Biomedical subjects

M Hasenfratz

Publications and source records attributed to M Hasenfratz.

At least 19 recordsLinked to original sources

PubMed1997

Effects of a 2-day abstinence from smoking on dietary, cognitive, subjective, and physiologic parameters among younger and older female smokers.

In a field study, dietary intakes, subjective ratings of well-being, cognitive performance, blood pressure, and heart rate were assessed during 6 days of ad libitum smoking and 2 days without smoking by using an electronic diary. The subjects were 59 younger and older female smokers, aged 25-35 and 55-65 years, respectively. Smoking abstinence significantly lowered heart rate, blood pressure, and saliva cotinine levels, indicating a good compliance by the subjects. Smoking abstinence was also followed by subjectively reported decreased levels of relaxation and activity and by higher levels of sleepiness, negative strain, and craving for smoking. Mental performance as assessed with the Stroop task was not affected by smoking abstinence. Whereas the percentage distribution of the macronutrients did not change with smoking abstinence, the intake of total energy increased significantly by 182 kcal/day. Main effects of age were found on some of the dietary parameters and Stroop performance variables only. A post hoc analysis revealed a significant influence of the employment status factor on the excess caloric intake and the increased frequency of sweet consumption when under abstinence. These increases were significantly greater in nonemployed (housewives, jobless) than in working women. Further correlational analysis revealed strong relations between caloric intake and simultaneous craving for smoking and food during abstinence but not during nonabstinence days, whereas no relation between caloric intakes and saliva cotinine or respiratory carbon monoxide were obtained. These findings suggest that the availability of food products and subjective withdrawal symptoms are probably more important moderators of increased dietary intake following smoking cessation than any pharmacologic systemic effects of nicotine.

Adult↗

PubMed1995

Comparison of the effects of nicotine on a fixed rate and a subject-paced version of the rapid information processing task.

In a modified "subject-paced" rather than fixed rate version of a rapid information processing (RIP) task, the presentation rate of the stimuli is continuously adapted to the individual performance level. Thus, this modified task version probably assesses a continuous "speed function" rather than mere "vigilance". In order to compare the two task versions more directly, we carried out a study which assessed the effects of a regular nicotine cigarette and the nearly nicotine-free cigarette NEXT on both task versions under the same experimental conditions. The dominant alpha frequency pointed to a greater arousal evoked by the subject-paced RIP version compared with the fixed rate version. With the fixed rate version, smoking nicotine cigarettes reduced reaction times, whereas with the subject-paced version, processing rate was improved. Additionally, smoking NEXT decreased craving less than smoking the regular cigarettes. It was concluded that the two task versions are sensitive to different cognitive functions. Whereas the subject-paced version was more sensitive to effects on the speed of processing, the fixed rate version was more sensitive to effects on reaction time.

Adult↗

PubMed1995

Switching to ultralow nicotine cigarettes: effects of different tar yields and blocking of olfactory cues.

Twelve female smokers smoked two of each of three types of cigarettes in three sessions. One cigarette was smoked with and the other one without nose blocking. Total puff volumes increased for ultralow tar/nicotine (tn) cigarettes as compared with habitual regular tar/nicotine (TN) cigarettes and regular tar/ultralow nicotine (Tn) cigarettes, as the result of an increase in the number of puffs. TN and tn, but not Tn cigarettes changed heart rate and beta-power in the electroencephalogram; all three reduced craving, although they differed considerably in subjective acceptance. Blocking of olfactory cues influenced respiration and reduced the average puff volumes, taste, and enjoyment, but it did not differentially affect any parameters among the TN, tn, and Tn cigarettes, which suggests that olfaction plays a minor role in regulating puffing behavior. It was concluded that as compared with regular TN cigarettes, only the tn, but not the Tn cigarettes were oversmoked by about 35%, and that Tn cigarettes might be useful for assessing nonnicotinic factors in cigarette smoking.

Adult↗

PubMed1994

Acute dose-effect relationships of caffeine and mental performance, EEG, cardiovascular and subjective parameters.

