Previous literatures have well-documented the health disparities experienced by the sexual minorities. These studies have reported that compared to the general population, lesbian, gay, and bisexual (LGB) individuals are having more adverse health conditions [1-11]. LGB people have poorer mental health statuses [3-5, 10,11], with more prevalent suicidal ideation [6]. Similarly, the prevalence of several chronic diseases [3], including insomnia and dermatitis [1], is higher in the LGB population than in the general population. Furthermore, higher prevalence of risky health behavior is observed among LGB adults, such as heavy drinking [8,9] or smoking [2,8,9].

Despite such findings, studies on the health of LGB people are lacking in South Korea (hereafter Korea). According to a systematic review by Lee et al. [12], there are only 123 published studies that have investigated the health of sexual minorities in Korea as of 2013. Among them, 101 articles (78.9%) were clinical investigations, mostly case reports of sex reassignment surgeries of transgender and intersex individuals by healthcare institutions. Only 30 out of the 123 studies have examined the health status of LGB individuals, with even a fewer number of studies (n= 25) analyzing the health disparities and the social factors that may be associated with their health.

Due to the paucity of existing studies in the field, previous literatures regarding health disparities of LGB population in Korea have the following limitations. First, most studies were on the health disparities of LGB adolescents, using the Korea Youth Risk Behavior Web-based Survey which is the only nationally representative data that includes sexual orientation in the questionnaire [13-15]. On the other hand, because of the absence of sexual orientation measure in national health surveys targeting adults, there are only few studies on health disparities of adult sexual minorities. Second, no previous research has compared the health status of lesbian and bisexual individuals with the general population. There were few studies examining health disparities of gay men or men who have sex with men (MSM) [16-19], but there was no study on the health disparities of lesbian and bisexual women. Also, studies on MSM have not distinguished between homosexual and bisexual men [16]. Third, studies compared the health status of gay men and MSM with heterosexual adult men sampled these populations separately for their analysis [16-19] and sample size of those studies was relatively small with the largest such study only having 129 MSM participants. Lastly, the health outcomes investigated in the existing studies are limited to only some mental health conditions and health behaviors. Despite previous studies reporting that the Korean LGB population has a higher prevalence of risky health behaviors [14], and have higher prevalence of depressive symptoms [14,17,20] and suicide risk [15,17], none of these studies have studied physical health.

To fill these gaps in knowledge, this study aimed to explore the health disparities between LGB adults and the general population in Korea. The purpose of this study was to compare the health status of LGB individuals and the general population in diverse aspects, including self-rated health, mental health (depressive symptoms, suicidal ideation, suicide attempts), physical health (musculoskeletal pains), and health-related behaviors (smoking and hazardous drinking).

The present study showed that the overall health of the LGB adults in Korea is poorer than that of the general population. Compared to the general population, there was a higher prevalence of depressive symptoms, suicidal ideation and attempts, and musculoskeletal pains among Korean LGB adults. For women, the prevalence of reporting poor self-rated health and smoking was higher in the LGB population, and the prevalence of hazardous drinking was higher in the LGB population, with the exception of bisexual men, than in the general population. These findings are consistent with previous studies on health disparities of the LGB population [1-11].

The results about suicidal ideation and attempts in the Korean LGB adults particularly deserve attention. Our findings revealed that the prevalence of suicidal ideation among LGB adults was about 6.25 (lesbians) to 10.93 (bisexual men) times higher, and the prevalence of suicide attempts over the past 12 months was about 7.11 (lesbians) to 37.65 (bisexual men) times higher than in the general population. Korea has the highest suicide rate among Organization for Economic Cooperation and Development countries (29.1 suicides per 100,000 population) as of 2013 [22] and suicide is the main leading cause of death in Korean adults in their 20s-50s [23]. Considering these facts, our finding about suicidality of Korean LGB adults is very alarming.

To explain the health disparities of Korean LGB adults observed in this study, the minority stress processes in LGB population may be a useful framework [24]. Meyer [24] termed the stress experienced by sexual minorities in society due to their minority status as “minority stress” and theorized the process through which minority stress influences the mental health of sexual minorities. According to this model, all humans experience stressors in their daily lives but sexual minorities experience additional stressors leading to adverse health outcomes such as experiences of prejudice events, internalized homophobia, and expectations of rejection [24-29].

