Episodic memory impairment in Addison's disease: results from a telephonic cognitive assessment

Increased Resting-State Functional Connectivity in Patients With Autoimmune Addison Disease

CONTEXT

Individuals with autoimmune Addison disease (AAD) take replacement medication for the lack of adrenal-derived glucocorticoid (GC) and mineralocorticoid hormones from diagnosis. The brain is highly sensitive to these hormones, but the consequence of having AAD for brain health has not been widely addressed.

OBJECTIVE

The present study compared resting-state functional connectivity (rs-fc) of the brain between individuals with AAD and healthy controls.

METHODS

Fifty-seven patients with AAD (33 female) and 69 healthy controls (39 female), aged 19 to 43 years were scanned with 3-T magnetic resonance imaging (MRI).

RESULTS

Independent component and subsequent dual regression analyses revealed that individuals with AAD had stronger rs-fc compared to controls in 3 networks: the bilateral orbitofrontal cortex (OFC), the left medial visual and left posterior default mode network. A higher GC replacement dose was associated with stronger rs-fc in a small part of the left OFC in patients. We did not find any clear associations between rs-fc and executive functions or mental fatigue.

CONCLUSION

Our results suggest that having AAD affects the baseline functional organization of the brain and that current treatment strategies of AAD may be one risk factor.

Cognitive dysfunction in patients with primary adrenal insufficiency: A systematic review

Addison's disease (AD) entails a chronic insufficient production of gluco- and mineralocorticoids. Fatigue and decreased quality of life are frequently reported symptoms, but little is known about its effects on cognition. This study aims to explore the existence of cognitive impairment in patients with AD and the influence of treatment regimens. We conducted a systematic review. Inclusion criteria were met by 10 articles, most of them ranked as intermediate quality. Three studies analyzed the relationship between AD and cognitive impairment; one explored the effect of delaying treatment showing no effect on cognitive performance, and another one studied the effect of fludrocortisone treatment. Episodic memory was the most frequent cognitive domain impaired across studies, in comparison to healthy controls. Two papers investigated the relationship between impaired sleep quality and poor cognitive performance. Two studies related cognitive impairments with hypocortisolism-derived brain neuroglycopenia. Two studies investigated the effect of DHEA substitution. In conclusion, patients exhibit a moderately reduced performance in verbal learning. The pathophysiology of this impairment is likely multifactorial. Future studies should include larger sample sizes, the use of comprehensive and multi-domain neuropsychological and behavioral protocols, and neuroimaging.

Glucocorticoids and cognitive function: a walkthrough in endogenous and exogenous alterations

PURPOSE

The hypothalamic-pituitary-adrenal (HPA) axis exerts many actions on the central nervous system (CNS) aside from stress regulation. Glucocorticoids (GCs) play an important role in affecting several cognitive functions through the effects on both glucocorticoid (GR) and mineralocorticoid receptors (MR). In this review, we aim to unravel the spectrum of cognitive dysfunction secondary to derangement of circulating levels of endogenous and exogenous glucocorticoids.

METHODS

All relevant human prospective and retrospective studies published up to 2022 in PubMed reporting information on HPA disorders, GCs, and cognition were included.

RESULTS

Cognitive impairment is commonly found in GC-related disorders. The main brain areas affected are the hippocampus and pre-frontal cortex, with memory being the most affected domain. Disease duration, circadian rhythm disruption, circulating GCs levels, and unbalanced MR/GR activation are all risk factors for cognitive decline in these patients, albeit with conflicting data among different conditions. Lack of normalization of cognitive dysfunction after treatment is potentially attributable to GC-dependent structural brain alterations, which can persist even after long-term remission.

CONCLUSION

The recognition of cognitive deficits in patients with GC-related disorders is challenging, often delayed, or mistaken. Prompt recognition and treatment of underlying disease may be important to avoid a long-lasting impact on GC-sensitive areas of the brain. However, the resolution of hormonal imbalance is not always followed by complete recovery, suggesting irreversible adverse effects on the CNS, for which there are no specific treatments. Further studies are needed to find the mechanisms involved, which may eventually be targeted for treatment strategies.

