Lorentz E. Wittmers

Attenuated adrenocortical and blood pressure responses to psychological stress in ad libitum and abstinent smokers

Chronic smoking may alter physiological systems involved in the stress response. This study was designed to examine the effects of ad libitum smoking and abstinence on adrenocortical and cardiovascular responses to acute psychological stress in dependent cigarette smokers. We evaluated differences among abstinent smokers, smokers who continued to smoke at their normal rate, and nonsmokers in salivary cortisol concentrations, systolic and diastolic blood pressure (BP), heart rate (HR), and mood reports. Measurements were obtained during rest and in response to acute psychological stress (public speaking) in one session (stress session) and during continuous rest in a control session. Thirty-eight smokers (21 women) and 32 nonsmokers (18 women) participated. Smokers were assigned to either abstain from smoking the night prior to and the day of each session, or to continue smoking at their normal rate before each session. All groups showed significant stress-induced changes in BP and HR. Smokers, regardless of their assigned condition, showed attenuated systolic BP responses to the public-speaking stressor when compared to nonsmokers. While resting cortisol levels were greater among smokers than nonsmokers, no cortisol response to the acute stressor was demonstrated in either ad libitum or abstinent smokers. These results indicate that chronic smoking diminishes adrenocortical and cardiovascular responses to stress, and that short-term abstinence does not correct these alterations.

Adrenocortical and hemodynamic predictors of pain perception in men and women

&NA; Research has demonstrated that women report more pain than men, and clinical observations suggest that attenuated adrenocortical activity is associated with high pain sensitivity. The extent to which cortisol concentrations and hemodynamics contribute to gender differences in pain sensitivity has not been investigated. Thirty‐four women and 31 men performed the hand cold pressor test (CPT). Participants rated their pain every 15 s during a 90‐s CPT and a 90‐s post‐CPT recovery period and reported pain using the McGill Pain Questionnaire (MPQ). Salivary cortisol samples and cardiovascular measures were collected prior to, during, and after the CPT. Women reported greater pain than men during and after the CPT and on the MPQ (Ps<0.01). CPT disrupted the expected diurnal decline in cortisol, as shown by a significant increase in cortisol concentration post‐CPT (P<0.01) in men and women. Regression analyses revealed that pre‐CPT cortisol concentrations predicted lower pain reports during and after CPT in men only (P<0.01). Systolic blood pressure (BP) and stroke volume correlated negatively with pain reports only in women (Ps<0.05). Controlling for potential confounding variables did not alter these relationships. The negative association between pre‐CPT cortisol and pain perception in men and the association between BP and pain in women demonstrate different physiological predictors of pain perception in men and women.

Psychophysiological effects of nicotine abstinence and behavioral challenges in habitual smokers.

We tested the hypothesis that psychophysiological responses to behavioral challenges are enhanced by short-term abstinence from smoking. Blood pressure (BP), salivary cortisol levels, and withdrawal symptoms were measured after a period of smoking abstinence (18 h) or ad libitum smoking, during rest, and in response to acute behavioral challenges. Thirty habitual smokers (15 women and 15 men) participated in two laboratory sessions conducted on two separate days (after abstinence or ad libitum smoking). Cotinine concentrations in saliva and expired carbon monoxide were measured in both conditions. Abstinence produced significant withdrawal symptoms in all participants, with women reporting greater desire to smoke than men. Participants showed greater systolic BP responses to the behavioral challenges in the abstinence condition than the control condition. They also showed worse cognitive performance on the challenges in the abstinence than in the ad libitum condition. Men had greater salivary cortisol levels than women, and both men and women showed the expected decline in cortisol levels across time, but showed no difference between the abstinence and ad libitum smoking conditions in the laboratory or during ambulatory measurements. These results indicate that abstinence alters mood, performance, and BP responses to acute challenges but not adrenocortical responses. It is possible that these changes mediate stress-related vulnerability to smoking relapse.

