Somatosensory function in patients with secondary adrenal insufficiency treated with two different doses of hydrocortisone—Results from a randomized controlled trial

Background Low cortisol levels are associated with several functional pain syndromes. In patients with secondary adrenal insufficiency (SAI), the lack in endogenous cortisol production is substituted by the administration of oral hydrocortisone (HC). Our previous study showed that a lower dose of HC led to an increase in reported subjective pain symptoms. Whether different doses of HC substitution alter somatosensory functioning in SAI patients has not been established yet. Methods In this randomized double blind cross-over trial, forty-six patients with SAI participated. Patients randomly received either first a lower dose (0.2–0.3 mg HC/kg body weight/day) for 10 weeks followed by a higher dose (0.4–0.6 mg HC/kg body weight/day) for another 10 weeks, or vice versa. After each treatment period, blood samples were drawn and somatosensory functioning was assessed by determining the mechanical detection threshold (MDT), mechanical pain threshold (MPT), mechanical pain sensitivity (MPS) and the pain pressure threshold (PPT), according to the Quantitative Sensory Testing (QST) battery by the German Network on Neuropathic Pain. Results The administration of the higher dose of HC resulted in significantly higher levels of cortisol (mean [SD] 748 [245] nmol/L) than the lower dose (537 [250] nmol/L, P<0.001). No differences were found in MDT, MPT, MPS and PPT z-scores between the two doses of HC. Furthermore, the number of patients showing sensory abnormalities did not differ between the two different doses. Conclusions The results suggest that the dose of HC has no impact on somatosensory functioning in response to mechanical stimuli in patients with SAI, despite previously found altered subjective pain reports.

A randomized double blind cross-over study of the effects of low dose and high dose hydrocortisone replacement therapy on cognition, quality of life, metabolic profile and somatosensation in patients with secondary adrenal insufficiency Version 3, August 2012

Rationale:
A wide variety in hydrocortisone (HC) substitution dose-regimens are considered physiological for patients with adrenal insufficiency. However, it is likely that cognition is negatively influenced by higher cortisol exposure to the brain. No studies have been performed to assess the effects of treatment regimens with a low physiological HC substitution dose on cognition in comparison to a high physiological HC substitution dose. These treatment regimens should take body weight and multiple dosing into account. In addition, substitution doses should be monitored by clinical evaluation and biochemical analysis for adverse effects associated with over-or under-replacement.

Objective:
The aim of this study is to investigate whether a physiologically low HC dose is better for cognition as compared to a high HC dose. In addition quality of life, metabolic profile and somatosensation will be described in relation to HC dose.
Study design: Randomized, double blind cross-over design.
Study population: Sixty-six patients diagnosed with secondary adrenal insufficiency on conventional replacement therapy. Participants will be 18-75 years old and on stable hormonal replacement therapy for at least six months.

Intervention:
Patients will be randomized in two groups matched for sex and body weight to receive either a low dose HC (0.2-0.3 mg/kg body weight) for 10 weeks followed by 10 weeks of high dose HC (0.4-0.6 mg/kg body weight) or high dose HC followed by a low dose of HC.

Main study parameters/endpoints:
The primary endpoint is cognitive performance. The secondary endpoints are quality of life including somatic complaints during treatment, metabolic profile and somatosensation.
Nature and extent of the burden and risks associated with participation, benefit and group relatedness: Burden: At baseline and after completion of both treatment arms patients will undergo neuropsychological evaluation. During these 3 visits (duration ± 4 hours for each visit) they will also fill in quality of life questionnaires. Blood samples will be drawn before and after the test battery. During both treatment periods patients will keep a diary regarding common somatic complaints and mood. Risks: All HC dosing schemes can be considered safe and are published in literature. Additional hydrocortisone dose escalation is allowed to prevend hypocortisolism. The risk of severe hypocortisolism on study dose-regimens of HC is small and estimated to be similar to conventional treatment at the outpatient clinic. Benefit: participant"s potential preference to either dosing scheme in addition to insight in risks and benefit of high or low dose HC treatment.

