Changes in renal function and morphological variations of kidney diseases in rheumatoid arthritis patients

Urinary albumin-to-creatinine ratio for predicting risk of all-cause mortality and specific-cause mortality in patients with rheumatoid arthritis: evidence from NHANES 1999-2018

OBJECTIVE

To explore the relationship between urinary albumin-to-creatinine ratio (uACR) and all-cause/specific-cause mortality among patients with rheumatoid arthritis (RA).

METHODS

This study included 1354 RA patients in the National Health and Nutritional Examination Surveys (NHANESs) during 1999-2018. The mortality status was assessed by linkage to death certificate data reported in the National Death Index (NDI) until December 31, 2019. Cox proportional hazards models and Kaplan-Meier (K-M) analysis were used to elucidate the relationship between uACR and all-cause/specific-cause mortality. Restricted cubic spline (RCS) was used to visualize the association of uACR with all-cause mortality risk. Stratified analyses were employed to identify patients with higher mortality risk.

RESULTS

Over a median of 115 months of follow-up, 298 deaths occurred. Cox proportional hazards models indicated that RA patients with higher uACR had an increased risk of all-cause mortality, but not cardiovascular disease, kidney disease, and cancer mortality. K-M survival curves showed a significant difference (log-rank, p < 0.001) in all-cause mortality among uACR tertiles. RCS analysis revealed an L-shaped association between uACR and all-cause mortality, and patients with uACR above the threshold points (5.96 mg/g) had a 13.2% increased risk of all-cause mortality (HRs 1.132; 95% CI 1.011, 1.267) for each ln unit increase in uACR. The stratified analysis revealed consistent patterns for correlations between uACR and all-cause mortality.

CONCLUSIONS

High uACR, even in the normal range, was associated with an increased risk of all-cause mortality (not specific-cause mortality) in individuals with RA. Identifying high-risk populations using uACR assessment may contribute to target risk interventions among RA patients in the future. Key points • uACR, even within the normal range, significantly increased the hazard for all-cause mortality among RA patients. • uACR has good performance in identifying populations with different mortality risk levels in RA patients. • uACR, independent of varied well-recognized cardiovascular risk factors, is a predictor of mortality in RA patients.

Association of urinary albumin excretion with all-cause and cardiovascular mortality among patients with rheumatoid arthritis: a national prospective study

Background

Rheumatoid arthritis (RA) patients suffering from chronic renal insufficiency tend to exhibit subtle manifestations at the beginning. Urine albumin to creatinine ratio (ACR) is a sensitive indicator for early assessment of renal function. However, it is unclear whether it serves as an independent risk factor influencing the prognosis of RA patients.

Methods

National Health and Nutrition Examination Survey (NHANES) data from 2009-2018 were included. Kaplan-Meier (K-M) curves were plotted to compare the cumulative survival probability of RA patients with different urinary albumin excretion. The association of ACR with mortality among RA patients was investigated with Cox regression model, restricted cubic spline (RCS) and stratified analyses. The prognostic efficacy of ACR and estimated glomerular filtration rate (eGFR) was evaluated by receiver operating characteristic (ROC) curves.

Results

The Cox regression model adjusted with covariates showed a 53% (HR 1.53, 95% CI 1.06-2.21) increase in all-cause mortality and a statistically non-significant increase in cardiovascular disease (CVD) mortality in RA patients with microalbuminuria (30mg/g ≤ACR<300mg/g). ACR≥300mg/g was associated with an increase in all-cause mortality (HR 2.62, 95% CI 1.55-4.45) and CVD mortality (HR 5.67, 95% CI 1.96-16.39). RCS demonstrated a nonlinear correlation between ACR and all-cause mortality in RA patients with microalbuminuria. Subgroup analysis showed that CVD mortality was higher in RA patients with microalbuminuria characterized by the following features: female, other ethnicity, eGFR≥60 ml/min/1.73 m2, hypertension or hyperlipidemia. Compared with eGFR, ACR provided better prognostic efficacy than eGFR with higher values of the area under the curve (AUC) for all-cause mortality (AUC=0.683, 95% CI 0.613-0.754) and CVD mortality (AUC=0.681, 95% CI 0.541-0.820).

Conclusion

ACR is an independent risk factor affecting the prognosis of RA patients. The all-cause mortality was increased in RA patients with albuminuria. There was an upward trend in the CVD mortality of those with macroalbuminuria when ACR increased.

Updates on interstitial lung disease and other selected extra-articular manifestations of rheumatoid arthritis

PURPOSE OF REVIEW

To discuss changes in epidemiology, recent advances in understanding of the pathogenesis and management of selected extraarticular manifestations of rheumatoid arthritis (ExRA).

RECENT FINDINGS

The incidence of ExRA overall and subcutaneous rheumatoid nodules in particular is declining after 2000. These trends reflect improved RA disease activity with early effective immunosuppressive treatments; changing environmental risk factors can be contributing. ExRA continues to carry a two-fold increased mortality risk. RA-associated interstitial lung disease (RA-ILD) is a major contributor to mortality, with no decline in incidence and scant therapeutic options. Individualized risk stratification for RA-ILD based on patient-level risk factors and biomarker profile is evolving with MUC5B as a major genetic risk factor. Clinical trials are underway to evaluate the benefits of novel antifibrotic therapies and targeted therapies for RA-ILD. The risk of cardiovascular disease in RA is generally amendable to treatment with disease-modifying antirheumatic drugs, although cardiovascular risk associated with JAK inhibition is not fully understood.

SUMMARY

Despite reduction in incidence of ExRA overall, the incidence of RA-ILD shows no significant decline and remains a major therapeutic challenge. The use of novel antifibrotics and immunosuppressive drugs shows promise in slowing the progression of RA-ILD.