Sugar or salt? The relative roles of the glucocorticoid and mineralocorticoid axes in traumatic shock.

BACKGROUND: Glucocorticoid deficiency (GD) has been proposed as a key contributor to shock states, but the presence and role of acute mineralocorticoid deficiency may be of equal or greater significance. We sought to analyze the incidence and degree of acute mineralocorticoid deficiency and GD in an animal model of severe hemorrhage and shock. METHODS: Fifty-seven swine underwent 35% volume-controlled hemorrhage followed by aortic cross-clamping for 50 minutes to induce truncal ischemia-reperfusion. Protocol-guided resuscitation was performed. Laboratory analysis included cortisol, aldosterone, and plasma renin activity. The aldosterone-to-renin ratio (ARR) was calculated at each time point, and changes were correlated to markers of perfusion. RESULTS: Mean baseline cortisol levels were 5.8 µg/dL. Following hemorrhage, there was a significant increase in mean cortisol to 9.2 µg/dL (p < 0.001). After 1 hour of reperfusion, there was no change in mean cortisol levels (9.8 µg/dL, p = 0.12). Mean baseline aldosterone was 13.3 pg/mL. Aldosterone levels before cross-clamp removal increased significantly to 115.1 pg/mL (p < 0.001) and then rapidly declined to 49.2 pg/mL (p < 0.001) after 1 hour of reperfusion. Conversely, baseline plasma renin activity was 0.75 ng/mL per hour and increased significantly before cross-clamp removal (1.8) and at 1 hour (8.9, both p < 0.001). The ARR at baseline was 96.1 and increased to 113.5 (p = 0.68) before cross-clamp removal but significantly declined following 1 hour of reperfusion to 7.6 (p < 0.001). Overall, this represented a 93% reduction in mean ARR following reperfusion. The degree of aldosterone deficiency correlated with degree of systemic shock as measured by arterial base deficit (r = 0.47, p = 0.04), while cortisol showed no correlation. CONCLUSION: Hemorrhagic shock with ischemia-reperfusion injury resulted in only modest impact on the glucocorticoid axis, but major dysfunction of the mineralocorticoid axis and severe hyperreninemic hypoaldosteronism. The degree of aldosterone deficiency may provide prognostic information or offer potential targets for pharmacologic intervention. LEVEL OF EVIDENCE: Diagnostic study, level III.

Adrenal disorders in human immunodeficiency virus (HIV) infected patients.

Human Immunodeficiency Virus (HIV) infection is associated with adrenal disorders, which must not be underestimated. Adrenal morphologic changes are primarily related to opportunistic infections, mostly by cytomegalovirus and mycobacteria, and malignant tumours such as non-Hodgkin's lymphoma and Kaposi's sarcoma. The most frequent biological alteration reported to date is the increases in cortisol concentrations which results from a decrease in cortisol metabolism and hyperactivity of the hypothalamo-pituitary-adrenal axis commonly referred to as pseudo-Cushing's syndrome. These modifications can be a consequence of antiretroviral therapy and do not require any investigation or specific treatment. Conversely, adrenal insufficiency, either iatrogenic or secondary to glandular infiltration by neoplasms or infections, needs long-term substitution with hydrocortisone, but at present occurs more rarely and usually at late stages of disease progression. The impact of HIV infection on the other adrenocortical functions has been less reported in the literature although several studies show low levels of adrenal androgens, especially dehydroepiandrostenedione (DHEA). Impairment in mineralocorticoid function appears occasional and remains a subject of debate.

Insuficiência adrenal aguda / Acute adrenal insufficiency

A insuficiência adrenal (IA) consiste em síndrome clínica rara, decorrente da deficiência de glicocorticoides e/ou mineralocorticoides, podendo ser primária. A insuficiência adrenal aguda consiste em emergência endócrina rara, resultante da diminuição súbita do cortisol circulante, ou de aumento significativo da demanda por esse hormônio em pacientes com algum grau de disfunção adrenal, ocorrendo mais frequentemente no contexto da IA primária. O prognóstico da doença depende do reconhecimento e intervenção terapêutica precoces

Adrenal insuficiency (AI) consists of a rare clinical syndrome resulting from glucocorticoids and/or mineralocorticoids deficiency. Adrenal insufficiency may be primary. The acute AI is a rare endocrine emergency resulting from sudden decrease of circulating cortisol or, elevated demand for this hormone in patients with some degree of adrenal disfunction, occuring more frequently in primary AI. The prognosis depends on early recognition and precocious therapeutic intervention

Mineralocorticoid deficiency in post-operative cerebral salt wasting.