INTRODUCTION AND RATIONALE
Patients with adrenal insufficiency are treated with glucocorticoids (GCs) to compensate for the loss of endogenous cortisol production. Usually this is done by oral administration of hydrocortisone (HC) or cortisonacetate (CA). The aim is to mimic the endogenous cortisol rhythm, with peak values in the early morning before waking and a nadir at bedtime. In many countries HC is generally considered to be the first choice for a glucocorticoid (GC) regimen, because CA must undergo hepatic conversion to cortisol to become active.
HC substitution dose and regimens has varied over the previous decades. Initial doses of 30 mg/day were based on previously estimated values of cortisol production rates of 12-15 mg/m 2 /day, resulting in over-replacement (1). Currently, endogenous cortisol production rate in adults with intact adrenal reserve is estimated to approximate 6-10 mg/m 2 /day (2;3). As a result a wide variety of replacement doses is recommended. However, evidence comes from observational studies or unsystematic clinical experience and is graded as a very weak recommendation (grade 2C) because of absence of randomized controlled trials (4). Therefore, current practice varies widely, as evidenced by our own outpatient clinic where approximately half of the patients are on low physiological GC substitution while the other half is treated with a high physiological GC dose (5).
It is generally suggested to use the lowest GC dose that relieves symptoms of GC deficiency and avoids signs and symptoms of GC excess. Some advocate the use of normative day-curve cortisol values for the assessment of the adequacy of hydrocortisone therapy (6) but others suggest that clinical assessment alone works equally well (7). If the replacement dose is too low symptoms of apparent glucocorticoid deficiency are present (f.e. hypoglycemia, muscle weakness). In contrast, if the dose is too high excessive weight gain, hypertension and dyslipidemia may be present.
The effects of hydrocortisone substitution are likely to depend on body weight, as this was found to be the most important variable determining hydrocortisone clearance (6). Experts recommend a weight-adjusted hydrocortisone dose of 0.12 mg/kg body weight for the morning dose (1). Thrice-daily weight adjusted administration mimics the day-curve of cortisol seen in healthy volunteers and is necessary because of the short half-life (6).
GC substitution therapy, although referred to as physiological, has its imperfections. Current GC dose-regimens inevitably result in over-or under-replacement during certain periods of the day. This may result in poor quality of life (1). In addition, some non-specific symptoms, such as fatigue and headache in the early morning, are frequent in this group of patients (8). Filipsson and colleagues found that GC substitution, especially in higher physiological doses (> 20 mg/day) was associated with an unfavorable metabolic profile when compared with patients with normal adrenal function (9).
Besides physical side effects, mental side effects are reported in patients treated with pharmacological doses of GC, or in healthy individuals. With regard to cognition, especially deficits in memory and executive functioning are reported at higher cortisol doses as illustrated in the next two paragraphs. However, evidence is mainly derived from healthy volunteers with normal adrenal function (10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20).
There is ample evidence that GCs are necessary for learning and memory in humans (10-13;15;16;18;19;21-23). At least in healthy humans, elevation of basal cortisol levels is associated with reduced hippocampal volume and impairments on learning and memory tasks which depend upon the integrity of the hippocampus (22). Memory can be divided in emotional and neutral memory, i.e. respectively memory for events with or without an emotional charge (that can be the valence of the stimulus or the context of an event). Glucocorticoïds have been found to affect emotional memory, likely through actions in the amygdala (22;24). Indeed, Maheu and colleagues demonstrated that the valence of the tobe-remembered material, modulates the effects of stress on human declarative memory (i.e. knowledge that we have conscious access to, including personal and world knowledge) (25). Furthermore, emotionally arousing and stressful experiences influence declarative memory likely through their interaction with GC receptors located in the frontal lobes, amygdala and hippocampus (26)(27)(28)(29).
Executive functions also appeared to be sensitive to the variations of GCs (14;17;20;30). The prefrontal cortex, which is strongly associated with executive functioning, contains a high concentration of glucocorticoïd receptors (31) and is an important site for regulation of the Hypothalamus-Pituitary-Adrenal-axis (32). Thus it is reasonable to expect that GCs would have an impact on executive functions, such as working memory and that there exist a quadratic function between GCs and executive function (14). Working memory was found to be more sensitive to the acute (i.e. given by infusion) effects of GCs than declarative memory (14). Working memory is important for acquisition and consolidation of information and therefore for all kind of memories. In addition, cortisol may lead to less salient encoding of meaningful stimuli and may impair selective attention, thereby reducing an individual"s ability to discriminate relevant and important information from irrelevant and unimportant information (23). However, later studies suggest that cortisol does not affect attention (10;19). Because attention is of great importance for almost all cognitive functions, it is important to know the effects of GCs on attention. Furthermore we will perform some quantitative sensory testing (QST), including thermal as well as mechanical testing procedures (33). We expect increased basal mechanical pain sensitivity but decreased perceptual wind-up in patients in the low dose group compared to the high dose group, based on a study by Kuehl and colleagues (34).
In conclusion, a wide variety in HC substitution dose-regimens is considered physiological for patients with adrenal insufficiency. However, it is likely that cognition is negatively influenced by higher cortisol exposure to the brain. No studies have been performed to assess the effects of treatment regimens with a low physiological HC substitution dose on cognition in comparison to a high physiological dose. These treatment regimens should take body weight and multiple dosing into account. In addition, substitution doses should be monitored by clinical evaluation and biochemical analysis for adverse effects associated with over-or under-replacement.

