Increased response of cortisol and ACTH to corticotrophin releasing hormone in centrally obese men, but not in post-menopausal women

There is evidence for enhanced hypothalamo-pituitary-adrenal axis (HPAA) activity in centrally obese premenopausal women. This has led to the hypothesis that increased cortisol production rates may be an aetiological factor in the genesis of central obesity. However, the relationship of obesity and body fat distribution to HPAA activity in men and postmenopausal women has not been established. We carried out CRH tests in 13 men and 8 post-menopausal women. We measured 24 h urine cortisol metabolites prior to the CRH test in each subject, as an indication of cortisol production rate. There was a significant direct relationship between central obesity as measured by the ratio of subscapular:triceps skinfold thickness (STR)--and the ACTH/cortisol response to CRH in men, but not in postmenopausal women. There was no relationship between obesity or body fat distribution and 24h urine cortisol metabolites. This study provides evidence for hyperactivity of the HPAA in centrally obese men, but not in postmenopausal women.

Giant lamellar bodies as a feature of pulmonary low-grade MALT lymphomas

AIMS

Giant lamellar bodies (GLBs) are rare pulmonary inclusions, most frequently described in sclerosing haemangiomas. Following a recent report of their presence in a case of pulmonary lymphoma of MALT origin, our aims were to determine their frequency in pulmonary lymphoproliferative disorders, examine their structure and investigate their aetiology further.

METHODS AND RESULTS

We reviewed a series of 29 pulmonary lymphomas (23 low-grade, six high-grade) and 18 cases of reactive pulmonary lymphoid hyperplasia. Five of 23 (22%) low-grade lymphomas contained GLBs, 4/4 of which stained for surfactant apoprotein A but not for surfactant apoprotein B. No GLBs were seen in 18 cases of reactive pulmonary lymphoid hyperplasia or six high-grade primary pulmonary lymphomas. Ultrastructural examination revealed concentrically arranged extracellular material forming roughly spherical structures up to 25 microm in diameter. The GLBs were often surrounded by foamy cells and cholesterol clefts, supporting an origin, at least in part, from products of cell breakdown and surfactant degradation.

CONCLUSION

These findings support the idea that the presence of lamellar bodies is in part due to stasis of products arising from degradation of surfactant, in association with certain types of chronic pulmonary pathology. Given their absence in reactive pulmonary lymphoid hyperplasia, the presence of GLBs as an epiphenomenon in a pulmonary lymphoid infiltrate should warrant careful investigation with regard to the diagnosis of low-grade MALT lymphoma.

Central obesity, depression and the hypothalamo-pituitary-adrenal axis in men and postmenopausal women

OBJECTIVE

We examined the relationship of adiposity to pituitary-adrenal responses to corticotrophin-releasing hormone (CRH) in men and postmenopausal women, controlling for the influence of depression.

DESIGN

Studies of CRH responses, cortisol metabolite levels and depression scores in relation to adiposity in men and postmenopausal women.

SUBJECTS

Thirteen men: age (median, interquartile range) 62 y (52-63), body mass index (BMI) 29.0 kg/m2 (26.3-33.1), waist circumference (waist) 105 cm (97-111), waist:hip ratio (WHR) 1.03 (0.98-1.07), subscapular to triceps skinfold thickness ratio (STR) 2.0 (1.2-2.4), total body fat (TBF) 25.4 kg (19.8-28.8); and eight women: age 54 y (53-62), BMI 30 kg/m2 (23-41), waist 86 cm (79-117), WHR 0.94 (0.87-1.10), STR 1.0 (0.85-1.07), TBF 35.0 kg (18.7-48.8).

MEASUREMENTS

A standard CRH test was conducted with additional basal samples taken for leptin and interleukin 6 (IL-6). Total urine cortisol metabolites (TCM) and the ratio of urinary cortisol:cortisone (Fm/Em) metabolites were measured. Depression scores were measured by the General Health Questionnaire (GHQ-30) and Hospital Anxiety and Depression Scale (HAD) questionnaire. All subjects completed an overnight dexamethasone suppression test.

