Waist Circumference as the Best Predictor of Noninsulin Dependent Diabetes Mellitus (NIDDM) Compared to Body Mass Index,Waist/hip Ratio and Other Anthropometric Measurements in Mexican Americans—A 7-Year Prospective Study

Although a number of obesity-related variables are recognized risk factors for NIDDM, few studies have addressed which one is the best predictor. A cohort of 721 Mexican Americans aged 25–64 years who were free of NIDDM at baseline were followed for an average of 7.2 years; 105 new cases of NIDDM were diagnosed. Body weight, body mass index (BMI), waist and hip circumferences, waist/hip ratio (WHR), triceps and subscapular skinfolds were all positively predictive of NIDDM independent of age and sex. There were modest to strong correlations between these anthropometric variables, however, waist circumference was the strongest predictor of NIDDM. The predictive power of a single measurement of waist circumference was at least equal to that of WHR and BMI combined. The risk of NIDDM for those in the highest quartile of waist circumference was 11 times greater than for those in the lowest quartile (95% confidence interval: 4.2–28.8). The waist-NIDDM relation was stronger in subjects with BMI ≤ 27 kg/m² (OR: 6.0 for a 1 SD difference) than in subjects with BMI > 27 kg/m2 (OR: 1.7 for a 1 SD difference). In multivariate analysis, waist circumference was the only significant predictor of NIDDM in models that included other anthropometric variables either separately or simultaneously. WHR and BMI were independent predictors of NIDDM after adjustment for each other, however, their predictive abilities disappeared after adjustment for waist circumference. The data indicate that waist is the best obesity-related predictor of NIDDM. This finding suggests that the distribution of body fat, especially abdominal localization, is a more important determinant than the total amount of body fat of the development of NIDDM in Mexican Americans.     

Psychiatric III-Health of Women and Its Relationship to Obesity and Body Fat Distribution

Objective : Abdominal obesity is associated with serious, prevalent diseases. Previously, psychiatric symptoms and ill-health has been found in this condition in men. The results of a similar study in women is reported herein. Research Methods and Procedures : A cohort of 1464 women, aged 40 years and recruited by systematic sampling, was examined (77.7% participation rate). Items regarding use of anxiolytics, hypnotics, and antidepressive drugs were registered, as well as symptoms of dyspepsia, sleeping disturbances, melancholy, and degree of life satisfaction. Smoking and alcohol consumption, as well as self-measured weight, height, waist, and hip circumferences, were reported, from which body mass index [BMI; weight (kg)/height² (m²), kg/m²] and the waist/hip circumference ratio (WHR) were calculated. Results : In bivariate analyses, BMI was associated with use of anxiolytics, antidepressive drugs, various sleeping disturbances, and a low degree of life satisfaction. After controlling for “the WHR, alcohol, and tobacco use in multivariate analysis, the associations between BMI and use of anxiolytics and sleeping disturbances remained significant. The WHR correlated with dyspepsia, sleeping problems, and use of antidepressive drugs. After adjustments for BMI, smoking, and alcohol, the relationship to dyspepsia and antidepressants remained significant. Discussion : The results suggest that elevated BMI (obesity) and elevated WHR (central fat distribution) are associated in different ways with symptoms of psychiatric ill-health in women. Obesity alone shows no such relationships to psy chiatric ill-health in men, whereas central fat distribution shows independent associations to all of the measured variables studied in this report in women, suggesting gender differences in these associations.     

Waist-to-hip ratio versus body mass index as predictors of fitness in women

The claim that men prefer women with low waist-to-hip ratios (WHR) has been vigorously disputed. We examine self-report data from 359 primiparous Polish women (with normal singleton births and healthy infants) and show that WHR correlates with at least one component of a woman’s biological fitness (her first child’s birth weight, a variable that significantly affects infant survival rates). However, a woman’s Body Mass Index (BMI) is a better predictor of her child’s neonatal weight in small-bodied women (<54 kg). The failure to find a preference for low WHR in some traditional populations may thus be a consequence of the fact that, even in western populations, body mass is a better predictor of fitness in those cases characterized by low maternal body weight. Boguslaw Pawłowski Ph.D., D.Sc., is a researcher and lecturer in biological anthropology at the University of Wrocław, Poland. His research interests focus on mechanisms of human evolution (with special attention to the evolution of subcutaneous fat tissue distribution) and human mate choice. Robin Dunbar Ph.D., FBA is British Academy Research Professor of Evolutionary Psychology at the University of Liverpool, England, and co-Director of the British Academy Centenary Research Project. His research interests focus on the evolutionary and environmental determinants of social and reproductive strategies, with particular references to humans, nonhuman primates, and ungulates.     

