Autoimmunity predominates in a large South African cohort with Addison's disease of mainly European descent despite long-standing disease and is associated with HLA DQB*0201

Clinical profile, etiology, and diagnostic challenges of primary adrenal insufficiency in Sudanese children: 14-years' experience from a resource limited setting

OBJECTIVES

Primary adrenal insufficiency (PAI) in children is an uncommon condition. Congenital adrenal hyperplasia (CAH) is the commonest cause followed by autoimmune disorders. Diagnosis and management are challenging especially in resource-limited settings. Studies from Africa are scanty and here we describe for the first time the clinical presentation, possible etiologies, and challenges in diagnosis and management of PAI in a large cohort of Sudanese children.

METHODS

This was a descriptive hospital-based study where all patients diagnosed with PAI between 2006 and 2020 were reviewed. The diagnosis was based on clinical presentation, low morning cortisol ± high adrenocorticotropic hormone (ACTH), or inadequate response of cortisol to synacthen stimulation. Challenges faced in diagnosis and management were identified.

RESULTS

From 422 PAI suspected patients, 309 (73.2%) had CAH, and 33 (7.8%) had PAI-like symptoms and were not furtherly discussed. Eighty patients (19%) had fulfilled the study criteria: 29 had Allgrove syndrome, nine auto-immune polyendocrinopathy syndrome, seven adrenoleukodystrophy, and one had an adrenal hemorrhage. Hyperpigmentation was the cardinal feature in 75 (93.8%) while the adrenal crisis was not uncommon. Lack of diagnostic facilities has obscured the etiology in 34 (42.5%) patients.

CONCLUSIONS

PAI is not uncommon in Sudanese children where genetic causes outweigh the autoimmune ones. Many cases were missed due to nonspecific presentation, lack of awareness, and difficult access to tertiary health care facilities. In addition to the clinical findings, early morning cortisol ± ACTH levels can be used in diagnosis where facilities are limited particularly synacthen stimulation test.

Characteristics and Challenges of Primary Adrenal Insufficiency in Africa: A Review of the Literature

BACKGROUNDS

Africa comprises 54 countries with varying degrees of economic development. As with other healthcare systems, rare diseases such as adrenal insufficiency are neglected and poorly documented.

OBJECTIVES

We wished to explore primary adrenal insufficiency (PAI) in Africa, its prevalence, aetiology, genetics, presentation, diagnosis, and treatment and to determine the unmet needs in clinical care, education, and research.

MATERIALS AND METHODS

A narrative nonsystematic review of the literature was undertaken. We searched two online databases (PubMed and Google scholar) using the search terms "Addison's disease/PAI, primary adrenal insufficiency coupled with "Africa," "country names," and "genetic disorders." A total of 184 PAI records were reviewed. The exclusion of abstracts, conference proceedings, single case reports, and duplicate studies covering the same subject matter yielded 124 articles, of which 97 informed the final manuscript.

RESULTS

A wide range of aetiology of PAI was encountered, but their true prevalence is unknown. Aetiology varied with region and age of presentation as reflected by predominantly TB, HIV, and infective causes occurring in sub-Saharan Africa and more congenital forms described in North Africa associated with consanguinity. In Africa, the diagnostic criteria for PAI do not universally accord with conventional criteria, and there is a heavy reliance on clinical suspicion and biochemistry, including random cortisol of <400 nmol/L, rather than the tetracosactide test where stimulated cortisol <500-550 nmol/L confirms the diagnosis.

CONCLUSIONS

A high index of suspicion is warranted to diagnose PAI in resource-limited settings, especially where tetracosactide tests are not universally available.

Health-related quality of life in hypothyroidism-A population-based study, the WHO MONICA Project

OBJECTIVE

To explore health-related quality of life (HRQoL) among subjects with hypothyroidism compared to subjects without hypothyroidism in the general population. HRQoL is important in clinical practice. Hypothyroidism is prevalent, mainly found in women, and increasing with age.

DESIGN

Cohort study of random population sample.

PATIENTS

Women and men, n = 414 (39-78 years) from the WHO MONICA project, Gothenburg, Sweden, participated. Hypothyroidism was defined as subjects having levothyroxine supplementation or serum thyroid-stimulating hormone (S-TSH) >4.2 mU/L.

MEASUREMENTS

Health-related quality of life was measured with Psychological General Well-Being Index (PGWB), Nottingham Health Profile (NHP), Short Form 36 Health Survey (SF-36) and a single item self-rated health scale (0-100), and stress was rated 1-6. The results were adjusted for age, sex and comorbidity using analysis of covariance (ANCOVA).