RESULTS

The basal to peak percentage increments (%inc.) in adrenocorticotrophic hormone (ACTH) and cortisol in men correlated directly with STR (ACTH %inc. r=0.70, P<0.01; cortisol %inc. r=0.55, P=0.05); this relationship was independent of depression scores. In women, the ACTH area under incremental curve (AUIC) correlated negatively with STR (r=-0.81, P<0.05). In men, but not in women, there was a significant correlation between GHQ-30 score and ACTH AUIC (r=0.62, P<0.05) and cortisol AUIC (r=0.72, P<0.01). Depression scores were consistently and directly related to indices of obesity and central obesity. There were no significant relationships in either sex between urinary TCM or Fm/Em ratio and BMI, waist, WHR, TBF, STR or CRH responses. The urinary Fm/Em ratio was higher in men than in women (median 0.74 vs 0.66, P<0.05). In men, but not in women, GHQ-30 scores correlated positively with urinary TCM (r=0.57, P=0.05) and HAD-depression scores were inversely related to the urine Fm/Em ratio (r=-0.65, P<0.05). All subjects suppressed normally with dexamethasone.

CONCLUSIONS

Cortisol metabolite levels were increased in depression in men, but were not related to adiposity in either sex. We demonstrate that central obesity in men, but not postmenopausal women, is associated with an enhanced pituitary-adrenal response to CRH and that this relationship is independent of depression score. International Journal of Obesity (2000) 24, 246-251

Sensory and hedonic associations with macronutrient and energy intakes of lean and obese consumers

OBJECTIVE

To establish differences between lean and obese subjects in subjective reports of predominant taste and texture attributes of 'foods as eaten', and the relationships of these qualities to hedonic preference and objective measures of dietary intake and composition.

DESIGN

Free-living subjects received instruction in a laboratory and kept diaries of foods eaten at home.

SUBJECTS

41 lean (body mass index (BMI) 20-25 kg/m2) and 35 obese (BMI > or = 30 kg/m2), non-dieting healthy adults.

MEASUREMENTS

Subjects kept four-day weighed dietary intake records, simultaneously assigning ratings for perceived pleasantness and predominant sensory attributes (taste and texture) of food eaten, and completed the Dutch Eating Behaviour questionnaire (DEBQ). Anthropometric measures included body composition assessed by bioelectrical impedance.

RESULTS

By all anthropometric measures (except height) the obese group was significantly larger than the lean group, but no significant differences were found for DEBQ scores. There were no significant group differences between pleasantness scores overall, nor for foods classified by predominant taste. Whilst macronutrient intakes did not differ, the obese group's mean dietary energy density was significantly higher, and they reported significantly greater dietary energy from 'salty' foods. For the obese group, the percentage of 'salty' foods eaten correlated strongly with energy density. A strong positive association was found between 'liking extremely' and 'sweet' foods for the lean group, but no clear associations were found for any particular taste and hedonic rating for the obese group. Whilst both groups used similar texture descriptors, there were not clear or unambiguous differences in their assignment or association with other measures.

CONCLUSIONS

The results suggest that obese and lean subjects do not self-select diets with markedly different perceived sensory or hedonic attributes. However obese subjects appear to consume a diet higher in energy density, which is particularly associated with intakes of salty/savoury (rather than sweet) food items.

