Altered insulin requirement in patients with type 1 diabetes and primary adrenal insufficiency receiving standard glucocorticoid replacement therapy

Type 1 Diabetes Mellitus and Autoimmune Diseases: A Critical Review of the Association and the Application of Personalized Medicine

Type 1 Diabetes Mellitus (T1DM) is a common hyperglycemic disease characterized by the autoimmune destruction of insulin-producing beta cells of the pancreas. Various attempts have been made to understand the complex interplay of genetic and environmental factors which lead to the development of the autoimmune response in an individual. T1DM is frequently associated with other autoimmune illnesses, the most common being autoimmune thyroid disorders affecting more than 90% of people with T1D and autoimmune disorders. Antithyroid antibodies are present in around 20% of children with T1D at the start of the illness and are more frequent in girls. Patients with T1DM often have various other co-existing multi-system autoimmune disorders including but not limited to thyroid diseases, parathyroid diseases, celiac disease, vitiligo, gastritis, skin diseases, and rheumatic diseases. It is a consistent observation in clinics that T1DM patients have other autoimmune disorders which in turn affect their prognosis. Concomitant autoimmune illness might affect diabetes care and manifest itself clinically in a variety of ways. A thorough understanding of the complex pathogenesis of this modern-day epidemic and its association with other autoimmune disorders has been attempted in this review in order to delineate the measures to prevent the development of these conditions and limit the morbidity of the afflicted individuals as well. The measures including antibody screening in susceptible individuals, early identification and management of other autoimmune disorders, and adoption of personalized medicine can significantly enhance the quality of life of these patients. Personalized medicine has recently gained favor in the scientific, medical, and public domains, and is frequently heralded as the future paradigm of healthcare delivery. With the evolution of the ‘omics’, the individualization of therapy is not only closer to reality but also the need of the hour.

Characteristics of Patients with Type 1 Diabetes and Additional Autoimmune Disease in the DPV Registry

CONTEXT

Autoimmune diseases affect ~8% of the population. Type 1 diabetes mellitus (T1DM) is linked to other autoimmune diseases (AIDs), such as autoimmune thyroid disease or Addison's disease (AD), that may impact diabetes therapy and outcome.

OBJECTIVE

To analyze demographic and clinical characteristics of other AIDs in T1DM from a large standardized registry, the Prospective Diabetes Follow-up Registry (DPV).

METHODS

We searched the registry for T1DM with the additional diagnosis of Hashimoto's thyroiditis (HT), Graves' disease (GD), and/or AD. T1DM with other AIDs (n = 6166, 5.4%) were compared with isolated T1DM (n = 107 457). For group comparisons, we used multivariable regression models with age, sex, diabetes duration, migration background, and type of insulin regimen as basic adjustments (microvascular endpoints: additionally adjusted for glycated hemoglobin).

RESULTS

Patients with additional AIDs were more often female (54.7 vs 32.0%, P < .001) and had a longer diabetes duration (7.9 [4.2-12.5] vs 6.7 [2.7-12.9] years, P < .001). After adjustment, daily insulin dosage was higher in AD and HT than in isolated T1DM (0.858 ± 0.032 and 0.813 ± 0.005 vs 0.793 ± 0.001 IU/kg per day). Retinopathy was less common in HT (1.5%), whereas it was more frequent in GD (3.1%) than in isolated T1DM (1.8%). In both GD and HT, microalbuminuria occurred less often (10.6% and 14.3% vs 15.5%) and neuropathy (2.1% and 1.8% vs 0.8%) was more common than in isolated T1DM. All P < .05.

CONCLUSION

T1DM with additional AIDs show heterogeneous differences compared with isolated T1DM. T1DM plus AD or HT requires more insulin. Further, the rate of neuropathy is higher in HT or GD, whereas the rate of microalbuminuria is lower.

