# Age-related trajectories of blood lipids and lipoproteins by sex, region, and waist circumference changes in Korea: a longitudinal cohort study

## TL;DR

This study tracks how blood lipid levels change with age in Korean men and women, finding differences by sex and waist circumference changes.

## Contribution

The study reveals sex-specific age-related trends in lipid profiles and the impact of waist circumference changes in Korea.

## Key findings

- Females show increasing TC, non-HDL-C, and LDL-C levels until their 60s, followed by a decline.
- HDL-C levels in females increase until the early 50s, decline, then rise again in the 70s.
- Decreasing waist circumference improves lipid profiles in both sexes.

## Abstract

This study aimed to evaluate the longitudinal trajectories of lipid and lipoprotein levels with aging according to sex and changes in waist circumference (ΔWC) from midlife to late life.

We included 4,345 male and 4,804 female participants aged 40-69 years at baseline from the Korean Genome and Epidemiology Study (2001-2018). The annual ΔWC was estimated using linear regression. Marginal models were fitted using mixed-effects regression.

The trajectories of total cholesterol (TC), non-high-density lipoprotein cholesterol (non-HDL-C), and low-density lipoprotein cholesterol (LDL-C) levels displayed an increasing trend until the 60s age range in females (approximately 10-15 mg/dL) and the late 40s in males (approximately 3-5 mg/dL), with a subsequent decline. In females, HDL-C levels increased until the early 50s, declined thereafter, and rose again from the 70s onward, with a more pronounced rise in urban than in rural areas, while remaining relatively stable in males. Triglyceride (TG) levels decreased with advancing age in males, whereas in females they increased up to the age of 70 years, followed by a decrease. Females exhibited greater increases in TC, non-HDL-C, HDL-C, LDL-C, and TG across all ages compared with males. Both males and females with a decrease in waist circumference (WC) during follow-up showed improvements in lipid and lipoprotein profiles relative to those with stable or increased WC.

Trends in lipid and lipoprotein levels vary according to age and sex, and a decrease in WC significantly improves lipid and lipoprotein profiles.