Recent studies have shown that reduced fetal growth is associated with the development of the insulin resistance syndrome in adult life. The mechanisms are not known. However increased activity of the hypothalamic-pituitary-adrenal axis (HPAA) may underlie this association; the axis is known to be reset by fetal growth retardation in animals, and there is evidence in humans of an association between raised HPAA activity and the insulin resistance syndrome. We have, therefore, examined the relations among size at birth, plasma cortisol concentrations, and components of the insulin resistance syndrome in a sample of healthy men. We measured 0900 h fasting plasma cortisol and corticosteroid-binding globulin levels in 370 men who were born in Hertfordshire, UK, between 1920-1930 and whose birth weights were recorded. Fasting plasma cortisol concentrations varied from 112-702 nmol/L and were related to systolic blood pressure (P = 0.02), fasting and 2-h plasma glucose concentrations after an oral glucose tolerance test (P = 0.0002 and P = 0.04), plasma triglyceride levels (P = 0.009), and insulin resistance (P = 0.006). Plasma cortisol concentrations fell progressively (P = 0.007) from 408 nmol/L in men whose birth weights were 5.5 lb (2.50 kg) or less to 309 nmol/L among those who weighed 9.5 lb (4.31 kg) or more at birth, a trend independent of age and body mass index. These findings suggest that plasma concentrations of cortisol within the normal range could have an important effect on blood pressure and glucose tolerance. Moreover, this study provides the first evidence that intrauterine programming of the HPAA may be a mechanism underlying the association between low birth weight and the insulin resistance syndrome in adult life.

Elevated plasma cortisol concentrations: a link between low birth weight and the insulin resistance syndrome?

Low birth weight is linked with raised blood pressure in adult life. Recent evidence has suggested that a neuroendocrine disturbance involving the hypothalamic-pituitary-adrenal axis could mediate this link. We therefore investigated the relation between birth weight and fasting plasma cortisol concentrations and the association of cortisol with current blood pressure in population samples of 165 men and women born in Adelaide, South Australia, from 1975 to 1976, 199 men and women born in Preston, UK, from 1935 to 1943, and 306 women born in East Hertfordshire, UK, from 1923 to 1930. Fasting plasma cortisol was measured in plasma samples obtained between 8 and 10 AM. Blood pressure was measured with an automated sphygmomanometer. Low birth weight was associated with raised fasting plasma cortisol concentrations in all 3 populations. A combined analysis that allowed for differences in the gender composition, age, and body mass index between the studies showed that cortisol concentrations fell by 23.9 nmol/L per kilogram increase in birth weight (95% CI 9.6 to 38.2, P<0.001). Fasting plasma cortisol concentrations also correlated positively with the subjects' current blood pressure. However, the association between cortisol and blood pressure was most marked in subjects who were obese (P=0.038 for interaction between body mass index and cortisol, P=0.01 for interaction between waist-to-hip ratio and cortisol). These results show that low birth weight is associated with raised fasting plasma cortisol concentrations. Increased activity of the hypothalamic-pituitary-adrenal axis may link low birth weight with raised blood pressure in adult life.

Low Birth Weight Predicts Elevated Plasma Cortisol Concentrations in Adults From 3 Populations

It has been suggested that increased activity of the hypothalamic-pituitary-adrenal axis may link low birth weight with subsequent development of cardiovascular risk factors and disease. Two hundred and five men, aged 66-77 yr, who were born and still live in East Hertfordshire underwent an overnight very low dose (0.25 mg) dexamethasone suppression test followed by a low dose 1-microgram ACTH-(1-24) stimulation test. A 24-h urine sample was collected for analysis of cortisol metabolites by gas chromatography/electron impact mass spectrometry. Men with lower birth weight had enhanced responses of plasma cortisol to ACTH-(1-24) (P = 0.03), increased total urinary cortisol metabolite excretion (after adjustment for confounding effects of increased obesity and lean body mass in high birth weight men; P = 0.04), but no difference in plasma cortisol after dexamethasone. Features of the metabolic syndrome were independently associated with enhanced adrenal responsiveness to ACTH-(1-24) (raised blood pressure, P = 0.02; glucose intolerance, P = 0.09; hypertriglyceridemia, P = 0.02), with trends to increased urinary cortisol metabolite excretion, but not with differences in plasma cortisol after dexamethasone. Men with low birth weight and/or the metabolic syndrome have increased activity of the hypothalamic-pituitary-adrenal axis. This may be an important mechanism underpinning the effects of events in early life on later cardiovascular disease.

Altered control of cortisol secretion in adult men with low birth weight and cardiovascular risk factors.

We compared the effects of single doses of etomidate and thiopentone on adrenocortical function in a randomised controlled clinical trial involving 35 critically ill patients who needed a general anaesthetic. Just before induction of anaesthesia, a baseline blood cortisol sample was taken. Twenty-four hours later we performed a short adrenocorticotrophic hormone stimulation test. No patient had a low cortisol level (< 160 nmol.l−1) at any time during the study. Baseline, pre-ACTH and post-ACTH cortisol levels were similar in the two groups. However, significantly more patients in the etomidate group had an ACTH-stimulated cortisol increment < 200 nmol.l−1. The clinical significance of these findings is not clear, but we conclude that single doses of etomidate may interfere with cortisol synthesis for at least 24 h in the critically ill.

Adrenocortical function in critically ill patients 24 h after a single dose of etomidate.

Irritable Bowel Syndrome Patients Show Enhanced Modulation of Visceral Perception by Auditory Stress

A MOORE\", R AITKEN\"\", C BURKEt, S GASKELL+. G GROOM+. G H 0 L DE R § , C S E L BY II and P WOO D ~ Fromthe\" Nuffield Department of Clinical Biochemistry, Radcliffe Infirmary, Oxford, \"\" Department of Biochemistry, General Hospital, Kettering, i Department of Endocrinology, Radcliffe Infirmary, Oxford, i Tenovus Institute for Cancer Research, Welsh National School ofMedicine, Cardiff, §Departmento!Clinical Endocrinology, Birmingham and Midland Hospitalfor Women, Birmingham, IIDepartmentofChemical Pathology, City Hospital, Nottingham, ~Departmentof ChemicalPathology, General Hospital, Southampton, UK

https://journals.sagepub.com/doi/pdf/10.1177/000456328502200501

C Burke

Papers

Cortisol assays: guidelines for the provision of a clinical biochemistry service.