Hypotheses:
We hypothesize that a low physiological HC dose results in better cognitive performance and improved metabolic risk profile, but in decreased quality of life with excess common somatic complaints and increased values of somatosensation in patients with secondary adrenal insufficiency when compared to a high physiological HC dose.

Study Aim:
In this double blind cross-over study we will investigate the effects of a low physiological HC substitution on cognition, quality of life, metabolic profile and somatosensation, in patients with secondary adrenal insufficiency and compare them to a high physiological HC substitution dose.

OBJECTIVES
Primary objective: to study the effects of a low versus high physiological HC substitution on cognition.
Secondary objectives: to study the effects of a low versus high physiological HC substitution on: -Quality of life (QofL), -common somatic complaints in relation to mood -Metabolic profile -Somatosensation

STUDY DESIGN
This is a randomized double blind cross-over trial of the effects of low dose and high dose hydrocortisone replacement therapy.
The protocol can be summarized as below: Patients will be treated for 10 weeks after which a switch in study dose will take place.

Population (base)
Approximately, 400 patients with secondary adrenal insufficiency without prior evidence of hormonal overproduction (e.g. acromegaly, Cushing"s disease and prolactinoma) have a regular follow-up at the Endocrine outpatient clinic at the UMCG. Because of this number we think that it is feasible to collect 66 out of 400 patients who will meet the inclusion criteria. Patients included in this study will be 18-70 years old, all on stable GC replacement for at least six months. The in-and exclusion criteria of potential candidates will be checked by the physician responsible for the endocrine outpatient care and by information available in the medical records. In the Informed Consent form, patients can give permission if they agree with the fact that other people (as stated in the general brochure) can see their medical data.

Sample size and calculation
No relevant data can be inferred from literature to estimate a reasonable treatment effect of HC dose in secondary adrenal insufficiency on cognition. Because of the absence of relevant data from literature, we chose to perform a power analyses.
A study with 2 arms with each 25 patients (total number of patients: 50) is able to detect an effect size of 0.4 (two sided α = 0.05 and β = 0.80) in test results even when between test correlations are poor (0.50).
An effect size of 0.4 was chosen because it is considered a relevant change in a small to medium size effect.
To allow for a drop-out rate of ±25% a total number of 66 patients is needed.

5.
TREATMENT OF SUBJECTS

5.1
Investigational product/treatment Patients with secondary adrenal insufficiency will be treated with oral hydrocortisone tablets adjusted to their weight according to the following dose-regimens: 0.2-0.3 mg/kg body weight/day or 0.4-0.6 mg/kg body weight/day in three divided doses.

5.2
Use of co-intervention Subjects are allowed to use co-medication, except for the drugs that are mentioned in the exclusion criteria.

5.3
Escape medication Patients are allowed to double or triple their HC dose in cases of small medical operations (e.g. when visiting a dentist) or in cases of fever (body temperature > 38 0 C). Patients are already familiar with the escape medication rules which do not differ from regular practice at the Endocrine outpatient practice. Because the study aims to investigate two different dosing-schemes increasing the dose of HC is allowed for a maximum of 1 week (i.e. 10% of the study time) and not in the week preceding M2 or M3.

