You asked

How many Gulf War 1 (1991) veterans have some form of pituitary disorder (i.e. hypopituitarism, hypogonadism, hypothyroidism, unusually low or high testosterone etc.) and how much higher is that commonality compared to the average similar age within the population?

We said

Thank you for your enquiry.

We do not hold any information on the health of veterans. The Ministry of Defence may be better placed to help you: https://www.gov.uk/government/organisations/ministry-of-defence.