Adrenal insufficiency

Adrenal insufficiency (AI) is a condition characterized by an absolute or relative deficiency of adrenal cortisol production. Primary AI (PAI) is rare and is caused by direct adrenal failure. Secondary AI (SAI) is more frequent and is caused by diseases affecting the pituitary, whereas in tertiary AI (TAI), the hypothalamus is affected. The most prevalent form is TAI owing to exogenous glucocorticoid use. Symptoms of AI are non-specific, often overlooked or misdiagnosed, and are related to the lack of cortisol, adrenal androgen precursors and aldosterone (especially in PAI). Diagnosis is based on measurement of the adrenal corticosteroid hormones, their regulatory peptide hormones and stimulation tests. The goal of therapy is to establish a hormone replacement regimen that closely mimics the physiological diurnal cortisol secretion pattern, tailored to the patient's daily needs. This Primer provides insights into the epidemiology, mechanisms and management of AI during pregnancy as well as challenges of long-term management. In addition, the importance of identifying life-threatening adrenal emergencies (acute AI and adrenal crisis) is highlighted and strategies for prevention, which include patient education, glucocorticoid emergency cards and injection kits, are described.

Acute illness in patients with concomitant Addison's disease and type 1 diabetes mellitus: Increased incidence of hypoglycaemia and adrenal crises

BACKGROUND

Patients with Addison's disease (AD) and comorbid type 1 diabetes mellitus (T1DM) are at increased risk of certain acute metabolic disorders relative to patients with one of these conditions only. The reasons for this are unknown.

METHODS

All attendances for acute illness by AD patients at the emergency department of a Sydney hospital between 2000 and 2017 were reviewed. Physiological parameters and illness management strategies were compared between AD patients, those with T1DM and AD combined, and a control group of patients with T1DM.

RESULTS

There were 39 presentations for an acute medical illness by 20 nondiabetic AD (28 attendances) and 5 diabetic AD patients (11 presentations) and 40 attendances by 10 T1DM controls. In AD patients, 17 (43.6%) attendances were medically diagnosed adrenal crises (AC) (63.6% [n = 7] in diabetic AD and 35.7% [n = 10] in nondiabetic AD). This corresponded to an estimated incidence of 12.5 AC/100 patient-years (PY) for diabetic AD patients compared to 4.7 AC/100PY for nondiabetic AD patients (P < .05). Glucocorticoid stress doses preceded 61.5% (n = 24) of all attendances. Patients who used stress doses had more presentations than those who did not (2.0 ± 1.3 vs 1.2 ± 0.5, P = .01). Diabetic AD patients had a lower mean blood glucose level on presentation (5.6 ± 3.9 mmol/L) than the T1DM control sample (11.6 ± 6.2 mmol/L) P < .001. No T1DM patients had hypoglycaemia in the 3.0-3.9 mmol/L range but 2 (18.2%) of the diabetic AD patients had presenting blood glucose levels in this category (P < .05). Hyperglycaemia was more common among T1DM control patients (62.5%, n = 26) than diabetic AD patients (18.2%, n = 2), P < .01.

CONCLUSION

Addison's disease patients with T1DM have a higher incidence of adrenal crisis (AC) and hypoglycaemia than nondiabetic AD patients and a lower incidence of hyperglycaemia than those with T1DM alone. This information may be of value in counselling patients with T1DM and AD about AC and hypoglycaemia prevention.

Autoimmune Addison's disease

Primary adrenal insufficiency (PAI) occurs in 1/5000-1/7000 individuals in the general population. Autoimmune Addison's disease (AAD) is the major cause of PAI and is a major component of autoimmune polyendocrine syndrome type 1 (APS1) and type 2 (APS2). Presence of 21-hydroxylase autoantibodies (21OHAb) identifies subjects with ongoing clinical or pre-clinical adrenal autoimmunity. AAD requires life-long substitutive therapy with two-three daily doses of hydrocortisone (HC) (15-25 mg/day) or one daily dose of dual-release HC and with fludrocortisone (0.5-2.0 mg/day). The lowest possible HC dose must be identified according to clinical and biochemical parameters to minimize long-term complications that include osteoporosis and cardiovascular and metabolic alterations. Women with AAD have lower fertility and parity as compared to age-matched healthy controls. Patients must be educated to double-triple HC dose in the case of fever or infections and to switch to parenteral HC in the case of vomiting, diarrhoea or acute hypotension.

Dual-release hydrocortisone vs conventional glucocorticoids in adrenal insufficiency

BACKGROUND

Dual-release hydrocortisone (DR-HC) improves metabolism in patients with adrenal insufficiency. The aims of this study were to compare the cardiovascular and metabolic effects of conventional glucocorticoids (GCs) vs. DR-HC and of high vs. low doses of GCs, after 48 months of observation.

