The effect of cardiorespiratory fitness on age-related lipids and lipoproteins

Abstract

Background: Evidence on the effect of cardiorespiratory fitness (CRF) on age-related longitudinal changes of lipids and lipoproteins is scarce.

Objectives: This study sought to assess the longitudinal aging trajectory of lipids and lipoproteins for the life course in adults and to determine whether CRF modifies the age-associated trajectory of lipids and lipoproteins.

Methods: Data came from 11,418 men, 20 to 90 years of age, without known high cholesterol, high triglycerides, cardiovascular disease, and cancer at baseline and during follow-up from the Aerobics Center Longitudinal Study. There were 43,821 observations spanning 2 to 25 health examinations (mean 3.5 examinations) between 1970 and 2006. CRF was quantified by a maximal treadmill exercise test. Marginal models using generalized estimating equations were applied.

Results: Total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), triglycerides, and non-high-density lipoprotein cholesterol (non-HDL-C) presented similar inverted U-shaped quadratic trajectories with aging: gradual increases were noted until age mid-40s to early 50s, with subsequent declines (all p < 0.0001). Compared with men with higher CRF, those with lower CRF developed abnormal values earlier in life: TC (≥200 mg/dl), LDL-C (≥130 mg/dl), non-HDL-C (≥160 mg/dl), and triglycerides/HDL-C ratio (≥3.0). Notably, abnormal values for TC and LDL-C in men with low CRF were observed around 15 years earlier than in those with high CRF. After adjusting for time-varying covariates, a significant interaction was found between age and CRF in each trajectory, indicating that CRF was more strongly associated with the aging trajectories of lipids and lipoproteins in young to middle-age men than in older men.

Conclusions: Our investigation reveals a differential trajectory of lipids and lipoproteins with aging according to CRF in healthy men and suggests that promoting increased CRF levels may help delay the development of dyslipidemia.

Keywords: aging; lipid profile trajectories; longitudinal study.

Figure 1

Participant Flow Diagram

Figure 2. The Estimated Trajectories of Lipids and Lipoproteins With Aging by Levels of CRF

The purple solid line represents a crude overall trajectory; the other lines represent each category of CRF (orange dotted-dashed line for high CRF, blue dotted line for middle CRF, and green dashed line for low CRF), assuming constant WC residual (−0.179, mean of the residual). The shaded areas represent 95% confidence intervals for each CRF category. The red horizontal solid line in each panel indicates the established abnormal cutoff for lipid and lipoproteins: (A) LDL-C ≥130 mg/dl; (B) TG ≥150 mg/dl; (C) ≥60 mg/dl for HDL-C; (D) ≥160 mg/dl for non-HDL-C; (E) TG/HDL-C ≥3.0. No abnormal cutoff was established for (F) total cholesterol/HDL-cholesterol ratio and (G) LDL-cholesterol/HDL-cholesterol ratio. CRF was categorized into low (lower than 33.3th percentile), middle (those within 33.3th to 66.7th percentile) and high CRF categories (higher than 66.7th percentile), according to the distribution of age-standardized CRF at baseline. CRF = cardiorespiratory fitness; HDL-C = high-density lipoprotein cholesterol; LDL-C = low-density lipoprotein cholesterol; TG = triglycerides; WC = waist circumference.

Figure 2. The Estimated Trajectories of Lipids and Lipoproteins With Aging by Levels of CRF

The purple solid line represents a crude overall trajectory; the other lines represent each category of CRF (orange dotted-dashed line for high CRF, blue dotted line for middle CRF, and green dashed line for low CRF), assuming constant WC residual (−0.179, mean of the residual). The shaded areas represent 95% confidence intervals for each CRF category. The red horizontal solid line in each panel indicates the established abnormal cutoff for lipid and lipoproteins: (A) LDL-C ≥130 mg/dl; (B) TG ≥150 mg/dl; (C) ≥60 mg/dl for HDL-C; (D) ≥160 mg/dl for non-HDL-C; (E) TG/HDL-C ≥3.0. No abnormal cutoff was established for (F) total cholesterol/HDL-cholesterol ratio and (G) LDL-cholesterol/HDL-cholesterol ratio. CRF was categorized into low (lower than 33.3th percentile), middle (those within 33.3th to 66.7th percentile) and high CRF categories (higher than 66.7th percentile), according to the distribution of age-standardized CRF at baseline. CRF = cardiorespiratory fitness; HDL-C = high-density lipoprotein cholesterol; LDL-C = low-density lipoprotein cholesterol; TG = triglycerides; WC = waist circumference.

Figure 2. The Estimated Trajectories of Lipids and Lipoproteins With Aging by Levels of CRF

The purple solid line represents a crude overall trajectory; the other lines represent each category of CRF (orange dotted-dashed line for high CRF, blue dotted line for middle CRF, and green dashed line for low CRF), assuming constant WC residual (−0.179, mean of the residual). The shaded areas represent 95% confidence intervals for each CRF category. The red horizontal solid line in each panel indicates the established abnormal cutoff for lipid and lipoproteins: (A) LDL-C ≥130 mg/dl; (B) TG ≥150 mg/dl; (C) ≥60 mg/dl for HDL-C; (D) ≥160 mg/dl for non-HDL-C; (E) TG/HDL-C ≥3.0. No abnormal cutoff was established for (F) total cholesterol/HDL-cholesterol ratio and (G) LDL-cholesterol/HDL-cholesterol ratio. CRF was categorized into low (lower than 33.3th percentile), middle (those within 33.3th to 66.7th percentile) and high CRF categories (higher than 66.7th percentile), according to the distribution of age-standardized CRF at baseline. CRF = cardiorespiratory fitness; HDL-C = high-density lipoprotein cholesterol; LDL-C = low-density lipoprotein cholesterol; TG = triglycerides; WC = waist circumference.

