critical illness) and male-to-female sex ratio. The immune system-activating properties of DHEA may account for the association of DHEA levels with mortality [1,2]. These findings would support an assessment of the benefit of DHEA treatment in the postacute phase of critical illness, HTC notably in men [24].We found that in-hospital mortality was associated with low plasma IGF-1 levels. To our knowledge, this postacute phase relationship has been assessed in only one small cohort study [6]. A low IGF-1 level is considered a valuable marker of growth hormone (GH) deficiency, which is considered deleterious [25] and has inspired clinical trials [26,27]. Unfortunately, one randomized clinical trial has shown that the administration of GH increased mortality in critically ill patients [26].

Because GH was administered during the acute phase of critical illness in the Takala et al. trial [26], one may argue that GH administration should be tested during the prolonged phase of critical illness. Moreover, it has recently been shown that critical illness-associated mortality was not associated with IGF-1 level but with increased GH level (measured in the acute phase) [28]. It has to be noted that decreases in circulating IGF-1 levels can result from various causes frequently encountered in critically ill patients, such as malnutrition, chronic liver disease or diabetes [17]. In contrast to previous reports [29,30], we did not find that plasma IGF-1 levels differed between women and men.Female sex and increased blood glucose levels have been shown to be independently associated with increased mortality [31-33].

Therefore, these relationships can support our finding that blood glucose levels were higher in women who did not survive. It is also known that menopause is associated with type 2 diabetes mellitus. Preexisting diabetes was not more frequent in female patients who did not survive. It is conceivable that the conjunction of menopause and critical illness induce insulin resistance. Although such a benefit has not been reported in a large trial [34,35], it would be worth assessing the effect of strict glucose control in postmenopausal female patients in the ICU.Limitations of the studyThe biological effects of hormones depend not only on their circulating levels but also on specific and nonspecific hormone-binding proteins and on the expression and regulation of hormone receptors.

Since we did not assess binding protein levels or hormone receptor activity, we cannot exclude that a given hormone is associated with mortality on the basis of serum levels alone. Similarly, tissue hormone levels Dacomitinib might also have a prognostic value, but obviously they are not assessable in a living patient. Thus, Arem et al. [36] found that tissue thyroid hormone levels were lower in most organs of more patients who died as a result of critical illness than in those of patients who died as a result of trauma.