Trends in TC/HDL and LDL/HDL Ratios across the Age Span: Data from the 2007-2018 National Health and Nutrition Examination Survey (NHANES)

Background. Cholesterol levels in total cholesterol (TC), low-density lipoprotein (LDL-C), high-density lipoprotein (HDL-C), and triglyceride (TG) contribute to atherosclerosis and its clinical consequences. Objectives. This study aimed to examine the trends in serum TC/HDL and LDL/HDL ratio across the age span. Methods. This is an observational study. Blood lipid measurements, taken from 85,646 noninstitutionalized participants, aged 6 to 80, were obtained from the National Health and Nutrition Examination Survey (NHANES) study. We compared the TC/HDL and LDL/HDL ratio trends in three distinct cross-sectional surveys during 2007-2010, 2011-2014, and 2015- 2018. Results. Cholesterol ratios changed by age and differed by sex. Mean TC/HDL ratios declined from 4.03 (95% CI, 4.01-4.05) in 2007-2010, to 3.84 (95% CI, 3.81-3.87) in 2015-2018 (p<.05 for linear trend) in male; mean TC/HDL ratios declined from 3.69 (95% CI, 3.67-3.70) in 2007- 2010, to 3.45 (95% CI, 3.42-3.47) in 2015-2018 (p<.05 for linear trend) in female. Mean LDL/HDL ratios declined from 2.30 (95% CI, 2.28-2.32) in 2007-2010, to 2.18 (95% CI, 2.15- 2.20) in 2015-2018 (p<.05 for linear trend) in male; mean LDL/HDL ratios declined from 2.04 (95% CI, 2.02-2.06) in 2007-2010, to 1.96 (95% CI, 1.94-1.98) in 2015-2018 (p<.001 for linear trend) in female. Conclusions. Between 2007 and 2018, favorable trends in lipid ratio levels were observed among noninstitutionalized residents in the US.