6.2
Summary of findings from non-clinical studies Details can be found in the SPC page 6.

6.3
Summary of findings from clinical studies Details can be found in the IMPD / SPC pages 1-6.

6.4
Summary of known and potential risks and benefits Risks: All HC dosing schemes can be considered safe and are published in literature. Additional hydrocortisone escape medication to provide an imitation of physiological stress response is allowed. The risk of severe hypocortisolism on study dose-regimens of HC is small and estimated to be similar to conventional treatment at the outpatient clinic. Higher HC doses may slightly increase plasma glucose, triglycerides and blood pressure and may produce some weight gain. During a 10 week treatment period with the physiological treatment doses these changes are expected to be small. Benefit: participant"s potential preference to either dosing scheme in addition to insight in risks and benefit of high or low dose HC treatment.

Description and justification of route of administration and dosage
The route of administration is oral. The dosages are published dosage schemes and widely recommended by leading health organizations and expert groups. They can be inferred from endogenous cortisol production rates in healthy volunteers which are known to vary from 6-15 mg/m 2 /dag. Thrice daily administration mimics the day-curve of cortisol seen in healthy volunteers. To mimic peak values in the early morning the highest substitution doses are before breakfast.

Dosage modification
Patients are allowed to double or triple their HC dose in cases of small medical operations (e.g. when visiting a dentist) or in cases of fever (body temperature > 38 0 C). Patients are already familiar with the escape medication rules which do not differ from regular practice at the Endocrine outpatient practice. Because the study aims to investigate two different dosing-schemes increasing the dose of HC is allowed for a maximum of 7 days (i.e. 10% of the study time) and not in the week preceding M2 or M3.

Method of administration
Oral tablets 6.7 Preparation and labelling of Investigational Medicinal Product Tiofarma B.V. is responsible for labeling the hydrocortisone tablets. The labels comply with annex 13 of the GMP; it contains all the requirements placed on the labels.

6.8
Drug accountability Tiofarma B.V. is responsible for delivery of the study medication by courier to the pharmacy of UMCG. The pharmacy reviewes the medication and distrubutes them on the basis a study patient nummer provided by the prinicipal investigator.
Remaining tablets will be counted after each treatment period and compared to patient"s recording of HC tablet intake. Remaining drug tablets will be taken by the pharmacy and destroyed in the UMCG.

Main study parameter/endpoint
Cognitive performance.

Secondary study parameters/endpoints
Quality of Life (QoL), -Common somatic complaints in relation to mood Metabolic profile Somatosensation

Other study parameters (if applicable)
Not applicable.

7.2
Randomisation, blinding and treatment allocation This will be a randomized (group A or group B), double blind, cross-over study.

M1
10 weeks M2  Approximate duration of each visit will be 3 hours and 45 min.
Cognitive test Battery: see appendix 1.
The Daily mood and symptom report: see appendix 2.
Quality of Life questionnaires: see appendix 3.

24-h urine collection for creatinin, free cortisol and steroid profile.
Hair Beard hair will be collected with the help of a dry razor blade on the morning of M2 and M3 and stored dry at minus 80 degree until analyzed. Cortisol in hair is measured on the LCMS-MS (courtesy of Prof IP Kema).

Withdrawal of individual subjects
Subjects can leave the study at any time for any reason if they wish to do so without any consequences. The attending physician can decide to withdraw a subject from the study for urgent medical reasons.

7.5
Replacement of individual subjects after withdrawal Not applicable. In anticipation, we included ± 25 % more patients than we need to find significant differences as described in section 4.4. For this reason, patients will not be replaced when they decide to discontinue with the study.

7.6
Follow-up of subjects withdrawn from treatment Withdrawal from the study has no consequences for further treatment. All patients, including withdrawn patients, will continue their regular visits to the department of Endocrinology of the UMCG.

7.7
Premature termination of the study Premature ending of this study is not to be suspected. If there is a premature ending of the study it will not have any consequences for the treatment of patients.

