Genetic variability within the S100B gene influences the personality trait self-directedness.

Elevated serum levels of S100B have proven useful as an indicator of brain-injury but have also been shown in patients diagnosed with psychiatric disorders. Recently, associations were found between variations in the S100B gene and schizophrenia as well as bipolar affective disorder. The aim of the present study was to investigate whether some of these genetic variations influence general aspects of human behaviour as portrayed by normal dimensions of personality. Two single nucleotide polymorphisms within the S100B gene, 2757C>G and 5748C>T, were genotyped in two population based cohorts consisting of 42-year-old women (n=270) and 51-year-old men (n=247), respectively. The two polymorphisms were analysed with respect to personality traits assessed using the Temperament and Character Inventory (TCI). In men, the 2757C>G polymorphism was found to significantly influence the TCI dimension self-directedness with higher scores in 2757G homozygotes. A similar tendency towards association was seen in the female cohort; however, this correlation did not remain significant after correction for multiple comparisons. Furthermore, the 5748C>T polymorphism was highly associated with self-directedness in men. Self-directedness is an overall estimate of adaptive strategies to adjust behaviour to conceptual goals as well as coping strategies and is strongly correlated to general mental health and absence of personality disorder. These preliminary findings suggest that the S100B gene may be implicated not only in certain pathological brain conditions but also in processes involved in normal behaviour.

Further exploration of the possible influence of polymorphisms in HTR2C and 5HTT on body weight.

Receptors of the 5-HT2C subtype are of importance for the influence of serotonin on food intake, and 2 single nucleotide polymorphisms in this gene (HTR2C)--Cys23Ser (rs6318) and -759C>T (rs3813929)--have been reported to be associated with weight and/or antipsychotic-induced weight gain. The present study aimed to replicate these associations; in addition, the 5-HTTLPR polymorphism in the promoter region of the serotonin transporter gene (SLC6A4) was assessed. The polymorphisms were genotyped in subjects recruited from the normal population (n = 510), and possible associations between genotype and body mass index (BMI) were assessed. The Ser23 allele was more common in underweight subjects (BMI <20) than in normal- and overweight (BMI > or =20) subjects (P = .006). The T allele of the -759C/T polymorphism was less common in the overweight group (BMI > or =25) (P = .007). Homozygosity for the short allele of 5-HTTLPR was more frequent in underweight subjects (P = .015). Our results are in agreement with previous studies, suggesting polymorphisms in HTR2C to be associated with body weight, particularly in women; and they also suggest that 5-HTTLPR may influence this phenotype. Further studies on the importance of the investigated genes for eating disorders and drug-induced weight gain are warranted.

Influence of androgen receptor repeat polymorphisms on personality traits in men.

BACKGROUND: Testosterone has been attributed importance for various aspects of behaviour. The aim of our study was to investigate the potential influence of 2 functional polymorphisms in the amino terminal of the androgen receptor on personality traits in men. METHODS: We assessed and genotyped 141 men born in 1944 recruited from the general population. We used 2 different instruments: the Karolinska Scales of Personality and the Temperament and Character Inventory. For replication, we similarly assessed 63 men recruited from a forensic psychiatry study group. RESULTS: In the population-recruited sample, the lengths of the androgen receptor repeats were associated with neuroticism, extraversion and self-transcendence. The association with extraversion was replicated in the independent sample. LIMITATIONS: Our 2 samples differed in size; sample 1 was of moderate size and sample 2 was small. In addition, the homogeneity of sample 1 probably enhanced our ability to detect significant associations between genotype and phenotype. CONCLUSION: Our results suggest that the repeat polymorphisms in the androgen receptor gene may influence personality traits in men.

Association between the AGTR1 polymorphism +1166A>C and serum levels of high-sensitivity C-reactive protein.

