N. Erandika*, D. Basnayake, S. Hewapathiranage, C. Weerakoon, I. Hasantha, D. Herath, N. Nanayakkara
Centre for Research, National Hospital Kandy, Sri Lanka
Rationale: The kidneys play major role in maintaining the proper level of phosphorus and calcium in the blood which mainly helps to sustain healthy bones. The aim of this study was to evaluate the association between serum calcium and phosphorus levels with unexplained arthralgia among chronic kidney disease unknown origin (CKDu) which is not well described yet.
Methods: The present descriptive cross-sectional study was carried-out among 201 CKDu patients from Wilgamuwa endemic region in Sri Lanka from March 2021 to April 2021. Blood samples were obtained for serum creatinine, calcium, phosphorus, urea and uric acid. Moreover, interviewer administered questionnaire was used to collect the data regarding demographic factors and the presence of arthralgia. Data analysis was done by SPSS version 20.
Results: The mean age of the study participants was 57.79 (SD=8.094) years and males were made up the majority of the study group (77.1%; n=155), Mean serum calcium and the phosphorus levels were 2.17 mmol/L (SD=0.224) and 1.13 mmol/L (SD=0.256). Among them, hypocalcemia [2.15 mmol/L, hypophosphatemia (<1.12 mmol/L] and arthralgia were presented with 47.8% (n=96) 48.3% (n=97) and 48.8% (n=98) respectively. Although, serum calcium level had significant associations with arthralgia (p=0.002; r=0.215), association with low serum phosphorus level was not statistically significant (p=0.494; r=0.049). However, 26.9% (n=54) and 25.4% (n=51) of the patients complained arthralgia with low serum calcium and phosphorus level. Moreover, statistically significant difference was not shown between CKD stages and the aimed biochemical parameters.
Conclusion: Hypocalcemia associated with increased risk of having arthralgia in CKDu patients while hypophosphatemia was not associated. But nearly, 25% of the patients complained arthralgia with above low mineral levels. Otherwise, unexplained arthralgia is common in CKDu and significantly associated with hypocalcemia. Further studies are required to identify the link between two parameters.