FST and diabetes mellitus: Circulating follistatin associated with an elevated risk of diabetes, hazard ratio (HR) per 1-SD increase in follistatin levels for T2D is 1.29 (CI: 1.19–1.40, p < 0.001), adjusted for age and sex; and 1.24 (CI: 1.04–1.47, p < 0.05) adjusted for multiple risk factors (Table 2).