Lipid Variability--Influence of Stress
To investigate the variability of lipids and specifically the effects of stress on serum triglyceride levels, total cholesterol, HDL, and LDL in a 2.5 year epidemiological study.
|Study Design:||Observational Model: Natural History
Time Perspective: Longitudinal
|Study Start Date:||July 1990|
|Estimated Study Completion Date:||December 1992|
While researchers had documented some of the behavioral contributors to fluctuation in individuals' lipid levels (e.g., nutrition patterns, smoking, exercise), little attention had been given to psychosocial stress. Early reports utilizing accountants, race car drivers, and air traffic controllers provided some uncontrolled data associating stress with cholesterol increases. Yet, no empirical research on stress that concomitantly examined other related influences was available. This paucity of data was probably due to lack of objective measures of stress and difficulty in measuring lipid subfractions.
Based on the results of their pilot study, and their research observations, the investigators predicted significant positive associations between stress level and triglycerides. A total of 228 public accountants (148 men and 80 women to provide comparable power between the sexes) were recruited from the greater Birmingham, Alabama area. Participants were evaluated monthly for 18 months, across three stressful and non-stressful work intervals (i.e., tax seasons). The investigators also collected data (during this same time frame) to closely monitor the following variables that affect lipids: dietary intake (including alcohol, caffeine, total calories, total fat, saturated fat, and dietary cholesterol), smoking, and physical activity, and oral contraceptive use, pregnancy status and menstrual stage among the women. Additionally, a substudy presented a unique opportunity for them to investigate the relation between stress and triglyceride-rich lipoproteins in the formation of foam cells.