Artificial Gravity Bed rest study

Recruitment & Eligibility

Status: Completed

Sex: Not specified

Target Recruitment: 24

Inclusion Criteria

* Physically and mentally healthy test subjects that are able and declare their willingness to participate in the entire study and successfully passed the psychological and medical screening
* Aged between 24 and 55 years old with a Body Mass Index (BMI) of 19 - 30 kg/m2, height between 153 -190 cm
* Non-smoker, for at least six months before the start of the study
* Capable of completing the study
* Willing to stay in bed with or without weight-bearing (artificial gravity) for 60 days
* Demonstrable medical insurance and official certificate of absence of criminal record
* Demonstrable dentist certificate

Exclusion Criteria

Drug, medication or alcohol abuse (regular consumption of more than 20-30 g alcohol/day)
* A requirement for any prescription medications
* Vegetarian, vegan (during the study)
* Migraine, chronic headache
* Insomnia or other sleep disorders
* Previous psychiatric illness
* Claustrophobia
* Increased intraocular pressure
* Any eye disorder that could significantly impact or jeopardize visual function
* Hyperopia > +5.0 Diopters
* Myopia > - 6 Diopters
* Astigmatism > 3 Diopters
* History of laser surgery, glaucoma and retinal surgery
* Hiatus hernia
* Gastro-oesophageal reflux
* Gastrointestinal stenosis, dysphagia
* Current or history of chronic bowel disease
* Diabetes mellitus
* Rheumatic illness
* Current or a history of (chronic) pulmonary disease
* Current muscle or joint disease or disorder
* History of prolapsed intervertebral disc
* Chronic back complaints
* Bone fractures less than 1 year prior to study
* Kidney disorder: deviations from normal values for creatinine in plasma. Deviations from normal values (Normal values for creatinine in plasma < 1.20 mg/dl)** and eGFR***
* History of kidney stones
* History of (chronic) cystitis, hydronephrosis, pyelonephritis
* Anaemia: Hb under normal values. (Normal values of Hb for men: 13.0-17.5 g/dl; women 12.0-16.0 g/dl)**
* Elevated risk of thrombosis ****
* Pronounced orthostatic intolerance (< 10 min standing and/or not able to withstand artificial gravity)
* History of elevated intracranial pressure and associated central nervous disorders
* Current or history of hemorrhagic diathesis or coagulations disorders
* History of spinal cord disease, including radiculopathy, myelopathy, or neuropathy
* History of skull/cranial surgeries
* History of adverse events to local anesthesia
* An abnormal androgen or estrogen status (tested only upon speculation)
* Female candidate is pregnant
* Female candidate is on oral contraceptives or contraceptive patch up to 4-6 months prior to study start
* Female candidate is in menopause or post-menopause, or is on hormone replacement therapy
* Female subjects without a normal length menstrual cycle (20-36 days)
* Inability or unwillingness to perform the required tests
* A medical or orthopedic condition that would preclude bed rest or exercise, as is determined by the examining and overseeing physician of the bed rest study
* Not within two standard deviations of normal bone mineral density (measured by dual-energy x-ray absorptiometry) for hip and lumbar spine based on T-score (young adult-peak bone mass, Caucasian, sex, but not age-adjusted)
* Metal implants (or objects like metallic slivers in the eyes, or bullets or shrapnel in the body) or other kinds of bone synthesis materials that are not well-fixed; tattoos or permanent make-up incompatible with MRI
* Participation in a (clinical) study within the last 3 months before start of this study that confounds participation in the AGBRESA study
* Known history of vertigo, nystagmus, neurological conditions, vestibular or gait disorders
* Previous heart surgery
* History of cerebrovascular or brain disease, tumor, injury, surgery or malformation
* Disorders of CSF circulation (i.e. hydrocephalus, idiopathic intracranial hypertension)
* Tinnitus; sensorineural hearing loss > 30 dB, or implanted hearing de