Clinical features and long-term renal outcomes of Japanese patients with obesity-related glomerulopathy

Background

Studies have suggested that obesity-related glomerulopathy (ORG) is one of the important disease entities leading to end-stage renal disease. However, information is limited regarding the clinical features and renal outcomes of Japanese ORG patients.

Methods

Among the patients whose renal biopsy was performed at our institute during the past 10 years, we identified 28 ORG patients. Among them, the renal prognosis of the 20 patients with more than 2 years of follow-up was further analyzed. The clinical features at biopsy and the renal outcomes were compared with those of other ORG cohorts.

Results

The average values at diagnosis were a body mass index of 32.0 kg/m², eGFR of 65 ml/min/1.73 m², and urinary protein excretion of 1.7 g/day. These features were less serious than those of the US cohort or the Spanish cohort and were compatible with those of the Chinese cohort. At the last observation, seven patients (35 %) showed a 50 % increase in their serum creatinine, and two patients (10 %) had a 100 % increase in serum creatinine and/or end-stage renal disease (end point). A multivariate analysis identified the time-averaged proteinuria during follow-up as an independent factor that was associated with the slope of renal function. The annual rate of patients reaching the end point in the US cohort, the Spanish cohort and the current cohort were 6.7, 6.9 and 1.6 % per year, respectively.

Conclusion

The long-term outcomes of Japanese ORG patients include progression to renal failure, emphasizing the importance of an accurate early diagnosis of this entity.