Acute hyponatremia, following neurosurgery, results from inappropriate antidiuretic hormone secretion (SIADH) or cerebral salt wasting (CSW). CSW is due to abnormally high atrial or brain natriuretic peptides (ANP, BNP), which block all stimulators of zona glomerulosa steroidogenesis, resulting in mineralocorticoid deficiency. A 3 year-old girl presented CSW at day 4, after resection of craniopharyngioma and hypophysectomy. Hyponatremia, hyperkalemia and high natriuresis occurred on day 8, with low renin and aldosterone and elevated BNP 120.3 ng/ml (undetectable before surgery). Fludrocortisone 100 microg/day controlled natriuresis and restored electrolytes within 24 hours. A 5 year-old boy presented CSW at day 6 after partial resection of optic glioma. Fludocortisone 100 microg/day restored electrolytes within 8 hours. ANP was elevated, 60.6 ng/l, aldosterone and renin were low. Fludrocortisone supplementation should be considered in CSW, as excessive natriuresis is controlled, and electrolytes are easily restored, avoiding life-threatening complications of this complex disorder.

Functioning adrenal adenoma in association with congenital adrenal hyperplasia.

We report a case of a young hypertensive male who was first seen in 1998 with a right thalamic haemorrhage and uncontrolled hypertension. CT abdomen showed a right adrenal tumour and a hyperplastic left adrenal gland. Laparoscopic adrenalectomy performed followed by histopathological examination confirmed the diagnosis of adrenal adenoma. He subsequently presented to us again a year later with persistent hyperkalaemia and asymptomatic hyponatraemia. Further investigations strongly suggested the presence of isolated mineralocorticoid deficiency with normal cortisol levels. This was confirmed to be due to partial or late-onset congenital adrenal hyperplasia (CAH). We discuss the association of partial CAH and adrenal tumours and the unmasking of the mineralocorticoid deficiency following adrenalectomy.

Effect of mineralocorticoid deficiency on ion and urea transporters and aquaporin water channels in the rat.

Mineralocorticoid deficiency is associated with impaired urinary concentration and dilution. The present investigation was undertaken to determine the effects of selective mineralocorticoid deficiency on renal sodium and urea transporters and aquaporin water channels and whether these perturbations can be reversed by maintenance of extracellular fluid volume. Mineralocorticoid deficiency was induced by bilateral adrenalectomies with glucocorticoid replacement. Mineralocorticoid deficient rats receiving plain drinking water (MDW) were compared with mineralocorticoid deficient rats receiving saline-drinking water (MDS) in order to maintain extracellular fluid volume, and with controls (CTL). In MDW rats, there was a significant decrease in renal outer medulla Na-K-2Cl co-transporter and outer medulla Na-K-ATPase as well as an increase in inner medulla aquaporins 2 and 3. There were no significant changes in aquaporin-1, aquaporin-4, or urea transporters. These alterations were reversed with maintenance of extracellular fluid volume in MDS rats. Our findings indicate that mineralocorticoid deficiency in the rat is associated with alterations in factors involved in the countercurrent concentrating mechanism (Na-K-2Cl, Na-K-ATPase) and osmotic water equilibration in the collecting duct (AQP2, AQP3). Maintenance of sodium balance and extracellular fluid volume is associated with normalization of these perturbations.

Focal segmental glomerular sclerosis in two patients with Addison's disease: any more than fortuitous development of glomerular disease?

Adjustment of the mineralocorticoid activity under substitution therapy is of primary importance in Addison's disease. We report the clinical and biological conditions of 2 patients with Addison's disease who developed nephrotic proteinuria during their deficient mineralocorticoid state. Renal biopsy was performed and the specimens processed using conventional histochemistry, Congo red staining, and indirect immunofluorescence. The renal biopsy specimens showed focal segmental glomerular sclerosis and nodular deposits of IgM and C3. Negative for Congo red staining. Serum complement, circulating immune complexes, and anti-DNA and hepatitis B and C and human immunodeficiency virus antibodies were all normal or negative. Absence of vesicoureteral reflux was assessed by X-ray studies. Our observations suggest that deficiency in mineralocorticoid substitution therapy inducing a status of hyperreninemia could play a role in the development of focal segmental glomerulosclerosis in patients with Addison's disease.