Role of BMI in the Relationship Between Dietary Inflammatory Index and Depression: An Intermediary Analysis

Abstract

Introduction: This study investigated this association and the role of BMI in the inflammatory process in a large population-based observational study.Methods: A total of 1,865 elderly people (≥55 years) were followed from the Community Cohort Study of Nervous System Diseases (CCSNSD) cohort study from 2018 to 2019 (Mean [SD] age, 66.31 [0.32] years; 716 [38.4%] males). The semi-quantitative FFQ and geriatric depression scale (GDS) were used to evaluate the diet and depressive symptoms of the elderly, respectively. The multivariable logistic regression model estimated the OR and 95% CI between Empirical Dietary Inflammatory Index (E-DII) and depression. The interaction of E-DII and BMI on depressive events was tested, and the mediation analysis of BMI was performed.Results: As measured by E-DII, the mean (SE) value of the inflammatory potential of the diet in our study was 1.56 (0.12). E-DII ranged from 5.23 to 5.58. In comparison with the first quartile, the elderly from the second quartile (OR: 1.15 [95% CI: 1.09, 1.28]) to the fourth quartile (OR: 1.31 [95% CI: 1.16, 1.42]) have a higher risk of depression before adjustment for BMI. An interaction was observed between E-DII and BMI in terms of the risk of depression (PInteraction < 0.001). The whole related part is mediated by BMI (31.06%).Conclusion: Our findings indicate that the higher pro-inflammatory potential of diet is associated with a higher risk of depression, and this association may be mediated by BMI. Further research is needed to verify our findings and clarify the latent mechanism.

Peripheral Inflammatory Markers TNF-α and CCL2 Revisited: Association with Parkinson’s Disease Severity

“…Serum immune marker levels are also influenced by a number of other factors, such as diet, body mass index, sleep, smoking, thyroid hormone levels, exercise, coffee use, frailty, or depression, and can, therefore, be regarded as non-specific [28,29]. These elements might have influenced how this study resulted [40][41][42][43][44]. Therefore, results from such studies should be evaluated with the proper caution in light of all these uncontrollable factors.…”

Response to Boonpor et al: Types of diet, obesity, and incident type 2 diabetes: Findings from the UK Biobank prospective cohort study

“…A number of previous studies have assessed a potential mediating role of BMI (or weight change, as the modelling implies that a change in diet would cause a change in weight) with regards to diet and disease using observational data. [2][3][4] It is well known that adjustment for total energy intake in these analyses implies an isocaloric comparison between diets, that is, the average relative causal effect of the exposure. 5 Studies can also consider the effect of increasing intake of some foods or macronutrients on top of the usual diet, that is, the total causal effect.…”

“…On the other hand, some previous studies have assessed the mediating role of weight change using total energy intake-adjusted estimates for foods or dietary variables (for example [2][3][4] ). As the energy-adjusted estimate implies an isocaloric comparison of foods or diet compositions at that time point, it is unclear how changes in weight would be achieved under this model.…”

The association between dietary inflammation index and depression

“…Details of the study design and data collection have been previously described. 1 Among 42,143 adult participants (aged ≥18 years) were included, and we excluded (1) special dietary, abnormal energy intake (daily energy intake ≤500 kcal or ≥5,000 kcal) or missing dietary records (n = 11,061); (2) without depression assessment results (n = 1,952); (3) without fasting plasma glucose (FPG) or insulin value (n = 15,826); (4) without demographics [gender, education level, race, marital status and poverty index ratio (PIR)] or serum cotinine data or physical examination data [height, weight and waist circumference (WC)] or medical history data [diabetes mellitus (DM), cardiovascular diseases (CVD) and hypertension] (n = 2,353). Finally, 10,951 participants were obtained for the statistical analysis (Figure 1).…”

“…Depression is one of the most common mental illnesses and a leading cause of disability worldwide, which has become an increasingly serious public health problem ( 1 , 2 ). At present, the exact etiology and mechanism of depression are not fully understood, but it is certain that inflammation plays a key role in the occurrence and development of depression ( 1 ). Elevated levels of inflammatory factors such as C-reactive protein (CRP) and interleukin 6 (IL-6) may promote the development of depression ( 3 ).…”