Final answer:
Leukoplakia is commonly associated with individuals who have compromised immune systems, such as smokers, rather than primarily the elderly or immunocompromised. Smoking impairs immune functions, which can increase the susceptibility to oral pathologies like leukoplakia.
Step-by-step explanation:
The question pertains to the prevalence of leukoplakia in different populations. When considering factors for predisposing conditions, we should look into various lifestyle and health factors. Smokers are at a greater risk of developing numerous oral conditions, including leukoplakia. Tobacco smoke impairs the lungs' immune defenses, which could facilitate opportunistic infections such as leukoplakia. Evidence also indicates that opportunistic infections and diseases, such as candidiasis and Kaposi's sarcoma, can manifest in individuals with compromised immune systems. Although leukoplakia can appear in any demographic, a significant percentage is often found in populations with weakened immune responses.
Based on provided contexts that include young individuals with compromised immune systems presenting opportunistic infections and serious diseases, it is reasonable to infer that such infections are not confined to the elderly population or the immunocompromised individuals alone. Therefore, as for the percentage of leukoplakia cases, the highest likelihood would be among smokers, as they are known to be highly at risk due to tobacco's detrimental effects on immune defense mechanisms and oral health. This connection follows the pattern of compromised mucosal defenses and increased susceptibility to oral pathologies.