There's bad cholesterol (LDL) and good cholesterol (HDL). Which one are they talking about? Or are they talking about the sum of the two? From what I understand you can't have too little bad cholesterol, but it
is possible to have too little good cholesterol. According to Wikipedia, good cholesterol should be 60 mg/dL or more. Bad cholesterol should be less than 100 mg/dL. Having less bad cholesterol than an average american is a very healthy thing.
If your husband's good cholesterol is high enough, then the insurance company doesn't know what they're talking about. Tell them to pull their heads out of their statistical asses.
Wikipedia cholesterol article Good cholesterol Bad cholesterol