[onlyrealcuzzo]

When you have TC (total cholesterol) < 200 mg/dL (milligrams per deciliter) - each 1mmol/L (millimoles per liter) reduces mortality.

When you have TC > 200 mg/dL - each 1mmol/L increases mortality.

The confidence interval was high.

> In the age groups of 18–34, 35–44, 45–54, 55–64, 65–74, and 75–99 years, each 1 mmol/L higher TC increased mortality by 14%, 13%, 8%, 7%, 6%, and 3%, respectively (P < 0.001 for each age group), for TC ≥ 200 mg/dL, while the corresponding TC changes decreased mortality by 13%, 27%, 34%, 31%, 20%, and 13%, respectively, in the range < 200 mg/dL (P < 0.001 for each age group). TC had U-curve associations with mortality in each age-sex group. TC levels associated with lowest mortality were 210–249 mg/dL, except for men aged 18–34 years (180–219 mg/dL) and women aged 18–34 years (160–199 mg/dL) and 35–44 years (180–219 mg/dL). The inverse associations for TC < 200 mg/dL were stronger than the positive associations in the upper range.

[twoWhlsGud]

Speculation in the discussion section is that while lower TC (below the limits cited above) is correlated with lower cardiac risk, it seems to be correlated with a higher risk of death. So the implication is there's something else bad for your health about being out of the sweet spot they observed in the data.

[gumby]

I remember reading about 20 years ago that low cholesterol was correlated with increased mortality due to increased incidence of suicide.

[stavros]

So basically the 170 mg/dL TC limit that my lab shows is very suboptimal, and I should go for 230 instead?

[sooheon]

No. Please don't make health decisions off of incorrect inferences from observational studies. https://news.ycombinator.com/item?id=30893041

[imtringued]

Imagine you have container ships named HDL and it is loaded with containers called triglycerides. You don't know how many containers you have. You just know you have this many container ships. Do you have too many containers? Do you have too many ships? That question cannot be answered with just one absolute number.

This is why the HDL to triglycerides ratio exists.

[jeffbee]

170 would be in the lowest quartile for American adults, no? Seems like an unreasonable limit.

[stavros]

I'm in Greece, but it seems fairly unreasonable here as well. Other labs have the limit at 200 (it varies per lab), but 170 seems too low.

[myle]

Greeks tend to have higher "normal" cholesterol levels. In other labs I have seen in Greece, they write as the limit 200.

I know of someone with TC around 240 and the doctor didn't prescribe statins. Not a medical advice.