Glucocorticoid replacement therapy for primary and secondary adrenal insufficiency and their impact on cognition

Patients with adrenal insufficiency (AI) are treated with conventional or modified-release glucocorticoid (GC) replacement therapy (GRT). Although current GRT regimens aim to mimic the physiological circadian pattern of cortisol secretion, temporary phases of hypo- and hypercortisolism are common. There is good evidence that prolonged phases of hypo- or hypercortisolism are associated with impaired cognitive functioning. However, little is known about cognitive functioning in patients with AI regarding the effects of dosage and duration of glucocorticoid replacement therapy. There is also little data available comparing the effects of GC therapy on patients with primary and secondary forms of AI as well as with respect to different formulas. This Mini-Review gives an overview of the current studies on GRT for primary and secondary AI and their impact on cognition. Strengths and weaknesses of the studies and their Implications for clinical daily routine are discussed with a special emphasis on practical considerations for the treating endocrinologist.

Neurocognitive and mental health impact of adrenoleukodystrophy across the lifespan: Insights for the era of newborn screening

X-linked adrenoleukodystrophy (ALD) is a rare inherited neurological disorder that poses considerable challenges for clinical management throughout the lifespan. Although males are generally more severely affected than females, the time course and presentation of clinical symptoms are otherwise difficult to predict. Opportunities to improve outcomes for individuals with ALD are rapidly expanding due to the introduction of newborn screening programs for this condition and an evolving treatment landscape. The aim of this comprehensive review is to synthesize current knowledge regarding the neurocognitive and mental health effects of ALD. This review provides investigators and clinicians with context to improve case conceptualization, inform prognostic counseling, and optimize neuropsychological and mental health care for patients and their families. Results highlight key predictive factors and brain-behavior relationships associated with the diverse manifestations of ALD. The review also discusses considerations for endpoints within clinical trials and identifies gaps to address in future research.

Brain structure in autoimmune Addison's disease

Long-term disturbances in cortisol levels might affect brain structure in individuals with autoimmune Addison's disease (AAD). This study investigated gray and white matter brain structure in a cohort of young adults with AAD. T1- and diffusion-weighted images were acquired for 52 individuals with AAD and 70 healthy controls, aged 19-43 years, using magnetic resonance imaging. Groups were compared on cortical thickness, surface area, cortical gray matter volume, subcortical volume (FreeSurfer), and white matter microstructure (FSL tract-based spatial statistics). Individuals with AAD had 4.3% smaller total brain volume. Correcting for head size, we did not find any regional structural differences, apart from reduced volume of the right superior parietal cortex in males with AAD. Within the patient group, a higher glucocorticoid (GC) replacement dose was associated with smaller total brain volume and smaller volume of the left lingual gyrus, left rostral anterior cingulate cortex, and right supramarginal gyrus. With the exception of smaller total brain volume and potential sensitivity of the parietal cortex to GC disturbances in men, brain structure seems relatively unaffected in young adults with AAD. However, the association between GC replacement dose and reduced brain volume may be reason for concern and requires follow-up study.

Young adult Swedish patients with autoimmune Addison's disease report difficulties with executive functions in daily life despite overall good cognitive performance

OBJECTIVES

Sub-optimal replacement of glucocorticoids (GC) in autoimmune Addison's disease (AAD) may affect cognitive functioning. The present study therefore sought to investigate cognitive performance and self-reported problems with executive functions in a cohort of young adult patients with AAD.

DESIGN AND METHODS

67 patients with AAD (39 females), mean age 32 yrs. (range 19-41), and 80 control participants (43 females), mean age 29 yrs. (range 19-43), completed neuropsychological tests estimating verbal and non-verbal intellectual ability, learning, memory and executive functioning, in addition to self-report scales assessing problems with executive functions, fatigue and symptoms of anxiety and depression.

RESULTS

Patients performed within the average range on all cognitive tests compared to population norms. However, female AAD patients reported more problems than controls with both hot (emotion regulation) and cold (cognitive regulation) executive functions in daily life. Moreover, experienced problems with executive functions in both male and female patients were associated with increased mental fatigue and lower GC replacement doses.

CONCLUSIONS

Despite average performance in neuropsychological tests by both sexes, young adult female patients with AAD experience problems with executive functions in daily life. Coping with mental fatigue and optimization of pharmacotherapy may be important factors to be addressed in order to provide timely support for patients. Future research is needed to further determine other risk factors for experiencing executive function impairments in AAD.

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.

Poor quality of life and sleep in patients with adrenal insufficiency-another cause of increased mortality?

Background

Patients with adrenal insufficiency (AI) are treated with glucocorticoid replacement therapy (GRT). Although current glucocorticoid regimens aim to mimic the physiological circadian rhythm of cortisol secretion, temporary phases of hypo- and hypercortisolism are common undesired effects which lead to a variety of consequences like increased cardiovascular risk and premature mortality. Additionally, poor quality of life (QoL) and impaired sleep have been reported. However, little is known about these topics regarding the effects of daily dosage, duration of therapy, and patients with different forms of AI (primary, PAI, and secondary, SAI).