METHODS

We selected 27 patients on hydrocortisone (mean dose 17.5 ± 4.2 mg/day) and 20 patients on cortisone acetate (mean dose 37.5 ± 12.1 mg/day) who maintained this treatment (group A) and 53 patients switched to DR-HC (mean dose 22 ± 4.8 mg/day) (group B). At baseline and after 48 months, clinical and metabolic parameters and Framingham Risk Score (FRS) were obtained.

RESULTS

After 48 months, patients in group A had a significant increase from baseline in BMI (P < 0.001), waist circumference (P = 0.001), systolic blood pressure (P = 0.001), LDL cholesterol (P = 0.018), HbA1c (P = 0.020) and FRS (P = 0.002). By contrast, patients in group B had a significant decrease in BMI (P = 0.002), waist circumference (P = 0.015), diastolic blood pressure (P = 0.031), total (P = 0.006) and LDL cholesterol (P = 0.005), HbA1c (P < 0.001) and FRS (P = 0.015) compared to baseline. No significant differences between high and low doses of both conventional GCs and DR-HC were observed.

CONCLUSIONS

DR-HC is associated with an improvement of metabolic parameters and cardiovascular risk compared to conventional GCs, which are associated with a worsening of these parameters, regardless of the dose used.

Early Clinical Indicators of Addison Disease in Adults With Type 1 Diabetes: A Nationwide, Observational, Cohort Study

CONTEXT

Patients with type 1 diabetes mellitus (T1DM) have an increased risk of Addison disease (AD) development, but prediction of those at risk is not possible.

OBJECTIVE

To determine whether there are early clinical indicators that may denote the development of AD in adults with T1DM.

DESIGN

Observational, matched-cohort study.

SETTING

Patient data from Swedish national registries [National Diabetes Register (NDR), Inpatient Register, and Prescription Drug Register].

PARTICIPANTS

All patients with T1DM diagnosed with concomitant AD (n = 66) among the 36,514 adult patients with T1DM in the NDR between 1998 and 2013. Each case was matched to five controls with T1DM alone (n = 330).

MAIN OUTCOME MEASURES

Clinical data and drug prescriptions were assessed prior to baseline (inclusion into the study) and prior to AD diagnosis. Analysis of covariance and estimated group proportions were used for comparisons.

RESULTS

Prior to baseline, cases had a higher frequency of thyroid/antithyroid drug prescription than controls (9.1% vs 1.8%). Prior to AD diagnosis, cases had higher frequencies of diabetic retinopathy (12.1% vs 2.1%), infections requiring hospital admission (16.7% vs 2.1%), thyroid/antithyroid drug prescription (28.8% vs 7.0%), and glucagon prescription (18.2% vs 6.4%). There was no difference in glycated Hb between the groups prior to baseline or prior to AD diagnosis.

CONCLUSIONS

These data suggest that medical treatment of thyroid disease, a severe infection, and glucagon prescription for severe hypoglycemia should raise the suspicion of AD development in adults with T1DM. Development of diabetic retinopathy might also be associated with glucocorticoid deficiency and the development of AD among patients with T1DM.

Improved insulin sensitivity and secretion in prediabetic patients with adrenal insufficiency on dual-release hydrocortisone treatment: a 36-month retrospective analysis

OBJECTIVE

Dual-release hydrocortisone (DR-HC) provides physiological cortisol exposure, leading to an improvement of anthropometric and metabolic parameters. The aim of the study was to evaluate the effects of DR-HC on insulin secretion and sensitivity and cardiometabolic risk, indirectly expressed by the visceral adiposity index (VAI).

DESIGN AND PATIENTS

Retrospective analysis of 49 patients, 13 with primary and 36 with secondary adrenal insufficiency (AI), respectively, on conventional glucocorticoid treatment at baseline and switched to DR-HC for 36 months. Overall, 24 patients had AI-pre-diabetes (impaired fasting glucose, impaired glucose tolerance and the combination), and 25 had AI-normal glucose tolerance (NGT).

MEASUREMENTS

Clinical and metabolic parameters, including VAI, insulin secretion and sensitivity indexes (fasting insulinaemia, AUC_{2 h insulinaemia} , oral disposition index [Dio] and ISI-Matsuda), were evaluated.