Longitudinal study of leptin concentrations during puberty: sex differences and relationship to changes in body composition

Leptin may have a role in the initiation of puberty and the regulation of subsequent weight gain, but this hypothesis has not been tested by longitudinal study. We report data from 40 normal children (20 boys and 20 girls) followed from 8-16 yr of age with hormone measurements and auxology every 6 months. Before the onset of puberty, leptin levels were similar in boys and girls: G1, mean (95% confidence interval), 2.63 (2.17-3.20) ng/mL; B1, 2.47 (2.08-2.94) ng/mL (P = 0.64) and increased with age in both sexes (B, 0.107 +/- 0.042; P = 0.02). With the onset of puberty, leptin levels increased in girls (B2-B5, P < 0.0005), but decreased in boys (G2-G5, P < 0.0005). Similar positive independent relationships were seen between leptin and fat mass in girls (B, 0.106 +/- 0.022; P < 0.0005) and boys (B, 0.121 +/- 0.020; P < 0.0005), and negative relationships were found with fat-free mass [girls: B, -1.104 +/- 0.381 (P < 0.005); boys: B, -1.288 +/- 0.217 (P < 0.0005)]. Girls gained more fat mass than boys, whereas boys gained more fat-free mass, and this explained the sex difference in leptin levels. Leptin levels correlated significantly with a large number of other hormones, but none was independent of changes in body composition. In girls, but not in boys, low leptin levels during prepuberty (B1) predicted subsequent gains in the percent body fat during puberty (r = -0.75; P = 0.005). The sexual dimorphism in leptin levels during puberty reflects differential changes in body composition. Prepubertal leptin levels in girls also predict gains in the percent body fat.

Sensory and hedonic judgments of common foods by lean consumers and consumers with obesity

OBJECTIVE

To establish differences between lean subjects and subjects with obesity in subjective reports of predominant taste and texture attributes of common foods, and the relationships of these qualities and foods with overall liking.

RESEARCH METHODS AND PROCEDURES

Twenty lean (body mass index: 20 to 25 kg/m2) nondieting healthy adults and 23 (body mass index: > or = 30 kg/m2) nondieting healthy adults with obesity assigned ratings for pleasantness and predominant sensory attributes to 50 common foods in 14 food groups using a questionnaire. They completed the Dutch Eating Behavior Questionnaire. Body composition was assessed by bioelectrical impedance.

RESULTS

There were no significant group differences between pleasantness scores overall; however, lean subjects assigned higher scores to fruits and vegetables, to foods self-classified as sweet and as salty/savory, and to foods grouped in the highest and lowest quintiles of percentage food energy from fat. There were no group differences in free-choice texture descriptors applied to foods, but correspondence analysis revealed that subjects with obesity associated coarse, slippery, tough, and fatty textures with "dislike extremely," whereas lean subjects associated grainy, moist, doughy, and fibrous texture with "like extremely." Analyses reduced texture terms to 39 key descriptors for use in subsequent work. Groups did not significantly differ in reported external or restrained eating behaviors, but subjects with obesity scored significantly higher for reported emotional eating.

DISCUSSION

Differences in preferences for listed common foods exist between weight status groups according to taste, food group, and texture. Consumers can make textural descriptions of foods that could be used to assess sensory and hedonic qualities of actual food choices.

Nondisruptive, in vivo method for biomechanical characterization of linear incision wound healing: preliminary report

