A new study suggests higher levels of remnant cholesterol may increase the risk of depression.
Remnant cholesterol is a type of lipoprotein that contains triglycerides and cholesterol and has been linked to atherosclerosis and cardiovascular disease.
This large study found remnant cholesterol levels were significantly higher in people with depression compared to those without.
Key facts:
- Remnant cholesterol is a triglyceride-rich lipoprotein associated with cardiovascular disease risk.
- Researchers analyzed data from over 8,000 adults in the National Health and Nutrition Examination Survey.
- 5.88% of participants had depression based on a Patient Health Questionnaire score ≥10.
- Those with depression had higher remnant cholesterol levels on average compared to those without depression.
- After adjustments, the highest remnant cholesterol quartile had a 49% higher odds of depression versus the lowest quartile.
- Associations were stronger in men, younger adults, non-obese, and those with diabetes.
Source: BMC Psychiatry 2023
Remnant cholesterol & depression link: Inflammatory effect?
The mechanisms linking remnant cholesterol to depression risk are not fully understood.
However, chronic inflammation may play an important role.
Remnant cholesterol particles can penetrate the arterial wall and be absorbed by macrophages, promoting inflammation.
Inflammation has been linked to depression through several pathways:
- Inflammatory cytokines may access the brain and directly alter neuron functioning
- Inflammation can activate the hypothalamic-pituitary-adrenal axis, influencing neurotransmitters
- Vascular inflammation can impair cerebral blood flow and contribute to depressive symptoms
Overall, the study authors hypothesize remnant cholesterol may trigger systemic inflammation, endothelial dysfunction, and microvascular changes in the brain that predispose individuals to depression.
More research is needed to confirm the mechanisms.
Study Methods & Design: Cholesterol Levels & Depression
This cross-sectional study analyzed data from the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2016.
NHANES is an ongoing survey conducted by the CDC designed to assess health and nutritional status in a representative sample of non-institutionalized US civilians.
In total, data from over 8,200 adults aged 18 years and older was included in the analysis.
Depression was measured using the Patient Health Questionnaire (PHQ-9), a validated 9-item screening tool.
A score of 10 or higher was considered indicative of major depression.
Remnant cholesterol levels were calculated as total cholesterol minus LDL cholesterol minus HDL cholesterol.
All participants had fasted prior to blood draws.
The researchers performed weighted logistic regression models accounting for the complex survey sampling methods.
Models were adjusted for demographics, socioeconomics, health behaviors, comorbidities, and other cholesterol markers.
High Remnant Cholesterol & High Odds of Depression
The weighted prevalence of depression in the study population was 5.88%.
Participants with depression had significantly higher remnant cholesterol levels – 26.13 mg/dL versus 23.05 mg/dL in those without depression.
In adjusted models, those in the highest remnant cholesterol quartile had a 49% higher odds of depression compared to the lowest quartile.
There was a significant linear trend between increasing remnant cholesterol level quartiles and higher depression odds.
In subgroup analyses, associations were stronger in men (102% higher odds), younger adults (62%), non-obese (83%), and diabetics (288%).
Sensitivity analyses using different cut points, statistical methods, and exclusions supported the robustness of the findings.
Implications and Future Research
This large population-based study provides compelling evidence that remnant cholesterol may be an important risk factor for depression, especially in men, younger adults, and those with diabetes.
The findings suggest evaluating remnant cholesterol levels could aid in assessing depression risk.
However, additional prospective cohort studies are needed to determine causality and directionality.
Randomized trials could also assess whether lowering remnant cholesterol through diet or medication reduces depression incidence.
Understanding the mechanisms linking elevated remnant cholesterol to depression pathogenesis remains an important area for further study.
The Takeaway: Remnant Cholesterol a Risk Factor
Remnant cholesterol is an emerging cardiovascular risk factor that has been linked to inflammation, endothelial dysfunction, and atherosclerosis.
This new research suggests remnant cholesterol may also adversely impact mental health.
Individuals with high remnant cholesterol had significantly higher odds of depression in this study.
While more research is still needed, the findings highlight the potential role of vascular and metabolic factors in depression.
Evaluating remnant cholesterol may help identify individuals at risk for depression, especially when considered along with other lifestyle, genetic, and environmental factors.
With further confirmation, managing remnant cholesterol levels could provide a modifiable target for reducing depression vulnerability.
References
- Study: Association of remnant cholesterol with depression among US adults
- Authors: Yang Wang & Ruhua Shen (2023)
