blaming (OR = 0.89, CI = 0.81-0.99), and physical aggression (OR = 1.16, CI = 1.06-1.27) had direct effects on baseline smoking, whereas planning (OR = 0.90, CI = 0.82-0.99) and impulse control (OR = 1.15, CI = 1.02-1.28) had indirect effects on adolescent smoking at baseline through baseline peer smoking. There were no significant direct or indirect effects of the self-control indices on smoking progression. There was a direct effect of peer smoking progression (number of peers who smoked) on adolescent smoking progression, such that increases in the number of peers who smoked across time increased the odds that an adolescent would progress to a higher level of smoking. CONCLUSIONS: Youth smoking prevention and intervention program outcomes may potentially improve by addressing self-control behaviors as they appear to have direct effects on smoking and indirect effects through peers who smoke.

Adolescent↗

PubMed2005

Investigation of mechanisms linking media exposure to smoking in high school students.

BACKGROUND: Media exposure has been found to impact adolescent smoking, although the mechanisms of this relationship have not been thoroughly investigated. Drive for thinness and tobacco advertising receptivity, both shown to be associated with smoking, are two potential mediators. METHODS: 967 twelfth grade students completed a self-report survey as part of a longitudinal study of biobehavioral predictors of smoking. Exposure to magazines and television, drive for thinness, tobacco advertisement receptivity, and twelfth grade smoking level were the primary variables of interest. Effects of gender, race, BMI, smoking exposure, and perceived physical appearance were controlled for in the model. RESULTS: Exposure to fashion, entertainment, and gossip magazines had indirect effects on smoking via drive for thinness and tobacco advertisement receptivity. There was a direct effect of health, fitness, and sports magazine reading on smoking. Television watching had no significant effects on smoking. CONCLUSIONS: Adolescents who read fashion, entertainment, and gossip magazines may be more likely to smoke, in part, because of a higher drive for thinness and greater receptivity to cigarette advertisements. Conversely, adolescents reading Health and Fitness magazines may be less likely to smoke. Drive for thinness and tobacco advertising receptivity are thus potential targets for adolescent smoking intervention.

Adolescent↗

PubMed2005

Longitudinal analysis of the effect of prenatal nicotine exposure on subsequent smoking behavior of offspring.

We explored the influence of maternal smoking during pregnancy on the likelihood of smoking among offspring in adolescence and adulthood using data from two similar British birth cohort surveys, the 1958 National Child Development Study and the 1970 British Birth Survey. Similar information was available in each cohort on maternal age at delivery, offspring sex, maternal smoking during pregnancy, parental and offspring socioeconomic status, and parental smoking at the time offspring smoking was assessed at age 16 years. Offspring smoking at 16 years and at 30/33 years were the primary outcomes of interest. Our data support an association between maternal smoking during pregnancy and an increased risk of offspring smoking later in life among female offspring but not among male offspring. Female offspring of mothers who smoked during pregnancy were more likely to smoke at 16 years than were their male counterparts. Moreover, in this same subgroup, female offspring smoking at 16 years was associated with an increased likelihood of smoking at 30/33 years. Further investigation in larger studies with greater detail of factors shaping smoking in childhood and adulthood and biochemically verified outcome measures would be desirable to clarify the relationship.

Adolescent↗

PubMed2005

Physical activity, global physical self-concept, and adolescent smoking.

BACKGROUND: Previous research supports a possible protective effect for physical activity against adolescent smoking. However, it is not clear whether the effect of physical activity on smoking is direct (e.g., time spent in physical activity) or indirect through another variable. One such variable is global physical self-concept (GPSC). Briefly, GPSC is a general perception of one's physical self, including appearance and physical activity competence. PURPOSE: This study tested a structural equation model of the relationship between physical activity and smoking, with direct effects from physical activity to smoking and an indirect effect through GPSC. METHODS: Participants were 983 12th graders taking part in a study of the biobehavioral predictors of adolescent smoking adoption. RESULTS: Controlling for covariates of adolescent smoking (e.g., peer smoking, alcohol use) and GPSC (e.g., body mass index, perceived physical appearance), physical activity had an indirect effect on smoking through its effects on GPSC, suggesting that the potential beneficial effects of physical activity on adolescent smoking may depend, in part, on GPSC. CONCLUSIONS: These results suggest that an adolescent's perception of the physical self may be one important factor to consider in youth smoking interventions. Further research is necessary to evaluate the longitudinal relationship between physical activity, GPSC, and smoking.

Adolescent↗

PubMed2005

Emergency diagnosis of congestive heart failure: impact of signs and symptoms.

