Rise in morning saliva cortisol is associated with abdominal obesity in men: a preliminary report.

An abnormal regulation of the hypothalamic-pituitary-adrenal (HPA) axis is associated with risk factors for cardiovascular disease and Type 2 diabetes mellitus. The objective of this study was to examine if morning saliva cortisols show similar associations. Twenty-eight men, all 53 yr of age, delivered during an ordinary working day saliva cortisol samples immediately upon awakening and 15 min thereafter as well as at different times during the day, including after a standardized lunch. Dexamethasone (0.5 mg) suppression of cortisol was also measured. The rise of morning cortisol values was positively associated with body mass index (r: 0.45, p=0.016), waist/hip ratio (r: 0.54, p=0.003), abdominal sagittal diameter (r: 0.54, p=0.003), glucose (r: 0.54, p=0.003), insulin (r: 0.57, p=0.002) and triglycerides (r: 0.46, p=0.014). The morning rise also correlated positively with the elevation of cortisol following lunch (r: 0.45, p=0.043) but not with other cortisol measurements or dexamethasone suppression. Elevation of cortisol immediately after awakening has previously been found to provide a simple indicator of HPA axis regulation, as suggested also by the results of this study, and an elevated rise has been reported after exposure to frequent or chronic perceived stress. The rise of cortisol immediately after awakening might be an indicator of an increased risk of developing serious, prevalent diseases via the metabolic syndrome.

A 5-year follow-up study of disease incidence in men with an abnormal hormone pattern.

OBJECTIVES: Previous studies have suggested that abnormal levels of cortisol and testosterone might increase the risk of serious somatic diseases. To test this hypothesis, we conducted a 5-year follow-up study in middle-aged men. METHODS: A population-based cohort study conducted in 1995 amongst 141 Swedish men born in 1944, in whom a clinical examination supplemented by medical history aimed to disclose the presence of cardiovascular disease (CVD) (myocardial infarction, angina pectoris, stroke), type 2 diabetes and hypertension were performed at baseline and at follow-up in the year 2000. In addition, salivary cortisol levels were measured repeatedly over the day. Serum testosterone concentrations were also determined. Using the baseline data, an algorithm was constructed, which classified the secretion pattern of cortisol and testosterone from each individual as being normal or abnormal. RESULTS: By the end of follow-up, men with an abnormal hormone secretion pattern (n = 73) had elevated mean arterial pressure (P = 0.003), fasting insulin (P = 0.009) and insulin : glucose ratio (P = 0.005) compared with men with a normal secretion pattern (n = 68). Body mass index, waist circumference, and waist : hip ratio were significantly elevated in both groups. However, the 5-year incidence of CVD, type 2 diabetes, and hypertension were significantly higher (P < 0.001) in men with an abnormal neuroendocrine secretory pattern compared to men with a normal pattern. CONCLUSIONS: These data suggest that an abnormal neuroendocrine secretory pattern is prospectively associated with an increased incidence of cardiovascular-related events and type 2 diabetes.

Association between a dinucleotide repeat polymorphism of the estrogen receptor alpha gene and personality traits in women.

Estrogens are known to play a key role in the regulation of various aspects of behavior. In order to study the potential contribution of genetic variation in the estrogen receptor (ER) alpha to specific personality traits, we investigated a repeat polymorphism in the ER alpha gene in 172 42-year-old women who had been assessed using the Karolinska Scales of Personality (KSP). Based on the hypothesis that there is a relationship between the length of a repeat polymorphism and gene function,(1) the alleles were divided into two groups: short and long. In order to elucidate the possible influence of the ER alpha gene on the different aspects of personality measured by means of the KSP, the possible association between this gene and four different factors ('neuroticism', 'psychoticism', 'non-conformity', and 'extraversion') was analysed. 'Neuroticism', 'psychoticism', and 'non-conformity' all appeared to be associated with the ER alpha gene. After correction for multiple comparisons by means of permutation analysis, the associations with the factor 'non-conformity'--including the subscales 'indirect aggression' and 'irritability'--and the factor 'psychoticism'--including the subscale 'suspicion'--remained significant. The results suggest that the studied dinucleotide repeat polymorphism of the ER alpha gene may contribute to specific components of personality.

