Psychophysiology 11 5 579- 590 cialis online prescription Sensitivity analysis by study quality Baillargeon 2004; Chou 2003; Fleming 2002; Hoeger 2004; Maciel 2004; Morin Papunen 2012; Pasquali 2000; Tang 2006 eliminated overall heterogeneity I 2 0 and the results indicated no evidence of metformin on fasting glucose concentrations MD 0 mmol L, 95 CI 0