Genetic factors have been shown to influence high-sensitivity C-reactive protein (hsCRP) levels, however, which genes that are involved in this process remains to be clarified. The renin-angiotensin system (RAS) is of importance for the regulation of inflammation, and blockade of angiotensin II type 1 receptors (AGTR1) influences hsCRP levels. These findings prompted us to investigate whether a polymorphism in the AGTR1 gene may influence hsCRP levels. Additionally, a polymorphism in the CRP gene that has previously been shown to influence hsCRP levels was genotyped. Serum levels of hsCRP were measured in 270 42-year-old women recruited from the population registry. Two single nucleotide polymorphisms were analysed: +1166A>C and +1444C>T of the AGTR1 and CRP gene, respectively. The A allele of the AGTR1 polymorphism +1166A>C was dose-dependently associated with higher hsCRP levels (p=0.014, adjusted for confounding factors and multiple comparisons). hsCRP levels were not significantly influenced by the CRP +1444C>T genotype; however, an interaction between the two studied polymorphisms with respect to hsCRP levels was observed (p=0.018). The significant association between the AGTR1 polymorphism and hsCRP levels, which appears to be independent of anthropometric and metabolic traits, is yet another indication of a direct influence of RAS on inflammation.

A 5-year follow-up study of 3 polymorphisms in the human glucocorticoid receptor gene in relation to obesity, hypertension, and diabetes.

Glucocorticoid receptors (GRs) are cytoplasmaticreceptors regulating the expression of cortisol and bind to specific sites on chromatin. The glucocorticoid receptor gene (GRL) is located on chromosome 5q31 and encodes for either a 777-amino acid (GRalpha) or a 742-amino acid (GRbeta) polypeptide. The objective of the current study was to examine the prospective association of 3 polymorphisms-a Tth111I restriction fragment in the promoter region, a BclI polymorphism in intron 2, and an A/G polymorphism in exon 2-of the GRL gene on estimates of obesity, hypertension, and diabetes in 163 unrelated Swedish men born in 1944. These data showed a significant increase in body weight, body mass index, abdominal obesity, fasting glucose, insulin, and homeostasis model assessment over the 5-year follow-up among homozygotes for the rare BclI allele. In contrast, no significant associations with the Tth111I or A/G polymorphism were detected. It is concluded that the genetic information about GRL would be useful for further genetic study of obesity, diabetes, and related metabolic diseases.

Association between serum levels of C-reactive protein and personality traits in women.

BACKGROUND: While low-grade inflammation has consistently been observed in subjects with depression, studies on the possible relationship between inflammation and other aspects of brain function are as yet sparse. In this study, we aimed to investigate the possible association between serum levels of the inflammation marker C-reactive protein (CRP) and personality traits. METHODS: In this study, serum levels of high-sensitivity CRP were determined by ELISA in a population of 270 42-year-old women recruited from the population registry who had been assessed using the Temperament and Character Inventory. Self-reported previous or ongoing depression was also recorded. Unpaired two-tailed t-tests were used for comparison between two groups and correlations were evaluated by the calculation of Pearson's r-coefficient. RESULTS: The temperament trait harm avoidance was positively (r = 0.227, p < 0.05) and the character trait self-directedness was negatively (r = -0.261, p < 0.01) associated with serum levels of CRP (p-values corrected for multiple comparisons). The correlations between the personality traits and CRP were observed also after exclusion of subjects reporting ongoing depression (n = 26). Whereas women reporting ongoing depression showed significantly increased levels of CRP as compared to non-depressed women (n = 155), women reporting a history of depression displayed no significant difference in CRP levels as compared to women that reported that they had never been depressed. CONCLUSION: Serum levels of CRP in women was found to be associated with the personality traits harm avoidance and self-directedness. In addition, moderately elevated levels may be a state dependent marker of depression.

Catechol O-methyltransferase val158-met polymorphism is associated with abdominal obesity and blood pressure in men.

Catechol O-methyltransferase (COMT) degrades catecholamines and estrogens, both of which are of known importance for cardiovascular risk factors such as obesity and hypertension. The gene coding for COMT contains a val158-met polymorphism that exerts a considerable influence on enzymatic activity. We hypothesized that this polymorphism might influence risk factors for cardiovascular disease. Deoxyribonucleic acid samples and data regarding blood pressure and anthropometry were collected from 240 Swedish men, all 51 years old. Subjects homozygous for the low-activity allele (met) displayed higher blood pressure, heart rate, waist-to-hip ratio, and abdominal sagittal diameter as compared with heterozygous subjects, who in turn displayed higher blood pressure, heart rate, waist-to-hip ratio, and abdominal sagittal diameter than subjects homozygous for the high-activity allele (val). All measured variables were significantly correlated; however, the associations between COMT val158-met and cardiovascular variables, and the association between COMT val158-met and anthropometry, respectively, were partly independent of each other, as revealed by multiple linear regression.