The present study investigated the dose-effect relationship of caffeine on mental performance using a caffeine-sensitive rapid information processing task (RIP) in a pre/post cross-over design. Twenty female nonsmoking regular coffee drinkers received 0, 1.5, 3 and 6 mg/kg caffeine in a balanced order and the measurements were extended to cardiovascular, EEG and mood parameters. Surprisingly, the dose-effect curves for the different parameters were rather heterogeneous. Whereas increasing effects with increasing caffeine doses were observed for alpha- and beta-EEG frequencies, anxiety, wakefulness, and some coffee ratings, negative dose-effect relationships were obtained for RIP processing rate and blood pressure. No apparent dose-effect relationships were seen for reaction time and motor activity. Thus, it was concluded that the dose-response relationships are rather shallow and heterogeneous and that the different parameters have different ranges in which they are sensitive to caffeine. The caffeine doses which might have beneficial behavioral effects are at the lower end of the tested dose range and comparable to those found in caffeine-containing beverages.

Adult↗

PubMed1994

Ultralight cigarettes: activity, cardiovascular, dietary, and subjective parameters.

In a field study, 24-h heart rate, physical activity, and cigarette consumption were continuously recorded, whereas resting heart rate, blood pressure, dietary intake, and subjective parameters were assessed six times per day. Smoking habitual and ultralight cigarettes for two days each was compared in a sample of 48 smokers, consisting of 24 office and 24 nonoffice workers of both sexes. Nonoffice workers smoked more and revealed higher respiratory CO and Fagerstrom index values, whereas other group differences were unrelated to smoking or its effects. Switching to ultralight cigarettes with four- to eightfold lower nicotine yields than the habitual cigarettes significantly decreased respiratory CO by 5 ppm, saliva cotinine by 30%, resting heart rate by 2.5 bpm, systolic blood pressure by 3.5 mmHg, and diastolic blood pressure by 3.0 mmHg, but increased fat intake by about 400 kJ, whereas activity and subjective well-being were not affected. Thus, the reduction in saliva cotinine was considerably smaller than the reduction in nicotine yield, and the effects on physiological parameters therefore were rather modest.

Adult↗

PubMed1994

Circadian and ultradian rhythms in heart rate and motor activity of smokers, abstinent smokers, and nonsmokers.

In a field study, heart rate and motor activity were assessed continuously in 12 male smokers during 2 smoking and 2 abstinence days and in 12 male nonsmokers during 4 days. A circadian analysis revealed earlier activity acrophases in smokers than nonsmokers and earlier heart rate acrophases in abstinent than smoking smokers. Furthermore, heart rate acrophases of smoking smokers significantly anticipated activity acrophases, whereas in abstinent smokers and nonsmokers the two parameters oscillated in phase. With the use, in smoking smokers, of the individual average smoking interval as a hypothetical ultradian period length, significant periodicities were found for heart rates in 16 and for activity in 15 of 24 observation days. These rhythms were nicotine independent and based on heart rate and activity increases prior to lighting up the cigarettes. Individual frequency spectra for the 16 h after getting up and the 7 h after going to bed did not reveal single dominant frequencies but rather complex frequency distributions. Power spectra of the daytime data revealed no group differences for activity and no heart rate differences between smoking smokers and nonsmokers. In abstinent smokers, however, a significant reduction of heart rate frequencies slower than 1 cycle/135 min and a significant increase of heart rate frequencies faster than 1 cycle/20 min were observed as compared with all other groups. This effect persisted over the 2 abstinence days, suggesting an activity-independent change in the frequency distribution of heart rates after quitting smoking.

Activity Cycles↗

PubMed1993

Psychophysiological interactions between smoking and stress coping?

Earlier studies with different types of stressors suggested that cigarette smoking might selectively dampen physiological stress reactions in passive rather than in active coping situations. This hypothesis was tested in the present study using the same task for both types of coping, but with two different instructions. Twenty-four female regular smokers were assigned either to a group requiring active coping or to a group requiring passive coping with ongoing electric shocks, and tested in two sessions where they performed a pre- and a postsmoking/non-smoking trial of the rapid information processing task (RIP). Smoking increased RIP task performance, cardiovascular and electrocortical arousal, and reduced anxiety throughout the session. Active coping, as compared to passive coping, produced greater increases in heart rate and blood pressure, a greater pre- to post-treatment decrease in reaction time and higher pain ratings of the electrical shocks. However, interactions between the effects of smoking and the type of coping were few and did not suggest a plausible concept. Thus, it was concluded that, although the typical effects of smoking as well as the differentiation between active and passive coping seen earlier with the same paradigm were confirmed, cigarette smoking did not affect the effects of the two coping conditions in a differential way.

