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Biomedical subjects

L H Epstein

Publications and source records attributed to L H Epstein.

At least 109 records · Page 6Linked to original sources

Ten-year follow-up of behavioral, family-based treatment for obese children.

Using a prospective, randomized, controlled design, we examined the effects of behavioral family-based treatment on percent overweight and growth over 10 years in obese 6- to 12-year-old children. Obese children and their parents were randomized to three groups that were provided similar diet, exercise, and behavior management training but differed in the reinforcement for weight loss and behavior change. The child and parent group reinforced parent and child behavior change and weight loss, the child group reinforced child behavior change and weight loss, and the nonspecific control group reinforced families for attendance. Children in the child and parent group showed significantly greater decreases in percent overweight after 5 and 10 years (-11.2% and -7.5%, respectively) than children in the nonspecific control group (+ 7.9% and + 14.3%, respectively). Children in the child group showed increases in percent overweight after 5 and 10 years (+ 2.7% and + 4.5%, respectively) that were midway between those for the child and parent and nonspecific groups and not significantly different from either. At 10 years, child height was related strongly to the height of the parent of the same sex (r = .78 children were 1.8 cm taller than their parents, with no differences in height between groups.

Analysis of Variance↗

Growth in obese children treated for obesity.

This study assesses the growth patterns during a 5-year period in children aged 6 to 12 years treated for obesity using behavioral family-based treatment procedures. Previous studies have suggested a decrease in height velocity after weight reduction, but these results did not consider either the height of the parent or the greater height of obese than nonobese children. Results show that at entry, obese children are taller than their nonobese peers (74th percentile), and that even after 5 years, they remain taller than the norm (65th percentile). Child weight and level of physical maturity accounted for 54% of the variance in predicting baseline height percentile. Entrance height and parental height accounted for 9% of the variance in changes in height percentile, both adjusted for parental height. Weight change did not correlate with growth adjusted for parental height. These results do not suggest that negative effects on height are a long-term side effect of child weight control.

Behavior Therapy↗

Effects of smoking context on habituation to a repeated cognitive task.

This study assessed the role of smoking-related cues on habituation of electrodermal responding and facial neuromuscular responses in male smokers. In three of the four groups, subjects smoked for the first five trials followed by the laboratory arithmetic task. On the sixth trial one group of subjects continued to smoke nicotine cigarettes, while the context was changed for subjects in the other groups by 1) omitting the pharmacological cues (smoking a non-nicotine cigarette) or 2) omitting both the pharmacological and behavioral cues (not smoking). Subjects in a non-smoking control group did not smoke before any of the six trials. During trials 1-5, smoking significantly increased the rate of habituation of electrodermal activity. On trial 6, electrodermal activity significantly increased for subjects who had a change in smoking context, whether it involved removal of pharmacological or smoking plus pharmacological cues. No differences in electrodermal activity were observed between subjects in these groups compared to non-smoking control subjects. Smoking increased zygomatic activity (predominant during smiling) during trials 1-5, consistent with an interpretation of the positively reinforcing nature of smoking. Corrugator activity (predominant during frowning or concentration) increased for subjects who had both the pharmacological and behavioral smoking cues omitted on trial 6.

Adolescent↗

Behavioral performance effects of nicotine in smokers and nonsmokers.

Performance on finger-tapping and handsteadiness, tasks opposite in response requirements, was compared between male smokers and nonsmokers (n = 10 each) on two occasions, once following intake of nicotine (15 micrograms/kg) by measured-dose nasal spray and once following placebo. Compared with nonsmokers, smokers had significantly greater increase in finger-tapping speed due to nicotine. On the other hand, smokers tended to have improved performance on handsteadiness (i.e., less involuntary movement) due to nicotine, while nonsmokers had impaired performance, although this difference was not significant. Nicotine-induced changes in performance on each task were inversely related, suggesting specificity of the behavioral effects of nicotine depending on task demands, rather than a generalized effect. These effects of nicotine on behavioral performance may be important in understanding the reinforcing value of nicotine intake, and differences in effects as a function of smoking history may suggest chronic adaptation to nicotine.

Adult↗

Perception and hedonics of sweet and fat taste in smokers and nonsmokers following nicotine intake.

Nicotine's effects on reducing perception and/or hedonics of sweet and fat taste may lead to less intake of sweet tasting, high-fat foods by smokers, helping to explain their generally lower body weights. Smokers and nonsmokers (n = 10 males each) rated perception (intensity and sensitivity) and hedonics (liking) of sweet/fat taste in milk samples varying both in sucrose (0, 5, 10, 20% w/w) and fat (0.1, 3.5, 11.7, 37.6% w/w) concentration on two occasions, once following intermittent presentation of nicotine (15 micrograms/kg) via measured dose nasal spray and the other following placebo. Nicotine significantly reduced perceived intensity of fat but not sweet taste and had no effect on sensitivity to either taste. There was no effect of nicotine on hedonics of sweet/fat taste. On the other hand, although there were no differences between smokers and nonsmokers in perception of sweet or fat, hedonics of sweet/fat taste was reduced in smokers regardless of nicotine or placebo intake. Thus, nicotine may acutely decrease fat taste perception without influencing sweet/fat hedonics, while long-term exposure (i.e., being a smoker) may produce chronically decreased taste hedonics without altering perception.