Interleukin-6 gene polymorphism -174G/C influences plasma lipid levels in women.

Elevated levels of the pro-inflammatory cytokine interleukin-6 (IL-6) have been associated with cardiovascular risk factors. The objective of this study was to investigate potential associations between the promoter polymorphism IL-6 -174G/C and the following indices of metabolism: BMI, waist-to-hip ratio, and plasma levels of IL-6, cholesterol, low-density lipoprotein, triglycerides, high-density lipoprotein, leptin, and C-reactive protein in 252 42-year-old women and 245 51-year-old men. Subgroups were also studied 5 years later. The CC genotype of the IL-6 polymorphism was associated with lower levels of cholesterol and low-density lipoprotein (p < 0.001) in women. This finding was replicated in the follow-up, when a significant association between the CC genotype and low triglycerides was also observed. The association between the C allele and lipid pattern found in women was not found in men, where on the contrary, C carriers tended to display elevated triglycerides. IL-6 genotype was not associated with IL-6 plasma levels in either sample. The results suggest different effects of the IL-6 polymorphism on metabolic indices in women and men. None of the associations between IL-6 genotype and lipid pattern seemed to result from an effect of the polymorphism on IL-6 plasma levels.

A brief update of glucocorticoid receptor variants and obesity risk.

Excess body fat, obesity, is one of the most common disorders in clinical practice. Obese individuals are at increased risk for physical ailments, such as type 2 diabetes, coronary heart disease, hypertension, and several types of cancer. The location of the body fat is a major determinant of the degree of excess morbidity and mortality due to obesity. More specifically, the amount of subcutaneous truncal or abdominal fat, and the amount of visceral fat located in the abdominal cavity independently predicts obesity-related adverse health outcomes. The obesity gene map shows putative loci on all chromosomes except Y. More than 300 genes, markers, and chromosomal regions have been associated or linked with human obesity phenotypes. These genes can be divided into two broad categories: (a) rare gene variants that have a strong influence, and (b) common gene variants that have a weaker influence on obesity phenotypes. Studies in humans have suggested a positive association between obesity, hypertension, and insulin resistance, with alleles at the glucocorticoid receptor gene. In this article, we will estimate the risk by which such gene polymorphism mediates a role in obesity.

Androgen excess in women--a health hazard?

A significant body of evidence suggests that androgens in women may play a role in the genesis of central adiposity and type 2 diabetes. There are two principal sources of circulating androgens in females: the ovary and the adrenal gland. In hyperandrogenic women, there are elevated serum concentrations of androstenedione and testosterone and, in up to 50% of the women, dehydroepiandrosterone sulfate (DHEAS). The androgen precursor DHEAS is of exclusive adrenal origin, suggesting that hyperandrogenic women have an elevated proportion of adrenal androgen production and secretion. Another cause of androgen excess in reproductive-age women is a decreased conversion of testosterone to estradiol by the aromatase enzyme complex. In this review, we will discuss the hypothesized clinical sequel of elevated androgens in women - an aspect of women's health highly neglected. Furthermore, an attempt is made to appreciate what causes the androgens to initially rise from normal levels, allowing the onset of pathophysiological processes towards diseases.

Sex steroid-related genes and male-to-female transsexualism.

Transsexualism is characterised by lifelong discomfort with the assigned sex and a strong identification with the opposite sex. The cause of transsexualism is unknown, but it has been suggested that an aberration in the early sexual differentiation of various brain structures may be involved. Animal experiments have revealed that the sexual differentiation of the brain is mainly due to an influence of testosterone, acting both via androgen receptors (ARs) and--after aromatase-catalyzed conversion to estradiol--via estrogen receptors (ERs). The present study examined the possible importance of three polymorphisms and their pairwise interactions for the development of male-to-female transsexualism: a CAG repeat sequence in the first exon of the AR gene, a tetra nucleotide repeat polymorphism in intron 4 of the aromatase gene, and a CA repeat polymorphism in intron 5 of the ERbeta gene. Subjects were 29 Caucasian male-to-female transsexuals and 229 healthy male controls. Transsexuals differed from controls with respect to the mean length of the ERbeta repeat polymorphism, but not with respect to the length of the other two studied polymorphisms. However, binary logistic regression analysis revealed significant partial effects for all three polymorphisms, as well as for the interaction between the AR and aromatase gene polymorphisms, on the risk of developing transsexualism. Given the small number of transsexuals in the study, the results should be interpreted with the utmost caution. Further study of the putative role of these and other sex steroid-related genes for the development of transsexualism may, however, be worthwhile.

