The average man is at greater cardiovascular risk than his female counterpart, developing their first cardiovascular (CV) event when 5–10 years younger. Many theories for this well-established fact have been proposed, centring mostly on effects of female sex hormones to either directly or indirectly lessen vascular risks. Remarkably, in the 1960s, researchers randomized men to differing levels of conjugated oestrogen vs. placebo to test effects on CV outcomes. 1 A significant early increase in myocardial infarction rates with higher doses of conjugated oestrogen led to premature cessation of this arm. In doing so, this trial emphasized that sex differences in CV risk are more complex than appreciated and not simply ‘resolved’by addition of sex hormones. On the other side of the equation, type 2 diabetes (T2DM) is generally considered to enhance CV risk more in women than in men. 2 However, further high-quality data addressing this topic are needed as not all recent data showed such consistent patterns. 3, 4 In this issue of the European Heart Journal, Malmborg and colleagues have taken advantage of their excellent Danish hospital databases to ask several relevant questions. 5 They sought to determine not only whether relative risks for a combined major adverse cardiovascular event and incident heart failure (MACE-HF) endpoint increase in women more than men in the context of T2DM, but also whether such patterns differ by age. They also asked to what extent sex differences in CV risk changes were evident for recurrent events, ie after a patient’s first event.

Their main findings support a 15% greater relative risk increase in MACE-HF due to T2DM in women vs. men. This T2DM-induced excess relative risk increase in women was also evident across all ages but highest between ages 50 and 60 for the combined MACE-HF