Methods

In this study, 40 adults with AI substituted with hydrocortisone (HC) and 20 matched healthy controls completed questionnaires evaluating depressive symptoms, subjective health status, quality of sleep and daytime sleepiness. Furthermore, demographic data, dosage of HC, duration of therapy and co-medication were evaluated. Patients were compared in different groups.

Results

Patients assessed general health significantly worse than controls; likewise, daytime sleepiness was reported significantly more often. Depressive symptoms differed significantly in the two groups but did not reach clinically relevant scores. There was no difference between patients with PAI and SAI. High dosage of hydrocortisone had negative impact on mental health but not on sleep quality or daytime sleepiness.

Conclusions

The present data highlight that poor QoL and impaired sleep are still severe and underrated issues in current GRT and might be additional factors for premature mortality in patients with AI. Some AI patients reach normal or near-normal self-assessed QoL and sleep, even despite unphysiological replacement.

Dual-release hydrocortisone and its benefits on cognitive function and quality of sleep

PURPOSE

Patients with adrenal insufficiency are usually treated with conventional hydrocortisone replacement therapy which fails to mimic the circadian rhythm of cortisol secretion. Dual-release hydrocortisone (DR-HC) resembles the daily normal cortisol profile improving metabolic parameters and quality of life. However, currently little is known about its impact on cognitive function. Aim of this study was to evaluate cognitive function and well-being in DR-HC treated patients compared to healthy controls and conventional HC treatment.

METHODS

Twenty adults with adrenal insufficiency treated with DR-HC (Plenadren®) underwent 10 neuropsychological tests, evaluating cognitive functions. Furthermore, demographic data, quality of life, symptoms of depression, and quality of sleep were evaluated by well-established questionnaires. Patients were compared by diagnosis (PAI/SAI) and dose (≥20 mg). In addition, eighteen DR-HC treated adults were compared to eighteen matched conventionally treated adults.

RESULTS

With respect to diagnosis patients with PAI performed significantly better on intellectual abilities (p = 0.038) and on executive functioning (p = 0.026) and reported a significant longer time to fall asleep (p = 0.026). Regarding DR-HC dosage, there were no significant differences in cognitive functions. Patients on high dose reported a better subjective quality of sleep (p = 0.028) than patients on low dose. In comparison to conventional HC treatment, patients with DR-HC tended to show better results in executive functioning (p = 0.099).

CONCLUSION

Patients with PAI reached better results in several cognitive functions and had a worse quality of sleep than patients with SAI. Our data suggest a positive impact of DR-HC on quality of sleep. DR-HC may be better for executive functioning.

Impaired attention in patients with adrenal insufficiency - Impact of unphysiological therapy

Patients with adrenal insufficiency (AI) are treated with glucocorticoid (GC) replacement therapy. Although current GC regimens aim to mimic the physiological circadian rhythm of cortisol secretion, temporary phases of hypo- and hypercortisolism are common undesired effects. Both conditions may lead to impairment in cognitive functioning. At present, little is known about cognitive functioning in patients with AI, especially regarding the effects of dosage and duration of glucocorticoid replacement therapy. There is also little data available comparing the effects of GC therapy on patients with primary (PAI) and secondary (SAI) forms of AI. In this study 40 adults with AI (21 PAI, 19 SAI) substituted with hydrocortisone (HC) and 20 matched healthy controls underwent 10 different neuropsychological tests evaluating memory, executive functioning, attention, psychomotricity and general intellectual ability. Furthermore demographic data, dosage of HC, duration of therapy and co-medication were evaluated. Patients were compared in groups with regard to diagnosis, dosage and duration of therapy. Patients showed worse performance than controls in attention, though patients with PAI and SAI seemed to be equally impaired. There were no limitations in intellectual abilities or memory function. High dosage of HC was found to impair attention, visual-motoric skills and executive functioning while the duration of therapy showed no significant impact on cognitive functions. In conclusion, our study showed that AI patients on HC replacement therapy reveal significant cognitive deficits concerning attention. There was no difference between patients with PAI and SAI. Furthermore, high dosage seems to have a negative impact especially on executive functioning.

