PTH levels and not serum phosphorus levels are a predictor of the progression of kidney disease in elderly patients with advanced chronic kidney disease.
BACKGROUND
At present, there is a high incidence of elderly patients with advanced chronic kidney disease (CKD) and it is important to know the long term progression and the factors that influence it.


OBJECTIVE
To analyse the progression of advanced CKD in elderly patients and the influence of bone-mineral metabolism.


METHODS
Retrospective study of 125 patients ≥70years of age with CKD stages 4-5 who started follow-up from January 1, 2007 to December 31, 2008, showing the progression of CKD (measured by the slope of the regression line of the estimated glomerular filtration rate [eGFR] by MDRD-4) over 5years.


RESULTS
Progression in the entire group (median and 25th and 75th percentiles): -1.15 (-2.8/0.17) ml/min/1.73m2/year, CKD-4: -1.3 (-2.8/0.03) ml/min/1.73m2/year, CKD-5: -1.03 (-3.0/0.8) ml/min/1.73m2/year; the slope of the regression line was positive in 35 patients (28%: CKD does not progress) and negative in 90 patients (72%: CKD progresses). Negative correlation (Spearman) (slower progression): PTH, albumin/Cr ratio and daily Na excretion (all baseline measurements). No correlation with eGFR, serum P, urinary P excretion, protein intake and intake of P (all baseline measurements). In the linear regression analysis (dependent variable: slope of progression): albuminuria and PTH (both at baseline measurements) influenced this variable independently. Logistic regression (progresses vs. does not progress): PTH, albuminuria and eGFR (all at baseline measurements) influenced significantly.


CONCLUSIONS
In our group of elderly patients, impairment of renal function is slow, particularly in CKD-5 patients. Albuminuria and PTH at baseline levels are prognostic factors in the evolution of renal function.
Unidad de Gestión Clínica Nefrología-Urología, Hospital Universitario Virgen del Rocío, Sevilla, España. Electronic address: ngabrieltg@gmail.com.
Néstor Gabriel
NG
Toapanta Gaibor
Unidad de Gestión Clínica Nefrología-Urología, Hospital Universitario Virgen del Rocío, Sevilla, España.
Nathasha Carolina
NC
Nava Pérez
Unidad de Gestión Clínica Nefrología-Urología, Hospital Universitario Virgen del Rocío, Sevilla, España.
Yeleine
Y
Martínez Echevers
Unidad de Gestión Clínica Nefrología-Urología, Hospital Universitario Virgen del Rocío, Sevilla, España.
Rafael
R
Montes Delgado
Unidad de Gestión Clínica Nefrología-Urología, Hospital Universitario Virgen del Rocío, Sevilla, España.
María Ángeles
MÁ
Guerrero Riscos
D000368:Aged; D018450:Disease Progression; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood*; D008137:Longitudinal Studies; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood*; D010758:Phosphorus / Q000097:blood*; D011379:Prognosis; D012189:Retrospective Studies
D010281:Parathyroid Hormone; D010758:Phosphorus
Advanced chronic kidney disease; Ancianos; Bone mineral metabolism; Chronic kidney disease; Elderly patients.; Enfermedad renal crónica; Enfermedad renal crónica avanzada; Fósforo sérico; Metabolismo óseo mineral; Predialysis; Prediálisis; Progresión de enfermedad renal; Progression of kidney disease; Serum phosphorus