Introduction
In 2019, 9.3% of the adult population aged 20–79 years were living with type 2 diabetes worldwide1 with a rapid prevalence increase in regions facing an epidemiological transition. Three major risk factor categories for type 2 diabetes are recognised: biological risk factors such as unfavourable genetic and epigenetic modifications (eg, related to maternal or paternal obesity) and hormonal status (eg, high testosterone levels in women or low sex hormone-binding globulin levels),2 3 a low socioeconomic status2 4 5 and cardiometabolic risk factors (eg, obesity,6 smoking,7 physical inactivity,8 depression9). In vivo, these categories are not mutually exclusive, and individuals find themselves at their intersections.10
Previous literature reported sex differences in type 2 diabetes epidemiology: worldwide and in high-income countries, men display an approximately 1-3-1.5-fold higher prevalence of type 2 diabetes than women.11–13In high-income Western countries in 2019, an age-standardised prevalence is of 7.3% in men and 5.3% in women,14 although women are predominant among youth-onset diabetic patients.3 Sex-disaggregated data on type 2 diabetes in Switzerland are scarce, but one study reported an age-adjusted prevalence of 7.8% in men and 5.7% in women.11 Concerning socioeconomic status, women tend to have a less favourable position than men (eg, lower educational level and job qualification, more often living alone and/or raising children alone)15 16 and their professional stress increased in the last decade.17 Regarding exposure to cardiometabolic risk factors, women tend to display a more favourable cardiometabolic profile and healthier health-related behaviours patterns (eg, smoking, drinking alcohol, alimentation) than men.15 18 Moreover, the probability of developing type 2 diabetes after cardiometabolic2 19–21 and socioeconomic4 risk factor exposition is higher for women and they have an excess risk of CVD compared with men exposed to the same risk factors,2 3 supporting the hypothesis of women developing type 2 diabetes at worse metabolic states than men.22 Nevertheless, available research on type 2 diabetes epidemiology mainly set hypotheses on sex differences a posteriori and study biological, cardiometabolic and socioeconomic risk factors separately failing to provide thorough explanations of the combined effects of these different categories.
Restricting research to the man/woman variable may be limiting as it entangles potential biological and social factors on one hand and prevents the integration of the other social dimensions and systemic power relations that modulate the intersectional social positions of women and men on the other hand. More precisely, intersectionality posits that individual identities and social locations such as gender, race, and class intersect and represents unique experiences that are overlooked by focusing on one identity over another.23 We assume this conceptualisation of gender as one aspect of the social positions shaping the life experience of individuals. Gender medicine research has highlighted how gender influences risk exposure, health-related behaviours and access to healthcare.24 It also defined three different levels of the gender dimension (ie, individual, interactional and institutional): as an example, risk-taking behaviours are proxy for the conformity to (masculine) gender norms on the individual level and job-related physical intensity for gender roles on the interactional level (figure 1). In recent years, this new focus on medical research challenged the sex dichotomy in how epidemiological science and knowledge are conceived and different research methods on how to integrate gender in clinical research are being developed.24–28 The authors advocate for disentangling sex and gender, illustrating how neglecting gender in its predefined sense reinforces health disparities, and arguing for robust methods to improve the reproducibility of these emerging approaches. Nevertheless, operationalisation of gender as an intersectional sociological concept remains a challenge.29 To the best of our knowledge, only a limited number of studies have delved into the multidimensional impact of gender on acute coronary syndrome30 and, more recently, metabolic syndrome.31
The originality of this study is its contribution to explore the added value of a latent class analyses (LCA) approach to describe and understand the role of the intersectional social position (including multidimensional gender, sociodemographic and health-related behaviour variables) in contributing to the differences observed between women and men related to their risk of developing type 2 diabetes.