Associations of lifestyle characteristics with circulating immune markers in the general population based on NHANES 1999 to 2014.

Lifestyles maybe associated with the immune and inflammatory state of human body. We aimed to comprehensively explore the relationship between lifestyles and circulating immune-inflammatory markers in the general population. Data from NHANES 1999-2014 was used. Lifestyle factors included leisure-time physical activity (LTPA), diet quality (Healthy Eating Index-2015, HEI-2015), alcohol consumption, cigarettes smoking, sleep hour and sedentary time. Immune makers included C-reactive protein (CRP), neutrophil-lymphocyte ratio (NLR), systemic immune-inflammation index (SII), platelet-lymphocyte ratio (PLR) and monocyte-lymphocyte ratio (MLR). Generalized linear regression models were used to adjust confounders. Regressions of restricted cubic splines were utilized to evaluate the potentially non-linear relationships between exposures and outcomes. As results, HEI was negatively associated with CRP (P < 0.001), SII (P < 0.001), and NLR (P < 0.001). Cigarettes per day was positively associated with CRP (P < 0.001), SII (P < 0.001), and NLR (P = 0.008). Alcohol consumption was negatively associated with CRP (P < 0.001), but positively associated with PLR (P = 0.012) and MLR (P < 0.001). Physical activity was negatively associated with CRP (P < 0.001), SII (P = 0.005), and NLR (P = 0.002), but positively associated with PLR (P = 0.010). Participants with higher healthy lifestyle score had significantly lower CRP, SII and NLR (all P values < 0.05). Most of the sensitivity analyses found similar results. In conclusion, we found significant associations between lifestyles and immune markers in the general population, which may reflect a systemic inflammatory response to unhealthy lifestyles.