High binding site occupancy of corticosteroid-binding globulin by progesterone increases fetal free cortisol concentrations.

OBJECTIVE: Corticosteroid-binding globulin (CBG) binds and transports cortisol in the circulation in high cortisol-binding affinity (haCBG) and low affinity (laCBG) forms, the latter resulting from enzyme cleavage to target cortisol delivery at sites of inflammation. CBG also has substantial progesterone binding affinity, 3-fold less than cortisol. Progesterone and cortisol are important in the maintenance of pregnancy and in fetal development, respectively. The interactions of cortisol, progesterone and CBG affinity forms have not been studied together. We examined the interaction between progesterone and cortisol with CBG during fetal development. STUDY DESIGN: A retrospective cohort analysis of 351 neonates born between January and December 2012 at the Women's and Children's Hospital, Adelaide, South Australia. Cord blood serum samples were collected immediately following delivery. Clinical data was provided by hospital records. Total cortisol, free cortisol, total progesterone, total CBG and haCBG were measured by immunoassay. RESULTS: Cord blood total and free cortisol, and progesterone concentrations increased with gestational age. Cord blood progesterone concentrations were 100-fold luteal and 10-fold those in late pregnancy maternal circulation. The proportion of haCBG to total CBG was similar to that in healthy non-pregnant adults. However, free cortisol comprised approximately 15% of total cortisol, 3-fold higher than that in adults. CONCLUSION: In a manner unique to fetal life, very high progesterone concentrations are capable of elevating free cortisol concentrations through competition with cortisol at CBG's hormone binding site, without altered binding affinity through CBG cleavage or altered CBG hormone-binding affinity. High circulating fetal progesterone concentrations compete for CBG binding with cortisol, leading to a 3-fold increase in the free cortisol fraction in cord blood. Higher free-to-bound cortisol may alter fetal cortisol distribution facilitating cortisol's roles such as neurodevelopment in concert with dehydroepiandrosterone (sulfate) and lung maturation, or support cortisol action at times of low ambient cortisol. This mechanism may underlie the known association between cortisol, progesterone and CBG, and be relevant principally in the fetal circulation due to the high progesterone concentrations encountered.

Low-dose hydrocortisone replacement improves wellbeing and pain tolerance in chronic pain patients with opioid-induced hypocortisolemic responses. A pilot randomized, placebo-controlled trial.

UNLABELLED: Long-term opioid therapy has been associated with low cortisol levels due to central suppression of the hypothalamic-pituitary-adrenal axis. The implications of hypocortisolism on wellbeing have not been established. Our aim was to determine whether intervention with physiologic glucocorticoid replacement therapy improves wellbeing and analgesic responses in patients with chronic non-cancer pain on long-term opioid therapy with mild cortisol deficiency. We performed a pilot randomized, double-blind, placebo-controlled crossover study of oral hydrocortisone replacement therapy in 17 patients recruited from a Pain Clinic at a single tertiary center in Adelaide, Australia. Patients were receiving long-term opioid therapy (≥ 20 mg morphine equivalents per day for ≥ 4 weeks) for chronic non-cancer pain with mild hypocortisolism, as defined by a plasma cortisol response ≤ 350 nmol/L at 60 min following a cold pressor test. The crossover intervention included 28-day treatment with either 10mg/m(2)/day of oral hydrocortisone in three divided doses or placebo. Improvement in wellbeing was assessed using Version 2 of the Short Form-36 (SF-36v2), Brief Pain Inventory-Short Form, and Addison's disease quality of life questionnaires; improvement in analgesic response was assessed using cold pressor threshold and tolerance times. Following treatment with hydrocortisone, the bodily pain (P=0.042) and vitality (P=0.013) subscales of the SF-36v2 were significantly better than scores following treatment with placebo. There was also an improvement in pain interference on general activity (P=0.035), mood (P=0.03) and work (P=0.04) following hydrocortisone compared with placebo. This is the first randomized, double-blind placebo-controlled trial of glucocorticoid replacement in opioid users with chronic non-cancer pain and mild hypocortisolism. Our data suggest that physiologic hydrocortisone replacement produces improvements in vitality and pain experiences in this cohort compared with placebo. TRIAL REGISTRATION: Therapeutic Goods Administration Clinical Trials Notification Scheme (Drugs), Trial Number 2012/0476.

Psychosis and cardiovascular disease: is diet the missing link?

OBJECTIVE: To explore the diets of people living with psychotic disorders, and to compare their dietary composition to the general population. METHOD: 184 people with psychotic disorders in Adelaide, South Australia completed a food frequency questionnaire. Physical information and mental health status were collected. Outcome measures included energy and macronutrient intake; fish, sodium, fruit and vegetable intake; micro-nutrient intake; body mass index; waist circumference; and diagnoses of diabetes and hypertension. The RDI of nutrients was derived from Australian Government publications. Comparison dietary data was obtained from surveys carried out by the Australian Bureau of Statistics. RESULTS: The majority of participants were overweight or obese (78%) and 77.5% met the criteria for at-risk waist circumference; and 58% of participants consumed salt and saturated fat in excess of the RDI. Most did not achieve the RDI for fruits and vegetables (97.8%), fibre (88.6%), fish (61.4%), magnesium (73.4%) or folate (86.4%). Women with psychosis had significantly higher intakes of vitamins and minerals compared to women in the general population. Men and women with psychosis consumed more daily total fat, saturated fat and sodium compared to adults in the Australian population, but lower fibre and vitamin E than their male and female counterparts. CONCLUSION: People with psychosis, especially women, report poor dietary choices including increased energy and fat intake, heightening their risk for cardiovascular disease. Women with psychosis report higher intake of vitamins and minerals than women in the general population. Whilst dietary intake contributes to obesity in psychosis, other factors including antipsychotic agents, decreased physical activity and smoking add to the cardiovascular risk.