Secular trends in serum lipid profiles in young adults in Norway, 2001-19

Lower prevalence of major cardiovascular disease (CVD) risk factors, such as dyslipidemia, hypertension and smoking, can explain a substantial part of the decline in CVD mortality and incidence for the past decades in Western countries. However, some studies have indicated less favorable trends in risk factors in recent years. We have assessed time trends in lipid profiles among young adults in Norway measured between 2001 and 2019.

Samples of serum lipids analyzed at one large medical laboratory in Oslo, Norway, mainly requisitioned by primary care physicians, were analyzed cross-sectionally to estimate year-to-year trends among men and women aged 18-49 years. We also assessed the lipid distributions and proportions with adverse lipid levels.

In total, more than 2,6 million blood samples, comprising more than 1 million individuals (mean age 37.7 years) from all regions of Norway were included. All measures improved among all age groups in both women and men, especially in total and non-HDL cholesterol (-0.22 and -0.25 mmol/l per decade, respectively). There were downward shifts in the population distribution of total, non-HDL-C and LDL-C. The overall prevalences of total cholesterol ≥5.0 mmol/l and non-HDL-C ≥3.9 mmol/l similarly decreased, from ∼63 to 46% and from ∼52 to 34%, respectively. More than 1/3 had elevated levels of total and/or non-HDL-C in 2019.

In a large proportion of the Norwegian population aged 18-49 years old, the lipid profiles improved during the last two decades. As the use of lipid-lowering medications is low in this age group, this likely reflects favorable secular trends.