Mental Distress,Obesity and Body Fat Distribution in Middle-Aged Men

Previous epidemiological studies have suggested that psychiatric symptoms are associated with obesity and abdominal distribution of body fat in women. The aim of the present study was to examine this in middle-aged men. In 1992 a cluster selected cohort of 1040 men born in 1944 (participation rate 79.9%) was examined. Registrations of symptoms of depression and anxiety, sleep disturbances, psychosomatic disease as well as degree of life satisfaction were analyzed in relation to body mass index (BMI) and the waist/hip circumference ratio (WHR). In univariate analyses both BMI and WHR correlated with these factors. BMI and WHR were, however, closely interrelated (p=0.61), necessitating analyses of separate, independent relationships in multivariate analyses. When adjusted for WHR all the significant relationships with BMI disappeared. In contrast the WHR, adjusted for BMI, showed remaining significant associations with the use of anxiolytics (p=0.018), hypnotics (p=0.029), antidepressive drugs (p=0.008), degree of melancholy (p=0.002), and life satisfaction (p=0.002, negative), difficulties to sleep (p=0.014) and fall asleep (p=0.047), tendency to wake up from sleep (borderline, p=0.070) and dyspepsia (p < 0.001). Since smoking and alcohol are known to influence on the WHR, these factors were, in addition to BMI, entered into the analyses as confounding variables. The mentioned associations then remained statistical significant (use of hypnotics borderline, p=0.074) except difficulties to fall asleep and tendency to wake up. It was concluded that in contrast to BMI, the WHR is associated with symptoms of depression and anxiety with associated sleep disturbances, as well as psychosomatic symptoms and dissatisfaction. It was hypothesized that the mechanism involved might be increased secretion of Cortisol, directing storage fat to central adipose tissue depots.     

Which Metric of Relative Weight Best Captures Body Fatness in Children?

Objective: To evaluate the relative merits of BMI (kilograms per meter squared) and age‐ and gender‐adjusted BMI, age‐ and gender‐specific z score of BMI, and age‐ and gender‐specific percentiles of BMI as surrogate measures of body fatness among a sample of youth. Research Methods and Procedures: The sample comprised 596 children and adolescents 5 to 18.7 years old and was 40% male and 55% white. Height and weight were measured by trained research staff. DXA was used to determine body fat mass. BMI, age‐ and gender‐specific percentile of BMI, and age‐ and gender‐specific z scores of BMI were computed, and these metrics were compared with measured body fatness. Results: The BMI values in the sample ranged from 12.9 to 55.0 kg/m², with a mean of 24.9 kg/m². The Spearman correlations with percentage body fat were similar for all of the BMI metrics (r = 0.82 to 0.88). Linear regression models with age‐ and gender‐specific percentiles of BMI explained significantly less of the variance (65%) than models with log‐transformed BMI (81%) or age‐ and gender‐specific z scores of BMI (75% to 79%). z scores were the most accurate at classifying children who were overfat (sensitivity = 0.84, specificity = 0.96 for z score ≥1). However, using a BMI ≥85th percentile or a BMI ≥20 kg/m² was also accurate at classifying youth. Discussion: The BMI metrics had similar correlations with body fatness, but age‐ and gender‐specific percentiles of BMI were the least accurate proxy measure of body fatness. However, a BMI z score ≥1, BMI percentile ≥85, and BMI ≥20 kg/m² are all useful for identifying children who may be overfat.     

雪雀属鸟类栖息地在中国的分布

雪雀属（Montifringilla)属典型的高原鸟类,主要分布于我国青藏高原及其毗邻地区。本文依据现有雪雀属种类的采集记录、文献记载的分布资料,结合野外实地考察,运用GIS（地理信息系统）的叠加和分析功能,综合生境类型资料,建立其野生动物－栖息地关系模型,并预测该属种类栖息地分布。该模型依据适宜于雪雀分布的植被类型和高度叠加后产生雪雀的适宜栖息地,与县界的行政区划图叠加后产生预测有可能分布的县级单元。预测产生的分布图包含高度适宜、适宜和不适宜三种生境类型。本研究预测雪雀属种类的栖息地分布图显示,青藏高原大部分缺乏采集记录的地区具有适宜于雪雀分布的生境类型,具有雪雀分布所必须的潜在条件。而那些有采集记录的县,也仅仅在那些适宜的生境类型中才会有雪雀的分布。     

Blockade of the Glucocorticoid Receptor with RU 486: Effects In Vitro and In Vivo on Human Adipose Tissue Lipoprotein Lipase Activity