Section 10 WMO event
In accordance to section 10, subsection 1, of the WMO, the investigator will inform the subjects and the reviewing accredited METC if anything occurs, on the basis of which it appears that the disadvantages of participation may be significantly greater than was foreseen in the research proposal. The study will be suspended pending further review by the accredited METC, except insofar as suspension would jeopardize the subjects" health. The investigator will take care that all subjects are kept informed.

Adverse and serious adverse events
Adverse events are defined as any undesirable experience occurring to a subject during a clinical trial, whether or not considered related to the investigational drug. All adverse events reported spontaneously by the subject or observed by the investigator or his staff will be recorded.
A serious adverse event (SAE) is any untoward medical occurrence or effect that at any dose: -results in death; -is life threatening (at the time of the event); -requires hospitalization or prolongation of existing inpatients" hospitalisation; -results in persistent or significant disability or incapacity; -is a congenital anomaly or birth defect; -is a new event of the trial likely to affect the safety of the subjects, such as an unexpected outcome of an adverse reaction, lack of efficacy of an IMP used for the treatment of a life threatening disease, major safety finding from a newly completed animal study, etc.
All SAEs will be reported through the web portal ToetsingOnline to the accredited METC that approved the protocol, within 15 days after the sponsor has first knowledge of the serious adverse reactions. SAEs that result in death or are life threatening should be reported expedited. The expedited reporting will occur not later than 7 days after the responsible investigator has first knowledge of the adverse reaction. This is for a preliminary report with another 8 days for completion of the report.

Suspected unexpected serious adverse reactions (SUSAR)
Adverse reactions are all untoward and unintended responses to an investigational product related to any dose administered.
Unexpected adverse reactions are adverse reactions, of which the nature, or severity, is not consistent with the applicable product information (e.g. Investigator"s Brochure for an unapproved IMP or Summary of Product Characteristics (SPC) for an authorised medicinal product).
The sponsor will report expedited the following SUSARs through the web portal ToetsingOnline to the METC: SUSARs that have arisen in the clinical trial that was assessed by the METC; SUSARs that have arisen in other clinical trials of the same sponsor and with the same medicinal product, and that could have consequences for the safety of the subjects involved in the clinical trial that was assessed by the METC.
The remaining SUSARs are recorded in an overview list (line-listing) that will be submitted once every half year to the METC. This line-listing provides an overview of all SUSARs from the study medicine, accompanied by a brief report highlighting the main points of concern. The expedited reporting of SUSARs through the web portal ToetsingOnline is sufficient as notification to the competent authority.
The sponsor will report expedited all SUSARs to the competent authorities in other Member States, according to the requirements of the Member States.
The expedited reporting will occur not later than 15 days after the sponsor has first knowledge of the adverse reactions. For fatal or life threatening cases the term will be maximal 7 days for a preliminary report with another 8 days for completion of the report.
The pharmacy of the UMCG is able to break the code to find out whether the patient is in a low or high hydrocortisone condition.

Annual safety report
In addition to the expedited reporting of SUSARs, the sponsor will submit, once a year throughout the clinical trial, a safety report to the accredited METC, competent authority, Medicine Evaluation Board and competent authorities of the concerned Member States. This safety report consists of: a list of all suspected (unexpected or expected) serious adverse reactions, along with an aggregated summary table of all reported serious adverse reactions, ordered by organ system, per study; a report concerning the safety of the subjects, consisting of a complete safety analysis and an evaluation of the balance between the efficacy and the harmfulness of the medicine under investigation.

8.3
Follow-up of adverse events All adverse events will be followed until they have abated, or until a stable situation has been reached. Depending on the event, follow up may require additional tests or medical procedures as indicated, and/or referral to the general physician or a medical specialist.

8.4
Data Safety Monitoring Board (DSMB) Not applicable 9 STATISTICAL ANALYSES 9.1 Descriptive statistics Data on demographic and baseline characteristics will be summarized by mean (or median), standard deviation (or 25 th or 75 th percentiles), minimum and maximum for continuous variables and by proportions (percentages) for discrete variables.

Treatment analysis
Treatment effects will be assessed by analysis of differences between M2 and M3 using a paired samples t-test or a non-parametric test where appropriate. M1 serves as a reference within the cognitive functioning of patients at baseline (that is: on their conventional HC doses therapy).
In case of confounding variableswhat we do not expectwe will decide to use a Linear Mixed Effect model.

