Men tend to have noticeably lower HDL levels, with smaller size and lower cholesterol content, than women. Men also have an increased incidence of atherosclerotic heart disease.
In general, your risk for heart disease, including a heart attack, increases if your HDL cholesterol level is less than 40 mg/dL. More specifically, men are at particular risk if their HDL is below 37 mg/dL, and women are at particular risk if their HDL if their HDL is below 47 mg/dL.
An HDL 60 mg/dL or above helps protect against heart disease.