Nephrotic syndrome in elderly: Etiologies, management, and prognosis

The elderly population has significantly increased in the world. Nephrotic syndrome (NS) is one manifestation of glomerular nephropathy in the elderly. The objective of our study is to determine NS particularities in the elderly and to identify the factors predicting progression to chronic end-stage renal disease (ESRD). This is a retrospective and descriptive study, carried out between January 1, 1975 and December 31, 2017. It includes participants aged 65 years old or over hospitalized for NS. A multivariate study was carried out and the dependent variable was the evolution to ESRD. We studied 115 patients with an average age of 71 ±5 years (65-83) and a sex ratio (male/female) of 1.7. Twenty-three percent of patients were diabetic. The median proteinuria was 4.7 g/L (3-19.5). NS was impure in 89.5% of patients. Renal biopsy was performed in 45 patients (39.13%). NS was secondary in 65.2% of cases mainly to amyloidosis (35.6%). Idiopathic nephropathy was dominated by membranous nephropathy (9.5%). Treatment was etiopathogenic in only 18 patients (15.6%). At the end of follow-up, 15.8% of patients achieved complete or partial remission and 56.6% progressed to ESRD. The multivariate study found as independent risk factors of progression to ESRD: uremia >17 mmol/L [adjusted odds ratio (aOR) = 33.2 (1.3-837.7); P <0.05],, phosphoremia ≥1.6 mmol/L [aOR = 22.1 (1.8-266.5); P <0.05], serum potassium ≥4.3 mmol/L (aOR = 24.7 (2.4, 251.5); P <0.01], extra-renal signs [aOR = 38.9 (2.4-634.3); P = 0.01], secondary nephropathy [aOR = 74 (3.1-1788.2); P <0.01] and membranoproliferative glomerulonephritis [aOR = 48 (1.4-1675.5); P <0.05]. The protective factors were hemoglobinemia ≥9.3 g/dL [aOR = 0.007 (0-0.2); P <0.01], kidneys well differentiated [0.032 (0.003-0.4); P<0.01] and treatment with two diuretics [aOR = 0.03 (0.00-30.4); P <0.01]. It is important to recognize the spectrum of kidney diseases in the elderly to improve the progression factors to ESRD.