An Examination of Changes in Diet Quality, Measures of Inflammation, Depressive Symptoms, and Metabolic Syndrome Symptom Severity across the First Semester in College
Open Access
- Author:
- Davis, Kristin
- Graduate Program:
- Biobehavioral Health
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- September 29, 2022
- Committee Members:
- Penny Kris-Etherton, Outside Unit & Field Member
Christopher Engeland, Major Field Member
Kyle Murdock, Chair & Dissertation Advisor
Stephanie Lanza, Major Field Member
Thomas Gould, Program Head/Chair - Keywords:
- Diet quality
immune function
college students
depression
metabolic syndrome
inflammation - Abstract:
- Metabolic Syndrome (MetS), a cluster of cardiometabolic abnormalities including elevated waist circumference, low high-density lipoprotein (HDL) cholesterol, high triglycerides, high blood pressure, and elevated fasting glucose, affects nearly 35% of American adults. The presence of MetS both predicts and contributes to the development of cardiovascular diseases and type 2 diabetes (i.e., cardiometabolic disease). MetS and cardiometabolic diseases are commonly comorbid with Major Depressive Disorder (MDD), the leading cause of disability in the United States. Chronic inflammation may drive the development of both MetS and MDD. While many factors influence inflammation, low diet quality may be particularly important due to the role of diet in regulating immune function. Poor diet quality is a leading modifiable contributor to MetS development, and is also associated with MDD. Primary prevention programs targeting diet quality could therefore be an effective means of reducing both MetS and MDD, possibly via reducing inflammation. While the development of such primary prevention programs would be a valuable public health tool, efforts are limited by the lack of measures available to detect at-risk individuals prior to disease onset. Given that inflammation is a plausible mechanism driving MetS and MDD development, inflammatory markers may be a useful avenue for assessing long-term disease risk. However, circulating markers of inflammation are often below the level of measurable detection in young and healthy individuals, limiting their use in primary prevention research. Ex vivo lipopolysaccharide (LPS) stimulated cytokine production is less prone to floor effects, and may be a more viable marker of immune function in young samples. The present study examines concurrent associations among diet quality, depressive symptoms, MetS symptom severity, circulating cytokines, and ex vivo stimulated cytokine production in incoming college students, as well as change in these variables across the first semester. A sample of 110 incoming first-year students was recruited at the Pennsylvania State University, University Park campus. Data were collected at two study visits. Visit 1 occurred within the first 4 weeks of the fall 2021 semester; visit 2 occurred at the end of the same semester, during the last 2 weeks of classes. At each visit, participants’ height, weight, waist circumference, blood pressure, HDL-cholesterol, triglycerides, fasting glucose, circulating cytokines, and ex vivo LPS stimulated cytokine production were assessed. Demographic information, diet quality, and depressive symptoms were also assessed at each visit. Diet quality and MetS symptom severity were significantly correlated at both visit 1 (r = -.419, p = .001) and visit 2 (r = -.355, p = .001). After controlling for sleep quality, physical activity, and perceived stress in a regression model, diet quality still significantly predicted MetS symptom severity at both visit 1 (B = -0.024, p < .001) and visit 2 (B = -0.021, p < .001). In both the correlational and regression analyses, higher diet quality was associated with significantly lower (i.e., better) MetS symptom severity. Across the semester, diet quality significantly declined (mean change = -3.093, p = .008) while MetS symptom severity significantly increased (mean change = 0.152, p < .001). In sum, these findings underscore the need for developing lifestyle-based primary prevention programs aimed at reducing cardiometabolic disease risk in younger individuals. The entry into college may be an ideal time to initiate such programs, particularly dietary interventions, to help attenuate the decline in diet quality and increase in MetS symptom severity that occurs across the first semester.