Previous work on in vivo biomechanical characterization of soft tissues and wound healing has led to the development of a methodology for nondisruptive, in vivo biomechanical analysis of linear incision wounds. The purpose of this preliminary study was to define nondisruptive biomechanical parameters that characterize progressive healing and compare them with an in vivo disruptive parameter of ultimate pressure at failure (in vivo strength). Male Sprague-Dawley rats (n = 60), each weighing 250 to 300 gm, were anesthetized and underwent creation of paired full-thickness linear incision wounds. The rats were divided into three groups (n = 10/group per time period): control group, nothing applied to either wound; carrier group, bovine serum albumin applied to each wound; transforming growth factor-beta2 group, transforming growth factor-beta2 in bovine serum albumin applied to each wound. On postoperative days 5 and 10, rats from each group underwent in vivo biomechanical testing using the Dimensional Analysis System (Dimensional Analysis Systems, Inc., Nashville, Tenn.). This computer-driven device integrates a video camera and processor with a vacuum controller, valve, and transducer to provide measurements of tissue deformation (in millimeters) and negative pressure (mmHg) as a multiaxial stress (vacuum) is applied to a wound. On each rat, one incision was tested disruptively and the other incision was tested nondisruptively. Disruptive data were measured as ultimate pressure (mmHg) at failure, or the amount of pressure required to disrupt the wound. Nondisruptive data were measured for tissue stiffness (kiloPascals) during application of negative pressure (maximum, 80 mmHg). On postoperative day 5, wounds treated with transforming growth factor-beta2 had significantly increased in vivo wound strength compared with carrier wounds. The nondisruptive parameter of tissue stiffness was also significantly increased for the transforming growth factor-beta2 treated wounds, thus supporting the disruptive data. On postoperative day 10, there was no difference in mean wound strength or mean tissue stiffness among any of the groups. These preliminary data represent the first report of in vivo, nondisruptive biomechanical characterization of linear incision wounds. The results suggest that through in vivo measurements of tissue stiffness, differences can be detected between treatment groups. Because the healing wound may be characterized without the need for disruption, this methodology should allow for consecutive, in vivo biomechanical testing of wounds in future wound healing studies.

Fractionated high dose rate brachytherapy moulds--a precise treatment for carcinoma of the pinna

BACKGROUND AND PURPOSE

The aim of this paper is to describe a fractionated high dose rate brachytherapy procedure for the treatment of small superficial cancers of the pinna and to report the outcome in a small series of patients.

MATERIALS AND METHODS

Thirteen patients with superficial cancers of the pinna, not invading cartilage, have been treated and in the majority of cases the tumour thickness was determined by a transdermal ultrasound measurement. For the single-plane moulds the prescribed surface dose was 45 Gy in eight fractions over 5 days and the moulds were constructed such that the full thickness of the disease, as determined by the ultrasound measurement, would lie within the 80% isodose surface. One case was treated with a sandwich mould and in this case the dose was reduced to 42.5 Gy. The treatment machine was a high dose rate microselectron, which contains a single stepping iridium source.

RESULTS

The radiation reactions were of moderate severity, but were limited to the high dose volume. In all cases there was complete tumour resolution and rapid healing occurred leaving a barely perceptible scar. There were no recurrences over a minimum follow-up time of 18 months and there were no late radiation complications in this period.

CONCLUSIONS

The treatment of superficial carcinoma of the pinna by means of HDR moulds is a safe and reliable technique. In this small series of patients there was total tumour control with excellent cosmesis.

Adjustment in patients with rheumatoid arthritis and their children

OBJECTIVE

To assess everyday life stress and emotional adjustment in patients with rheumatoid arthritis (RA) and their children.

METHODS

We conducted a 6 month study of 14 patients with RA with children aged 4-16 years (25 children) and 24 control families (53 children). Life event stress and functional capacity were assessed at the beginning and end of the study, and minor stressors (hassles), positive events (uplifts), and salivary cortisol were recorded weekly. Emotional adjustment was measured monthly in adults by self-report, and bimonthly in children using the Child Behavior Checklist (completed by parents). Social support and psychological coping responses were also measured.

RESULTS

Patients with RA experienced fewer positive events than did controls, and they tended to have smaller support networks. Daily hassle levels correlated with severity of disability, and differences in psychological coping were also observed. Children from RA families reported nearly 50% more hassles per week than did controls, and their social networks were significantly smaller. They were rated as having greater problems of social adjustment than controls. Cortisol concentration was greater among children who experienced more life event stress over the study period, but did not differ between groups.

CONCLUSION

The patients with RA in this study showed good adaptation, but experienced less pleasure in their daily lives. The children of patients with RA may have heightened vulnerability to stress related problems, with fewer social resources and difficulties in behavioral adjustment.