The minority stress model suggests that the hostile social environment for sexual minorities in Korea may be a key factor that exacerbates the health of sexual minorities. According to the Social Integration Survey in 2016, 55.8% of the respondents stated that they “do not accept” homosexuals [30]. Compared to the social acceptance toward other minority groups (North Korean defectors 12.1%, foreign immigrants or laborers 7.1%, people with disabilities 1.3%), the social acceptance for homosexuals is very low in Korea [30]. Furthermore, anti-lesbian, gay, bisexual, and transgender (LGBT) movement has been rapidly organized in Korea since the mid-2000s, and hate expressions against LGBT people have emerged as an important social problem [31-33]. In such social environment, various negative social experiences that sexual minorities face may worsen their health. Korean studies reported associations between social stigma and low life satisfaction in LGB adults [34] and between the experience of anti-gay violence and suicide risk in gay adolescents [35]. Further studies are needed to understand to what extent negative social experiences within the hostile environment of Korea explain for health disparities of LGB adults found in this study.

Another notable finding of this study is the differences in health status within the LGB population. Although the SPRs for mental health and physical symptoms against the general population were high in all the sexual minority groups, there were differences in self-rated health and health-related behaviors within the groups. The prevalence of poor self-rated health was higher in lesbians and bisexual women than in the general population, but no statistical difference was found among men. While lesbians and bisexual women showed a significantly higher prevalence of smoking than did the general population, gay and bisexual men showed a significantly lower prevalence of smoking than did the general population. Furthermore, SPRs for hazardous drinking was the highest in lesbians, followed by bisexual women and gay men, while there was no significant difference between bisexual men and the general population.

Previous studies also showed differences in health status among LGB population, but the findings were not consistent [1-5]. Further studies are needed to identify the factors and mechanisms behind health disparities within sexual minorities. More detailed examination on socio-demographic variables, such as gender, age, and socioeconomic status, is needed from an intersectional perspective before simply adjusting for them in the analysis. Additionally, more studies are needed to explore the health of lesbians and bisexual women. Both of them are relatively neglected populations in Korea LGBT health researches.

The present study has the following limitations. First, we cannot exclude the possibility that SPRs might be overestimated due to the difference in survey methods between our survey and the national health surveys used for the general population. Although the same questionnaires were used, we conducted an online survey while all the national-level health surveys were administered through face-to-face interview. Given the fact that sensitive questions, such as suicidal ideation and attempts, are more likely to be underreported in an in-person interview, it is difficult to completely exclude the possibility of overestimation of SPRs for suicidal behaviors. Second, there may be the possibility of potential under estimation of SPRs for musculoskeletal pains and healthrelated behaviors due to the difference in survey participants. Among our survey participants 33.5% were students, while participants of the KWCS used as a comparison group were limited to economically active population. Considering that the prevalence of musculoskeletal pains and health-related behaviors is generally higher in working populations, there is a possibility that the SPRs for those were underestimated. Third, the comparison group may have LGB individuals because those nationally representative surveys did not include sexual orientation measure in their questionnaires. Hence, it should be noted that the findings of this study were only a comparison of the health status of the Korean LGB adults with the general population, and not a comparison between LGB adults and their heterosexual counterparts.

Finally, the limitation of our study is that the representativeness of the sample cannot be ensured, as we used convenience sampling. The majority of participants were in their 20s-30s (90.9%) with high levels of education and income. It may be attributable to the fact that survey promotion and recruitment relied heavily on online and offline networks of sexual minority organizations and communities, as low-income and low-educated older LGB individuals may have lower access to such networks. In that case, there is a possibility that the SPRs in this study might be underestimated.

To address the limitations of this study and to gain a more systematic understanding of the health disparities of the Korean LGB population, nationally representative surveys should include sexual orientation in their questionnaires. A growing number of health surveys in North America and Europe include sexual orientation as a demographic variable, based on which many studies are conducted to investigate health disparities of sexual minorities [1-3,6,7,9,10,36,37]. The Korea Youth Risk Behavior Web-based Survey is the only national-level health survey in Korea measuring sexual orientation by asking respondents to indicate the gender of the person with whom they had a sexual intercourse. These data enabled studies to compare the health status of LGB adolescents with heterosexual counterparts [13-15]. To facilitate LGBT health studies in Korea, sexual orientation needs to be included as a demographic variable in national-level health surveys, such as the KNHANES and Work Environment Survey.

The present study aimed to investigate the magnitude of health disparities faced by the Korean LGB adults using the largest Korean dataset on LGB individuals. Future studies should take a step further to identify social factors that might worsen or improve their health. Furthermore, policy interventions should be implemented to improve the health and quality of life of sexual minorities in Korea.