Adaptation, Psychological↗

PubMed1993

Nicotine or tar titration in cigarette smoking behavior?

A significant problem in assessing the relative relevance of nicotine and tar yield for compensatory smoking after switching from high to low yield cigarettes is that nicotine and tar yield are highly intercorrelated across conventional cigarettes and that the tar/nicotine ratios vary only within a modest range. A better differentiation between the impacts of nicotine and tar yield was expected by comparing in a laboratory experiment a new low nicotine/medium tar cigarette ("Next") with conventional low nicotine/low tar (ultra-light) cigarettes and with medium nicotine/medium tar cigarettes with respect to nicotine absorption and physiological effects. Twelve females, habitually smoking medium type cigarettes (> or = 0.7 mg nicotine) participated in the study. Neither the number of cigarettes smoked under field conditions nor the puffing behavior during the laboratory experiment differed between the three types of cigarettes. In the laboratory, Next produced only very small increases in plasma nicotine and changes in cardiovascular or EEG measures, whereas the effects of the medium cigarettes were in the expected range and those of the ultra-light cigarettes about halfway in between. The nicotine absorption/nicotine yield and the CO absorption/CO yield ratios were similar for Next and the habitual cigarettes, but about twofold higher for the ultra-light cigarettes. This suggests that gustatory and olfactory sensations, which are supposed to be more dependent on tar than on nicotine yield, may play a greater role for the regulation of smoking behavior than hitherto believed.

Adult↗

PubMed1993

Cigarette smoking related variation of heart rate and physical activity with ad libitum smoking under field conditions.

A recently developed device was used in a field study to continuously assess physical activity, heart rate, and cigarette lighting during 2 workdays and 2 days off in 12 female smokers and 12 female non-smokers. Heart rates did not differ between smokers and non-smokers or between workdays and days off; however, the nonsmokers showed significantly higher physical activity during the workdays. An averaging procedure used to obtain plots for smoking related changes of activity (SRA), pulse (SRP), and the pulse-activity ratio (SRpai) revealed four observations. a) "Lighting" responses consisting of parallel increases of SRA and SRP start a few minutes before lighting, reach a maximum with lighting, and drop immediately after lighting. b) The subsequent "smoking" responses last about 6 min and are characterized by a sustained postlighting SRA depression but immediate recovery of SRP, resulting in an increased SRpai level. c) Ten minutes prelighting and 10 min postlighting SRA and SRP are highly similar. d) The pattern of this response was similar for workdays and days off.

Adult↗

PubMed1993

Antagonistic effects of caffeine and alcohol on mental performance parameters.

Scientific experiments done so far allow no clear conclusions about the popular belief that freshly brewed coffee can offset the debilitating effects of alcoholic intoxication. This question was addressed using a computer-controlled and subject-paced rapid information processing task (RIP) which was shown earlier to be sensitive to psychoactive substances. Nine male students were tested in a Latin square design before and after the intake of 3.3 mg/kg caffeine (or placebo) followed by 0.7 g/kg alcohol (or placebo). Whereas the mean RIP-task processing rate and the mean reaction time were impaired by alcohol and improved by caffeine, no changes were observed after the combination of alcohol and caffeine. Thus, it was concluded that under the tested conditions, caffeine was able to offset the debilitating effects of alcohol.

Adult↗

PubMed1993

Smoking-related subjective and physiological changes: pre- to postpuff and pre- to postcigarette.

Twenty-six female regular smokers participated in two sessions, smoking a cigarette and drinking for comparison a cup of coffee in each. Cardiovascular, electromyogram (EMG), motor activity, and electroencephalogram (EEG) parameters were assessed before and after smoking a cigarette or drinking a cup of coffee. The same variables were averaged for 5-s periods preceding, during, and following the first six puffs and sips. As the expected psychophysiological changes might be related to pleasure, the experimental design included both pleasant-tasting coffee and cigarettes and preparations manipulated to be unpleasant. Comparing pre/post consumption and pre/post puffing changes, heart rate increased as expected pre/post a cigarette but not pre/post puffing. On the other hand, there was no change in heart rate pre/post a cup of coffee but a transient increase pre/post sipping. The pre/post puffing and pre/post sipping changes in the EEG power distribution were similar for both drugs, occurred already in anticipation of puffing and sipping, and qualitatively suggested sedation as opposed to the pre/post cigarette arousing effects. These results might explain the observations of subjective tranquilizing effects during the consumption of a stimulant. Although the taste manipulations produced significant subjective effects, they did not influence the anticipatory effects.