RESULTS

In patients with AI-NGT and AI-prediabetes, a significant decrease in BMI (P = .017 and P < .001), waist circumference (P = .008 and P < .001), HbA1c (P = .034 and P = .001) and a significant increase in HDL-C (P = .036 and P = .043) was, respectively, observed. In addition, in prediabetic patients, only we found a significant decrease in insulinaemia (P = .014), AUC_{2 h insulinaemia} (P = .038) and VAI (P = .001), in concomitance with a significant increase in DIo (P = .041) and ISI-Matsuda (P = .038).

CONCLUSIONS

Long-term DR-HC therapy is associated with an improvement in insulin secretion and sensitivity in patients with prediabetes. However, all patients appear to benefit from the treatment in terms of improvement of metabolic and anthropometric parameters. Larger studies are required to confirm our preliminary data.

MANAGEMENT OF ENDOCRINE DISEASE: Risk of overtreatment in patients with adrenal insufficiency: current and emerging aspects

The effects of long-term replacement therapy of adrenal insufficiency (AI) are still a matter of controversy. In fact, the established glucocorticoid replacement regimens do not completely reproduce the endogenous hormonal production and the monitoring of AI treatment may be a challenge for the lack of reliable clinical and biochemical markers. Consequently, several AI patients are frequently exposed to relative glucocorticoid excess potentially leading to develop chronic complications, such as diabetes mellitus, dyslipidemia, hypertension and fragility fractures with consequent impaired QoL and increased mortality risk. This review deals with the pathophysiological and clinical aspects concerning the over-replacement therapy of primary and secondary AI.

Mortality in patients with diabetes mellitus and Addison's disease: a nationwide, matched, observational cohort study

OBJECTIVE

Our hypothesis was that patients with diabetes mellitus obtain an additional risk of death if they develop Addison's disease (AD).

DESIGN AND METHODS

Nationwide, matched, observational cohort study cross-referencing the Swedish National Diabetes Register with Inpatient, Cancer and Cause of Death Registers in patients with diabetes (type 1 and 2) and AD and matched controls with diabetes. Clinical characteristics at baseline, overall, and cause-specific mortality were assessed. The relative risk of death was assessed using a Cox proportional hazards regression model.

RESULTS

Between January 1996 and December 2012, 226 patients with diabetes and AD were identified and matched with 1129 controls with diabetes. Median (interquartile range) follow-up was 5.9 (2.7-8.6) years. When patients with diabetes were diagnosed with AD, they had an increased frequency of diabetes complications, but both medical history of cancer and coronary heart disease did not differ compared with controls. Sixty-four of the 226 patients with diabetes and AD (28%) died, while 112 of the 1129 controls (10%) died. The estimated relative risk increase (hazard ratio) in overall mortality in the diabetes and AD group was 3.89 (95% confidence interval 2.84-5.32) compared with controls with diabetes. The most common cause of death was cardiovascular in both groups, but patients with diabetes and AD showed an increased death rate from diabetes complications, infectious diseases and unknown causes.

CONCLUSIONS

Patients with the rare combination of diabetes and AD showed a markedly increased mortality and died more frequently from infections and unknown causes than patients with diabetes alone. Improved strategy for the management of this combination of metabolic disorders is needed.

Positive autoantibodies to ZnT8 indicate elevated risk for additional autoimmune conditions in patients with Addison's disease

Autoimmune Addison's disease (AAD) associates with exceptional susceptibility to develop other autoimmune conditions, including type 1 diabetes (T1D), marked by positive serum autoantibodies to insulin (IAA), glutamic acid decarboxylase (GADA) and insulinoma-associated protein 2 (IA-2A). Zinc transporter 8 (ZnT8) is a new T1D autoantigen, encoded by the SLC30A8 gene. Its polymorphic variant rs13266634C/T seems associated with the occurrence of serum ZnT8 antibodies (ZnT8A). This study was designed to determine the prevalence of serum ZnT8A and their clinical implication in 140 AAD patients. Other beta cell and thyroid-specific autoantibodies were also investigated, and ZnT8A results were confronted with the rs13266634 genotype. ZnT8A were detectable in 8.5 %, GADA in 20.7 %, IA-2A in 5.7 %, IAA in 1.6 % and various anti-thyroid antibodies in 7.1-67.8 % individuals. Type 1 diabetes was found in 10 % AAD patients. ZnT8A were positive in 57.1 % of T1D patients and 3.4 % non-diabetic AAD. Analysis of ZnT8A enabled to identify autoimmunity in two (14.3 %) T1D individuals previously classified as autoantibody-negative. ZnT8A-positive patients revealed significantly higher number of autoimmune conditions (p < 0.001), increased prevalence of T1D (p < 0.001) and other beta cell-specific autoantibodies. Carriers of the rs13266634 T-allele displayed increased frequency (p = 0.006) and higher titres of ZnT8A (p = 0.002). Our study demonstrates high incidence of ZnT8A in AAD patients. ZnT8A are associated with coexisting T1D and predictive of T1D in non-diabetic subjects. Moreover, positive ZnT8A in AAD indicate elevated risk for additional autoimmune conditions. Autoantibodies to beta cell antigens, comprising ZnT8, could be included in routine screening panels in AAD.