Fishing for understanding: nurses knowledge and attitudes in relation to nutritional care

Many studies have demonstrated that malnutrition is a significant problem amongst hospital patients, but little is known about what nurses actually do, and what factors influence this. This study aimed to explore the nutritional attitudes, knowledge base and nursing care of qualified nurses in an acute hospital. A survey of nurses' records for documented nutrition related activities was carried out for all (141) patients from five wards for two weeks, followed by a questionnaire, focused on nutrition-related attitudes, activities and knowledge, to all qualified nurses of these and a further four wards (110 nurses). Results revealed evidence of some knowledgeable and pro-active attitudes and nursing care; however, there was little association between knowledge, stated attitudes and behaviour and discrepancies were observed between questionnaire responses and documented activities. Ajzen and Fishbein's (1980) theory relating beliefs, attitudes, intentions and behaviour was not supported although this might be attributed, in part at least, to nurses not regarding weighing patients as nutritional assessment. Behaviour appeared to have been influenced by a variety of factors and relationships between attitudes, knowledge and activities seemed far from straightforward.

Helicobacter rodentium sp. nov., a urease-negative Helicobacter species isolated from laboratory mice

A spiral-shaped bacterium with bipolar, single, nonsheathed flagella was isolated from the intestines of laboratory mice. The organism grew at 37 and 42 degrees C under microaerobic and anaerobic conditions, did not hydrolyze urea, was weakly positive for catalase and oxidase, reduced nitrate to nitrite, did not hydrolyze indoxyl acetate or hippurate, and was resistant to cephalothin and nalidixic acid. This is the first urease-negative, murine Helicobacter spp. isolated from intestines. Also, Helicobacter pullorum and this bacterium are unique among the genus Helicobacter in having nonsheathed flagella. The new bacterium appears to be part of the normal intestinal flora; although its pathogenic potential is unknown, this organism was also isolated from scid mice with diarrhea that were co-infected with Helicobacter bilis. On the basis of 16S rRNA gene sequence analysis data and biochemical and phenotypic criteria, the new organism is classified as a novel helicobacter, for which we propose the name Helicobacter rodentium. The type strain is MIT 95-1707 (= ATCC 700285).

Nutrition: a hard nut to crack. An exploration of the knowledge, attitudes and activities of qualified nurses in relation to nutritional nursing care

Provision of adequate nutrition is recognized as essential, yet malnutrition continues to be reported in patients admitted to hospital. The effects of malnutrition in hospital patients have been well documented; however, most work relating to nutritional management has been produced by members of Nutrition Support Teams, nurse specialists and interested clinicians, whilst the majority of hospitals are still without such specialist posts. This study used two data collection methods to gain information about the attitudes, nutritional knowledge base and nutrition-related nursing care in a large trust hospital in the South of England. A survey of care plans for documentation of nutrition-related nursing activities, carried out on the day of discharge for all patients from five wards over a period of a fortnight (totalling 141 sets of documentation), was followed by a questionnaire to all qualified nurses on these and a further four wards (110 nurses). Results demonstrated that nurses generally felt that nutritional assessment was primarily their responsibility. Whilst there was evidence of knowledgeable and proactive nursing care, it also appeared that there were fairly widespread deficiencies in the knowledge, communication and co-ordination required to ensure consistent good practice.

Critical incidents, crucial issues: insights into the working lives of registered nurses

The critical incident technique has been used in nursing in a number of ways: in developing understanding of the nursing role, as a quality assurance strategy, as an assessment and evaluation tool, and as an aid in the fostering of reflective practice. This article describes how the technique, used as a theoretical course assessment for a group of students studying long ENB courses, could be used to shed light upon issues regarded as crucial in the daily working lives of this group of registered nurses, and upon the reflective skills which they were able to employ.