RESULTS

Hypothyroidism was found in 70 subjects (17%). They scored worse HRQoL than controls regarding Sleep (p < .001), Social isolation (p = .01) and Total NHP (p < .05), and had more medication in general 2.7 ± 2.5 vs. 1.8 ± 2.1, p < .05. Subjects with levothyroxine (n = 40) showed similar results as the total hypothyroid group. Subjects unaware of their newly detected elevated STSH (n = 30) showed lower HRQoL in Sleep (p < .01) and Pain (p < .05) in NHP. HRQoL was similar in subjects with and without positive thyroperoxidase antibodies (TPO-Ab) either in those with hypothyroidism (44% TPO-Ab) or controls (9% TPO-Ab).

CONCLUSION

Men and women with hypothyroidism in the general population reported having more issues with Sleep and Social isolation than those without hypothyroidism irrespective of TPO-Ab. Scores were similar in all of the other HRQoL domains measuredAQ5.

Addison's disease associated with hypokalemia: a case report

BACKGROUND

Primary adrenal insufficiency (Addison's disease) is a rare medical condition usually associated with hyperkalemia or normokalemia. We report a rare case of Addison's disease, coexisting with hypokalemia, requiring treatment.

CASE PRESENTATION

In this case, a 42-year-old man was admitted to the intensive care unit with a history of loss of consciousness and severe hypoglycemia. His blood tests showed metabolic acidosis, low concentrations of cortisol 6 nmol/L (normal 68-327 nmol/L), and high plasma adrenocorticotropic hormone 253 pmol/L (normal 1.6-13.9 pmol/L), and he was diagnosed with primary adrenal insufficiency. Surprisingly, his serum potassium was low, 2.3 mmol/L (normal 3.5-5.1 mmol/L), requiring replacement over the course of his admission. Computed tomography scan of the adrenal glands showed features suggestive of unilateral adrenal tuberculosis. Investigations confirmed renal tubulopathy. The patient responded favorably to cortisol replacement, but never required fludrocortisone.

CONCLUSIONS

Coexistence of hypokalemia with Addison's disease is unusual. We recommend investigation of the cause of hypokalemia in its own right, if it occurs with primary adrenal insufficiency.

Tiered healthcare in South Africa exposes deficiencies in management and more patients with infectious etiology of primary adrenal insufficiency

OBJECTIVE

We wished to determine the prevalence, etiology, presentation, and available management strategies for primary adrenal insufficiency (PAI) in South Africa (SA), hypothesizing a prevalence greater than the described 3.1 per million. There is great inequity in healthcare allocation, as two parallel healthcare systems exist, potentially modifying PAI patients' clinical profiles, private being better resourced than public healthcare.

METHODS

An online survey of physicians' experience relating to PAI.

RESULTS

The physicians were managing 811 patients, equal to a prevalence of 14.2 per million. Likely causes of PAI in public/ academic vs private settings included: AIDS-related [304 (44.8%) vs 5 (3.8%); p<0.001], tuberculosis [288 (42.5%) vs 8 (6.0%); p<0.001], autoimmune disease [50 (7.4%) vs 88 (66.2%); p<0.001], malignancy [27 (4.0%) vs 7 (5.3%); p = 0.500], genetic including adrenoleukodystrophy (ALD) [5 (0.7%) vs 16 (12.0%); p<0.001], respectively. Overall, more patients presented with nausea [101 (74.3%) and vomiting 89 (65.9%), than diarrhoea 76 (58.9%); p = 0.008 and 126 (15.5%) in adrenal crisis. Features suggestive of a crisis were hypoglycaemia [40 (78.4%) vs 42 (48.8%); p = 0.001], shock [36 (67.9%) vs 31(36.9%); p<0.001], and loss of consciousness [25 (52.1%) vs 27 (32.9%); p = 0.031]. Greater unavailability of antibody testing in the public vs. the private sector [32 (66.7%) vs 30 (32.1%); p = 0.001], [serum-ACTH 25 (52.1%) vs 16 (19.5%); p<0.001] and glucocorticoids were [26 (54.2%) vs 33 (40.2%); p = 0.015]. Many patients, 389(66.7%) were not using identification, indicating that they need steroids in an emergency.