Effects of glucocorticoids on leptin levels and eating behaviour in women.

OBJECTIVE: Long-term treatment with glucocorticoids induces weight gain and increased risk to develop obesity-related metabolic complications. The underlying mechanisms are not fully understood. Glucocorticoid therapy has previously been associated with increased levels of circulating leptin. In this study the eating behaviour was therefore studied in relation to leptin levels before and after short-term prednisolone treatment. DESIGN: Within-subject design. SUBJECTS: Twelve healthy postmenopausal women with a mean body mass index (BMI) of 28.9 kg m-2 (+/-0.8 SEM) volunteered after recruitment by an advertisement in the local paper. INTERVENTIONS: The subjects received 25 mg prednisolone daily for 7 days. MAIN OUTCOME MEASUREMENTS: Fasting serum samples were obtained before, during and after treatment for determination of leptin and insulin, glucose and fractionated lipoproteins in plasma. The microstructure of the eating behaviour was registered with a universal eating monitor, VIKTOR. Appetite was estimated by visual analogue rating scales and food intake by a 48-h recall. RESULTS: Serum leptin increased after 2 and 7 days of glucocorticoid administration (P < 0.01), and the food intake measured by VIKTOR after 7 days of treatment (P < 0.05). No statistically significant changes were however, found in the 48-h food- recall or in the subjective appetite registrations. Insulin levels were borderline elevated (P = 0.062) after treatment, but no significant changes of fasting glucose were seen. High density lipoprotein cholesterol (HDL) increased (P < 0.05), whilst low density lipoprotein cholesterol (LDL) decreased (P < 0.05). CONCLUSION: Food intake was elevated after glucocorticoid administration as observed with an objective, quantitative method, in spite of increased levels of circulating leptin.

Reductions in adipose tissue and skeletal growth in rat adult offspring after prenatal leptin exposure.

Leptin is involved in regulating food intake, energy balance and bone formation. Increasing evidence suggests that leptin is also involved in fetal growth and development. The aim of this study was to determine if increased maternal leptin is followed by changes in body composition, skeletal growth or hormonal regulation in the adult rat offspring. Pregnant rats were given injections of either human recombinant leptin (3.5 mg/kg, i.p.) or vehicle on days 8, 10 and 12 of gestation. Both genders of leptin-exposed offspring showed significantly reduced adipose tIssue weight at adult age. Skeletal growth and cortical bone dimensions were significantly reduced. Circulating testosterone levels were significantly increased in female leptin-exposed offspring, and male leptin-exposed offspring had significant testicular enlargement. No significant effects were seen on circulating leptin levels or hypothalamic protein levels of the leptin receptor. The results demonstrate that maternally administered leptin is involved in fetal growth and development, leading to lean offspring with reduced skeletal growth.

Phenotypic and genotypic characteristics of women in relation to personality traits.

The associations were examined in women between personality traits and steroid hormones, particularly androgens, as well as polymorphisms in genes regulating androgen concentration and effects. Women, all 42 years of age and premenopausal (n = 270), were recruited randomly. Conventional "masculine" and "feminine" personality traits were examined by questionnaire and set in relation to psychosocial and socioeconomic conditions, behavior in childhood, hormones, risk factors for disease, and polymorphisms in microsatellites in the CYP aromatase and the androgen receptor gene. The proportions of personality traits considered as being dominated by "masculinity" (M) or "femininity" (F) were 44.9%, respectively 15.0%, the rest consisting of a combination of M and F (33.2%) or "undifferentiated" (6.9%). M characteristics were positively associated with education, sporting, self-confidence, and good adaptation to work situation. M scores correlated with reports of "tomboyism" as girls. There was essentially no difference in hormones or disease risk factors between M and F women. The number of (CAG) repeats in the microsatellite of the transactivating domain of the androgen receptor was 19 (2.3; M and SD). M characteristics were more pronounced in the presence of longer repeat stretches (n > 20). No associations were found with F scores. There were no significant associations to the number of tetranucleotide repeats (TTTA) in the fourth introne of the aromatase gene. It was concluded that a majority of women showed M type of personality traits, associated with normal hormones, somatic health, and a long microsatellite in the transactivating domain of the AR gene.