A combined test using desmopressin and corticotropin-releasing hormone in the differential diagnosis of Cushing's syndrome

To assess the ability of desmopressin to differentiate between pituitary and ectopic ACTH-dependent Cushing's syndrome and to determine whether diagnostic accuracy could be improved by administering it together with human sequence CRH, we examined its effects on cortisol and ACTH secretion when given alone or in combination with CRH in patients with Cushing's syndrome of varied etiology and compared these data to the results of a standard CRH test in the same individuals. Each patient was studied on three occasions, in random order, separated by at least 48 h. At 0900 h, via an indwelling forearm cannula, 10 micrograms desmopressin, 100 micrograms CRH, or a combination of the two were given as an iv bolus; thereafter, blood was drawn every 15 min for 2 h. The responses to the individual agents were determined according to the timing and calculation criteria suggested by Nieman et al. (1993). A total of 25 patients with Cushing's syndrome were studied: 17 patients with pituitary-dependent Cushing's syndrome, Cushing's disease (CD); 5 patients with occult ectopic ACTH secretion (EC); and 3 patients with primary adrenal (ACTH-independent) Cushing's syndrome. In this series, the best discrimination among ACTH-dependent patient groups was achieved using the combined test. Using the responses of plasma cortisol, all 17 patients with CD showed a rise greater than any of the 5 patients with EC, whereas 1 patient with CD showed a plasma ACTH response within the range seen in the patients with EC. Plasma cortisol responses to desmopressin alone were seen in 14 of 17 patients with CD and 1 of 5 patients with EC and, after CRH alone, in 15 of 17 patients with CD but in no patient with EC. In contrast, plasma ACTH responses after CRH alone were seen in 14 of 17 patients with CD and 2 of 5 patients with EC and, after desmopressin alone, in 12 of 17 with CD and 3 of 5 with EC, thus indicating overlapping responses between the groups and poorer discrimination. No responses were seen in the ACTH-independent group. These data indicate that desmopressin causes the secretion of ACTH and cortisol in patients with ACTH-dependent Cushing's syndrome, and that in combination with CRH, it may provide an improvement over the standard CRH test in the differential diagnosis of ACTH-dependent Cushing's syndrome. Furthermore, these data suggest that there may be abnormalities in vasopressin receptor function or number in ACTH-secreting tumors.

Growth hormone treatment in hypopituitary GH deficient adults reduces circulating cortisol levels during hydrocortisone replacement therapy

OBJECTIVES

Patients with GH deficiency frequently have multiple hormone deficiencies and require hydrocortisone replacement. We have investigated whether GH treatment alters circulating cortisol levels in hypopituitary patients receiving stable replacement therapy.

DESIGN

Subjects were studied during 6 or 12 months of s.c. GH at a dose of 0.25 IU/kg/week (0.125 IU/kg/week for the first 4 weeks), and after a wash-out period of at least 2 months off GH (range 2-5 months).

PATIENTS

Fourteen hypopituitary patients (2F:12M) receiving stable hydrocortisone replacement and thyroxine, gonadal steroids and bromocriptine therapy as required.

MEASUREMENTS

Serum cortisol values were measured throughout the day over 10.5 hours. Thyroid hormones and cortisol binding globulin (CBG) were measured in the baseline sample. Comparisons of the serum cortisol peak after receiving the first dose of hydrocortisone, the time when the serum cortisol peak was obtained, the area under the curve (AUC) for the cortisol values and the levels of unbound cortisol on and off GH therapy were made. The results are expressed as mean +/- SEM. Comparisons were carried out within individuals, using the Wilcoxon signed rank test. A P-value less than 0.05 was considered statistically significant.

