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Biomedical subjects

L H Epstein

Publications and source records attributed to L H Epstein.

At least 19 recordsLinked to original sources
PubMed1992

Effects of nicotine on hunger and eating in male and female smokers.

We tested whether the inverse relationship between smoking and body weight may be due in part to nicotine's acute effects on reducing hunger and eating. On four mornings, male and female smokers (n = 10 each), abstinent overnight from smoking and food, received one of three nicotine doses (7.5, 15, and 30 micrograms/kg) or placebo (0) via nasal spray every 30 min for 2 h. Self-reported hunger and satiety ("fullness") and craving for cigarettes were obtained after each dose presentation. Subjects subsequently ate ad lib from a large array of food items varying in sweet taste and fat content. For both males and females, nicotine had no effect on self-reported hunger, but cigarette craving was decreased. Rather than being decreased, caloric intake during the meal was unexpectedly increased following nicotine compared with placebo. Cigarette craving increased after the meal, and this increase was unaffected by nicotine dose. There were virtually no differences between males and females in any effects of nicotine. These results indicate that nicotine may not acutely suppress appetite in fasting smokers and suggest that other actions of nicotine or smoking may account for the lower body weights of smokers.

Adolescent↗
PubMed1992

Habituation and dishabituation of human salivary response.

Habituation may be relevant for understanding how sensory stimuli influence factors related to ingestive behavior. In the first of three experiments in humans we showed that salivation and hedonic ratings to lemon or lime juice habituated within 10 presentations, and dishabituation of the salivation and hedonic ratings to the original juice were observed after a new juice was presented. Experiment 2 replicated the habituation and decrease in hedonics to lemon juice, and showed both dishabituation and a relative increase in hedonics when chocolate taste, rather than another juice, served as the dishabituating stimulus. In a third experiment we showed a video game, a nontaste stimulus, could serve as a distractor to prevent the development of habituation, as well as a dishabituator after habituation had occurred.

Adolescent↗
PubMed1992

Abstinence from smoking decreases habituation to food cues.

Smokers typically gain weight after cessation due, in part, to increased caloric intake. This increase may be due to enhanced responding to sensory characteristics of foods resulting from a failure to habituate to food cues. To test this possibility, salivation to eight presentations of strawberry yogurt was assessed in male smokers and nonsmokers in two sessions. To test stimulus specificity, on the ninth trial, subjects were presented either more strawberry yogurt or lemon yogurt. Smokers were studied under nonabstinent or abstinent conditions. Salivation for nonabstinent smokers and nonsmokers decreased over presentations, while abstinent smokers showed little change. Nonabstinent smokers and nonsmokers recovered salivation when the new flavor yogurt was presented, and showed greater consumption on the final trial for the different versus same flavor yogurt. Nonabstinent smokers participated in additional within-session smoking sessions to control for withdrawal. Nonabstinent subjects were not different across smoking or not smoking sessions, suggesting the effects are not due to the acute effects of withdrawal.

Adolescent↗
PubMed1992

Effect of food change on consumption, hedonics, and salivation.

This study assessed the influence of introducing a new food after repeated presentations of one food on food consumption, hedonics, and salivation. Male subjects were provided repeated 150-calorie courses of pizza or cheeseburger until satiety. Hedonics and salivation were measured before each course. Subject were then provided an additional 450 calorie course of the same or the new food. During the development of satiety, subjects showed reliable increases in fullness and decreases in hunger and hedonics. Salivation briefly increased to maximal salivation, followed by reliable decreases. No differences in pattern of change for fullness, hunger, hedonics or salivation were noted across foods. Presentation of the new food resulted in significantly greater caloric consumption than another serving of the same food (130 vs. 44.5 kcal), an increase in hedonics and salivation relative to presentation of the same food, with no influence on hunger or fullness. These results suggest that after satiety develops, response recovery for subjective, physiological, and behavioral components of eating can be observed when new, palatable foods are presented.

Adolescent↗
PubMed1992

Effects of nicotine on subjective arousal may be dependent on baseline subjective state.