Sleep, Cognition and Cortisol in Addison's Disease: A Mechanistic Relationship

Sleep is a critical biological process, essential for cognitive well-being. Neuroscientific literature suggests there are mechanistic relations between sleep disruption and memory deficits, and that varying concentrations of cortisol may play an important role in mediating those relations. Patients with Addison's disease (AD) experience consistent and predictable periods of sub- and supra-physiological cortisol concentrations due to lifelong glucocorticoid replacement therapy, and they frequently report disrupted sleep and impaired memory. These disruptions and impairments may be related to the failure of replacement regimens to restore a normal circadian rhythm of cortisol secretion. Available data provides support for existing theoretical frameworks which postulate that in AD and other neuroendocrine, neurological, or psychiatric disorders, disrupted sleep is an important biological mechanism that underlies, at least partially, the memory impairments that patients frequently report experiencing. Given the literature linking sleep disruption and cognitive impairment in AD, future initiatives should aim to improve patients' cognitive performance (and, indeed, their overall quality of life) by prioritizing and optimizing sleep. This review summarizes the literature on sleep and cognition in AD, and the role that cortisol concentrations play in the relationship between the two.

Reversible Non-parkinsonian Bradykinesia with Impaired Frontal Lobe Function as the Predominant Manifestation of Adrenal Insufficiency

A 69-year-old Japanese man with a history of suprasellar surgery and irradiation developed bradykinesia and mild fatigue without muscle weakness, myalgia, pyramidal or extrapyramidal signs, parkinsonian symptoms, or ataxia. An endocrinological work-up revealed anterior hypopituitarism associated with secondary adrenal insufficiency. Higher brain function tests indicated an impaired frontal lobe function. The patient's bradykinesia, fatigue, and frontal lobe dysfunction improved within 2 weeks after the initiation of corticosteroid replacement therapy. To our knowledge, this is the first reported case of adrenal insufficiency manifesting as non-parkinsonian bradykinesia. Physicians should consider reversible non-parkinsonian bradykinesia associated with frontal lobe dysfunction as an unusual manifestation of adrenal insufficiency.

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.

Elevated Cortisol Leaves Working Memory Unaffected in Both Men and Women

Activation of the hypothalamic-pituitary-adrenal (HPA) axis (as might occur, for example, when the organism encounters a threat to allostatic balance) leads to the release of cortisol into the bloodstream and, ultimately, to altered neural functioning in particular brain regions (e.g., the prefrontal cortex (PFC)). Although previous studies suggest that exposure to acute psychosocial stress (and hence, presumably, elevation of circulating cortisol levels) enhances male performance on PFC-based working memory (WM) tasks, few studies have adequately investigated female performance on WM tasks under conditions of elevated cortisol. Hence, we compared associations between elevated (relative to baseline) levels of circulating cortisol and n-back performance in a South African sample (38 women in the late luteal phase of their menstrual cycle, 38 men). On Day 1, participants completed practice n-back tasks. On Day 2, some completed the Trier Social Stress Test (TSST), whereas others experienced a relaxation period, before completing 1-back and 3-back tasks. We measured self-reported anxiety and salivary cortisol at baseline, post-manipulation and end of session. We reconstituted group assignment so that all women with elevated cortisol were in one group (EC-Women; n = 17), all men with elevated cortisol were in another (EC-Men; n = 19), all women without elevated cortisol were in a third (NoEC-Women; n = 21), and all men without elevated cortisol were in a fourth (NoEC-Men; n = 19) group. Analyses suggested this reconstitution was effective: in EC, but not NoEC, groups cortisol levels rose significantly from baseline to post-manipulation. Analyses of n-back data detected significant relations to task load (i.e., better performance on 1-back than on 3-back tasks), but no significant relations to sex, performance accuracy/speed, or cortisol variation. The data patterns are inconsistent with reports describing sex differences in effects of stress on WM performance. We speculate that cross-study methodological differences account for these inconsistencies, and, particularly, that between-study variation in the magnitude of baseline cortisol levels might affect outcomes. For instance, diurnal cortisol rhythms of South African samples might have flatter curves, and lower baseline values, than predominantly Caucasian samples from the United States and western Europe due to greater prenatal and lifetime stress, more socioeconomic disadvantage and faster ancestral life history (LH) strategies. We describe ways to disconfirm this hypothesis, and urge further cross-national research exploring these possibilities.

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.