SEX DIFFERENCES IN PAIN AND HYPOTHALAMIC-PITUITARY-ADRENOCORTICAL RESPONSES TO OPIOID BLOCKADE

Objective Sex differences in pain sensitivity and stress reactivity have been well documented. Little is known about the role of the endogenous opioid system in these differences. This study was conducted to compare adrenocortical, pain sensitivity, and blood pressure responses to opioid blockade using naltrexone in men and women. Methods Twenty-six participants completed 2 sessions during which placebo or 50 mg of naltrexone was administered, using a double-blind, counterbalanced design. Thermal pain threshold and heat tolerance were assessed. Participants also rated pain during a 90-second cold pressor test (CPT) and completed the McGill Pain Questionnaire (MPQ) after each pain challenge. Blood and saliva samples and cardiovascular and mood measures were obtained throughout the sessions. Results Plasma cortisol, adrenocorticotropin, beta endorphin, prolactin, and salivary cortisol levels increased similarly in men and women after naltrexone administration compared with placebo. Women reported more pain during both pain procedures and had lower thermal pain tolerance. In response to naltrexone, women exhibited reduced blood pressure responses and reduced MPQ pain ratings after CPT. No effects of naltrexone on these measures were found in men. Conclusions Although men and women exhibited similar hormonal responses to opioid receptor blockade, women reported less pain and showed smaller blood pressure responses during CPT. Results suggest differential effects of the endogenous opioid system on pain perception and blood pressure in men and women.

Enhanced adrenocortical responses to stress in Hypertension-Prone Men and Women

Hypertension risk may be associated with increased adreno-cortical activity, but the extent to which this enhanced activation differs between men and women at rest and in response to psychological stress is not known. This study examined gender differences in adrenocortical responses to an extended public-speaking stressor in persons at high (resting systolic blood pressure > median; n = 21)or low risk (negative parental history and = median systolic blood pressure; n = 26). Salivary cortisol levels were assessed at rest and in response to public speaking in a repeated measure design on two test sessions held on separate days. Heart rate, systolic blood pressure, and diastolic blood pressure were obtained at 3-min intervals before, during, and after the task. High-risk participants showed greater cortisol, blood pressures, and heart rate responses to the public-speaking stressor than the low-risk group (ps < .01). Men showed greater cortisol concentrations than women (p < .05), independent of hypertension risk status. Cardiovascular measures during the acute stressor predicted subsequent cortisol production, but only in the high-risk group. Results suggest that hypertension risk is associated with enhanced physiological reactivity across sympathetic and adrenocortical systems, supporting the possibility that this exaggerated reactivity may represent a marker of risk in hypertension-prone men and women.

Blood pressure but not parental history for hypertension predicts pain perception in women

&NA; Previous work has suggested an attenuated sensitivity to painful stimulation in hypertensive men. We recently reported that, compared with persons with negative parental history, men, but not women, with a positive history for hypertension showed attenuated pain perception. This study specifically addressed factors that predict pain perception in women, including blood pressure, parental history and mood states. Fifty‐four normotensive women with positive (PH+; n=20) or negative parental history (PH−; n=34) for hypertension and high or low casual systolic blood pressure (BP) performed the cold pressor (CP) test. Participants rated their pain every 15 s during a 90‐s hand CP (0–4°C) and a 90‐s post‐CP rest period. Detailed mood ratings were obtained immediately before the CP test. Data were evaluated using multivariate repeated measure analyses of variance and regression analyses. PH+ and PH− women did not differ in age, height, weight, education, resting BP, or heart rate. PH+ and PH− women did not differ in pain ratings during or after the CP, or pain ratings using the McGill Pain Questionnaire (MPQ), and they did not differ in their cardiovascular responses to the CP, confirming our earlier study in a separate sample. Women with high casual systolic BP reported significantly less pain, especially after the CP (P<0.01). MPQ total scores confirmed this finding with high BP women reporting less pain than low BP women (P<0.05). Regression analyses confirmed these effects. Controlling for potential confounding variables did not alter these relationships. These findings suggest that in women, phenotype systolic BP may be a better predictor of hypoalgesia than parental history of hypertension.

Blunted Opiate Modulation of Hypothalamic-Pituitary-Adrenocortical Activity in Men and Women Who Smoke

