Patient case (clinical description): A 19-year-old male came to clinic with some sexual concern.  He recently engaged in a relationship and is worried about the satisfaction of his girlfriend. He has a "baby face" according to his girlfriend's statement and he is not as muscular as his classmates.  On physical examination, there is some pubic hair and poorly developed secondary sexual characteristics. He is unable to detect coffee smell during the examination, but the visual acuity is normal. Ultrasound reveals the testes volume of 1-2 ml. The hormonal evaluation showed serum testosterone level of 65 ng/dL with low levels of GnRH.

Patient's own account: I'm 19 years old guy and I just went to see a doctor at the clinic after I just got with my girlfriend. I'm kinda worried because she thinks that I have a baby face and to be honest, I'm way less muscular than my classmates. I don't have much hair down there, and yes, I don't have that macho look. The doctor made me smell some coffee and I couldn't smell anything special. I also had some eyesight checkups and the doctor told me everything was normal. I got my test results back and it says: testes volume is 1-2 ml and serum testosterone level of 65 ng/dL with low GnRH levels.

Clinical trial: Effects of Transdermal Testosterone and/or Monthly Vitamin D on Fall Risk in Pre--frail Hypogonadal Seniors

Eligibility criteria:
Inclusion Criteria:

          1. Men with documented total testosterone levels < 11.30 nmol/l

          2. Able to come to the study centre (Community-dwelling or institutionalized)

          3. Age 65+ years

          4. At a higher risk for falling

          5. Body mass index > 18.0 and < 35.0 kg/m2

          6. Understands German in reading and writing plus able to read, understand, and complete
             questionnaires and tests.

          7. Willingness to limit additional vitamin D3 intake to a maximum of 800 IU per day

          8. Willingness to limit calcium supplement intake to 500 mg/day

          9. Willingness to stop active vitamin D metabolites

         10. Willingness to forgo any additional use/application of testosterone products for the
             duration of the trial.

         11. Participant understands the study procedures, alternative treatments available and
             risks involved with the study and voluntarily agrees to participate by giving a
             written informed consent.

         12. Participant meets the routine clinical laboratory safety screening tests performed at
             screening visit.

         13. Participant is able and willing to perform all study tests, attend all required office
             visits, and provide blood and urine samples.

         14. Participant is able to apply the testosterone/placebo gel and is able to drink the
             vitamin D/placebo solution.

         15. Participant is mentally competent (judicious) defined by having score > 24 on the
             Folstein's mini mental state examination (MMSE) at the screening visit.

        Exclusion Criteria:

          1. Contraindications to the class of drugs under study, e.g. known hypersensitivity or
             allergy to class of drugs or the investigational product

          2. Treatment with vitamin K-antagonists, insulin, adrenocorticotropic hormone (ACTH),
             corticosteroid (>5mg/d)

          3. Elevated (≥ 4.0 ng/ml) prostate-specific antigen levels (at screening) and/or palpable
             signs of prostate cancer

          4. Palpable signs of breast-cancer

          5. Haemoglobin ≤ 100 g/l

          6. Haematocrit ≥ 0.50 L/L

          7. Liver function values (alanine aminotransferase, aspartate aminotransferase,
             Gamma-glutamyl transferase, alkaline phosphatase) more than 3 times the upper limit of
             normal.

          8. Consumption of >800 IU vitamin D on any day in the 6 months prior to enrolment.
             Provision: a person can be enrolled as soon as the mean intake in the last 6 months
             and since the last dose is ≤ 800 IU.

          9. Elevated serum calcium ≥ 2.60 mmol/l (adjusted for albumin )

         10. Estimated (Cockcroft and Gault formula ) creatinine clearance ≤ 30 ml/min

         11. Severe visual or hearing impairment

         12. History of cancer < 5 years prior to signing informed consent, except for adequately
             treated basal cell or squamous cell skin cancer

         13. Myocardial infarction in the last 3 months, unstable angina pectoris and/or exertional
             dyspnoea >=NYHA III

         14. Treatment worthy but untreated sleep apnoea or chronic (obstructive) pulmonary
             disease, epilepsy

         15. Significant end-stage disease, i.e. genitourinary, cardiovascular, hepatic, renal,
             endocrine, hematologic, psychiatric, or pulmonary disease, which, in the opinion of
             the investigator, may pose a high risk to the patient or impair the patient's ability
             to complete the trial or confound the results

         16. Uncontrolled hypertension (blood pressure mm Hg ≥ 180 systolic or ≥ 110 diastolic)

         17. Alcohol abuse or alcoholic disease

         18. Participation in another interventional research trial within the last 6 months prior
             to screening

         19. Severe gait impairment, e.g. due to Parkinson's disease or hemiplegia

         20. Previous enrolment into the current study

         21. Enrolment of the investigator, his/her family members, employees and other dependent
             persons
Male
No healthy subjects accepted to join the trial.
Subject must be at least 65 Years old.


Eligibility (NLI label): Contradiction