Improvement of anthropometric and metabolic parameters, and quality of life following treatment with dual-release hydrocortisone in patients with Addison's disease

In patients with Addison's disease (AD), a dual-release preparation of hydrocortisone (Plenadren, PLEN) has been demonstrated to maintain cortisol levels in a more physiological range than conventional glucocorticoid therapy, and to exert positive effects. This study aimed to assess variations of anthropometric, metabolic, and hormonal parameters in patients with AD after switching from conventional hydrocortisone (HC) treatment to PLEN. In nineteen AD patients (15 F and 4 M, age 27-65 years) treated with HC 20 mg/day thrice daily, body weight, BMI, waist circumference, fasting glucose, HbA1c, serum lipids, plasma renin activity, electrolytes, and blood pressure were evaluated at baseline, and 1, 3, 6, and 12 months after switching from HC to PLEN. At baseline, and after 1 and 12 months of PLEN, blood ACTH and cortisol (at 0800 h at fasting, and 30, 60, 90, 120, and 240 min after drug ingestion), and health-related quality of life (HRQoL), using 30-AddiQoL questionnaire, were evaluated. During PLEN, waist and serum lipid progressively decreased. After 12 months of PLEN, a significant difference was observed in waist circumference (P = 0.007), HbA1c (P = 0.002), total and LDL-cholesterol levels (P < 0.05). ACTH levels at 240 min and the area under the curve (AUC) were lower (P < 0.05) during PLEN than HC, while cortisol peaks and AUC were similar. 30-AddiQoL total score also improved (P = 0.04) during PLEN. In AD patients, PLEN reduces central adiposity, and improves glucose and metabolism parameters and HRQoL.

Recurrent nocturnal hypoglycaemia as a cause of morning fatigue in treated Addison's disease--favourable response to dietary management: a case report

BACKGROUND

Addison's disease, or primary adrenal insufficiency, is often associated with reduced well-being and fatigue despite use of currently recommended adrenal hormone replacement. Hypoglycaemia is a known manifestation of glucocorticoid deficiency, but is generally considered rare in adults and not relevant to troubling ongoing symptoms in patients with Addison's disease.

CASE PRESENTATION

A 43 year old woman with a three year history of Addison's disease complained of severe morning fatigue and headaches, despite standard glucocorticoid replacement therapy in the form of thrice daily hydrocortisone and mineralocorticoid replacement with fludrocortisone. Alternative glucocorticoid replacement regimens and the addition of dehydroepiandrosterone replacement therapy had no effect. Nocturnal hypoglycaemia was suspected and a 4-day continuous glucose monitor system (CGMS) revealed hypoglycaemia (interstitial glucose < 2.2 mmol/L) between 0200-0400 h on 3 of 4 days. The patient was counselled to take an evening snack designed to ensure slow absorption of ingested carbohydrates. Nocturnal hypoglycaemia was then absent on follow up CGMS assessment. The patient noted a marked symptomatic improvement in morning symptoms, but with persistent fatigue during the day.

CONCLUSION

Currently, the best strategy for control of non-specific symptoms in treated Addison's disease is unknown, but it may be that investigation for hypoglycaemia and treatment, where necessary, could assist some sufferers to achieve improved wellbeing. A systematic study of this phenomenon in Addison's disease is required.

Circadian hormone profiles and insulin sensitivity in patients with Addison's disease: a comparison of continuous subcutaneous hydrocortisone infusion with conventional glucocorticoid replacement therapy

CONTEXT

Conventional glucocorticoid replacement therapy in patients with Addison's disease (AD) is unphysiological with possible adverse effects on mortality, morbidity and quality of life. The diurnal cortisol profile can likely be restored by continuous subcutaneous hydrocortisone infusion (CSHI).