Objective: To examine the extent to which nicotine dependence alters endogenous opioid regulation of the hypothalamic-pituitary-adrenocortical (HPA) axis functions. Endogenous opiates play an important role in regulating mood, pain, and drug reward. They also regulate the HPA functions. Previous work has demonstrated an abnormal HPA response to psychological stress among dependent smokers. Methods: Smokers and nonsmokers (total n = 48 participants) completed two sessions during which a placebo or 50 mg of naltrexone was administered, using a double-blind design. Blood and saliva samples, cardiovascular and mood measures were obtained during a resting absorption period, after exposure to two noxious stimuli, and during an extended recovery period. Thermal pain threshold and tolerance were assessed in both sessions. Participants also rated pain during a 90-second cold pressor test. Results: Opioid blockade increased adrenocorticotropin, plasma cortisol, and salivary cortisol levels; these increases were enhanced by exposure to the noxious stimuli. These responses were blunted in smokers relative to nonsmokers. Smokers tended to report less pain than nonsmokers, and women reported more pain during both pain procedures, although sex differences in pain were significant only among nonsmokers. Conclusions: We conclude that nicotine dependence is associated with attenuated opioid modulation of the HPA. This dysregulation may play a role in the previously observed blunted responses to stress among dependent smokers. ACTH = adrenocorticotropin; BP = blood pressure; CO = cardiac output; CPT = cold pressor test; CRF = corticotrophin-releasing factor; HPA = hypothalamic-pituitary-adrenocortical; MPQ = McGill Pain Questionnaire.

Circulating leptin levels are associated with increased craving to smoke in abstinent smokers

The adipocyte hormone leptin regulates satiety and energy expenditure. Recent evidence suggests that leptin is associated with increased craving for alcohol and with shorter length of abstinence during alcohol treatment. This study examined leptins associations with craving for cigarettes and smoking relapse among smokers interested in cessation. Participants (32 smokers; 14 women) attended a laboratory session 24h following their designated quit day where circulating leptin levels and craving for smoking were assessed. Other measures of withdrawal symptoms, affect, physical symptoms, as well as neuroendocrine and cardiovascular measures were collected before and after performing two stress tasks (public speaking and cognitive tasks). High circulating leptin levels were associated with increased craving, withdrawal symptoms, negative affect, physical symptoms, and reduced positive affect. Circulating leptin levels were not related to cardiovascular and neuroendocrine measures, responses to acute stressors, or to smoking relapse. These results indicate that circulating leptin is a promising biological marker of craving for smoking and warrant further investigation of the links between appetite regulation and nicotine dependence.

Effect of adrenalectomy on the metabolism of glucose in obese (C57 B1/6J ob/ob) mice

The genetically obese mouse, C57 B1/6J ob/ob, has been suggested as an appropriate model for the study of obesity associated with diabetes mellitus. Employing glucose 14C(microliter) as a tracer, the data presented here indicate that obese mice are able to clear glucose from the blood compartment at the same rate as their lean littermates. This was demonstrated with or without an associated cold glucose load. The abnormal glucose tolerance curves observed in the obese animals may be a result of secretion of glucose into the blood. Removal of the adrenal glands from the obese mice and their lean littermate does not impair their ability to clear a glucose load from the vascular compartment. The capacity for endogenous glucose secretion of ob/ob mice is severely curtailed by adrenalectomy, in that the glucose tolerance curves of these adrenalectomized animals become similar to those of sham-operated lean littermates. Thus, it appears that a considerable component of the hyperglycemia in ob/ob mice reflects major adrenal involvement that is activated by stress, ie, ether anesthesia and blood sampling. The hyperglycemia in ob/ob mice may reflect glucocorticoid-dependent gluconeogenesis.

Problems in determination of skeletal lead burden in archaeological samples: an example from the First African Baptist Church population.

Human bone lead content has been demonstrated to be related to socioeconomic status, occupation and other social and environmental correlates. Skeletal tissue samples from 135 individuals from an early nineteenth century Philadelphia cemetery (First African Baptist Church) were studied by electrothermal atomic absorption spectrometry and X-ray fluorescence for lead content. High bone lead levels led to investigation of possible diagenetic effects. These were investigated by several different approaches including distribution of lead within bone by X-ray fluorescence, histological preservation, soil lead concentration and acidity as well as location and depth of burial. Bone lead levels were very high in children, exceeding those of the adult population that were buried in the cemetery, and also those of present day adults. The antemortem age-related increase in bone lead, reported in other studies, was not evidenced in this population. Lead was evenly deposited in areas of taphonomic bone destruction. Synchrotron X-ray fluorescence studies revealed no consistent pattern of lead microdistribution within the bone. Our conclusions are that postmortem diagenesis of lead ion has penetrated these archaeological bones to a degree that makes their original bone lead content irretrievable by any known method. Increased bone porosity is most likely responsible for the very high levels of lead found in bones of newborns and children.