Very high triglycerides can be caused by poor diet and not enough exercise. You may also have inherited very high triglycerides from a parent. Your doctor will tell you how to manage your triglycerides. If your weight is higher than what is considered healthy, losing even 5 pounds may help lower your triglycerides.
WORD likes it un-hyphenated but I don't. Long-term should be hyphenated but longtime should not be hyphenated, at least until a few more decades pass and the grammatical rules for the use of hyphens either relax or fade away. Here is part of an erudite commentary on this subject:
When numbers are not used as compound adjectives preceding nouns, donât use a hyphen. (But remember, all two-word numbers from twenty-one to ninety-nine must be hyphenated in all cases.). Examples: Suzanne won the race by a solid 15 feet. The room was 17 feet long.