CONCLUSION

A survey of South African physicians suggests a higher prevalence than previously reported. Patients presented with typical symptoms, and 15.5% presented in adrenal crisis. Significant disparities in the availability of physicians' expertise, diagnostic resources, and management options were noted in the public versus private settings. Greater awareness among health practitioners to timeously diagnose PAI is required to prevent a life-threatening outcome.

Significant barriers to diagnosis and management of adrenal insufficiency in Africa

BACKGROUND

The burden and management of primary adrenal insufficiency (PAI) in Africa have not been well documented. We aimed to identify specific disease characteristics, patient demographics, and patterns of clinical management in established PAI in Africa.

METHODS

An online survey of physicians' experience relating to PAI.

RESULTS

There were 1334 responses received, 589 were complete, and 332 respondents reported managing patients with hypoadrenalism. The described responses were related to a calculated pool of 5787 patients with hypoadrenalism (2746 females, 3041 males), of whom 2302 had PAI. The likely causes of PAI in Sub-Saharan Africa (SSA) vs the Middle East and North Africa (MENA) regions included autoimmune disease (20% vs 60.3%; P < 0.001), tuberculosis (34% vs 4.1%; P < 0.001), AIDS (29.8% vs 1%; P < 0.001), malignancy, and genetic conditions. Sixteen percent of AD patients (376/2302) presented in an adrenal crisis. Medical emergency identification was not used by 1233 (83.6%) SSA vs 330 (40.4%) MENA patients (P < 0.001), respectively. Relative non-availability of diagnostic tests across both regions included adrenal antibodies 63% vs 69.6% (P = 0.328), s-cortisol 49.4 % vs 26.7% (P = 0.004), s-ACTH 55.7% vs 53.3% (P = 0.217), and adrenal CT scans 52.4% vs 31.8% (P = 0.017) in the SSA and MENA region, respectively. Across the entire cohort, the overall hydrocortisone use and extrapolated proportion of synacthen use were 59.4% and 50.7%, respectively.

CONCLUSIONS

Through the perception and practice of healthcare professionals, we identified significant challenges in the diagnosis and management of PAI which may herald high mortality. Differences between regions may reflect the allocation of healthcare resources.

Epidemiology, pathogenesis, and diagnosis of Addison's disease in adults

BACKGROUND

Addison's disease (AD) is a rare disorder and among adult population in developed countries is most commonly caused by autoimmunity. In contrast, in children genetic causes are responsible for AD in the majority of patients.

PURPOSE

This review describes epidemiology, pathogenesis, genetics, natural history, clinical manifestations, immunological markers and diagnostic strategies in patients with AD. Standard care treatments including the management of patients during pregnancy and adrenal crises consistent with the recent consensus statement of the European Consortium and the Endocrine Society Clinical Practice Guideline are described. In addition, emerging therapies designed to improve the quality of life and new strategies to modify the natural history of autoimmune AD are discussed.

CONCLUSIONS

Progress in optimizing replacement therapy for patients with AD has allowed the patients to lead a normal life. However, continuous education of patients and health care professionals of ever-present danger of adrenal crisis is essential to save lives of patients with AD.

Reduced Slow-Wave Sleep and Altered Diurnal Cortisol Rhythms in Patients with Addison's Disease

OBJECTIVES

Cortisol plays a key role in initiating and maintaining different sleep stages. Patients with Addison's disease (AD) frequently report disrupted sleep, and their hydrocortisone medication regimes do not restore the natural diurnal rhythm of cortisol. However, few studies have investigated relations between sleep quality, especially as measured by polysomnographic equipment, and night-time cortisol concentrations in patients with AD.

METHODS

We used sleep-adapted EEG to monitor a full night of sleep in 7 patients with AD and 7 healthy controls. We sampled salivary cortisol before bedtime, at midnight, upon awakening, and at 30-minutes post-waking.

RESULTS

Controls had lower cortisol concentrations than patients before bedtime and at midnight. During the second half of the night, patient cortisol concentrations declined steeply, while control concentrations increased steadily. Whereas most controls experienced a positive cortisol awakening response, all patients experienced a decrease in cortisol concentrations from waking to 30-minutes post-waking (P = .003). Patients experienced significantly lower proportions of slow-wave sleep (SWS; P = .001), which was associated with elevated night-time cortisol concentrations.

CONCLUSION

Overall, these results suggest that patients with AD demonstrate different patterns of night-time cortisol concentrations to healthy controls, and that relatively elevated concentrations are associated with a reduction of SWS. These hormonal and sleep architectural aberrations may disrupt the routine sleep-dependent processes of memory consolidation, and hence may explain, at least partially, the memory impairments often experienced by patients with AD.

