Objective Adults with arthritis face an elevated risk of all-cause mortality. While baseline-reported metformin use is associated with lower mortality in other chronic conditions, whether a similar association exists in this high-risk population remains unknown. We therefore aimed to evaluate the association between baseline-reported metformin use and all-cause mortality in a large, population-based cohort of US adults with arthritis. Methods This cohort study analyzed data from 14,633 participants with self-reported arthritis in the National Health and Nutrition Examination Survey, 1999–2018. Participants were categorized as baseline-reported metformin users or non-users based on the 30-day prescription medication inventory collected during the baseline in-home interview. The study outcome was all-cause mortality, ascertained via linkage to the National Death Index. We used multivariable Cox proportional hazards models to estimate hazard ratios (HRs), complemented by propensity score-based analyses, including inverse probability of treatment weighting. Results The cohort, with a mean age of 62.87 years and 59.61% female, was followed for a median of 95 months, during which 4412 deaths occurred. After multivariable adjustment, baseline-reported metformin use was associated with a significantly lower risk of all-cause mortality (HR, 0.77; 95% confidence interval [CI] 0.68–0.86; P < 0.001). Propensity score analyses substantiated these findings, yielding an HR of 0.76 (95% CI 0.67–0.86, P < 0.001). The association was consistent across different arthritis subtypes and in various sensitivity analyses. Conclusion Our study found that baseline-reported metformin use was associated with a significantly lower risk of all-cause mortality among US adults with arthritis. Given the observational nature of this study and potential confounding by indication, these findings should be interpreted as associative rather than causal. Additional research is required to substantiate these findings. <Table Float="No" ID="Taba"> <tgroup cols="2"> <colspec align="left" colname="c1" colnum="1" /> <colspec align="left" colname="c2" colnum="2" /> <tbody> <row> <entry align="left" nameend="c2" namest="c1"> Key Points • Baseline-reported metformin use was associated with a significantly lower risk of all-cause mortality in adults with arthritis. • The association between baseline-reported metformin use and lower all-cause mortality was consistent across different arthritis subtypes. </entry> </row> </tbody> </tgroup> </Table>

Metformin use and risk of all-cause mortality in US adults with arthritis: a cohort study from NHANES 1999–2018

期刊论文
发表日期：

2026年4月1日

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Ziqi Xu,
Jun Li,
Shaomin Chen,
Lei Yu,
Li Tan

摘要

Objective

Adults with arthritis face an elevated risk of all-cause mortality. While baseline-reported metformin use is associated with lower mortality in other chronic conditions, whether a similar association exists in this high-risk population remains unknown. We therefore aimed to evaluate the association between baseline-reported metformin use and all-cause mortality in a large, population-based cohort of US adults with arthritis.

Methods

This cohort study analyzed data from 14,633 participants with self-reported arthritis in the National Health and Nutrition Examination Survey, 1999–2018. Participants were categorized as baseline-reported metformin users or non-users based on the 30-day prescription medication inventory collected during the baseline in-home interview. The study outcome was all-cause mortality, ascertained via linkage to the National Death Index. We used multivariable Cox proportional hazards models to estimate hazard ratios (HRs), complemented by propensity score-based analyses, including inverse probability of treatment weighting.

Results

The cohort, with a mean age of 62.87 years and 59.61% female, was followed for a median of 95 months, during which 4412 deaths occurred. After multivariable adjustment, baseline-reported metformin use was associated with a significantly lower risk of all-cause mortality (HR, 0.77; 95% confidence interval [CI] 0.68–0.86; P < 0.001). Propensity score analyses substantiated these findings, yielding an HR of 0.76 (95% CI 0.67–0.86, P < 0.001). The association was consistent across different arthritis subtypes and in various sensitivity analyses.

Conclusion

Our study found that baseline-reported metformin use was associated with a significantly lower risk of all-cause mortality among US adults with arthritis. Given the observational nature of this study and potential confounding by indication, these findings should be interpreted as associative rather than causal. Additional research is required to substantiate these findings.

Key Points

• Baseline-reported metformin use was associated with a significantly lower risk of all-cause mortality in adults with arthritis.

• The association between baseline-reported metformin use and lower all-cause mortality was consistent across different arthritis subtypes.