Role of stress in the pathogenesis of the metabolic syndrome.

Excess body fat, obesity, is one of the most common disorders in clinical practice. In addition, there is a clustering of several risk factors with obesity, including hypertension, glucose intolerance, diabetes mellitus, and hyperlipidemia, which is observed more frequently than by chance alone. This has led to the suggestion that these represent a single syndrome and is referred to as the Metabolic Syndrome. A growing body of evidence suggests that glucocorticoid secretion is associated with this complex phenotype. Continuously changing and sometimes threatening external environment may, when the challenge exceeds a threshold, activate central pathways that stimulate the adrenals to release glucocorticoids. In this review, we will discuss how such processes mediate a pathogenetic role in the Metabolic Syndrome.

Polymorphisms in oestrogen and progesterone receptor genes: possible influence on prolactin levels in women.

OBJECTIVE: Oestrogen and progesterone are known to influence the release of human prolactin. The present study was undertaken in order to investigate the possible influence of polymorphisms of the genes encoding the oestrogen receptor (ER)alpha, ERbeta and the progesterone receptor (PGR), on prolactin levels in premenopausal women. DESIGN AND MEASUREMENTS: Serum levels of prolactin were measured in the follicular phase of the menstrual cycle. Subjects were genotyped with respect to a TA repeat polymorphism of the ERalpha gene, a CA repeat polymorphism of the ERbeta gene, and two polymorphisms of the PGR gene: one insertion polymorphism (PROGINS) and one single nucleotide polymorphism (G331A). SUBJECTS: A population-based cohort of 270 42-year-old women. RESULTS: The CA repeat polymorphism of the ERbeta gene and the G331A polymorphism of the PGR gene appeared to be associated with prolactin levels. In contrast, we found no evidence for an influence of the PROGINS polymorphism of the PGR gene or the TA repeat polymorphism of the ERalpha gene on the levels of this hormone. CONCLUSIONS: These data suggest that genetic variants of both the ERbeta and the PGR may influence prolactin release.

Association between a functional polymorphism in the progesterone receptor gene and panic disorder in women.

Although genetic factors are known to be important risk factors for panic disorder there is as yet no conclusive data regarding specific gene variants. Prompted by evidence supporting progesterone to influence the pathophysiology of panic disorder, polymorphisms in the progesterone receptor gene, a single nucleotide polymorphism (G331A) and an insertion/deletion polymorphism (PROGINS) were investigated in 72 patients with panic disorder and 452 controls. The frequency of the A-allele of the G331A polymorphism was higher in panic disorder patients than in controls (p = 0.01). When male and female patients were analyzed separately, the association was observed in female patients only (p = 0.0009), with an odds ratio of 3.5. No differences between groups were observed for the PROGINS polymorphism. In conclusion, these data suggest that the G331A polymorphism in the progesterone receptor gene may influence the risk for panic disorder in women.

Dyslipidemia and high waist-hip ratio in women with self-reported social anxiety.

Previous research has indicated that phobic anxiety is associated with coronary heart disease. In this study, the possible association between social anxiety and various anthropometric, metabolic, and endocrine measurements known to be associated with cardiovascular disease were studied in a population-based cohort of 216 women 41-42 years old. Each participant was assessed by means of a DSM-IV based self-report questionnaire regarding social anxiety and related psychiatric diagnoses. Waist-to-hip ratio (WHR), body mass index (BMI), and serum levels of lipids and hormones were assessed. The prevalence of social anxiety was 14% (n=31). The social anxiety group displayed higher serum levels of triglycerides (1.3+/-0.9 vs. 1.0+/-0.5, P=0.003) and low-density lipoprotein (LDL) (3.3+/-0.8 vs. 3.0+/-0.7, P=0.03), but lower high-density lipoprotein (HDL) (1.4+/-0.3 vs. 1.6+/-0.4, P=0.04) and HDL/LDL ratio (0.46+/-0.15 vs. 0.57+/-0.22, P=0.008) than the other women. Serum levels of total testosterone (1.6+/-0.8 vs. 2.2+/-1.1, P=0.013) and free thyroxin (14+/-2 vs. 16+/-4, P=0.04) were lower in subjects confirming social anxiety. While WHR was significantly higher in the social anxiety group (0.83+/-0.06 vs. 0.80+/-0.07, P=0.016), BMI did not differ between the groups. Our data suggest that self-reported social anxiety is associated with two established risk factors for cardiovascular disease: dyslipidemia and increased WHR.