Allelic variants in the GABA(A)alpha6 receptor subunit gene (GABRA6) is associated with abdominal obesity and cortisol secretion.

INTRODUCTION: Cortisol is involved in the regulation of adipose-tissue differentiation, function and distribution, and in excess causes abdominal obesity. At the level of the brain, cortisol secretion is partly controlled by gamma-aminobutyric acid (GABA), which is the major inhibitory neurotransmitter in the vertebrate brain, and acts by binding to GABA(A) receptors. METHOD: We examined the potential impact of a 1519T>C polymorphism in the GABA(A)alpha6 receptor subunit (GABRA6) gene on obesity and obesity-related phenotypes as well as circulating hormones, including salivary cortisol in 284 unrelated Swedish men born in 1944. The subjects were genotyped by using PCR amplification of the 3' non-coding region of the GABRA6 gene followed by digestion with the restriction enzyme AlwNI. RESULTS: The frequency of allele T was 0.54 and 0.46 for allele C. Carriers for the T allele (n=211) had borderline significantly higher waist-to-hip ratio (P=0.094) and abdominal sagittal diameter (P=0.084) compared to homozygotes for the C allele (n=56). The homozygotes for the T allele had, in comparison to heterozygotes, significantly (P=0.004-0.024) higher mean cortisol levels at 11:45 am, and 30, 45 and 60 min after a standardized lunch and, finally, at 5:00 pm. In addition, T/T subjects had significantly (P=0.031) higher diurnal cortisol secretion compared to T/C subjects. Other hormones, glucose and serum lipids were not different across the genotype groups. CONCLUSION: These findings suggest a role of the 1519T>C polymorphism in GABRA6 in the predisposition to hypercortisolism and perhaps abdominal obesity. The pathophysiology may involve various environmental factors, particularly stress, that destabilize the GABA-hypothalamic-pituitary-adrenal systems in those with genetic vulnerability.

Central and peripheral glucocorticoid receptor function in abdominal obesity.

Abdominal obesity seems to be associated with a moderately deranged feedback regulation of the hypothalamic-pituitary-adrenal (HPA) axis where central glucocorticoid receptors (GR) are involved. Therefore, functions of central and peripheral GR were compared in this study. Furthermore, since trinucleotide repeats in early exons of steroid hormone receptor genes influence transcription, and therefore may influence receptor density, this was also studied. Ten middle-aged men, 5 with abdominal obesity and 5 controls, were studied. The suppression of dexamethasone (dex) on serum cortisol was used in dose-response tests to assess the function of central GR. Abdominal adipose tissue biopsies were incubated and exposed to cortisol in different concentrations, and the function of the peripheral GR assayed as induction of lipoprotein lipase (LPL) activity. Aberrant expansion of exonic trinucleotide repeats in the first coding exon of the GR gene was studied by sequencing of genomic DNA. Results showed that men with abdominal obesity showed less inhibition of serum cortisol by dex, particularly at lower concentrations, while in the controls cortisol secretion was inhibited in an apparent dose-response manner. LPL activity in adipose tissue was lower in abdominal obese men than in controls. However, the sensitivity to cortisol was not different between the groups. There was no evidence for expansion of trinucleotide repeats. These results suggest that the central GR and the peripheral GR in adipose tissue exhibit functional differences in abdominal obesity.

A C-1291G polymorphism in the alpha2A-adrenergic receptor gene (ADRA2A) promoter is associated with cortisol escape from dexamethasone and elevated glucose levels.