Adult↗

PubMed1992

No psychophysiological interactions between caffeine and stress?

In earlier studies, the predominantly beta-adrenergic effects of mental tasks and the alpha-adrenergic effects of caffeine on cardiovascular functions were observed to be simply additive without interaction. In the present study, annoying electrical shocks were superimposed on a mental task affording either active coping, which specifically raises beta-adrenergic activation, or passive coping, and the 40 female subjects were preselected so as to differ in subjective stress susceptibility. Caffeine as well as the type of coping and the considered personality dimension produced significant effects, but almost no interactions were obtained. The stress resistant subjects, who tended toward more extraversion, emotional stability and more masculinity, had lower anxiety scores, rated their performance higher and had a greater cardiac output than the stress non-resistant subjects, who represented a rather normal population according to the FPI personality dimensions. Caffeine increased EEG alpha and beta frequency and delta power and decreased beta power, raised blood pressure and enhanced stress reactions in respiration amplitude and pre-ejection period. Active stress coping induced greater stress reactions in heart rate (increase), left ventricular ejection time (decrease) and ear pulse arrival time (decrease) than passive coping.

Adult↗

PubMed1992

Twenty-four-hour monitoring of heart rate, motor activity and smoking behavior including comparisons between smokers and nonsmokers.

The present study was an attempt to monitor continuously and in parallel cigarette consumption, heart rate, and physical activity under field conditions. In a first experiment the test-retest reliability of the recording devices was evaluated with a small number of nonsmoking students on days with similar schedules. The intraday development of heart rate and activity revealed a remarkable intraindividual stability, and the test-retest reliability coefficients calculated between the totals of heart rate and activity revealed values of 0.73 and higher for heart rate and 0.47 and higher for activity on comparable days. The second experiment was done with housewives as subjects to see whether heart rate and/or activity might differentiate smokers from nonsmokers in subjects who are less strictly bound to a fixed daily work program. The smoker/nonsmoker comparisons revealed significantly higher heart rates for smokers but almost identical activity readings. In a third experiment it was tested whether partial smoking abstinence in the morning might differentiate the morning and afternoon heart rates in smokers. Heart rate but not activity was significantly decreased during the abstinence period. Taken together, the simultaneous monitoring of heart rate and activity might be a valuable instrument in smoking research, since it is sensitive enough to detect manipulations of the smoking behavior under natural conditions.

Adult↗

PubMed1992

Smoking deprivation in "early" and "late" smokers and memory functions.

Reports on smoking and nicotine effects upon memory are contradictory: improvement, no change, and impairment have been observed. These inconsistencies may be due at least in part to different types of learning tasks and to experimental designs: in most studies, acute nicotine effects were analysed after previous smoking deprivation. This study compared learning, retention, and retrieval between nonsmoking after previous deprivation and "usual" smoking without previous deprivation. Twenty female smokers (S) participated in two sessions, between 8.00 and 11.00 a.m. The Austin maze and a Word Recognition Task (WRT) were applied. During the WRT, ERP were recorded from Fz and Cz scalp locations. Heart rate, CO, and subjective ratings (dizziness and smoking need) but neither WRT nor maze performance discriminated between deprivation and smoking. However, significant differences were obtained between those Ss who usually start smoking within 1 h after getting up (ES) and those who start later (LS). In maze learning and WRT, LS performed better when deprived than smoking, and ES performed better when smoking than deprived, i.e. when the time of the tests met their usual smoking habits. Results are discussed in terms of a modulation of smoking effects on memory functions by the Ss' internal state.

Adult↗

PubMed1992

Action profiles of smoking and caffeine: Stroop effect, EEG, and peripheral physiology.