RESULTS

During GH therapy, there was a significant reduction in the mean cortisol peak (662.2 +/- 61.1 vs 848.0 +/- 58.6 nmol/l; P = 0.001), and in the AUC for cortisol (185.3 +/- 18.3 vs 230 +/- 17.9 nmol/l/10.5h; P = 0.03), but there was no significant change in the time of the cortisol peak (55.7 +/- 7.6 vs 57.8 +/- 4.9 minutes; P = NS). During GH therapy there was a significant reduction in CBG levels (33.64 +/- 1.16 vs 40.86 +/- 1.34 mg/l; P = 0.001); however, no changes were found in the levels of calculated unbound cortisol on and off GH (2.87 +/- 0.38 vs 2.90 +/- 0.30 nmol/l; P = NS). During GH therapy, there was a significant increase in serum triiodothyronine (T3) (1.88 +/- 0.15 vs 1.44 +/- 0.11 nmol/l; P = 0.01), and a significant decrease in thyroxine (T4) levels (74.9 +/- 11.1 vs 97.6 +/- 10.9 nmol/l; P = 0.02) but levels remained within the normal range. No change was observed in serum TSH levels (0.29 +/- 0.13 vs 0.83 +/- 0.71 mU/l; P = NS).

CONCLUSIONS

These results suggest that GH therapy in GH deficient adults produces an alteration in the measured serum cortisol profile, with a reduction in concentration of total cortisol in blood after orally administered hydrocortisone. These changes in circulating cortisol probably depend primarily on the fall in CBG levels, as no changes were found in the levels of calculated unbound cortisol on and off GH. Our data show that when measuring circulating cortisol levels, the results should be interpreted with caution in GH deficient patients on GH replacement, and different criteria may have to be applied to the circulating cortisol profile of these patients. The results highlight the importance of ensuring adequate corticosteroid replacement in patients starting GH therapy.

Delayed repair: the role of glutathione in a rat incisional wound model

Glutathione is a low molecular weight tripeptide that is a major intracellular antioxidant, modulates DNA synthesis, and may regulate signal transduction mechanisms. Our previous studies in rats suggested that intracellular stores of glutathione were sensitive to skin ischemia and, therefore, may regulate the early temporal course of wound healing. A 4-cm incision was placed on a rat's back and in vivo wound strength was measured over time. Animals were depleted of glutathione using L-buthionine-(S,R)-sulfoximine (BSO), an inhibitor of the enzyme gamma-glutamylcysteine synthetase. Some animals were treated in combination with allopurinol/BSO or with allopurinol alone. The data demonstrated at 4 days that BSO treatment produced a fourfold reduction in glutathione (3.51 +/- 1.78) over baseline (16.15 +/- 2.18) levels and twofold reduction (5.0 +/- 1.1) over untreated sham controls (11.1 +/- 2.3) (P < 0.05). Allopurinol provided no protection to glutathione levels. BSO treatment alone reduced wound burst strength compared to the other groups (P < 0.05). Allopurinol treatment enhanced wound strength over sham controls and BSO groups at 9 days after wounding (P < 0.05). Hydroxyproline content in wounds accumulated faster by Day 4 in the BSO-treatment groups compared to sham controls (P < 0.05), whereas the BSO-treatment groups had lower hydroxyproline levels measured at Day 6 (P < 0.05). These data provide the first evidence that wound healing is related to the temporal course of glutathione metabolism. The effect may not be related to oxidant stress since allopurinol provided enhanced wound burst strength without protecting wound glutathione levels.

Cardiovascular risk and responsivity to mental stress: the influence of age, gender and risk factors

BACKGROUND

Exaggerated cardiovascular and neuroendocrine responses to mental stress may enhance cardiovascular disease risk. Coronary heart disease and hypertension increase in prevalence with advancing age, whereas the excess male/female ratio declines in later middle age. Psychosocial factors may contribute to these changing risk profiles. The hypothesis that cardiovascular and neuroendocrine stress responses are associated with age and gender differences in cardiovascular disease risk was tested.

METHOD

132 healthy men and women from younger (30-40 years) and older (55-66 years) age bands were selected at random from general practice lists. They performed a series of mental stress tests during which blood pressure, heart rate, cardiovascular baroreflex sensitivity, cortisol, respiration patterns and electrodermal activity were monitored. A submaximal exercise test was performed and psychological characteristics were assessed by questionnaire.

