Biological variability in serum vitamin E concentrations: relation to serum lipids

Area of Science:

• Biochemistry
• Human Physiology
• Nutritional Science

Background:

• Understanding biological variation in serum nutrients and lipids is crucial for interpreting health markers.
• Serum vitamin E and lipid profiles (cholesterol, triglycerides, HDL-C, LDL-C, apo A-I, apo B) are key indicators of metabolic health.
• Previous research has not fully elucidated the interplay and annual rhythms of these components in healthy individuals.

Purpose of the Study:

• To investigate the biological variation of serum vitamin E in relation to major lipid variables over one year.
• To identify seasonal influences and temporal relationships between serum vitamin E and lipid profiles.
• To explore correlations between homeostatic setpoints of vitamin E and lipid parameters.

Main Methods:

• Monthly blood sampling from 26 healthy volunteers over a calendar year.
• Analysis of serum concentrations of vitamin E, cholesterol, triglycerides, HDL-C, LDL-C, apo A-I, and apo B.
• Calculation of inter- and intraindividual coefficients of variation (CVs) and index of individuality (I-index).
• Statistical analysis to assess seasonal variations, annual rhythms, and time-series correlations.

Main Results:

• Serum vitamin E exhibited significant interindividual (19.9%) and intraindividual (11.9%) variation, with an I-index of 0.59.
• Concentrations of vitamin E and all measured lipid variables were lower in spring.
• Significant annual rhythms were observed for vitamin E and lipid variables, inversely related to ambient temperature.
• Positive temporal correlations were found between serum vitamin E and cholesterol, triglycerides, and apo B.
• Individuals with higher cholesterol homeostatic setpoints also had higher setpoints for vitamin E, triglycerides, LDL-C, and apo B.

Conclusions:

• Serum vitamin E and lipid profiles display significant biological variation influenced by seasonal changes and annual rhythms.
• A coordinated homeostatic regulation appears to link vitamin E levels with cholesterol, triglycerides, and apo B.
• These findings highlight the dynamic nature of these biomarkers and suggest interconnected regulatory mechanisms.