Twenty female regular cigarette smokers and coffee drinkers performed a numerical Stroop task in a 2 x 2 (caffeine x smoking) prepost crossover design. In the easier of the two different versions, caffeine and smoking reduced the reaction times (RT's) when given alone, but there was no additive effect. The Stroop effect itself (difference between RT's to numbers and RT's to symbols) was reduced by the two treatments only in the more difficult version, but the combination did not differ from the placebo condition. The physiological reactions to both treatments were additive, although the two reaction profiles were different. Smoking increased heart rate, blood pressure, finger vasoconstriction, respiratory frequency, EEG dominant alpha-frequency, and beta power and reduced respiratory amplitude, EEG delta and theta power. Caffeine increased blood pressure, finger vasoconstriction, motor activity, frontal EMG, and EEG theta power and decreased heart rate and EEG beta power.

Adult↗

PubMed1991

Psychophysiological reactions during active and passive stress coping following smoking cessation.

This study investigated the effects of 9 days' smoking abstinence on psychophysiological stress reactions. The subjects were 40 female smokers; 20 of them intended to give up smoking in the course of the study, whereas the remaining 20 had no such intention. A first session was carried out before, a second and a third during days 3 and 9 of abstinence. The nonabstainers were tested at corresponding intervals. Each session consisted of a 30-min stress-coping phase with relaxation phases before and after. While performing a rapid information processing task (RIP) the subjects had to sustain electrical shocks which were, according to instructions, but not in fact, either avoidable (active coping) or not (passive coping). Generally, the active coping instruction produced greater responses to the RIP task than did the passive coping instruction for heart rate, systolic and diastolic blood pressure but not for finger pulse amplitude, thus resembling a beta-adrenergic stimulation. RIP processing rate was not affected, but the response rate (total of hits and commission errors) was greater during active than during passive coping. However, none of these stress reactions differed between abstainers and nonabstainers. On the other hand, both heart rate and the craving to smoke decreased significantly in the abstainer group across the 9 days. Thus, it is concluded that a deprivation of 1 h, 3 or 9 days has no differential effect on physiological stress reactions.

Adaptation, Psychological↗

PubMed1991

Nicotine absorption and the subjective and physiologic effects of nicotine toothpicks.

This study investigated a new tobacco-free smoking substitute intended to provide not only the nicotine but also, to some extent, the manipulative component of the smoking act. Nicotine uptake and cardiovascular and subjective effects of nicotine-containing toothpicks (4 mg) were compared with those of nicotine chewing gum (4 mg). After the two products were chewed for 5 minutes, the nicotine uptake from the toothpick was twofold that of the gum. However, comparing the total nicotine deliveries of both products, they are quite similar. The cardiovascular parameters showed a clear nicotine effect, but they did not differentiate between the two products. Among the subjective parameters there were only minor differentiations. However, the potential advantages of the toothpicks: (1) dental care and (2) a possible substitute for the manipulative component of the smoking act, remain to be verified in further experiments.

Absorption↗

PubMed1990

Development of central and peripheral smoking effects over time.

The present study compared for the first morning cigarettes CO and nicotine absorption as well as the effects on EEG and peripheral functions across a period of 90 min. Eighteen smokers participated in two sessions, one in which they smoked two cigarettes in succession and another in which they smoked three cigarettes at 30-min intervals. Smoking two cigarettes in succession produced a particularly wide range in nicotine absorption so that the subjects could be grouped into high (HN) and low (LN) nicotine absorbers, differing significantly in their CO and nicotine absorption. The smoking-induced cardioacceleration was greater and lasted longer in the HN than in the LN group. While the dominant alpha frequency increased to a significant extent in the HN group only, beta power increased in both groups, alpha power remained unaffected, theta power decreased in the HN group only and the effects on heart rate, dominant alpha frequency and beta power were significantly correlated with nicotine absorption across both groups. Smoking three cigarettes at 30-min intervals produced qualitatively similar but generally smaller effects. However, neither nicotine uptake nor any of the physiological parameters showed differential developments between the two groups, except the dominant alpha frequency, which increased in the HN group only. The development of acute tolerance to smoking across three cigarettes was observed only for finger vasoconstriction, craving to smoke and sickness after smoking, but not for cardioacceleration or any EEG parameters.

Adult↗