Cortisol is known to induce lipoprotein lipase (LPL) activity in human adipose tissue in vitro and in vivo such as in Cushing's syndrome. The significance of the glucocorticoid receptor (GR) for this induction was evaluated in the present study. The synthetic steroid molecule RU 486, a potent glucocorticoid antagonist, was used as a tool to block the GR, in vitro and in vivo. In addition to LPL activity, glucose tolerance, blood pressure and plasma lipids, all variables influenced by Cortisol, were studied in order to evaluate the peripheral antiglucocorticoid activity of RU 486 in vivo, in man. Addition of both Cortisol and RU 486 to incubations of human adipose tissue pieces significantly inhibited the increase in LPL activity that could be induced by Cortisol alone (p<0.01). In a ten-fold molarity excess RU 486 totally abolished Cortisol action (p<0.01). With Cortisol and RU 486 in equimolar concentrations the RU 486 blockade was probably incomplete and LPL activity induced (p<0.05). The results imply that the stimulating effect of Cortisol on LPL activity in human adipose tissue is mediated via the GR. Administration of 400 mg RU 486 at 2200 hours on two consecutive days to healthy men caused a significant rise in serum Cortisol levels measured at 0800 hours (p<0.05). The mean LPL activity in the subcutaneous abdominal adipose tissue remained unchanged. The mean level of serum triglycerides decreased significantly (p<0.01) and there was a negative correlation between change in LPL activity and change in triglyceride levels (r=-0.73, p<0.05). Glucose tolerance and blood pressure were not affected. In conclusion, a total blockade of the GR with RU 486 can be achieved in human adipose tissue in vitro. The blockade abolishes the stimulating effect of Cortisol on LPL activity suggesting that the stimulation is GR dependent. In vivo, with the dose used, the negative pituitary feedback regulation probably compensates for the blockade, at least during the morning hours, thus obviating any peripheral effect of blockade of the GR.     

A re-investigation of saliva collection procedures that highlights the risk of potential positive interference in cortisol immunoassay

Background

The use of saliva for measurement of cortisol permits non-invasive study of adrenal function, but collection can be technically difficult, particularly in small infants. Saliva collection can be assisted by citric acid to increase saliva flow, or by the use of cotton or polyester swabs in the mouth.

Aim

To determine whether different methods of saliva collection affect cortisol radioimmunoassay (RIA) performance.

Experimental

Cortisol was measured in saliva collected from 16 adults using intra-oral cotton swabs or polyester swabs, compared with saliva dribbled directly into a pot either alone (plain saliva) or after citric acid had been placed on the tongue. An in-house RIA, without prior extraction, was used to measure cortisol with an encapsulated sheep antibody.

Results

Mean (median) salivary cortisol was 10.9 (10.5) nmol L⁻¹ in plain saliva, 10.4 (8.4) nmol L⁻¹ in citric acid stimulated saliva; 25.3 (25.1) nmol L⁻¹ in saliva collected on cotton swabs, and 27.9 (27.3) nmol L⁻¹ collected on polyester swabs. Cortisol in saliva collected using citric acid was not significantly different from plain saliva (p = 0.997), but cortisol in saliva collected using cotton and polyester swabs was significantly higher than that of plain saliva (p < 0.01).

Conclusion

The use of cotton or polyester swabs for collection of saliva can result in spuriously high levels of cortisol when measured by RIA.     

Distribution of stomatin expressing in the central nervous system and its up-regulation in cerebral cortex of rat by hypoxia

Stomatin is an important membrane raft protein which can combine skeleton protein, some ion channel, and transporter to regulate their functions. However, until now no data on its expression and function in CNS are available. In this study, we examined distribution of stomatin in CNS of rat, and investigated the effects of hypoxia exposure and glucocorticoid on stomatin expression in cerebral cortex of rat. Immunofluorescence staining revealed a broad expression of stomatin protein in many areas of adult rat brain and spinal cord, including the ventral horn of spinal cord, causal magnocellular nucleus of hypothalamus, the V layer of the cerebral cortex, solitary nucleus, 10 and 12 nuclei, and so on. Hypoxia or ischemic hypoxia significantly up-regulated stomatin expression in cerebral cortex, and the up-regulation was independent on adrenocortical steroids since it also occurred in adrenalectomized (ADX) rats. Moreover, treatment of ADX or sham-operated rats with dexamethasone, a synthetic glucocorticoid alone could significantly stimulate expression of stomatin in lung and heart, but not in cerebral cortex. However, dexamethasone could enhance the hypoxia-stimulated expression of stomatin in cerebral cortex of ADX rats. These findings suggested that stomatin might be involved in various physiological functions and cellular events of neurons in CNS under physiological conditions and play a potential protective role under hypoxic conditions.     