OBJECTIVES: The objective of the current study was to examine the potential impact of a C right arrow G substitution at position -1291 of the alpha2A-adrenergic receptor gene (ADRA2A) promoter on obesity and estimates of insulin, glucose, and lipid metabolism as well as circulating hormones, including salivary cortisol in 284 unrelated Swedish men born in 1944. MAIN OUTCOME MEASURES: The subjects were genotyped by using PCR amplification of the promoter region of the ADRA2A gene followed by digestion with the restriction enzyme MspI. RESULTS: The frequencies were 0.23 for allele C and 0.77 for allele G. The observed genotype frequencies were 45.8 and 54.2% for C/G and G/G, respectively. Heterozygotes (n=121) had significantly (P=0.009) higher salivary cortisol levels after 0.5 mg dexamethasone compared with G/G homozygotes (n=143). Fasting glucose was found to be significantly (P=0.017) higher in heterozygotes than in G/G homozygotes. The latter group had also a borderline significantly (P=0.080) higher mean diastolic blood pressure. These results were all adjusted for the potential confounding effect of body mass index (BMI) and waist-to-hip ratio (WHR). Other measurements such as BMI, WHR, abdominal sagittal diameter, total testosterone, insulin-like growth factor I, serum leptin, fasting insulin and serum lipids were not different across the ADRA2A genotype groups. CONCLUSIONS: In conclusion, we have shown that an C --> G polymorphism at position -1291 of the ADRA2A gene is associated with a subnormal cortisol response to dexamethasone, elevated glucose levels and perhaps increased diastolic blood pressure. The pathophysiology could involve an altered density of the alpha2A-AR that destabilizes the sympathetic-hypothalamic-pituitary-adrenal systems in those with genetic vulnerability in the alpha2A-adrenergic receptor gene promoter.

A missense mutation in the human melanocortin-4 receptor gene in relation to abdominal obesity and salivary cortisol.

AIMS/HYPOTHESIS: The melanocortin-4 receptor (MC4-R) regulates food intake and possibly energy expenditure, and the inactivation of the MC4-R by gene targeting results in obesity, a phenotype strongly associated with Type II (non-insulin-dependent) diabetes mellitus. In our study, we addressed the hypothesis that a G-->A substitution at codon 103 (Val-103Ile) of the MC4R gene influences abdominal obesity, insulin, glucose, and lipid metabolism as well as circulating hormones, including salivary cortisol. METHODS: We genotyped the missense variant at codon 103 of the MC4R gene in 284 unrelated Swedish men born in 1944 by using polymerase chain reaction amplification followed by digestion with the restriction enzyme HincII. RESULTS: The frequency of allele G was 0.97 and 0.03 for allele A. The observed genotype frequencies were 95 % and 5 % for G/G and G/A, respectively. The heterozygotes had lower waist-to-hip ratio (p = 0.023) and trends for lower body mass index (p = 0.054) and abdominal sagittal diameter (p = 0.095) compared to G/G homozygotes. Moreover, G/A subjects had borderline lower serum leptin concentrations (p = 0.087) and total cholesterol (p = 0.082). The heterozygotes had also, in comparison to G/G subjects, significantly (p < 0.01) higher mean cortisol concentrations in the morning (21.4 vs 14.6 nmol/l), at ll:45 h (11.6 vs 7.0 nmol/l), 30 min after a standardized lunch (15.3 vs 8.0 nmol/l) and finally, 60 min after lunch (10.8 vs 6.7 nmol/l). CONCLUSION/INTERPRETATION: These findings suggest that the missense mutation in the MC4R gene could contribute to the variability in body mass, abdominal fat distribution and leptin concentrations in the general population. Moreover, the G/A mutation exhibits evidence of associations with diurnal cortisol levels.

A polymorphism in the regulatory region of the corticotropin-releasing hormone gene in relation to cortisol secretion, obesity, and gene-gene interaction.