BACKGROUND: The most useful features in the diagnosis of congestive heart failure (CHF) have been poorly investigated. OBJECTIVE: To determine the utility of signs and symptoms in the diagnosis of CHF in the emergency department. METHODS: Detailed clinical data were collected prospectively from 452 consecutive patients presenting with acute dyspnea to the emergency department. By using logistic regression analysis, significant predictors for the final discharge diagnosis of CHF (adjudicated after review of all patient records, including response to therapy) were assessed. RESULTS: In 217 of 452 patients (48%), CHF was the cause of acute dyspnea. Among symptoms, the OR for CHF was highest for weight gain (OR 3.6; 95% CI 1.9 to 7.0), nocturia (OR 2.4; 95% CI 1.6 to 3.7) and paroxysmal nocturnal dyspnea (OR 2.4; 95% CI 1.6 to 3.5), and lowest for fever (OR 0.36; 95% CI 0.22 to 0.56). Among signs, the OR was highest for elevated jugular venous pressure (OR 4.3; 95% CI 2.3 to 7.9), rales (OR 3.1; 95% CI 2.1 to 4.5), lower extremity edema (OR 2.8; 95% CI 1.9 to 4.3) and hepatojugular reflux (OR 2.7; 95% CI 1.4 to 5.2), and lowest for wheezing (OR 0.38; 95% CI 0.24 to 0.61). The overall sensitivity was low. The specificity was highest for elevated jugular venous pressure and hepatojugular reflux. CONCLUSIONS: Signs and symptoms are only moderately helpful in the diagnosis of CHF in patients with acute dyspnea. This emphasizes the need for additional diagnostic tools, such as echocardiography or B-type natriuretic peptide testing.

Acute Disease↗

PubMed2004

Use of B-type natriuretic peptide for the management of women with dyspnea.

In studies with predominately male patients, B-type natriuretic peptide (BNP) levels have been shown to be helpful in the evaluation and management of patients who present with acute dyspnea. The effect of BNP levels on the management of women has not been defined. This study evaluated a predefined subgroup of 190 women included in a prospective randomized controlled study of BNP testing for emergency diagnosis of acute dyspnea. Patients were randomly assigned to a diagnostic strategy with (n = 93, BNP group) or without (n = 97, control group) the use of BNP levels provided by a rapid bedside assay. Women differed significantly from men in baseline characteristics, symptoms, signs, and final discharge diagnoses. The use of BNP levels decreased the need for hospital admission (73% vs 86%, p = 0.034) and intensive care (12% vs 23%, p = 0.048). Median time to discharge was 6 days in the BNP group versus 10 days in the control group (p = 0.023). Total cost of treatment was $4,781 in the BNP group (95% confidence interval 3,854 to 5,708) versus $6,843 in the control group (95% confidence interval 5,611 to 8,074, p = 0.009). In-hospital mortality rates were 4% in the BNP group and 10% in the control group (p = 0.165). Thus, used in conjunction with other clinical information, rapid measurement of BNP decreased time to discharge and total cost of treatment in women who presented with acute dyspnea.

Acute Disease↗

PubMed2004

Construct validity analysis of the early smoking experience questionnaire for adolescents.

Analysis was undertaken to assess the construct validity of a measure of early smoking experience with a sample of adolescent smokers who had ever tried smoking. The results of this study support a two-factor structure of early smoking experience as well as the assertion that initial smoking experience can be characterized by both unpleasant and pleasant sensations. A cross-structure analysis with related and unrelated constructs supports the convergent and discriminant validity of the measure for an adolescent population.

Adolescent↗

PubMed2004

Applying a behavioral economic framework to understanding adolescent smoking.

Adolescents' choice to smoke may depend on substitute reinforcers for smoking, complementary activities to smoking, and individual differences in reinforcer value. The influence of these variables on smoking was determined among 983 adolescents. Substitutes were school involvement, academic performance, physical activity, and sports team participation: complements were peer smoking and substance use; delay discounting assessed individual differences in reinforcer value. Latent growth modeling indicated that substitute reinforcers reduced the odds of smoking progression almost two-fold, complementary reinforcers increased the odds by 1.14. and delay discounting indirectly influenced the odds of smoking progression through complementary reinforcers. Adolescents who smoke may have fewer reinforcers that protect against smoking and more reinforcers that promote smoking. Discounting of future rewards affects smoking through reinforcer type.

Adolescent↗

PubMed2004

Team sport participation and smoking: analysis with general growth mixture modeling.

OBJECTIVE: To assess the likelihood of smoking among adolescents with different patterns of team sport participation, grades 9-11. METHODS: Adolescents (N = 1098) participating in a longitudinal study of the biobehavioral predictors of smoking adoption completed items assessing various health-related behaviors, including team sport participation and smoking practices. General growth mixture modeling (GGMM) was used to analyze the data. RESULTS: Four patterns of team sport participation were found. Adolescents with decreasing or erratic participation were nearly three times more likely than adolescents with high participation to be current smokers in eleventh grade. Nonwhites were at particular risk for decreasing and erratic patterns of participation, and later smoking. Females were at high risk for low team participation. CONCLUSION: Results suggest that multiple patterns of team sport participation can be identified with GGMM and that these patterns may be useful in characterizing individuals at particular risk for future smoking.