Impaired quality and efficiency of sleep impairs cognitive functioning in Addison's disease

BACKGROUND

Standard replacement therapy for Addison's disease (AD) does not restore a normal circadian rhythm. Periods of sub- and supra- physiological cortisol levels experienced by patients with AD likely induce disrupted sleep. Given that healthy sleep plays an important role in memory consolidation, the novelty of the current study was to characterise, using objective measures, the relationship between sleep and memory in patients with AD, and to examine the hypothesis that poor sleep is a biological mechanism underlying memory impairment in those patients.

METHODS

We used a within-subjects design. Ten patients with AD and 10 matched healthy controls completed standardised neuropsychological tests assessing declarative memory (Rey Auditory Verbal Learning Test) and procedural memory (Finger Tapping Task) before and after a period of actigraphy-measured sleep, and before and after a period of waking.

RESULTS

Relative to healthy controls, patients with AD experienced disrupted sleep characterised by poorer sleep efficiency and more time spent awake. Patients also showed impaired verbal learning and memory relative to healthy controls (p=0.007). Furthermore, whereas healthy controls' declarative memory performance benefited from a period of sleep compared to waking (p=0.032), patients with AD derived no such benefit from sleep (p=0.448). Regarding the procedural memory task, analyses detected no significant between-group differences (all p's<0.065), and neither group showed significant sleep-enhanced performance.

CONCLUSIONS

We demonstrated, using actigraphy and standardized measures of memory performance, an association between sleep disturbances and cognitive deficits in patients with AD. These results suggest that, in patients with AD, the source of memory deficits is, at least to some extent, disrupted sleep patterns that interfere with optimal consolidation of previously-learned declarative information. Hence, treating the sleep disturbances that are frequently experienced by patients with AD may improve their cognitive functioning.

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.

Poor quality of life, depressed mood, and memory impairment may be mediated by sleep disruption in patients with Addison's disease

Standard replacement therapy for Addison's disease (AD) does not restore a normal circadian rhythm. In fact, hydrocortisone replacement in AD patients likely induces disrupted sleep. Given that healthy sleep plays an important role in improving quality of life, optimizing cognition, and ensuring affect regulation, the aim of this study was to investigate whether poor quality of life, mood alterations, and memory complaints reported by AD patients are associated with their disrupted sleep patterns. Sixty patients with AD and 60 matched healthy controls completed a battery of self-report questionnaires assessing perceived physical and mental health (Short-Form 36), mood (Beck Depression Inventory-II), sleep quality (Pittsburgh Sleep Quality Index), and cognition (Cognitive Failures Questionnaire). A latent variable model revealed that although AD had a significant direct effect on quality of life, the indirect effect of sleep was significantly greater. Furthermore, although AD had no direct effect on cognitive functioning, the indirect effect of sleep was significant. The overall model showed a good fit (comparative fit index = 0.91, root mean square of approximation = 0.09, and standardized root mean square residual = 0.05). Our findings suggest that disrupted sleep, and not the disease per se, may induce poor quality of life, memory impairment, and affect dysregulation in patients with AD. We think that improving sleep architecture may improve cognitive, affective, and physical functioning.

Diagnosis and management of adrenal insufficiency

Adrenal insufficiency continues to be a challenge for patients, their physicians, and researchers. During the past decade, long-term studies have shown increased mortality and morbidity and impaired quality of life in patients with adrenal insufficiency. These findings might, at least partially, be due to the failure of glucocorticoid replacement therapy to closely resemble physiological diurnal secretion of cortisol. The potential effect of newly developed glucocorticoid drugs is a focus of research, as are the mechanisms potentially underlying increased morbidity and mortality. Adrenal crisis remains a threat to lives, and awareness and preventative measures now receive increasing attention. Awareness should be raised in medical teams and patients about adrenal insufficiency and management of adrenal crisis to improve clinical outcome.