In recent years, a considerable body of evidence has emerged regarding the pathogenic role of cortisol in abdominal obesity. The regulation of the corticotropin-releasing hormone (CRH) gene might play an essential role because it is the primary hypothalamic neuropeptide involved in the control of adrenal secretion of cortisol. Therefore, we examined the hypothalamic-pituitary-adrenal function by repeated salivary samples for the assessment of cortisol as well as other endocrine, anthropometric, metabolic, and circulatory variables in middle-aged Swedish men (n = 284). With the restriction enzyme XmnI, a variant in the 5'-flanking region of the CRH gene was identified (T255G). The observed genotype frequencies were 89.9% and 9.7% for T/T and T/G, respectively. Only 1 subject was homozygous for the rare allele (0.4%; G/G). The results showed that the XmnI polymorphism of the CRH gene is not associated with an altered cortisol-secretory pattern or sensitivity to glucocorticoids or with obesity and its related metabolic and circulatory perturbations. However, when the interaction effect between a previously described TthlllI glucocorticoid-receptor gene polymorphism and the present XmnI CRH polymorphism was investigated, the cortisol levels before and during physiologic stress and the total diurnal cortisol secretion were significantly increased among subjects who were carriers for both variants. From these results, we conclude that an abnormal production rate of the CRH gene product in the presence of an inadequate glucocorticoid receptor density might lead to elevated cortisol levels.

Treatment of abdominally obese men with a serotonin reuptake inhibitor: a pilot study.

OBJECTIVE: To investigate the effects of a selective serotonin reuptake inhibitor (SSRI) on the neuroendocrine and autonomic nervous system perturbations found in abdominal obesity. DESIGN: Treatment for 6 months with citalopram and for 6 months with placebo using a double-blind, cross-over design, with a 2-month wash-out period between treatment periods. SUBJECTS: Sixteen healthy men, 45-60 years, moderately obese and with an abdominal fat distribution. MEASUREMENTS: Anthropometry, three different depression rating scales, serum lipids, testosterone, IGF-I, oral glucose tolerance test (OGTT), pituitary stimulation with corticotropin releasing hormone (CRH), arithmetic stress test, and excretion of cortisol and metoxycatecholamines in urine, collected during 24 h. RESULTS: Cortisol concentrations in the morning were low before treatment, indicating a perturbed function of the hypothalamic-pituitary-adrenal (HPA) axis. After treatment with citalopram morning cortisol concentrations rose to normal. Cortisol concentrations after stimulation with CRH or stress were elevated by citalopram treatment, but urinary cortisol excretion was unchanged. The glucose concentrations after OGTT (120 min) tended to be reduced, with unchanged insulin concentrations, whilst other metabolic values did not change during treatment. Heart rate after administration of CRH, and during laboratory stress test, decreased by treatment with citalopram. Diurnal urinary excretion of metoxycatecholamines tended to decrease. Neither body mass index nor waist/hip circumference ratio decreased. Depression scores were within normal limits before treatment and did not change. CONCLUSION: The results of this pilot study indicate improvements in the regulation of neuroendocrine-autonomic systems as well as metabolism in abdominal obesity during treatment with an SSRI.

Polymorphism in exon 6 of the dopamine D(2) receptor gene (DRD2) is associated with elevated blood pressure and personality disorders in men.

A deficient dopamine D(2) receptor (DA2) formation or action may contribute to hypertension via an increase of catecholamine release. In addition, Axis II personality disorders that appears odd or eccentric (cluster A) is associated with a low density of DA2. This study sought to examine if a NcoI restriction fragment length polymorphism (C to T transition) in exon 6 of the dopamine D(2) receptor gene (DRD2) was associated with these characteristics. The genotypes (CC, CT and TT) were compared in anthropometric, endocrine, metabolic and haemodynamic variables as well as estimates of personality disorders in 284 randomly selected 51-year-old men. Homozygotes for the C allele constituted 49% of the men and homozygotes for the T allele 9%, while heterozygotes were 41%. The TT genotype was associated with elevated systolic and diastolic blood pressure, independent of obesity and endocrine abnormalities, including the hypothalamic-pituitary-adrenal axis regulation. Moreover, the TT genotype was significantly more frequent among subjects with grade 1 (mild) hypertension (>140/90 mm Hg) compared to normotensive subjects (<130/85 mm Hg). The polymorphism in exon 6 of the DRD2 was also significantly associated with cluster A personality disorders. These results suggest that a polymorphism in exon 6 of the DRD2examined with the restriction enzyme NcoI is associated with an elevated blood pressure, independent of obesity. Paranoid or schizoid personality disorders is also associated with a polymorphism of the DRD2, which might be associated with a previously demonstrated low density of this receptor.

