Sex steroids, psychosocial factors, and lipid metabolism

Hostility-related differences in the associations between stress-induced physiological reactivity and lipid concentrations in young healthy women

We examined the relations of fasting lipid levels to stress-induced neuroendocrine and cardiovascular responses as a function of hostility in 36 healthy young women. Participants were women who scored above 17 (n = 23) or below 12 (n = 13) on the Cook-Medley Hostility (Ho) Inventory. Lipids were determined following an overnight fast. Individuals participated in a solvable anagram task, which evoked significant physiological responses in all participants. The Ho group by total serum cholesterol (TSC) and the Ho group by low-density lipoprotein (LDL) cholesterol interactions significantly predicted heart rate (HR) and norepinephrine (Ne) responses. For high Ho women, elevations in TSC and LDL cholesterol were associated with smaller HR responses and larger Ne responses. In contrast, for low Ho women, elevations in TSC and LDL cholesterol were associated with larger HR responses and smaller Ne responses. Results also indicated a significant Ho group by TSC to high density lipoprotein (HDL) cholesterol ratio interaction for cortisol. For high Ho women, larger cortisol responses were associated with a greater TSC to HDL cholesterol ratio. For low Ho women, larger cortisol responses were associated with a smaller TSC to HDL cholesterol ratio. Lastly, higher TSC and LDL cholesterol levels were significantly associated with larger epinephrine responses. The findings suggest that stress-induced physiological responses are differentially associated with fasting lipids as a function of hostility in healthy young women.

Stress reduction and preventing hypertension: preliminary support for a psychoneuroendocrine mechanism

Our objective was to identify endocrine-related mechanisms capable of mediating preventive effects of stress reduction in hypertensive heart disease. Since beneficial effects of stress reduction accrue over time, this cross-sectional, descriptive study sought differences between healthy students not practicing a systematic technique for reducing stress (the average stress, or AS, group, n = 33) and a similar group who for 8.5 years had practiced the Transcendental Meditation (TM) technique, used widely to reduce stress (the low stress, or LS, group, n = 22). The two groups of students, matched for age and area of study, performed timed collections of urine that included (separately) the entire waking and sleeping portions of 1 day. They also completed the Profile of Mood States and the State-Trait Anxiety Inventory, self-report instruments sensitive to subjective level of stress. Urine samples were analyzed for adrenocortical steroids by radioimmunoassay, for Na+, K+, Mg2+, Ca2+, and Zn2+ by atomic absorption spectrometry, and for neurotransmitter metabolites by reverse-phase, high-performance, liquid chromatography, and spectrophotometry. The two groups differed significantly on most measures. Specifically, the LS group was lower in cortisol and aldosterone and higher in dehydroepiandrosterone sulfate (DS) and the serotonin metabolite, 5-hydroxyindoleacetic acid (5-HIAA). Excretion of sodium, calcium, zinc, and the norepinephrine metabolite, vanillylmandelic acid (VMA), was also lower in this group, as were Na+/K+ ratio, mood disturbance, and anxiety. In women practicing TM, cortisol correlated inversely and DS directly with number of months of TM practice. The results identify improvements in mood state, adrenocortical activity, and kidney function as probable factors in the preventive and treatment effects of stress reduction. Because suboptimal levels of these parameters result from chronic, subjective stress, the findings add mechanistic support to the contention that hypertensive heart disease is avoidable, even in modern industrialized societies.

Premature ageing: the link between psychosocial risk factors and disease

In epidemiological studies from different countries, morbidity and mortality have been found to be increased in populations exposed to adverse psychosocial factors, e.g. low social class or poor social networks. Biological mechanisms must be operative to mediate this influence of social factors on clinical outcome. As increasing age is the common denominator for different categories of chronic disease, the ageing process itself in individuals may be studied in connection with data on exposure to negative psychosocial and lifestyle factors. A hypothesis is stated that premature ageing is the result of social pathology working on human physiology if buffering, health-preserving (salutogenic) mechanisms are not sufficient to counteract this effect. One measurable variable of the ageing process may be melatonin, known to decrease with age and to be lower in patients with coronary heart disease than in normal individuals.

Adverse effects of psychosocial stress on gonadal function and insulin levels in middle-aged males

OBJECTIVES

To investigate the relationship between gonadal function, insulin and psychosocial stress in middle-aged men.

DESIGN

A population-based, cross-sectional, observational study.

SETTING

Glostrup Hospital, Copenhagen, Denmark.

SUBJECTS

Four hundred and thirty-nine males, all aged 51 years.

MAIN VARIABLES

Body-mass index (BMI), waist-to-hip ratio (WHR), insulin, C-peptide, free testosterone, luteinizing hormone (LH), lipids, fibrinogen, lung function tests (FVC, FEV1, PEF), blood pressure, a self-administered questionnaire with questions on psychosocial variables, lifestyle and self-rated health.

RESULTS

Free testosterone correlated inversely (P < 0.05) with weight, BMI, WHR, and fibrinogen, and positively with FEV1. An independent correlation between free testosterone and insulin (P < or = 0.03), but not with C-peptide, was seen after controlling for BMI and WHR. Subjects with low levels of free testosterone, or those in the lowest quintile of the distribution of the hypogonadal index (HI: free testosterone/LH), showed a cluster of negative psychosocial variables, and psychological as well as health-related problems. Furthermore, hypogonadal men had lower (P < 0.05) levels of FEV1, peak flow and FVC, but higher (P < 0.01) levels of fibrinogen and higher pulse pressure than men with normal gonadal function. This gradient of variables, relative to HI, was not seen for possible confounders like BMI, WHR, and tobacco or alcohol consumption.

CONCLUSION

Psychosocial stress may be associated with a process of premature ageing in middle-aged males, corresponding to a hypogonadal state as well as to indirect signs of increased insulin resistance.

Aortic distensibility in post-menopausal women receiving Tibolone

Both oestrogen and androgens have been shown to affect the structural composition and biophysical properties of the arterial wall in vitro. A non-invasive Doppler ultrasound technique, based on the measurement of pulse wave velocity along the thoraco-abdominal aortic pathway, was used to assess aortic compliance C in vivo in 49 normotensive, normal, healthy post-menopausal female subjects. 23 of the women had been receiving Tibolone, a synthetic steroid structurally related to norethisterone, for at least 3 years. Since C varies with non-chronic changes in blood pressure, an index of intrinsic aortic distensibility, Cp, normally independent of blood pressure, was also calculated. No significant difference was found between the control group and those subjects receiving Tibolone for age, body mass index, systolic blood pressure, diastolic blood pressure, C or Cp. As one would expect the control group Cp values did not show a significant relationship with blood pressure (r = -0.1, not significant). However, in the Tibolone group some dependence of Cp values on pressure still remained (r = -0.58, p < 0.004), suggesting that oral administration of Tibolone had altered the dynamic relationship between structural and functional biophysical properties of the aortic wall in vivo.