As well as its effect on glycemia, insulin has been shown to inhibit TNF-α and macrophage inhibitory factor (when infused concomitantly with glucose). This has led to some doubts as to whether the effect in this study was due to normalization of blood glucose levels. However, multivariate analysis of all the risk factors for mortality, including severity of illness on admission, indicated that blood glucose determines the outcome; there was a 75% increase in risk of death per 50 mg/dl increase in blood glucose.