Prenatal cytokine exposure results in obesity and gender-specific programming.

Prenatal events appear to program hormonal homeostasis, contributing to the development of somatic disorders at an adult age. The aim of this study was to examine whether maternal exposure to cytokines or to dexamethasone (Dxm) would be followed by hormonal consequences in the offspring at adult age. Pregnant rats were injected on days 8, 10, and 12 of gestation with either human interleukin-6 (IL-6) or tumor necrosis factor-alpha (TNF-alpha) or with Dxm. Control dams were injected with vehicle. All exposed offspring developed increased body weight (P < 0.05--0.001), apparently due to an increase of 30--40% in adipose tissue weight (P < 0.05--0.01). Corticosterone response to stress was increased in the IL-6 group (P < 0.05-0.01). Dxm-treated male rats exhibited blunted Dexamethasone suppression test results. In male rats, insulin sensitivity was decreased after IL-6 exposure (P < 0.01), whereas basal insulin was elevated in the TNF-alpha group (P < 0.01). In female rats, plasma testosterone levels were higher in all exposed groups compared with controls (P < 0.01--0.001), with the exception of Dxm-exposed offspring. Males in the TNF-alpha group showed decreased locomotor activity (P < 0.05), and females in the IL-6 group showed increased locomotor activity (P < 0.05). These results indicate that prenatal exposure to cytokines or Dxm leads to increased fat depots in both genders. In females, cytokine exposure was followed by a state of hyperandrogenicity. The results suggest that prenatal exposure to cytokines or Dxm can induce gender-specific programming of neuroendocrine regulation with consequences in adult life.

Serotonin transporter gene polymorphisms are associated with anxiety-related personality traits in women.

Several studies have reported an association between anxiety-related personality traits and a promoter polymorphism in the human serotonin transporter (5-HTT) gene (5-HTT gene-linked polymorphic region, 5-HTTLPR). In the present study, a population of 251 subjects was assessed with the Karolinska Scales of Personality (KSP) and genotyped both for the 5-HTTLPR and for a variable number of tandem repeats polymorphism in the second intron of the same gene. The interpretation of previous studies has to some extent been confounded by the studied subjects differing with respect to ethnicity, sex, and age. To circumvent this problem, all included subjects were Caucasians, women, and born in the same year (1956). Associations were found between the 5-HTTLPR and four of the five anxiety-related KSP scales (psychic anxiety, muscular tension, psychasthenia, and lack of assertiveness), subjects being homozygous for the short allele displaying higher anxiety scores than those of the long/long or long/short genotype. In addition, an association was found between the intron 2 polymorphism and one anxiety-related personality trait (somatic anxiety).

Polymorphisms of the androgen receptor gene and the estrogen receptor beta gene are associated with androgen levels in women.

To elucidate the possible role of genetic variation in androgen receptor (AR), estrogen receptor alpha (ER alpha), and ER beta on serum androgen levels in premenopausal women, the CAG repeat polymorphism of the AR gene, the TA repeat polymorphism of the ER alpha gene, and the CA repeat polymorphism of the ER beta gene were studied in a population-based cohort of 270 women. Total testosterone, free testosterone, dehydroepiandrosterone sulfate, androstenedione, 17-hydroxyprogesterone, 3 alpha-androstanediol glucuronide, 17 beta-estradiol, LH, FSH, and sex steroid hormone-binding globulin (SHBG) were measured in serum samples obtained in the follicular phase of the menstrual cycle. Women with relatively few CAG repeats in the AR gene, resulting in higher transcriptional activity of the receptor, displayed higher levels of serum androgens, but lower levels of LH, than women with longer CAG repeat sequences. The CA repeat of the ER beta gene also was associated with androgen and SHBG levels; women with relatively short repeat regions hence displayed higher hormone levels and lower SHBG levels than those with many CA repeats. In contrast, the TA repeat of the ER alpha gene was not associated with the levels of any of the hormones measured. Our results suggest that the serum levels of androgens in premenopausal women may be influenced by variants of the AR gene and the ER beta gene, respectively.