The Role of Fludrocortisone in Cognition and Mood in Patients with Primary Adrenal Insufficiency (Addison's Disease)

BACKGROUND

Primary adrenal insufficiency (AI) requires hormone replacement therapy with fludrocortisone and hydrocortisone stimulating glucocorticoid (GR) and mineralocorticoid receptors (MR). Evidence from animal and human studies shows that MR function is crucial for cognitive function and mood. Regarding patients with AI, very little is known about the role of MR in cognitive function and mood.

METHODS

A repeated-measures within-subject design was used to determine whether cognitive function and mood are related to MR occupation in patients with AI. Intraindividually, patients were examined twice, with 1 week between testing days: once with fludrocortisone (high MR occupation) and once without fludrocortisone (low MR occupation). All patients kept their stable regimen of hydrocortisone. The assessment of cognitive function included executive function, attention, and verbal, visuospatial and working memory. Additionally, mood and blood pressure were measured.

RESULTS

Verbal memory improved significantly during high MR occupation (after fludrocortisone intake) compared to low MR occupation [without fludrocortisone, t(29) = -2.1, p = 0.046]. There were trend level differences in the Number-Combination test [t(29) = -1.9, p = 0.074] and in the Stroop interference task [t(29) = -1.9, p = 0.068]. No significant differences in visuospatial and working memory were found. Furthermore, the current mood state was better during high MR occupation compared to low MR occupation [t(29) = -2.4, p = 0.023] as was diastolic blood pressure [F(2, 29) = 3.6, p = 0.07].

CONCLUSIONS

Cognitive function and mood in patients with AI depend in part on MR occupation. Because the medium effect size indicates a potential clinical significance, further studies should systematically examine which dosages of fludrocortisone are associated with optimal cognitive function and mood in AI patients.

Mild cognitive deficits in patients with primary adrenal insufficiency

BACKGROUND

The brain is a major target organ for cortisol considering its high density of glucocorticoid receptors. Several states of hypothalamus-pituitary-adrenal dysregulation point towards impairments in cognitive functioning. However, there is a very limited body of research on the effects of hypocortisolism on cognitive functioning.

AIM

To evaluate cognitive functioning in patients with hypocortisolism (i.e., primary adrenal insufficiency (PAI)) and to examine the possible effect of postponing early-morning hydrocortisone intake on cognitive functioning.

METHODS

Thirty-one patients with PAI on regular morning hydrocortisone intake and 31 healthy matched controls underwent nine neuropsychological tests, evaluating memory and executive functioning. In addition, the effect of normal timing and postponement of morning hydrocortisone intake on neuropsychological tests were assessed in an additional 29 patients with PAI.

RESULTS

Compared to controls, patients with PAI performed worse on auditory and visual memory tasks (all P ≤ 0.024) and executive functioning tasks (all P ≤ 0.012). In contrast, patients performed better on a concentration and an attention task (both P<0.05). Postponement of hydrocortisone intake in the morning did not affect the outcomes of neuropsychological tests.

CONCLUSION

Patients on long-term hydrocortisone replacement for PAI show mild cognitive deficits compared to controls. There was no effect of postponement of regular hydrocortisone intake on cognition.

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.

Cognitive function in patients with primary adrenal insufficiency (Addison's disease)

BACKGROUND

Patients with primary adrenal insufficiency (AI) need to replace glucocorticoids and mineralocorticoids that act on glucocorticoid (GR) and mineralocorticoid receptors (MR). Both receptors are highly expressed in the hippocampus and are closely associated with cognitive function, which might be impaired by insufficient or increased GR and MR stimulation. However, little is known about cognitive function in patients with AI.

METHODS

It was examined whether patients with AI exhibit worse cognitive function compared to sex-, age-, and education-matched controls. Cognitive function (executive function, concentration, verbal memory, visual memory, working memory, and autobiographical memory) was assessed in 30 patients with AI (mean age 52.4 yrs. ±14.4, n=21 women, mean duration of illness 18.2 yrs. ±11.1) and 30 matched controls. We also measured depressive symptoms, body mass index (BMI), and blood pressure.

RESULTS

Patients with AI showed more depressive symptoms, had a greater BMI and lower systolic blood pressure compared to controls. Adjusted analyses controlling for these variables revealed that patients with AI performed significantly worse in verbal learning (F=7.8, p=.007). Executive function, concentration, working memory, verbal memory, visuospatial memory, and autobiographical memory did not differ between groups.

CONCLUSIONS

No clinically relevant cognitive impairment was found in patients with AI compared to matched controls. Even long-term glucocorticoid and mineralocorticoid substitution over almost two decades appears to have only subtle effects on cognition in patients with AI.