Adolescent↗

PubMed2004

Interacting effects of genetic predisposition and depression on adolescent smoking progression.

OBJECTIVE: The goal of the present study was to identify specific genetic associations with smoking progression in adolescents and to determine whether these genetic effects on smoking practices are potentiated by depression symptoms. METHOD: Effects of dopamine transporter (SLC6A3) and dopamine receptor (DRD2) genetic variants on smoking progression were evaluated in a cohort of 615 adolescents, including those who had never smoked, and in a subgroup including only adolescents who had been exposed to nicotine (i.e., smoked at least a puff of a cigarette) (N=292). These adolescents were followed from 9th to 11th grade. Depression symptoms were also assessed. RESULTS: In the model of adolescents with a previous smoking experience, the likelihood of progressing to a higher level of smoking by the 11th grade increased almost twofold with each additional DRD2 A1 allele. The likelihood of smoking progression with each additional A1 allele was more pronounced among adolescents with substantial depression symptoms. The model including never-smokers revealed no significant genetic effects. Neither model revealed effects of SLC6A3. CONCLUSIONS: These results provide the first evidence, to the authors' knowledge, for an association of the DRD2 A1 allele with smoking progression among adolescents. This effect is potentiated by depression symptoms. These effects appear to be specific to adolescents who have had at least some nicotine exposure (i.e., at least a puff of a cigarette).

Adolescent↗

PubMed2004

Identifying and characterizing adolescent smoking trajectories.

Our understanding of longitudinal patterns of adolescent smoking development and the determinants of these patterns is limited. The present study evaluated adolescent smoking trajectories and characterized these trajectories with social, psychological, and behavioral factors in a cohort of adolescents assessed annually from grades 9 to 12. Complete data (smoking practices, novelty seeking, academic performance, substance use, peer smoking, physical activity and sports participation, and tobacco ad receptivity) were available on 968 participants; data were analyzed using latent class growth modeling. Four adolescent smoking trajectories emerged: never smokers, experimenters, earlier/faster smoking adopters, and later/slower smoking adopters. Early adopters were characterized by their high novelty seeking personality, depressive symptoms, poorer academic performance, and receptivity to tobacco advertising, as well as their exposure to other smokers, and use of other substances. Later adopters were characterized quite similarly to the early adopters, although they tended to perform better in school and to be more involved in sports. Experimenters also shared many of these same risk characteristics but to a lesser degree. Overall, never smokers were the most conventional in their profile. These data suggest that there is significant heterogeneity in the timing, rate, and intensity of smoking progression. Adolescent smoking prevention and intervention programs will need to consider this heterogeneity and tailor or enhance attention to risk and protective factors depending on the subpopulation.

Adolescent↗

PubMed2003

Smoking progression and physical activity.

This study examined the relationship between changes in physical activity and changes in smoking among adolescents. We prospectively examined smoking progression, physical activity, demographic factors, and covariates in 978 high school students participating in a longitudinal cohort study of the predictors of smoking adoption. We used latent growth modeling with the parallel processes smoking progression and physical activity as our method, with smoking progression measured as an ordered categorical variable. Results indicated that higher levels of physical activity reduced the odds of progressing to smoking or a higher level of smoking by nearly 1.5 (1.44; P < 0.05). No race differences were found. However, being male increased the odds of smoking progression by 1.32 (P < 0.05). Higher levels of physical activity may reduce the risk of smoking during adolescence. Youth smoking prevention initiatives should incorporate strategies to promote physical activity to prevent smoking experimentation and escalation.

Adolescent↗

PubMedDate not supplied

Developmental heterogeneity in adolescent depressive symptoms: associations with smoking behavior.

OBJECTIVE: Previous research has indicated an association between smoking and depression in adolescents, although the nature of the relationship is controversial. We sought to understand this relationship better in a prospective study by investigating whether there are subpopulations of adolescents with different relationships between smoking and depressive symptoms. METHODS: Our sample was 925 adolescents attending one of five Northern Virginia high schools, grades 9 to 12. We used General Growth Mixture Modeling as our method because it allowed identification and characterization of depressive symptoms trajectories and assessment of the effects of trajectory on 12th grade smoking. We defined the binary variable 12th grade current smoking as smoking on 1 or more of the past 30 days and more than 100 cigarettes smoked in a lifetime, versus not having smoked in the past 30 days. RESULTS: We identified three trajectories: high, medium, and low depressive symptoms. For adolescents with high symptoms, 9th grade (baseline) smoking was associated with an overall deceleration of depressive symptoms, whereas for adolescents with moderate symptoms, baseline smoking was associated with an overall acceleration in depressive symptoms. Baseline smoking was not associated with rate of change in depressive symptoms for adolescents with low symptoms, nor was it associated with baseline depressive symptoms in any trajectory. CONCLUSION: These findings demonstrate that there is a relationship between smoking and depressive symptoms in adolescents, and that the relationship can vary by developmental trajectory, suggesting etiological heterogeneity.

Adolescent↗