Behavioral and physiological immunity under constraint: Pathogen disgust sensitivity relates to protein balance in chronic cardiovascular disease patients

The behavioral immune system (BIS) and physiological immune system (PIS) both defend against pathogens, but their relationship may differ across conditions. We tested preregistered predictions derived from complementary and resource-cost reasoning in a cross-sectional study of 110 chronic cardiovascular disease patients with non-acute but chronically burdened physiological systems. We assessed pathogen disgust sensitivity and perceived infectability alongside inflammatory markers (CRP, WBC, NLR, PLR, SII) and metabolic and protein-related indicators (glucose, lipids, bile acids, HbA1c, albumin/globulin ratio), controlling for age, sex, and BMI. Evidence for associations between BIS measures and inflammatory markers ranged from inconclusive to moderately favoring the null (all BF₁₀ ≤ 0.50). In contrast, pathogen disgust sensitivity was positively associated with albumin/globulin ratio (A/G; BF₁₀ = 12.38, ρ = 0.26), opposite to the preregistered negative prediction. Conventional metabolic indicators yielded evidence favoring the null or inconclusive results (all BF₁₀ ≤ 0.57). These findings do not support the preregistered predictions and highlight A/G as a potentially informative but nonspecific protein-related marker of the physiological context of behavioral immune differences. Resource preservation, resource affordance, and shared clinical burden remain possible explanations. Examining baseline physiological status, including metabolic and protein-related indicators, can extend tests of BIS–PIS relationships beyond acute cue-reactivity paradigms.