OBJECTIVE

The aim of this study was to compare circadian hormone rhythms and insulin sensitivity in conventional thrice-daily regimen of glucocorticoid replacement therapy with CSHI treatment in patients with AD.

DESIGN AND SETTING

An open, randomized, two-period, 12-week crossover multicentre trial in Norway and Sweden.

PATIENTS

Ten Norwegian patients were admitted for 24-h sampling of hormone profiles. Fifteen Swedish patients underwent euglycaemic-hyperinsulinaemic clamp.

INTERVENTION

Thrice-daily regimen of oral hydrocortisone (OHC) and CSHI treatment.

MAIN OUTCOME MEASURE

We measured the circadian rhythm of cortisol, adrenocorticotropic hormone (ACTH), growth hormone (GH), insulin-like growth factor-1, (IGF-1), IGF-binding protein-3 (IGFBP-3), glucose, insulin and triglycerides during OHC and CSHI treatment. Euglycaemic-hyperinsulinaemic clamp was used to assess insulin sensitivity.

RESULTS

Continuous subcutaneous hydrocortisone infusion provided a more physiological circadian cortisol curve including a late-night cortisol surge. ACTH levels showed a near normal circadian variation for CSHI. CSHI prevented a continuous decrease in glucose during the night. No difference in insulin sensitivity was observed between the two treatment arms.

CONCLUSION

Continuous subcutaneous hydrocortisone infusion replacement re-established a circadian cortisol rhythm and normalized the ACTH levels. Patients with CSHI replacement had a more stable night-time glucose level compared with OHC without compromising insulin sensitivity. Thus, restoring night-time cortisol levels might be advantageous for patients with AD.

Adrenal insufficiency: review of clinical outcomes with current glucocorticoid replacement therapy

Glucocorticoid replacement therapy in patients with adrenal insufficiency (AI), whether primary (Addison's disease) or secondary (due to hypopituitarism), has been established for some 50 years. The current standard treatment regimen involves twice- or thrice-daily dosing with a glucocorticoid, most commonly oral hydrocortisone. Based on previous small-scale studies and clinical perception, life expectancy with conventional glucocorticoid replacement therapy has been considered normal, with a low incidence of adverse events. Data from the past 10-15 years, however, have shown that morbidity remains high and life expectancy is reduced. The increased morbidity and decreased life expectancy appear to be due to both increased exposure to cortisol and insufficient cortisol coverage during infections and other stress-related events. This is thought to reflect a failure of treatment to replicate the natural circadian rhythm of cortisol release, together with a failure to identify and deliver individualized cortisol exposure and to manage patients adequately when increased doses are required. The resulting over- or under-treatment may result in Cushing-like symptoms or adrenal crisis, respectively. This review summarizes the morbidity and mortality seen in patients receiving the current standard of care for AI and suggests areas for improvement in glucocorticoid replacement therapy.

Treatment and health outcomes in adults with congenital adrenal hyperplasia

Congenital adrenal hyperplasia (CAH) is a genetic disorder caused by defective steroidogenesis that results in glucocorticoid deficiency; the most common underlying mutation is in the gene that encodes 21-hydroxylase. Life-saving glucocorticoid treatment was introduced in the 1950s, and the number of adult patients is now growing; however, no consensus has been reached on the management of CAH beyond childhood. Adult patients are prescribed a variety of glucocorticoids, including hydrocortisone, prednisone, prednisolone, dexamethasone and combinations of these drugs taken in either a circadian or reverse circadian regimen. Despite these personalized treatments, biochemical control of CAH is only achieved in approximately one-third of patients. Some patients have a poor health status, with an increased incidence of obesity and osteoporosis, and impaired fertility and quality of life. The majority of poor health outcomes seem to relate to inadequate treatment rather than the genotype of the patient. Patients receiving high doses of glucocorticoids and the more potent synthetic long-acting glucocorticoids are at an increased risk of obesity, insulin resistance and a reduced quality of life. Further research is required to optimize the treatment of adult patients with CAH and improve health outcomes.

What is the best approach to tailoring hydrocortisone dose to meet patient needs in 2012?

