LAUSR

Gender incongruence (GI) is defined as “an individual’s discontent with their assigned gender and their identification with a gender other than that associated with their birth sex based on physical sex characteristics” (1). The origin of GI appears to be complex and multifactorial. From the extensive research that has been conducted over the past few years, three main factors have been identified as key mechanisms for understanding GI: genes, hormones, and the environment. Accordingly, our Frontiers Research Topic includes twelve articles that cover very varied topics about GI, including cardiovascular effects of treatment, surgical outcomes, new treatment options and healthcare quality in a broader sense. This research involved the hard work of sixty-six authors that was carried out mainly in Europe (Austria, Belgium, Germany, Italy, Serbia, and Spain), Australia, and also the United States. An interesting study about the prevalence of cardiometabolic risk factors in transgender individuals receiving feminizing therapy for ≥6 months was carried out by Balcerek et al. in a sample of 296 transgender individuals. The authors found that a greater proportion of trans individuals ≥45 years of age were treated with transdermal estradiol. Of those who received oral estradiol, the median dose was lower. Importantly, relatively higher doses of estradiol put people at risk of cardiometabolic diseases, especially in combination with older age. The authors point out that the most prevalent cardiometabolic risk factor in the ≥45 years group was hypertension (29%), followed by current smoking (24%), obesity (20%), dyslipidaemia (16%) and diabetes (9%). On a related topic, Totaro et al., in a meta-analytic study, analyzed the risk of venous thromboembolism (VTE) in transgender people undergoing feminizing hormone treatment. The overall pooled prevalence estimate for VTE was 2%, but with a large heterogeneity across studies. A number of factors could contribute to the variable VTE risk in transgender people undergoing gender-affirming hormone treatment (GAHT), including the type of estrogen and the route of administration, age at the estrogen therapy onset, treatment duration, concomitant conditions such as smoking, obesity, thrombophilia and other comorbidities. This topic of cardiovascular health outcomes due to GAHT was also examined by Aranda et al. The authors present a review of the current literature on the effects of GAHT, in both transgender men and transgender women, on various cardiovascular health outcomes.