Figure 2. The Estimated Trajectories of Lipids and Lipoproteins With Aging by Levels of CRF

The purple solid line represents a crude overall trajectory; the other lines represent each category of CRF (orange dotted-dashed line for high CRF, blue dotted line for middle CRF, and green dashed line for low CRF), assuming constant WC residual (−0.179, mean of the residual). The shaded areas represent 95% confidence intervals for each CRF category. The red horizontal solid line in each panel indicates the established abnormal cutoff for lipid and lipoproteins: (A) LDL-C ≥130 mg/dl; (B) TG ≥150 mg/dl; (C) ≥60 mg/dl for HDL-C; (D) ≥160 mg/dl for non-HDL-C; (E) TG/HDL-C ≥3.0. No abnormal cutoff was established for (F) total cholesterol/HDL-cholesterol ratio and (G) LDL-cholesterol/HDL-cholesterol ratio. CRF was categorized into low (lower than 33.3th percentile), middle (those within 33.3th to 66.7th percentile) and high CRF categories (higher than 66.7th percentile), according to the distribution of age-standardized CRF at baseline. CRF = cardiorespiratory fitness; HDL-C = high-density lipoprotein cholesterol; LDL-C = low-density lipoprotein cholesterol; TG = triglycerides; WC = waist circumference.

Figure 2. The Estimated Trajectories of Lipids and Lipoproteins With Aging by Levels of CRF

The purple solid line represents a crude overall trajectory; the other lines represent each category of CRF (orange dotted-dashed line for high CRF, blue dotted line for middle CRF, and green dashed line for low CRF), assuming constant WC residual (−0.179, mean of the residual). The shaded areas represent 95% confidence intervals for each CRF category. The red horizontal solid line in each panel indicates the established abnormal cutoff for lipid and lipoproteins: (A) LDL-C ≥130 mg/dl; (B) TG ≥150 mg/dl; (C) ≥60 mg/dl for HDL-C; (D) ≥160 mg/dl for non-HDL-C; (E) TG/HDL-C ≥3.0. No abnormal cutoff was established for (F) total cholesterol/HDL-cholesterol ratio and (G) LDL-cholesterol/HDL-cholesterol ratio. CRF was categorized into low (lower than 33.3th percentile), middle (those within 33.3th to 66.7th percentile) and high CRF categories (higher than 66.7th percentile), according to the distribution of age-standardized CRF at baseline. CRF = cardiorespiratory fitness; HDL-C = high-density lipoprotein cholesterol; LDL-C = low-density lipoprotein cholesterol; TG = triglycerides; WC = waist circumference.

Figure 2. The Estimated Trajectories of Lipids and Lipoproteins With Aging by Levels of CRF

The purple solid line represents a crude overall trajectory; the other lines represent each category of CRF (orange dotted-dashed line for high CRF, blue dotted line for middle CRF, and green dashed line for low CRF), assuming constant WC residual (−0.179, mean of the residual). The shaded areas represent 95% confidence intervals for each CRF category. The red horizontal solid line in each panel indicates the established abnormal cutoff for lipid and lipoproteins: (A) LDL-C ≥130 mg/dl; (B) TG ≥150 mg/dl; (C) ≥60 mg/dl for HDL-C; (D) ≥160 mg/dl for non-HDL-C; (E) TG/HDL-C ≥3.0. No abnormal cutoff was established for (F) total cholesterol/HDL-cholesterol ratio and (G) LDL-cholesterol/HDL-cholesterol ratio. CRF was categorized into low (lower than 33.3th percentile), middle (those within 33.3th to 66.7th percentile) and high CRF categories (higher than 66.7th percentile), according to the distribution of age-standardized CRF at baseline. CRF = cardiorespiratory fitness; HDL-C = high-density lipoprotein cholesterol; LDL-C = low-density lipoprotein cholesterol; TG = triglycerides; WC = waist circumference.

Figure 2. The Estimated Trajectories of Lipids and Lipoproteins With Aging by Levels of CRF

The purple solid line represents a crude overall trajectory; the other lines represent each category of CRF (orange dotted-dashed line for high CRF, blue dotted line for middle CRF, and green dashed line for low CRF), assuming constant WC residual (−0.179, mean of the residual). The shaded areas represent 95% confidence intervals for each CRF category. The red horizontal solid line in each panel indicates the established abnormal cutoff for lipid and lipoproteins: (A) LDL-C ≥130 mg/dl; (B) TG ≥150 mg/dl; (C) ≥60 mg/dl for HDL-C; (D) ≥160 mg/dl for non-HDL-C; (E) TG/HDL-C ≥3.0. No abnormal cutoff was established for (F) total cholesterol/HDL-cholesterol ratio and (G) LDL-cholesterol/HDL-cholesterol ratio. CRF was categorized into low (lower than 33.3th percentile), middle (those within 33.3th to 66.7th percentile) and high CRF categories (higher than 66.7th percentile), according to the distribution of age-standardized CRF at baseline. CRF = cardiorespiratory fitness; HDL-C = high-density lipoprotein cholesterol; LDL-C = low-density lipoprotein cholesterol; TG = triglycerides; WC = waist circumference.

CENTRAL ILLUSTRATION. Trajectories of Total Cholesterol With Aging

The purple dashed line represents a crude overall trajectory; the other dashed lines represent each category of CRF (orange for high CRF, light blue for middle CRF, and green for low CRF), assuming constant WC residual (−0.179, mean of the residual). Shaded areas represent 95% confidence intervals for each CRF category. The solid blue horizontal line indicates the established abnormal cutoff of ≥200 mg/dl for TC. CRF = cardiorespiratory fitness; TC = total cholesterol; WC = waist circumference.