Triglycerides: the lipid that moves the most

Triglycerides are the main form of fat the body stores and burns. In the blood they travel inside lipoprotein particles, mostly VLDL made by the liver and chylomicrons made by the gut after a meal. A triglyceride result is reported in mg/dL in the US and mmol/L elsewhere (divide mg/dL by 88.5 to convert). It is part of every standard lipid panel, and it is also used to calculate LDL in many labs.

The guideline numbers

Online "optimal" figures of under 100 or even under 70 mg/dL come from the observation that risk keeps falling at lower levels. That is consistent with the data, but no guideline sets those numbers as targets.

What raises and lowers them

• Raises: a recent meal, alcohol, refined carbohydrate and sugar, excess weight and insulin resistance, poorly controlled diabetes, an underactive thyroid, kidney disease, pregnancy, some drugs (including steroids, some HIV drugs and retinoids), and inherited conditions.
• Lowers: weight loss, cutting alcohol and sugar, exercise, omega-3 at prescription doses, fibrates and statins, and better glucose control.

What it predicts

In the Copenhagen City Heart Study (JAMA, 2007), 7,587 women and 6,394 men had non-fasting triglycerides measured and were followed for a mean of 26 years. Risk rose steadily with level. In women, those at 5 mmol/L (442 mg/dL) or more had a multifactorially adjusted hazard ratio for heart attack of 5.4 compared with under 1 mmol/L (89 mg/dL). The finding that non-fasting levels predict as well as fasting ones fed into the 2016 EAS/EFLM consensus that fasting is not routinely needed.

Genetics adds an important twist. A 2019 Mendelian randomisation study of 654,783 people found that gene variants lowering triglycerides reduced heart disease risk by the same amount as variants lowering LDL, per unit of ApoB lowered. Once ApoB was accounted for, triglycerides added nothing. In other words, triglycerides matter mainly through the number of particles carrying them; see the ApoB page.

On GLP-1 drugs and weight loss

Triglycerides fall more than any other lipid on these drugs:

These are secondary measures, not controlled for multiple testing, so read them as direction and size. The GLP-1 blood work page has the full lipid table.

How to test

• Non-fasting is acceptable for routine screening, per the EAS/EFLM. A normal meal raises triglycerides by up to about 26 mg/dL on average.
• Fast 9 to 12 hours if a previous non-fasting result was over 440 mg/dL, or if you want results comparable with old fasting ones. Pick one approach and stick to it.
• No alcohol for 24 to 48 hours beforehand.
• Expect variation. Triglycerides vary more from day to day in the same person than any other lipid. Look at the trend across several draws.

Tracking it in Peptide AI

In Peptide AI, triglycerides sits in the metabolic panel. The app reads it from a lab PDF or manual entry, scores the panel from 0 to 100 alongside an overall grade, flags values that warrant prompt physician consultation, and plots each result against your dose timeline. Meals logged in nutrition tracking show what you ate the day before the draw. Log the draw date, whether you fasted, and anything unusual in the days before, such as illness, a hard session or a dose step, so the next result is compared like with like. Bloodwork tracking shows the series next to the dose log, weight and side effects, and the panels page lists every marker the app groups. More markers are in the bloodwork guides.