The often disparate and contrasting effects of nicotine on subjective arousal in smokers may be due in part to differences in presmoking subjective state. In Study 1, on each of 2 days, 10 male smokers were divided into high- and low-baseline subgroups on the basis of median split of resting predrug baseline subjective arousal. Then, subjects received intermittent nicotine (15 mu/kg) or placebo via measured-dose nasal spray, with drug conditions counterbalanced between days. In Study 2, 32 male and female smokers were similarly divided into high- and low-baseline subgroups on subjective arousal prior to either smoking or sham-smoking (n = 16 each) during a single session. Results were virtually identical between studies in showing that subjective arousal responses to nicotine (Study 1) or smoking (Study 2) were significantly inversely related to baseline arousal level; those initially low in arousal showed large increases following nicotine or smoking whereas those high in arousal showed little change. No such baseline dependency of responses was seen following placebo or sham smoking. Baseline dependency of cardiovascular responses to nicotine or smoking was also evaluated in similar fashion to determine generalizability of these effects to nonsubjective responses. In each study, systolic blood pressure response was related to baseline level but there was no effect of baseline level on heart rate and diastolic blood pressure responses. Implications of these results for explaining differential rewarding effects of smoking are discussed.

Administration, Intranasal↗
PubMed1992

Role of behavior theory in behavioral medicine.

Behavioral medicine is a multidisciplinary field that combines research methods and findings from behavioral and biomedical sciences. Many investigators in the field have tended to emphasize the contribution of the biomedical more than the behavioral sciences. This is evident in the emphasis on biological rather than behavioral outcomes and on the reductionist approach within the field to reduce mechanisms responsible for behavioral effects and disease to biological influences. There has been a similar shift in psychology toward mechanistic, bottom-up approaches to understanding mechanisms responsible for integrated and dynamic behavior. These shifts in emphasis have stimulated investigators to examine the use of biomedical methods and findings as causes and explanations for behavior, rather than to utilize newer findings in behavioral sciences. New advances in basic research on learning are used to illustrate that findings from behavioral science have implications for the field of contemporary behavioral medicine. Finally, the importance of developing new technologies for measuring behavior is presented.

Behavior Therapy↗
PubMed1992

National working conference on smoking and body weight. Task Force 1: Mechanisms relevant to the relations between cigarette smoking and body weight.

Careful, comprehensive, and empirical observations provide the building blocks of the sciences, whereas theory and mechanisms provide the "cement" to hold the blocks together and serve as blueprints to direct future building. This article resulted from several days of discussion regarding theories that may underlie the relation between cigarette smoking and body weight and the relation between smoking cessation and body weight. The working group composed of social and biological scientists who addressed this assignment considered what is already known within the smoking and body weight literature and also considered relevant findings from studies of smoking or body weight regulation that have not directly addressed the interaction of these variables. As expected, we were successful at listing some of what is not known and what is worth knowing. We also tried to identify fruitful possibilities for research activity that might clarify mechanisms of action and eventually lead to theoretical development. Because we do not believe that the present state of our deliberations merits the label of theories, we decided, instead, to report the summary of these deliberations as potential mechanisms relevant to the relation between smoking and body weight.

Adult↗
PubMed1991

Acute effects of nicotine on hunger and caloric intake in smokers and nonsmokers.

The inverse relationship between smoking and body weight may be due in part to nicotine's effects on reducing hunger and eating. Male smokers and nonsmokers (n = 10 each), abstinent overnight from smoking and food, participated in four sessions, involving consumption of a liquid caloric load or water followed by nicotine (15 micrograms/kg) or placebo via nasal spray every 20 min for 2 h. Hunger and satiety ("fullness") ratings were obtained prior to each dose presentation. At the end of the two sessions involving the caloric load (simulating breakfast), subjects were also presented with typical lunch/snack food items varying in sweet taste and fat content for ad lib consumption. Results indicated that, for both smokers and nonsmokers, the hunger-reducing effects of nicotine occurred only following caloric load consumption, and there was no effect of nicotine on hunger afer water consumption. Smokers unexpectedly reported greater satiation than nonsmokers following the caloric load regardless of nicotine or placebo condition. Nicotine also resulted in less caloric intake during the meal, and the decrease was not specific to consumption of sweet, high-fat foods. These results indicate that nicotine reduces appetite, possibly helping to explain the influence of smoking on body weight.

Adult↗
PubMed1991

Behavioral economic analysis of smoking: money and food as alternatives.