Obesity and depression: same disease, different names?

Obesity is a major public health problem, which occurs in epidemic proportions. Our understanding of the systems of the brain related to energy balance has increased over the last decade. As a result, drugs most commonly used today in the management of obesity have their primary effect in modulating the balance between monoaminergic neurotransmitters, among other serotonin. Serotonin is believed to be involved in the complex process of integrating physiological and behavioral systems geared towards energy balance. However, gradual weight gain seen in most people suggests that the regulatory system may not be sufficient under all circumstances. An insufficient serotoninergic neuronal function in the central nervous system has been shown in many studies to occur in patents with depression. In such serotonin-deficient patients, treatment with drugs increasing the concentration of serotonin at serotoninergic synapses gives a favorable clinical response. Taken together, this suggests to a certain extent a common pathophysiology between obesity and depression. Literature spanning several decades has addressed the relationship among obesity and depression. However, obesity and depression research have evolved as two independent disciplines, which rarely or never overlap. In this paper, we propose the notion that obesity and depression may represent different manifestations of the same disease process - Janus faces of the modern society.

Angiotensin-related genes in patients with panic disorder.

Enhanced respiratory variability and decreased heart rate variability have repeatedly been observed in patients with panic disorder. Prompted by the notion that angiotensin may be involved in the control of respiration, heart rate variability, and anxiety-like behavior, we investigated the putative association between polymorphisms in three angiotensin-related genes and panic disorder-angiotensinogen (AGT), angiotensin converting enzyme (ACE), and angiotensin II (ANG II) receptor type 1 (ATr1) in 72 patients with panic disorder and 504 controls. Allele and genotype distribution of the ATr1 A1166C allele and the AGT M235T did not differ between patients and controls. With respect to the ACE I/D polymorphism, the I allele was found to be more frequent in male (chi(2) = 8.042, df = 1, P = 0.005), but not female, panic disorder patients than in controls. The results of this investigation provide preliminary evidence for the suggestion that angiotensin-related genes may be associated with panic disorder in men.

A polymorphism in the serotonin receptor 3A (HTR3A) gene and its association with harm avoidance in women.

BACKGROUND: The brain neurotransmitter serotonin is known to affect various aspects of human behavior, including personality traits. Serotonin receptor type 3 is a ligand-gated channel encoded by 2 different subunit genes, HTR3A and HTR3B. A polymorphism (C178T) in the 5' region of the HTR3A gene has recently been identified and suggested to be of functional importance. OBJECTIVE: To elucidate the possible association between the C178T polymorphism in the HTR3A gene and personality traits in women. DESIGN: Two independent samples of 35- to 45-year-old Swedish women were recruited using the population register. Sample 1 (n = 195) was assessed via the Karolinska Scales of Personality and the Temperament and Character Inventory; sample 2 (n = 175) was assessed using the latter only. Both samples were genotyped with respect to the C178T polymorphism in the HTR3A gene. The A1596G polymorphism in the same gene was also investigated. RESULTS: A significant association between C178T genotype and the Temperament and Character Inventory factor harm avoidance was observed in sample 1 (corrected for multiple comparisons P =.04); this finding was subsequently replicated in sample 2 (P =.004) (pooled populations: P<.001). In the pooled sample, all harm avoidance subscales were found to be significantly associated with the C178T polymorphism: anticipatory worry (P =.001), fear of uncertainty (P<.001), shyness (P<.001), and fatigability and asthenia (P =.008). In addition, a significant association was found in sample 1 between the C178T polymorphism and the Karolinska Scales of Personality nonconformity factor (corrected P =.002), including the subscales of social desirability (P<.001), indirect aggression (P =.002), verbal aggression (P =.05), and irritability (P<.001). Participants homozygous for the less common T allele (<4%) differed from the remaining women by displaying lower ratings on harm avoidance and nonconformity. CONCLUSION: The C178T polymorphism in the HTR3A gene may affect the personality trait of harm avoidance in women.