2039
Analysis of hyperparathyroidism and its treatment in patients with non-dialysis chronic kidney disease
Abeygunaratne, T, Green, D, Chiu, D, Kalra, PA. Salford Vascular Research Group, University of Manchester, Manchester, United Kingdom.
Background: Abnormalities of chronic kidney disease-mineral bone disease (CKD-MBD) occur in early stages of CKD. The development of secondary hyperparathyroidism (HPTH) has been associated with increased morbidity. Guidelines remain vague as to the treatment of HPTH in CKD. The aim of this study was to observe the prevalence of CKD-MBD abnormalities in a non-dialysis CKD population according to the National Kidney Foundation Kidney Disease Outcomes Quality Initiative (NKF KDOQI) guidelines, and to assess frequency of use of phosphate binders and vitamin D analogues in its treatment. The KDIGO definition for HPTH was not used in this study as it was a cross-sectional analysis, and a rising PTH is part of the KDIGO definition (i.e. several PTH values required).
Method: This was a sub study of a prospective longitudinal cohort study of patients with non-dialysis requiring CKD managed in secondary care. Patients were categorized into CKD stages 3 to 5. Basic demographics were recorded. HPTH was defined according to the NKF KDOQI guidelines (stage 3: 35-75 pg/ml: stage 4 80-100 pg/ml: stage 5 150-300 pg/ml). Given that some patients had treated HPTH, patients who were within “normal PTH range” were further evaluated according to whether they received treatment.
Results: The 1667 patients had a mean age of 64.614.3 years, eGFR 32.516ml/min/1.73 m2, 65% males. The mean PTH was 9589.4 pg/ml and as expected a higher PTH and HPTH prevalence was observed in more advanced CKD. It was also evident that a higher percentage of patients received phosphate binders and vitamin D with declining eGFR.
All Patients / Stage 3a / Stage 3b / Stage 4 / Stage 5N / 1667 / 276(16.9%) / 485(29.1%) / 621(37%) / 285 (17.1%)
Age (years) / 64.6±14.3 / 62.6±13.6 / 65.0 ±13.8 / 66.4±13.9 / 62.8±15.5
eGFR(ml/min/1.72) / 32.5 ±16.1 / 51.1±4.0 / 36.6 ±4.18 / 21.9±3.9 / 11.7 ±4.5
PTH (pg/ml)
Ca (mmol/l)
Po4 (mmol/l) / 95 ±89.4
2.07±0.29
1.10±0.26 / 49±34.1
2.29±0.12
1.03±0.19 / 64±47.3
2.27±0.12
1.05±0.20 / 113±97.6
2.20±0.12
1.20±0.25 / 153±115.9
2.2±0.17
1.4±0.40
phosphate binders:all
Ca containing (%)
Non-Ca containing (%)
Vitamin D analogues / 8.5%
7.7%
0.8%
21.5% / 5.8%
5.4%
0.4%
8% / 4.3%
4.1%
0.2%
13.2% / 9%
8.2%
0.8%
27.9% / 16.8%
14.7%
6%
35.1%
KDOQI:
Below Range
EuPTH- within range
HPTH / 699 (41.9%)
464 (27.8%)
504 (30.3%) / 120(43.5%)
105 (38%)
51 (18.5%) / 139 (28.6%)
186 (38.4%)
160 (33%) / 273 (44%)
85 (13.6%)
263 (42.4% / 167 (58.6%)
88 (30.9%)
30 (10.5%)
Discussion: This observational study of an unselected cohort of patients at different stages of CKD shows that phosphate binder use was low (<10%) except in stage 5 CKD patients (17%); vitamin D analogue use increased progressively across the stages, reaching 28% and 35% in stages 4 and 5 CKD, respectively. There are several limitations to this study. The results only represent a cross sectional analysis, and because of this it was not possible to define HPTH according to KDIGO, which depends upon a PTH above the upper limit of normal as well as a rising PTH (i.e. serial measurements required) . The level of renal dysfunction was also defined by a single creatinine measurement used to estimate the eGFR. Further analysis with serial PTH measurements will be undertaken to increase the value of the study.