The relative reinforcing value of smoking versus two nonpharmacological reinforcers, money and food, was evaluated in young female smokers in two experiments. In Experiment 1 eight smokers worked for access to smoking or money on concurrent progressive variable ratio schedules of reinforcement (VR4 to VR50) across two days of Smoking Deprivation or No Deprivation. During No Deprivation money was reliably chosen over smoking. During Deprivation subjects initially (VR4) chose smoking over money, but at subsequent comparisons allocated equal time to work for smoking or money. In Experiment 2 eight smokers were provided access to smoking or food across four conditions: No Deprivation, Smoking Deprivation, Food Deprivation and Smoking + Food Deprivation, using the same progressive variable ratio schedules as in Experiment 1. Results showed an increase in the reinforcing value of food after Food Deprivation and smoking after Smoking Deprivation. On the dual deprivation day, subjects initially (VR4) chose to work for food, showed equal preferences over the next three schedule comparisons (VR8-VR20), and from VR25-VR50 shifted their choice to smoking. An increase in percent of calories as fat was observed during all deprivation conditions. The results demonstrate the use of the concurrent schedule paradigm for assessing choice among pharmacological and nonpharmacological reinforcers, and shows the relative reinforcing value of smoking depends on recent deprivation, response demands to obtain the reinforcer and availability of alternative reinforcers.

Adolescent↗
PubMed1991

Conditioned tolerance to the anorectic and corticosterone-elevating effects of nicotine.

We have shown that tolerance to the behavioral effects of nicotine is partially dependent on conditioned environmental cues that predict drug delivery. The present research extends this finding to physiological effects of nicotine by assessing both the appetite-suppressing and adrenocortical-activating effects of nicotine, as measured by plasma corticosterone (CORT). In the first study, male rats on a 22-h food deprivation schedule were injected daily with 0.33 or 0.66 mg/kg (free base) of nicotine bitartrate or saline in a distinctive environment and tested for milk intake. Nicotine initially suppressed milk intake and tolerance developed over 10 days. Changing cues associated with drug administration partially reversed tolerance since injection of nicotine in a new environment reduced milk intake of tolerant animals. Similarly, animals who repeatedly received nicotine in one environment exhibited CORT levels lower than rats injected for the first time, and this tolerance also was partially reversed when administration occurred in the new environment. The second experiment indicated that the increased CORT of Experiment 1 was not a stress response associated with injecting animals in a different environment. These results indicate that tolerance to both behavioral and neuroendocrine effects of nicotine is influenced by conditioning.

Animals↗
PubMed1991

Conditioned tolerance to the heart rate effects of smoking.

This study extended our findings that behavioral tolerance to nicotine in animals can be influenced by conditioning to cardiovascular tolerance in humans. Subjects smoked one-half a cigarette during each of five trials. In the ten-minute intersmoking interval the contexts that preceded smoking were varied. Smokers in the Changing group attended to a different five-minute segment of a Sherlock Holmes radio mystery before each trial, while those in the Repeated group listened to the same segment of the tape. Presmoking heart rates were stable across the groups from trials 1 to 5. As predicted, heart rate for subjects who smoked in the same context showed tolerance to smoking from trials 1 to 5 (84.5 to 78 bpm), while subjects who smoked in in the same context showed tolerance to 83.9 bpm). COa levels increased equally for both groups over the five trials. The results of this study suggest tolerance to smoking can be influenced by learning.

Adult↗
PubMed1991

Effects of dose, gender, and level of physical activity on acute metabolic response to nicotine.

The acute thermogenic effect of nicotine was examined in cigarette smokers under conditions of rest and two levels of low-intensity physical activity comparable to that normally engaged in by sedentary adults. Male and female smokers (n = 10 each) each received 0 (placebo), 7.5, 15, or 30 micrograms/kg nicotine via measured-dose nasal spray once every 30 min for 90 min, with each dose presented on a separate occasion. After each dose presentation, subjects engaged in 10 min of rest or low-intensity activity at 30 or 60 watts (W) using a bicycle ergometer. For males, results indicated that expenditure attributable to nicotine was more than twice as large during 60-W activity compared with rest, while that during 30-W activity was intermediate. For females, expenditure attributable to nicotine was generally similar to that of males during rest and 30-W activity but was significantly lower during 60-W activity, indicating an apparent "inverted-U" relationship with activity intensity. The enhanced effect of nicotine was specific to energy expenditure, since heart rate showed dose-dependent changes that were generally similar regardless of activity level. These findings confirm a mediating influence of physical activity level on the acute metabolic effect of nicotine, especially in males, and may have implications for explaining individual differences in body weight changes due to tobacco smoking and cessation.

Adult↗
PubMed1991

Behavioral economic analysis of food choice in obese children.