Regulation statement
This study will be conducted according to the principles of the declaration of Helsinki (version 2008).

Recruitment and consent
Patients with secondary adrenal insufficiency are recruited from the Endocrine outpatient clinic at the UMCG. The investigator will inform patients with secondary pituitary insufficiency about the study and ask for their consent after approval of their treating physician who will assess appropriateness of eligibility. The information will be by letter sent either by mail or handed out during a scheduled outpatient visit. It will be explained that participation is voluntary and refusal has no influence on the treatment of the patient. Any questions will be answered by the investigator. The subjects will be asked to react within two weeks if they want to participate by sending back a reaction form or by calling the investigator.

Objection by minors or incapacitated subjects (if applicable)
No incapacitated subjects or minors will be asked to participate.

Benefits and risks assessment, group relatedness
Benefit: participant"s potential preference to either dosing scheme in addition to insight in risks and benefit of high or low dose HC treatment. Risks: All HC dosing schemes can be considered safe and are published in literature. Additional hydrocortisone dose escape medication to prevend hypocortisolism is allowed.
The risk of hypocortisolism on study dose-regimens of HC is small and estimated to be similar to conventional treatment at the outpatient clinic.

Compensation for injury
The sponsor/ investigator has a liability insurance which is in accordance with article 7, subsection 6 of the WMO.
The sponsor (also) has an insurance which is in accordance with the legal requirements in the Netherlands (article 7 WMO and the Measure regarding Compulsory Insurance for Clinical Research in Humans of 23th June 2003). This insurance provides cover for damage to research subjects through injury or death caused by the study. 1. € 450.000,--(i.e. four hundred and fifty thousand Euro) for death or injury for each subject who participates in the Research; 2. € 3.500.000,--(i.e. three million five hundred thousand euro) for death or injury for all subjects who participate in the Research; 3. € 5.000.000,--(i.e. five million Euro) for the total damage incurred by the organization for all damage disclosed by scientific research for the Sponsor as "verrichter" in the meaning of said Act in each year of insurance coverage.
The insurance applies to the damage that becomes apparent during the study or whitin 4 years after the end of the study.

Incentives (if applicable)
There will be no special incentives or compensations for subjects who participate. They only will be compensated for the travel and parking costs they made.

Handling and storage of data and documents
Data will be handled confidentially and an identification code will be made. The codes are not based on the patients" initials or birth date. The key to the code will be safeguarded by the pharmacy of the UMCG. The handling of personal data will comply with the Dutch Personal Data Protection Act.

Amendments
Amendments are changes made to the research after a favourable opinion by the accredited METC has been given. All amendments will be notified to the METC that gave a favourable opinion.

Annual progress report
The sponsor/investigator will submit a summary of the progress of the trial to the accredited METC once a year. Information will be provided on the date of inclusion of the first subject, numbers of subjects included and numbers of subjects that have completed the trial, serious adverse events/ serious adverse reactions, other problems, and amendments.

End of study report
The investigator will notify the accredited METC of the end of the study within a period of 8 weeks. The end of the study is defined as the last patient"s last visit.
In case the study is ended prematurely, the investigator will notify the accredited METC, including the reasons for the premature termination.
Within one year after the end of the study, the investigator/sponsor will submit a final study report with the results of the study, including any publications/abstracts of the study, to the accredited METC.

Public disclosure and publication policy
Publication policy will comply with the CCMO statement.  3.

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Quantitative Sensory Testing (QST)
Mechanical QST tests consist of seven different parameters. The mechanical detection threshold (MDT) is determined by using a standardized set of modified von Frey filaments (Optihair2-Set, Marstock Nervtest, Germany). MDT is assessed by using the ''method of limits'' in which five threshold determinations are made, each with a series of ascending and descending stimulus intensities. The final threshold is the geometric mean of these five series.
The mechanical pain threshold (MPT) is measured using a custom made set of seven pinprick devices with fixed stimulus intensities that exerted forces of 8, 16, 32, 64, 128, 256, and 512 mN. The stimulators are applied in an ascending order until the first percept of sharpness is reached. The final threshold is the geometric mean of five series of ascending and descending stimuli.