RESULTS

At rest, systolic and diastolic blood pressure was higher in men than in women, while cardiac baroreflex sensitivity was greater in younger than in older participants. Blood pressure responses to tasks were substantial, with changes from the baseline averaging 18.6/8.11, 26.0/13.5 and 40.7/19.0 mmHg for computerized problem solving, mirror drawing and speech tasks, respectively. Men and women in the older age band did not differ from each other in blood pressure, heart rate or baroreflex sensitivity responses. Systolic blood pressure responses (mean +/- SEM) were larger in older than in younger women (mean peak difference 6.87 +/- 2.67 mmHg), and in the younger male compared with the younger female groups (mean peak difference 7.20 +/- 2.97 mmHg). Diastolic blood pressure and heart rate responses to mental stress were larger in younger than in older age participants of both sexes. Baroreflex sensitivity was inhibited during behavioural tasks, with significantly greater suppression in younger than in older groups (5.28 +/- 0.52 and 2.62 +/- 0.35 ms/mmHg, respectively). Cortisol responses were greater in men than in women, but did not vary with age. Across the entire sample, systolic blood pressure responsivity was negatively related to the expression of anger. Among older men, heightened blood pressure responses were associated with elevated fasting low-density lipoprotein cholesterol levels, and with lower concentrations of high-density lipoprotein cholesterol.

CONCLUSIONS

Systolic blood pressure stress responsivity increases with age in women but not in men. Other data do not support the notion that stress responsivity mediates age and gender differences in cardiovascular disease risk. However, in middle-aged men, ex-aggerated cardiovascular stress responsivity is associated with an unfavourable risk profile.

A single sleeping midnight cortisol has 100% sensitivity for the diagnosis of Cushing's syndrome

OBJECTIVE

The diagnosis of Cushing's syndrome remains a major challenge in clinical endocrinology. Various screening tests are commonly used to support a biochemical diagnosis in the context of clinical suspicion. The aim of this study was to compare the sensitivity in the diagnosis of Cushing's syndrome of a single in-patient sleeping midnight cortisol to a standard 48-hour in-patient low-dose dexamethasone suppression test (LDDST) during the same admission.

DESIGN

A retrospective analysis was performed on 150 patients investigated in our department between the years 1970 and 1994 with a confirmed diagnosis of Cushing's syndrome.

PATIENTS

One hundred and fifty patients with a diagnosis of Cushing's syndrome were analysed: 110 with Cushing's disease; 12 with tumours with ectopic ACTH secretion; 8 with ACTH dependent Cushing's syndrome of so far undetermined origin; 17 with cortisol secreting adrenal tumours; 3 with adrenocortical nodular hyperplasia. Twenty normal volunteers and nine patients with non-endocrine conditions were also investigated as controls.

MEASUREMENTS

Plasma cortisol was measured by radioimmunoassay (RIA) in the 122 patients presenting after 1980, and by fluorimetry prior to this date.

RESULTS

In all the control subjects the sleeping midnight cortisol was < 50 nmol/l, below the lowest standard of the routine in-house RIA. In every patient with Cushing's syndrome the sleeping midnight cortisol was detectable with a value greater than 50 nmol/l, with a range of 70-2000 nmol/l. In contrast, in three cases, all of whom had proven Cushing's disease on histology, there was uncharacteristic complete suppression of plasma cortisol to < 50 nmol/l following the LDDST.

CONCLUSION

In this series of 150 cases, a single in-patient sleeping midnight cortisol above 50 nmol/l had a 100% sensitivity for the diagnosis of Cushing's syndrome, clearly different from normal subjects. In contrast, the low-dose dexamethasone suppression test had a sensitivity of 98% even when the drug was administered as an in-patient. We recommend that a low-dose dexamethasone suppression test should not be used alone for confirmation of Cushing's syndrome since it may miss 2% of cases.