Adolescent↗

A behavioral economics analysis of food choice in humans.

Three studies on the behavioral economics of food choice were presented. In Experiment 1 subjects were provided a choice of working for food on concurrent VR4 VR20 schedules, and subjects allocated the majority of their responding to the VR4 schedule. Subjects in Experiment 2 were provided a choice between two foods differing in ratings of subjective liking. The lower rated food was available on an FR1 component of a concurrent schedule, while the higher rated food was available on the other component across six comparisons ranging from FR1 through VR32. Subjects initially chose to work for the higher rated food, but as the constraints for this food increased, subjects chose to work for the lower rated food. In Experiment 3, subjects were provided the choice of a breakfast they liked or the monetary equivalent during deprivation and non-deprivation conditions. The food and money were first compared on equal FR1 schedules. Schedule requirements for money were subsequently maintained on a VR2 schedule, while access to food was presented in four phases from VR4 through VR32. Under deprivation, subjects allocated their time to get the preferred food instead of money only at the FR1 FR1 comparison. Under non-deprivation subjects allocated almost all their responding to work for money. These results suggest that the laboratory choice task is sensitive to schedule differences when food is used as a reinforcer, that subjective liking and schedule constraints for food are both important in determining food choice, and that alternative reinforces can complete with food, but the effect is dependent on both the level of deprivation and constraints on access to food.

Adolescent↗

Effects of smoking cessation on consumption of alcohol and sweet, high-fat foods.

Smoking cessation may have significant effects on consumption of certain foods and other substances which may influence health. This study of seven young female smokers examined consumption of alcohol, coffee, soda, and sweets (sweet, high-fat foods) across 3 weeks, involving baseline ad lib smoking (week 1), complete cessation (week 2), and resumption of smoking (week 3). TV watching (i.e., nondietary activity) and subjective measures of craving and tension-anxiety also were assessed. Results showed increased intake of sweets and, to a lesser extent, alcohol after cessation which was reversed upon resumption of smoking. There were no significant changes across weeks in other substances. The changes in alcohol and sweet intake did not appear to be related directly to the subjective changes. These findings indicate that smoking cessation, a behavior change which promotes health, may lead to alterations in consumption of other substances, which may have adverse effects on health risk.

Adult↗

Treatment of laxative abuse in a female with bulimia nervosa using an operant extinction paradigm.

Chronic laxative abuse was treated using an operant extinction paradigm in a 29-year-old woman with bulimia nervosa. Access to self-administration of laxative and placebo were alternated in an ABAB design. Outcome was measured by self-reported craving for laxatives and rates of drug self-administration. During baseline, the subject exhibited high rates of both craving and self-administration. During placebo phases, cravings and drug self-administration declined. Both measures increased when active drug was reinstated. The final return to placebo led to a decrease in craving and extinction of drug self-administration to zero doses per day. This paper introduces the concept of laxatives as reinforcers and provides a new approach to the treatment of laxative abuse in women with bulimia nervosa.

Adult↗

Changes in energy balance following smoking cessation and resumption of smoking in women.

Caloric intake, resting metabolic rate (RMR), leisure-time physical activity, and sensitivity and preference for sweet taste were prospectively examined in 7 female smokers across 3 weeks during periods of normal smoking (Week 1), complete cessation (Week 2), and resumption of smoking (Week 3). Energy balance changed significantly across weeks, as caloric intake increased (largely as a result of alcohol consumption) and RMR decreased during cessation, followed by decreased caloric intake and increased RMR with resumption of smoking. Activity and taste sensitivity and preference remained unchanged. Smoking cessation may thus cause rapid change in energy balance, which is quickly reversed on resumption of smoking.

Adolescent↗

Five-year follow-up of family-based behavioral treatments for childhood obesity.

This article presents the 5-year outcome of family-based behavioral treatment of obesity for 6- to 12-year-old children in 162 families across 4 treatment outcome studies. Results suggest that treatments that use (a) conjoint targeting and reinforcement of child and parent behavior or (b) reciprocal targeting and reinforcement of children and parents are associated with the best child outcomes. Predictors of child success include self-monitoring, changing eating behavior, praise, and change in parent percent overweight. Parental outcome is predicted by self-monitoring weight, baseline parent percent overweight, and participation in fewer subsequent weight control programs.

