Serum carotenoids modify the association between porphyromonas gingivalis IgG and mortality: a prospective cohort study with 25.8 years of follow-up.

Abstract

Background: Porphyromonas gingivalis (P. gingivalis) is a vital pathogen that can increase mortality. However, whether serum carotenoids, commonly known antioxidants, modify the association of serum P. gingivalis immunoglobulin G (IgG) antibody levels with mortality remains uncertain. We aimed to explore the modification of this association by serum carotenoids.

Methods: The associations of serum P. gingivalis IgG levels with mortality among 7,043 participants from the Third U.S. National Health and Nutrition Examination Survey were assessed. The modifications of serum carotenoids on the associations were also examined. We used the recommended sampling weights to account for the complex survey design. Surveycox proportional hazards regression models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause and specific-cause mortality.

Results: We identified 2,646 deaths during a median follow-up period of 25.8 years. Compared with participants with low serum P. gingivalis IgG levels (< 69 EU), those with high levels (≥ 69 EU) were associated with an HR (95% CI) of 1.10 (1.04-1.16) for all-cause mortality. Similar results were found in mortality analyses for cardiovascular disease, cerebrovascular disease, and diabetes mellitus (all P < 0.05). Notably, significant interactions were detected between the serum α-carotene, β-carotene, or lutein/zeaxanthin concentrations and the serum P. gingivalis IgG levles on all-cause mortality (all P_int < 0.05). Compared with high P. gingivalis IgG participants with low carotenoids, low P. gingivalis IgG participants with high carotenoids had the lowest risk of all-cause mortality, with HR of 0.74 (0.68-0.80) for α-carotene, 0.78 (0.72-0.86) for β-carotene, 0.70 (0.64-0.76) for β-cryptoxanthin, 0.79 (0.73-0.85) for lutein/zeaxanthin and 0.64 (0.59-0.69) for lycopene, respectively.

Conclusion: Serum carotenoids mitigate the associations between serum P. gingivalis IgG levels and mortality.