Introduction: Because of the high associated morbi-mortality, phosphate and calcium disorders remain a major therapeutic challenge for nephrologists. Previous studies showed that only few patients had serum calcium, phosphate and parathyroid hormone within Kidney-Disease Outcomes Quality Initiative (K/DOQI) targets.
Patients and methods: The French calcium and phosphate observatory monitors mineral metabolism at local, regional and national level and its follow-up every six months since 2005. More than 200 nephrologists collected more than 9000 patients' data. We compared the results recorded in June 2005 with those collected in June 2008.
Results: As compared with June 2005, in June 2008 fewer patients were hypercalcemic according to the K/DOQI targets (-26.2%, p<0.001) and hyperphosphatemic (-16.5%, p<0.001), more patients were hypocalcemic (+45.5%, p<0.001) and hypophosphatemic (+8.8%, p<0.02). A greater number of patients had elevated serum PTH above 300ng/l (+17.6%, p<0.001) and fewer had a PTH lower than 150ng/l (-25.4%, p<0.001). Serum 25OH vitamin D level was 21.7+/-20.0microg/l in June 2008. Overall, 10.5% of patients met all three K/DOQI targets, an improvement compared with June 2005 (6.8%, p<0.001). Between 2005 and 2008, cinacalcet, lanthane carbonate and native vitamin D derivatives prescription increased whereas calcium-based phosphate binders, sevelamer-HCL and active vitamin D derivatives decreased.
Conclusion: Despite a significant improvement between 2005 and 2008, only few patients reach the three K/DOQI targets (10.5%) in 2008. The prospective biannual follow-up during three years will allow us to identify the impact of different treatments on calcium and phosphate metabolic control and patient's survival.