Behavior Therapy↗

Psychological stress and glucose metabolism in obese and normal-weight subjects: a possible mechanism for differences in stress-induced eating.

Acute psychological stress has been found to impair the handling of a glucose load in normal-weight individuals and to produce a delay in gastrointestinal transit time. The present study utilized the same paradigm to compare 10 obese and 10 normal-weight subjects. All subjects participated in two counterbalanced sessions (stress and nonstress). At each session, subjects were fed a carbohydrate load, and glucose was measured 0, 30, 60, 90, and 120 min after the load. On nonstress days, subjects relaxed after the drink; on stress days, subjects participated in 30 min of competitive tasks. The stressor significantly delayed the glucose response in the normal-weight subjects but did not affect the glucose response in obese subjects. This finding may have implications for differences between obese and normal-weight individuals in stress-induced eating, possibly explaining the decreased consumption of normal-weight individuals during stress.

Anger↗

Metabolic effects of nicotine after consumption of a meal in smokers and nonsmokers.

The thermogenic effect of nicotine intake after calorie consumption was investigated to determine if nicotine influences metabolic response to a calorie challenge. Smokers and nonsmokers (10 males in each group), matched for body weight, age, and physical fitness, each participated in four sessions that involved consuming a liquid calorie load (4.77 kcal/kg body wt) or water, followed by nicotine (15 micrograms/kg body wt) or placebo via nasal spray every 20 min for 2 h. Energy expenditure was significantly increased above baseline resting metabolic rate (RMR) over the 2 h by nicotine alone (6.5% of RMR, p less than 0.01). However, the combined effect of nicotine after calorie load (20.1% of RMR, p less than 0.001) was not significantly greater than the effect of calorie load alone (18.4% of RMR, p less than 0.001). Smokers and nonsmokers did not differ in baseline RMR or in response to nicotine or calorie load. These results confirm the thermogenic effect of nicotine but suggest that the effect of nicotine after calorie consumption is less than additive.

Administration, Intranasal↗

Cardiovascular effects of nicotine during physical activity and following meal consumption.

1. In two separate studies using healthy male smokers as subjects, the acute cardiovascular effects of a measured dose of nicotine (15 micrograms/kg) were examined in conjunction with light physical activity and following consumption of a meal, conditions typical of nicotine intake via smoking. 2. Increases in heart rate and systolic blood pressure attributable to nicotine were similar during rest, physical activity, and following eating, demonstrating additivity with the cardiovascular effects of activity and a caloric load. Diastolic blood pressure was less affected by nicotine. 3. These results indicate that cardiovascular activity is acutely increased following nicotine (smoking) regardless of other influences on the cardiovascular system. Such effects may help explain increased risks of acute cardiac abnormalities due to smoking.

Adolescent↗

Perception of activity in the Zygomaticus major and Corrugator supercilii muscle regions.

This study was designed to assess differences in perception of activity in the zygomaticus major (predominant during smiling) and corrugator supercilii facial muscles (predominant during frowning). Magnitude production psychophysical methods were used to relate subjective intensity to objective electromyographic activity using a psychophysical power function under four conditions: smiling, frowning, smiling concurrent with maintenance of a frown, and frowning concurrent with maintenance of a smile. High correlation coefficients for each power function for both zygomatic and corrugator activity were obtained. Differences in sensitivity evaluated by comparing the exponent for slope of the power functions showed differences across the muscles and as a function of the conditions. The exponent for frowning was greater than for smiling. Although the exponent for zygomatic activity was similar with and without frowning, significantly greater exponents were shown for corrugator activity when concurrently frowning and smiling than when only frowning. Maximal electromyographic activity was greater in the zygomaticus major muscle during smiling than in the corrugator supercilii muscle during frowning. These results provide a methodology for perception of electromyographic activity which could be a useful basis for analysis of the role of perception in regulating affect.

Adolescent↗

Depressive symptomatology in obese adults with type II diabetes.

This study compared depressive symptomatology in 32 obese subjects with type II (non-insulin-dependent) diabetes (16 men, 16 women) and their obese nondiabetic spouses. All subjects completed the Beck Depression Inventory (BDI) before participation in a behavioral weight-loss program. Diabetic subjects reported significantly more depressive symptomatology than their overweight nondiabetic spouses (10.6 +/- 6.4 vs. 7.5 +/- 6.2, P less than 0.04). Diabetic subjects scored higher than their spouses on 15 of 20 BDI items, with significant differences in feelings of being punished, perceived appearance, and interest in sex. Mean BDI score in the diabetic spouses was similar to that observed in the first 123 diabetic subjects to enter the weight-loss program (BDI 11.2 +/- 6.9). Further studies are needed to determine whether diabetic subjects differ from age-, sex-, and weight-matched nondiabetic individuals in clinical depression and depressive symptomatology.

Depression↗