Behavioral economic analysis has shown food choice in normal weight adults is influenced by both liking and constraints on access to food. The present study assessed the contributions of food liking and environmental constraints to choice of moderately liked, low-calorie foods or highly liked high-calorie foods in obese children. Access to the moderately liked food remained on a VR2 schedule, while response requirements for the highly liked food ranged from VR2 to VR32. Subjects chose to work for the higher-rated food at comparisons up to VR2/VR4, showed no preference at VR2/VR8 and their choice shifted to the lower rated food when response requirements for the highly liked food were increased to VR16. These results show that both subjective and environmental factors contribute to children's choice of foods.

Child↗
PubMed1991

Estimation of percent overweight within families.

When height and weight cannot be directly measured percent overweight can be estimated using self-reported height and weight, reports of others for height and weight, and matching of body shape to silhouettes. The present study assessed the relative benefits of each method for estimating percent overweight within families, as well as the potential for using matching of silhouettes for diagnosing obesity. Analysis of the relationship between percent overweight and silhouette ratings showed increases in percent overweight across the silhouettes. Correlations between self- or other-reported and measured percent overweight showed that self-reports correlated very highly with measured reports of percent overweight (r = .97, .96 for parents and children, respectively), but parent reports of their spouses and children percent overweight were lower (r = .87, .87) and child reports of sibling or parent percent overweight were even lower (r = .75, .75). Significant increases in accuracy of diagnosing obesity were observed when the combination of adjusted self-reports and silhouettes were used in comparison to self-reports alone.

Adolescent↗
PubMed1991

Smoking as a cue for subjective and behavioral responses to a stressor.

Smoking in conjunction with a repeated stressor may come to serve as a cue, or discriminative stimulus, for responses to the stressor. This study examined the effects of omitting a previously predictable smoking cue on subjective and behavioral responses to a stressor. Male smokers were instructed to smoke briefly on command immediately prior to ("smoke-pre", n = 10) or several minutes after ("smoke-post", n = 10) each of four acquisition trials of a mental arithmetic task. During two subsequent trials, both groups first engaged in the task without the smoking cue (Test Trial 1), a novel experience for smoke-pre, and then engaged in the task preceded by the smoking cue (Test Trial 2), a novel experience for smoke-post. Omission of the smoking cue during Test Trial 1 produced significantly poorer task performance and greater subjective stress in smoke-pre. Although not significant, insertion of the smoking cue during Test Trial 2 tended to produce poorer performance in smoke-post. Thus, a consistent pattern of smoking in association with a repeated stressor may subsequently lead to impaired responding to the stressor if smoking is omitted.

Adaptation, Psychological↗
PubMed1991

A "family-based" approach to the treatment of obese type II diabetic patients.

Forty-nine obese diabetic patients with obese spouses (diabetic or nondiabetic) were randomly assigned to an alone or together condition. Patients in the alone group participated by themselves in a 20-week behavioral weight control program; their spouses attended assessment sessions only. Patients in the together group attended the program with their spouses; both were targeted for weight loss and taught social support strategies. Weight losses of patients treated alone and together did not differ significantly at posttreatment (19.9 vs. 19.1 lb) or 1-year follow-up (11.6 vs. 7.0 lb). However, there was a significant interaction of treatment and gender; women did better when treated with their spouses, whereas men did better when treated alone. A "family-based" approach was not effective for these obese Type II diabetic patients as a whole but may be helpful for women.

Adult↗
PubMed1991

Behavioral economic analysis of activity choice in obese children.

Evaluated children's choice for sedentary versus vigorous activity. Experiment 1 assessed the influence of percent overweight (less than 20%, 20% to 80%, greater than 80%) on choice of a moderately liked vigorous activity at a constant variable ratio (VR) 2 reinforcement schedule versus a highly liked sedentary activity with the schedule varied from VR2 to VR32. All children chose the sedentary choice when the schedules were VR2. As the cost for sedentary activity increased, lean and moderately obese children switched to the vigorous activity, but the very obese children still chose the sedentary activity. Experiment 2 compared moderately obese children's choice between easily accessible, highly or least liked vigorous activities (VR2) and highly liked sedentary activity with the schedule varied from VR2 through VR16. When the reinforcement schedules were equal, and sedentary activity and vigorous activity were rated as equally linked, children chose the sedentary activity. All subjects switched from the sedentary to the vigorous activity, but there were no differences in choice as a function of liking for vigorous activities.

Child↗