Cortisol is an essential stress hormone and replacement with oral hydrocortisone is lifesaving in patients with adrenal insufficiency. Cortisol has a diurnal rhythm regulated by the central body clock and this rhythm is a metabolic signal for peripheral tissue clocks. Loss of cortisol rhythmicity is associated with fatigue, depression and insulin resistance. A general principle in endocrinology is to replace hormones to replicate physiological concentrations; however, the pharmacokinetics of oral immediate-release hydrocortisone make it impossible to fully mimic the cortisol rhythm and patients still have an increased morbidity and mortality despite replacement. Traditionally, physicians have replaced hydrocortisone with a total daily dose based on the diurnal 24-h cortisol production rate with hydrocortisone given twice or thrice daily, with the highest dose first thing in the morning. Monitoring treatment and dose titration has been much debated with some clinicians using cortisol day curves and others relying on clinical symptoms. The main challenge is that there is no established biomarker of cortisol activity. In addressing the clinical question, we have taken the view that an understanding of the cortisol circadian rhythm and hydrocortisone pharmacokinetics is essential when tailoring hydrocortisone dose. Using this approach, we have developed a thrice daily, weight-related, dosing regimen and a pharmacokinetic and clinical method to monitor treatment. Our argument for replicating the cortisol circadian rhythm is based on the observation that disruption of the rhythm is associated with ill health, and the few studies that have compared different treatment regimens. Further studies are required to definitively test the benefits of replacing the cortisol circadian rhythm in patients with adrenal insufficiency.

Glucocorticoid treatment regimen and health outcomes in adults with congenital adrenal hyperplasia

BACKGROUND

Adults with congenital adrenal hyperplasia (CAH) are treated with a wide variety of glucocorticoid treatment regimens.

OBJECTIVE, DESIGN AND METHODS

To test whether drug dose and timing of glucocorticoid treatment regimen impacts on health outcomes. This was a cross-sectional study of 196 adult CAH patients in whom treatment and health outcomes were measured. Glucocorticoid dose was converted to prednisolone dose equivalent (PreDEq) using three published formulae. Associations between the type of glucocorticoid regimen and PreDEq with specific health outcome variables were tested using partial correlation and principal components analysis (PCA).

RESULTS

Patients on dexamethasone had lower androgens and ACTH but greater insulin resistance compared with those receiving hydrocortisone or prednisolone. Dexamethasone dose and once daily administration were associated with insulin resistance. Partial correlation analysis adjusted for age and sex showed PreDEq weakly correlated (r < 0·2) with blood pressure and androstenedione. Mutation severity was associated with increased PreDEq (F(3,141)  = 4·4, P < 0·01). In PCA, 3 PCs were identified that explained 62% of the total variance (r(2) ) in observed variables. Regression analysis (age and sex adjusted) confirmed that PC2, reflecting disease control (androstenedione, 17-hydroxypregesterone and testosterone), and PC3, reflecting blood pressure and mutations (systolic and diastolic blood pressure and mutation severity), related directly to PreDEq (r(2)  = 23%, P < 0·001).

CONCLUSIONS

In adults with congenital adrenal hyperplasia, dexamethasone use was associated with lower androgens but greater insulin resistance, and increasing glucocorticoid dose associated with increased blood pressure, poor disease control and mutation severity.

Addisonian crisis in a young man with atypical anorexia nervosa

BACKGROUND

A 22-year-old man was admitted to an intensive care unit with severe hyponatremia, hypotension and somnolence. He had a 9-month history of weight loss and vomiting that had led to a previous diagnosis of atypical anorexia, and he had been transferred from a psychiatric clinic.

INVESTIGATIONS

Generalized hyperpigmentation and dehydration were noted on physical examination. Baseline concentrations of plasma adrenocorticotropic hormone, serum cortisol, plasma renin and serum aldosterone were analyzed. Determination of antibodies against adrenal steroid 21-hydroxylase, measurement of very-long-chain fatty acids and thyroid function tests were performed.

DIAGNOSIS

Primary adrenal insufficiency caused by isolated autoimmune adrenalitis and adrenal crisis.

MANAGEMENT

Immediate administration of hydrocortisone (100 mg bolus dose followed by 100 mg over 24 h per continuous infusion) and physiological saline infusions (initially 4 l over 24 h). After stabilization, initiation of chronic hormone replacement therapy with hydrocortisone (initially 30 mg per day) and fludrocortisone (0.1 mg daily). The patient was instructed on how to adjust hydrocortisone doses in stressful situations and provided with an emergency card.