The moderating role of diet and physical activity in insulin resistance and immunometabolic depression

Abstract

Insulin resistance (IR) and atypical depression share an immunometabolic pathway and present major health risks. Although IR has been associated with atypical depression, its link to immunometabolic depression (IMD) symptoms is less understood. Lifestyle factors like physical activity (PA) and diet may mitigate these conditions through anti-inflammatory and antidiabetic effects. This study examines how lifestyle factors moderate the IR-IMD relationship. We conducted a cross-sectional analysis using baseline data from the mPRIME study (n = 124). IR was measured via HOMA-IR, and IMD symptoms (hypersomnia, hyperphagia, loss of energy, tiredness) were assessed using a composite score derived from four Beck Depression Inventory-II items that have been previously linked to immunometabolic alterations. PA was tracked using accelerometers; diet via the empirical dietary inflammatory pattern (EDIP). Multiple linear regression and moderation analyses were applied. Ninety-four individuals (M(age) = 49.43, SD = 13.93; 48% IR) were analyzed. IR was significantly associated with the IMD-score (β = 0.817, p = 0.001). PA showed no direct or moderating effect (p > 0.05). A proinflammatory diet moderated the IR-IMD link in men (β = 0.718, p < 0.001), but not women (p > 0.05). Findings indicate an IR-IMD association, suggesting symptom monitoring in IR patients may aid early IMD detection and prevention.Trial registration Registered at https://www.drks.de/search/de/trial/DRKS00022774 Identifier no. DRKS00022774 (Registration date: 2021-03-08).

Keywords: Diet; Inflammation; Insulin resistance; Mental health; Physical activity.

Fig. 1

Relationships between CRP levels, lifestyle factors and IMD-score. Association between: (a) EDIP (empirical dietary inflammatory pattern) and log-transformed CRP levels, (b) MVPA (oderate-to-vigorous physical activity) and log-transformed CRP levels, (c) log-transformed CRP levels and IMD-score (immunometabolic depression score). All plots include a linear regression line with 95% confidence interval.

Fig. 2

Interaction Plot between HOMA-IR and EDIP in men. The x-axis represents HOMA-IR, while the y-axis shows the IMD-score (immunometabolic depression score). The interaction is shown for different EDIP (empirical dietary inflammatory pattern) scores defined as −1 (low), 0 (neutral) and + 1 (high). The graph illustrates how variations in EDIP influence the relationship between HOMA-IR and IMD-score with separate regression lines for each score of EDIP.