Endocrine dysfunction among adult patients with tuberculosis: An African experience

A broad spectrum of endocrine conditions has been reported among adult patients with tuberculosis in Africa. This review aims to describe the magnitude and pathogenesis of the following endocrinopathies among patients with tuberculosis in Africa: adrenal insufficiency, diabetes mellitus, disorders of calcium and vitamin D metabolism, thyroid dysfunction and hypogonadism. PubMed database and Google scholar were used to search for the relevant published English language studies and case reports relating to endocrine abnormalities and tuberculosis in Africa up to July 2013. The search terms used were endocrine dysfunction, endocrine abnormalities, adrenal insufficiency, diabetes mellitus, thyroid dysfunction, hypogonadism, disorders of calcium and vitamin D metabolism, tuberculosis, Africa. Reference lists of the identified articles were further used to identify other studies. Adrenal insufficiency, diabetes mellitus and calcium-vitamin D abnormalities were the most prevalent and frequently reported endocrine disorders among adult patients with tuberculosis in Africa. A meticulous endocrine evaluation among tuberculosis patients with suspected endocrine abnormalities should be encouraged in Africa and other high TB endemic regions. Treatment of these endocrine disorders has generally been shown to improve quality of life and reduce mortality.

Cardiovascular risk factors in patients with Addison's disease: a comparative study of South African and Swedish patients

BACKGROUND

Patients with Addison's disease (AD) in Scandinavia have an increased risk for premature death due to cardiovascular disease (CVD). Serum lipids are important risk factors for CVD and vascular mortality. Replacement doses of hydrocortisone have historically been higher in Sweden than South Africa. The primary aim was to study the lipid profiles in a large group of patients with AD with the hypothesis that the lipid profile in patients in Sweden would be worse than in South Africa.

METHODS

In a cross-sectional study, 110 patients with AD (55 from South Africa, 55 from Sweden) matched for age, gender, ethnicity and BMI were studied. Anthropometric measures, blood pressure, lipids, highly sensitive C-reactive protein (hs-CRP) and adiponectin were studied.

RESULTS

All patients were Caucasian and the majority were women N = 36 (65.5%). Mean (standard deviation; SD) ages of the Swedish and South African patients were 52.9 (13.0) and 52.6 (14.4) years and BMI 25.3 (3.2) and 25.8 (4.1) kg/m2, respectively. The mean total daily hydrocortisone dose was greater in the Swedish patients than the South African patients, [33.0 (8.1) versus 24.3 (8.0) mg; p<0.0001]. South African patients had higher median (interquartilerange; IQR) triglycerides (TG) [1.59 (1.1-2.46) versus 0.96 (0.74-1.6) mmol/l; p<0.001], total cholesterol (TC) [6.02(1.50) versus 5.13 (0.87) mmol/l; p<0.001], LDL-C [4.43 (1.44) versus 2.75 (0.80) mmol/l; p<0.001] and median hs-CRP [2.15 (0.93-5.45) versus 0.99 (0.57-2.10) mg/L; p<0.003] and lower HDL-C [0.80 (0.40) versus 1.86 (0.46) mmol/l; p<0.001] than the Swedish patients. Approximately 20% of the patients in both cohorts had hypertension and diabetes mellitus.

CONCLUSIONS

South African patients with AD have worse lipid profiles and higher hs-CRP compared to their matched Swedish patients, despite lower doses of hydrocortisone. It is uncertain at this time whether these are due to genetic or environmental factors.

Addison's disease symptoms--a cross sectional study in urban South Africa

Background

Addison’s disease is a potentially life-threatening disorder, and prompt diagnosis, and introduction of steroid replacement has resulted in near normal life-expectancy. There are limited data describing the clinical presentation of Addison’s disease in South Africa. It is hypothesised that patients may present in advanced state of ill-health, compared to Western countries.

Patients

A national database of patients was compiled from primary care, referral centres and private practices. 148 patients were enrolled (97 white, 34 mixed ancestry, 5 Asian and 12 black).

Methods

Demographic and clinical data were elicited using questionnaires. Biochemical data were obtained from folder reviews and laboratory archived results.

Results

The majority of the cohort was women (62%). The median and inter-quartile age range (IQR) of patients at enrolment was 46.0 (32.0–61.0) years, with a wide range from 2.8–88.0 years. The median and IQR age at initial diagnosis was 34.0 (20.0–45.0) years (range 0.02–77.0) years, indicating that at the time of enrolment, the patients, on average, were diagnosed with Addison’s disease 12 years previously. Hyperpigmentation was observed in 76%, nausea and vomiting occurred in more than 40%, and weight loss was noted in 25%. Loss of consciousness as a presenting feature was recorded in 20%. with a 95% confidence interval [CI] of (14–28%) and shock occurred in 5% CI (1.5–8.5%). Case-finding was recorded at 3.1 per million.

Conclusions

The usual constellation of hyperpigmentation, nausea, vomiting and weight loss suggests Addison’s disease, but a significant proportion present with an advanced state of ill-health and Addisonian crises. A lower prevalence rate, compared to Western countries is suggested.