Fish consumption and risk of rheumatoid arthritis: a dose-response meta-analysis

Abstract

Introduction: The association between fish consumption and rheumatoid arthritis (RA) is unclear. The aim of this paper was to summarize the available evidence on the association between fish consumption and risk of RA using a dose-response meta-analysis.

Methods: Relevant studies were identified by a search of MEDLINE and EMBASE through December 2013, with no restrictions. A random-effects dose-response meta-analysis was conducted to combine study specific relative risks. Potential non-linear relation was investigated using restricted cubic splines. A stratified analysis was conducted by study design.

Results: Seven studies (four case-controls and three prospective cohorts) involving a total of 174 701 participants and 3346 cases were included in the meta-analysis. For each one serving per week increment in fish consumption, the relative risk (RR) of RA was 0.96 (95% confidence interval (CI) 0.91 to 1.01). Results did not change when stratifying by study design. No heterogeneity or publication bias was observed. When fish consumption was modeled using restricted cubic splines, the risk of RA was 20 to 24% lower for 1 up to 3 servings per week of fish (RR =0.76, 95% CI: 0.57 to 1.02) as compared to never consumption.

Conclusions: Results from this dose-response meta-analysis showed a non-statistically significant inverse association between fish consumption and RA.

Figure 1

Flow chart of selection of studies for inclusion in the dose-response meta-analysis.

Figure 2

Study-specific relative risk estimates for rheumatoid arthritis with increasing levels of fish consumption (servings per week). Each panel refers to a study. Black squares indicate the relative risk estimates and whiskers their 95% CI. The vertical axis is on a log scale.

Figure 3

Relative risk of rheumatoid arthritis for every one serving per week increase in fish consumption.

Figure 4

Pooled dose-response association between fish consumption and rheumatoid arthritis risk (solid line). Fish consumption was modeled with restricted cubic splines in a multivariate random-effects dose-response model. Dashed lines represent the 95% CI for the spline model. The dotted line represents the linear trend. Tick marks below the curve represent the positions of the study-specific relative risks. The value of 0 servings per week served as referent. The relative risks are plotted on the log scale.