Absolute impact of lipid levels on coronary heart disease in a real-world primary prevention cohort of 730,236 people

Background and aims

The impact of the association of LDL-c levels with coronary heart disease is unambiguous in people with previous cardiovascular disease. In primary prevention, however, it has been poorly studied. We analyzed the impact of the association of lipid levels with coronary heart disease in a population with no previous cardiovascular disease. We included potential variations by sex and age.

Methods

Retrospective cohort analysis of records from the SIDIAP Catalan database, Spain. We selected ≥35-year-olds without previous cardiovascular disease or lipid-lowering medications. The LDL, HDL, and triglycerides levels were the exposure and coronary heart disease was the outcome. Cox regression and Lin additive models estimated the relative and absolute associations, respectively.

Results

We analyzed the records from 730,236 participants; follow-up: 6.7 years; mean (SD) age: 58.5 (13.9) years, and 42.2 % of them were men. The overall CHD incidence rate was 3.47 (3.42–3.52) events per 1000 person-years; it was higher in men than in women, with 4.98 (4.88–5.07) and 2.39 (2.33–2.45) events per 1000 person-years, respectively. One mmol/L increase in LDL-c, HDL-c, and TGs showed HRs (95 %CI) of 1.26 (1.24–1.29), 0.60 (0.57–0.63), and 1.16 (1.13–1.19), respectively. The absolute differences for LDL-c and TGs were less than one additional CHD event per 1000 person-years; and two fewer events for HDL-c.

Conclusions

The moderate to low increment in the incidence of CHD by 1 mmol/L of lipid increase represented low numbers of additional events in this low-risk Mediterranean population.