One of the senior poster in the Peak Testosterone Forum, who happens to have low testosterone, wrote the following:
“Being someone who struggled with severe childhood asthma and exercise and allergy induced adult asthma, this is a subject near and dear to my heart…The last link really makes me think if my use of asthma inhalers and corticosteroids for asthma is part of my current situation..”  What he was noticing is that there appear to be many links between asthma and testosterone, especially low testosterone. Isn’t asthma all about the lungs and testosterone about the brains and the groin? Sure, but we will show that they meet in the middle in many key ways.
The above poster accused his corticosteroid inhalers of causing his low testosterone. Basically, these drugs are designed as copies of cortisol and are used because cortisol suppresses the immune system. In asthma the immune system is “overreacting” and so a (supposedly) localized steroid is applied in order to help the situation. And, if you’ve poked around my site much, you know that almost anything that elevates cortisol is going to lower testosterone. I have many examples of Cortisol-Raising Stressors that Lower Testosterone for example.
But is this really the case? Why aren’t physicians noting the connection, considering the number of patients on these sort of asthma medications, if this is really a significant issue? And some research shows no real suppression of the HPAor testosterone with inhaled corticosteroids.  One study found that, while powerful oral steroids like prednisolone decreased testosterone by 33%, the inhaled version caused no significant drop in testosterone or leutinizing hormone. 
However, the real answer may lie somewhere in the middle: one study found that testosterone was suppressed by long term inhaled corticosteroid therapy, but only to a small degree. In this study average testosterone was only decreased by 18%.  So, yes, corticosteroids are not going to help, but they may not be the major factor at play here. So it may be the length of time that the inhalers are used, but it’s difficult to say at this point.
The authors also mentioned hypoxia, clinically low oxygen levels, as a possible issue that could drive down testosterone levels. One study on glucosteroids did indeed show a correlation between the degree of hypoxia and testosterone suppression.  A number of medical conditions, such as sleep apnea and COPD are linked to hypoxia. Sleep apnea has definitely been found to lower many key hormones, something I cover in my link on Apnea and Testosterone .
Did you know you can inexpensively do your own testing for most hormones? The industry leader is Discounted Labs..
In addition, asthma and testosterone are probably correlated through mitochondrial dysfunction. Loss of mitochondrial function is a whole theory of aging and there are definitely connections to both hypogonadism and asthma. Note the conclusions of this 2005 study in the journal Diabetes Care:
“These data indicate that low serum testosterone levels are associated with an adverse metabolic profile and suggest a novel unifying mechanism for the previously independent observations that low testosterone levels and impaired mitochondrial function promote insulin resistance in men..”  In other words, low T and mitochondrial issue go hand-in-hand and seem to help promote insulin resistance. The paper goes to actually explain that low testosterone itself may lead to mitochondrial dysfunction.
Furthermore, a number of studies have shown that mitochondrial dysfunction could lead to asthma or make it worse. One set of researchers stated clearly that “aging and animal model studies have revealed that mitochondrial dysfunction and oxidative stress are involved and play a large role in asthma.”  Yet another study showed that giving subjects a compound that improves mitochondrial dysfunction also improved asthma. 
So all of this could conceivably lead to a worse case scenario where asthma, through medications and hypoxia, may lower testosterone and lower testosterone may worsen asthma through mitochondrial dysfunction, i.e. a vicious circle would be created. Let’s hope there is more study work done as time goes on.
2) Vutr Boles, 1988, 27(4):29-32, “The serum testosterone level of patients with bronchial asthma treated with corticosteroids and untreated”
3) Respiratory Medicine, Nov 1992, 86(6):495 497, “Highdose inhaled steroid therapy and the cortisol stress response to acute severe asthma”
4) Respir Med, 1994 Oct, 88(9):659-63, “Testosterone levels during systemic and inhaled corticosteroid therapy”
5) American Journal of Respiratory and Critical Care Medicine, 2002, 165(5):708-712, “Role of Serum Cortisol Levels in Children with Asthma”
6) Respiratory Medicine, Oct 1994, 88*(9):659 663, “Testosterone levels during systemic and inhaled corticosteroid therapy”
7) Diabetes Care, Jul 2005, 28(7):1636-1642, “Relationship Between Testosterone Levels, Insulin Sensitivity, and Mitochondrial Function in Men”
8) http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3066010/, “Mitochondrial Dysfunction and Oxidative Stress in Asthma: Implications for Mitochondria-Targeted Antioxidant Therapeutics”
9) J Immunol, 2009 Aug 1, 183(3):2059-67, “Esculetin restores mitochondrial dysfunction and reduces allergic asthma features in experimental murine model”
10) British Med Journal, Oct 1985, Vol 291, “Plasma testosterone concentrations in asthmatic men treated with glucocorticoids”, p. 1051
11) Circulation, 2005, 112:2660-2667, “Selective Activation of Inflammatory Pathways by Intermittent Hypoxia in Obstructive Sleep Apnea Syndrome”