There are more effective interventions like cardiovascular exercise, increased monounsaturated fat intake, increased soluble fiber intake, decreased saturated fat intake (and cholesterol if part of the 30% of the population that's sensitive to it), and fish oil supplements. All of those have proven to be way, way, way more effective at treating cholesterol... And what a coincidence, many of them tend to aid with insulin sensitivity as well

Seriously, cinnamon supplements should be a last ditch effort for any change.