Renal Disease as a Predictor of Increased Mortality among Patients with Rheumatoid Arthritis

Abstract

Aims and Methods: Mortality among RA patients and controls was analyzed with special attention to renal disease in population-based material (originally screened in 1988) of 604 patients with RA (470 females, 134 males) and 457 age- and sex-matched controls (352 females, 105 males). In the original RA population, isolated hematuria (HU) was observed in 54, isolated proteinuria (PU) in 27, combined hematuria and proteinuria (HUPU) in 7, chronic renal failure (CRFtot) in 36 and isolated chronic renal failure without HU or PU (CRFisol) in 15 patients. Among the controls, HU was observed in 39, PU in 11, CRFtot in 32 and CRFisol in 16 subjects. HUPU was not observed in any of the controls. Microalbuminuria (20–200 µg/min) was observed in 34 RA patients and in 27 controls. Histologically confirmed amyloidosis was found in 13 RA patients and mesangial glomerulonephritis (MesGN) in 17 patients. The mortality was evaluated in 1999 from data of the Statistical Office of Finland. Statistical analysis was performed by Cox regression analysis. Results: Mortality was significantly increased in the RA population as compared to controls: hazard ratio (HR) 1.78 (95% CI 1.34–2.31) for all RA patients; HR 2.12 (1.52–2.94) for females; HR 1.15 (0.75–1.77) for males. In the RA material, increased mortality was detected in patients with HUPU (HR 4.45; 1.54–12.84), PU (HR 3.54; 1.88–6.65), CRFtot (HR 3.74; 2.55–5.56) or microalbuminuria (HR 2.77; 1.64–4.69) when compared to those with normal clinical renal findings, whereas HU (HR 1.49; 0.88–2.52), CRFisol (HR 1.71; 0.82–3.54), bacteriuria (HR 0.96; 0.35–2.59) or pyuria (HR 0.65; 0.09–4.65) did not predict mortality. Renal amyloidosis was associated with an over twofold mortality rate (HR 2.31; 1.03–5.15), whereas mortality was within expected limits in RA patients with MesGN (HR 1.61; 0.49–5.24). Conclusion: Our results show that nephropathy presenting with combined hematuria and proteinuria, proteinuria, microalbuminuria or histologically confirmed amyloidosis is associated with increased mortality in RA patients, whereas mortality is within expected limits in those with isolated hematuria or mesangial glomerulonephritis.

Rheumatoid Arthritis and the Kidney: Uneasy Companions

“…Amyloidosis caused death in 8% of RA patients, thereby accounting for roughly one third of all deaths [6]. This is well within the range of 4-26% that other studies have reported as the prevalence rate of amyloidosis in RA patients [7].…”

“…In order to address this question, Sihvonen et al [6], in this issue of Nephron Clinical Practice, report on a prospective case-control study of Finnish RA patients with renal disease followed for 10 years. They found a significantly increased mortality in all RA patients (26 compared to 16% in the control group), with a hazard ratio of 1.78, which is in line with most other studies on the topic.…”

Prognostic Factors for Renal Amyloidosis:A Clinicopathological Study Using Cluster Analysis

“…Renal amyloidosis is associated with increased mortality in hemodialysis patients (36,39) and in patients with rheumatoid arthritis (40). The …”

Renal disease in patients with rheumatoid arthritis treated with biological therapy

“…Kidney disease appeared in patients with RA most often during the first 10-15 years of RA disease; however, a significant percentage of patients with RA without baseline nephropathy progressed to CKD over time [9].…”

“…RA associated renal amyloidosis determines a higher mortality rate relative to rest of population [5]. Generally, the occurrence of proteinuria or CKD in patients with RA, was reported to associate with an increased risk of death [6], being identified also as an independent risk factor for cardiovascular events in such category [7].…”