Stress physiology as a predictor of survival in Galapagos marine iguanas

Although glucocorticoid hormones are considered important physiological regulators for surviving adverse environmental stimuli (stressors), evidence for such a role is sparse and usually extrapolated from glucocorticoid effects under laboratory, short-term and/or non-emergency conditions. Galápagos marine iguanas (Amblyrhynchus cristatus) provide an excellent model for determining the ultimate function of a glucocorticoid response because susceptibility to starvation induced by El Niño conditions is essentially their only major natural stressor. In a prospective study, we captured 98 adult male marine iguanas and assessed four major components of their glucocorticoid response: baseline corticosterone titres; corticosterone responses to acute stressors (capture and handling); the maximal capacity to secrete corticosterone (via adrenocorticotropin injection); and the ability to terminate corticosterone responses (negative feedback). Several months after collecting initial measurements, weak El Niño conditions affected the Galápagos and 23 iguanas died. The dead iguanas were typified by a reduced efficacy of negative feedback (i.e. poorer post-stress suppression of corticosterone release) compared with surviving iguanas. We found no prior differences between dead and alive iguanas in baseline corticosterone concentrations, responses to acute stressors, nor in capacity to respond. These data suggest that a greater ability to terminate a stress response conferred a survival advantage during starvation.     

Adrenalectomy and Dexamethasone Treatment Alter the Patterns of Basal and Acute Phase Response-induced Expression of Acute Phase Protein Genes in Rat Liver

Hormonal requirements for full hepatic expression of ₂-macroglobulin (₂M), ₁-acid glycoprotein (AGP), haptoglobin (Hp) and γ-fibrinogen (Fb) were assessed at the level of mRNA. Prior to exposure to turpentine-induced inflammation, rats were either depleted of glucocorticoids by adrenalectomy or supplemented with an excess of dexamethasone. Adrenalectomy alone did not affect the basal level of acute phase protein (APP) expression except for ₂M mRNA, the level of which was enhanced. In contrast, dexamethasone treatment alone promoted full induction of ₂M, significant, but not maximal increase of AGP and Hp mRNAs and suppression of Fb. In adrenalectomized rats, acute phase (AP)-cytokines, released in response to inflammation, promoted full expression of Fb and Hp and increased the level of AGP mRNA whereas ₂M mRNA remained at the basal level. Inflammation in dexamethasone pretreated rats elicited changes which, in comparison to mRNA values for dexamethasone unpretreated inflamed rats, were seen as overexpression of ₂M, full expression of AGP and incomplete expression of Hp, whereas Fb mRNA remained at the basal level. These data suggest that glucocorticoids are the principal inducers of ₂M and AP-cytokines of Fb. For full induction of AGP, additive actions of glucocorticoids and AP-cytokines are required whereas expression of Hp is predominantly controlled by AP-cytokines.     

Hippocampal damage abolishes the cortisol response to psychosocial stress in humans

The hippocampus (HC) is necessary for learning and memory, but it also plays a role in other behaviors such as those related to stress and anxiety. In support of the latter idea, we show here that bilateral HC damage abolishes the cortisol response to psychosocial stress. We collected salivary cortisol, heart rate, and affective responses to the Trier Social Stress Test (TSST) from 7 participants with bilateral HC lesions, 12 participants with damage outside the HC, and 28 healthy normal comparison participants matched to the HC participants on age and sex. HC participants showed elevated pre-stress cortisol, but no cortisol response to the TSST. Heart rate and affective responses in the HC group were similar to those of the comparison groups. Participants with brain damage outside the HC showed stress responses that were comparable to those of the healthy comparison group. These findings support the idea that the functions of the human HC extend beyond learning and memory, and suggest that the HC is necessary for producing the cortisol response to psychosocial stress.     

The awakening cortisol response: no evidence for an influence of body posture

It has recently been reported that the orthostatic challenge associated with postural change from sitting to an upright position is stimulatory to the hypothalamic-pituitary-adrenal axis as evidenced by increased salivary free cortisol. This stimulatory influence is potentially a confound for the many psychoneuroendocrine studies for which salivary free cortisol is the main dependent variable. This particularly relates to laboratory psychosocial stress procedures in which subjects are invited to stand in order to deliver public speech and the studies which have explored the cortisol response to awakening in which postural shift has not been controlled for. We therefore examined, in a balanced cross over design whether the awakening cortisol response was influenced by standing, shortly after awakening or remaining supine during the response study period. In addition and in the same subjects we measured the cardiovascular response and saliva cortisol response to the orthostatic challenge of shifting from a supine to a standing position later in the diurnal cortisol cycle. The expected cortisol response to awakening was demonstrated but there was no evidence that the postural shift, supine to standing, confounded the response. This same postural shift later in the day induced the expected increase in heart rate but cortisol simply followed the circadian decline. Under the conditions of the present study we found no evidence that the postural shift supine to standing could induce a cortisol secretory episode such as to contribute towards the awakening response.