Related Experiment Videos
Circannual variations in blood cholesterol levels
E Kristal-Boneh1, G Harari, M S Green
1Cardiovascular Epidemiology Unit, Occupational Health and Rehabilitation Institute, Ra'anana, Israel.
Insights
Blood cholesterol levels show seasonal variation, peaking in spring and lowest in summer. This annual cholesterol rhythm, influenced by environmental temperature, is significant for clinical evaluations.
Area of Science:
- Cardiovascular Disease Research
- Human Physiology
- Environmental Health
Background:
- The seasonality of blood cholesterol remains inconsistently documented, with studies reporting varied seasonal patterns or no significant changes.
- Previous research indicates potential circannual variations in cholesterol, often citing winter peaks and summer troughs.
Purpose of the Study:
- To investigate the circannual variation of serum cholesterol levels within a large cohort in Israel.
- To analyze seasonal patterns in cholesterol and their potential correlation with environmental factors.
Main Methods:
- Utilized data from the Israeli CORDIS study, including serum cholesterol and blood counts from 3,726 men and 1,514 women screened between 1985-1987.
- Employed cosinor analysis to assess the circannual rhythm of serum cholesterol levels.
Main Results:
- Serum cholesterol levels exhibited a statistically significant circannual rhythm.
- The highest serum cholesterol levels were observed in spring, while the lowest levels occurred in summer.
- A notable correlation was found between circannual cholesterol variation and environmental temperature changes.
Conclusions:
- Serum cholesterol demonstrates a considerable circannual variation, with distinct seasonal peaks and troughs.
- Environmental temperature is a potential contributing factor to the observed annual cholesterol fluctuations.
- The identified circannual changes in serum cholesterol warrant consideration during patient clinical evaluations.
Abstract:
The seasonality of blood cholesterol is still not well established. Some have described a seasonal pattern with highest levels during autumn and lowest in summer, whereas others have reported no change. A number of studies showed circannual variations with maximum levels in winter and minimum in summer. The aim of this study was to examine the circannual variation of cholesterol in a large cohort in Israel. In the Israeli CORDIS study, employees of 21 factories were screened for cardiovascular disease risk factors during 1985-7. As part of the information gathered, serum cholesterol and blood counts were available for 3,726 men and 1,514 women. Serum cholesterol levels fit a circannual rhythm assessed by the cosinor analysis. Highest levels of serum cholesterol were found in spring and lowest in summer. We conclude that there is a circannual change of serum cholesterol, which could be partially associated with changes in environmental temperature. The circannual variation in serum cholesterol was considerable and should be taken into account when carrying out clinical evaluation of patients.