my apologies, I mixed up which thread I was looking at. In that study I think gender is used because they are including transgender women as a population of interest, so similar to the other example gender is an aspect of what they are attempting to study, and sex hormones are the means by which it is being studied.
> We expect that our studies would serve to develop potential sex- and gender-specific treatments and recommendations for dosage of therapeutic agents to treat and prevent asthma in cis and transgender women.
It may also be that "sex and gender" is used because it isn't actually known what causes the differences observed in the population and that gendered socialization, treatment, or preferences could be contributing factors. This study for instance found that girls were less likely to see a doctor or get diagnosed with asthma even when controlling for symptom severity.
[1] Gonadal hormones as mediators of sex and gender influences in asthma - https://reporter.nih.gov/project-details/10891526
[2] A Mouse Model to Test the Effects of Gender-affirming Hormone Therapy on HIV Vaccine-induced Immune Responses - https://reporter.nih.gov/project-details/10849830