Serum intact parathyroid hormone levels in cats with chronic kidney disease

Abstract

Pesq. Vet. Bras. 33(2):229-235, fevereiro 2013 229 RESUMO.-[Avaliação das concentrações séricas de paratormônio intacto em gatos com doença renal crônica.] A doença renal crônica (DRC) em gatos é frequentemente observada e caracteriza-se como alteração multissistêmi-ca, causada por alterações metabólicas, e o hiperparatireoidismo secundário renal (HPTSR) seria o mais comum e usualmente está associada com progressão da doença renal e mau prognóstico. Esse estudo teve como objetivo determinar a frequência do HPTSR, e discutir os possíveis Chronic kidney disease (CKD) is frequently observed in cats and it is characterized as a multisystemic illness, caused by several underlying metabolic changes, and secondary renal hyperparathyroidism (SRHPT) is relatively common; usually it is associated with the progression of renal disease and poor prognosis. This study aimed at determining the frequency of SRHPT, and discussing possible mechanisms that could contribute to the development of SRHPT in cats at different stages of CKD through the evaluation of calcium and phosphorus metabolism, as well as acid-base status. Forty owned cats with CKD were included and divided into three groups, according to the stages of the disease, classified according to the International Renal Interest Society (IRIS) as Stage II (n=12), Stage III (n=22) and Stage IV (n=6). Control group was composed of 21 clinically healthy cats. Increased serum intact parathyroid hormone (iPTH) concentrations were observed in most CKD cats in all stages, and mainly in Stage IV, which hyperphosphatemia and ionized hypocalcemia were detected and associated to the cause for the development of SRHPT. In Stages II and III, however, ionized hypercalcemia was noticed suggesting that the development of SRHPT might be associated with other factors, and metabolic acidosis could be involved to the increase of serum ionized calcium. Therefore, causes for the development of SRHPT seem to be multifactorial and they must be further investigated, mainly in the early stages of CKD in cats, as hyperphosphatemia and ionized hypocalcemia could not be the only factors involved.INDEX TERMS: Renal disease in cats, ionized calcium, hyperphosphatemia, secondary renal hyperparathyroidism, metabolic acidosis.

Evaluation of Electrolyte Concentration and Pro-Inflammatory and Oxidative Status in Dogs with Advanced Chronic Kidney Disease under Dietary Treatment

“…In a previous study on dogs with CKD, the renal diet was unable to prevent the increase in PTH, although the animals had fewer uremic crises and increased survival time compared to the group fed a maintenance diet [15]. In the present study, serum PTH showed a positive correlation with creatinine and urea, but the correlation with phosphorus was not significant, although other studies have identified a positive correlation between PTH and phosphorus [3,5,44,45]. Similar to the present study, a previous report did not find a relationship between PTH and phosphorus and suggested that other variables in addition to phosphorus and calcium may be involved in the regulation of PTH.…”

Dystrophic mineralization in uremic dogs: an update

“…Hyperphosphatemia resulting from phosphorus retention due to progressive reduction in the glomerular filtration rate (GFR) (Geddes et al 2013) was the second most frequent change in mineral metabolism observed in this study. Such abnormality is frequent since the early stages of CKD, and has a direct correlation with the worsening of azotemia, as it intensifies with the loss of nephrons, which was observed in this study, as well as in felines and humans , Lazaretti et al 2006, Cortadellas et al 2010, Martinez & Carvalho 2010, Giovaninni et al 2013, Queiroz 2015, Valencia & Arango 2015.…”

“…Cortadellas et al (2010) demonstrated that, in dogs with CKD, SRHPT is frequent and may even be present at stage 1 of the disease, suggesting that reduced renal phosphorus excretion and, consequently, serum retention would start at the earliest stages of CKD. Giovaninni et al (2013) also found increased phosphorus and PTH concentrations in cats with mild azotemia.…”

Fibroblast Growth Factor‐23 Concentration in Dogs with Chronic Kidney Disease

“…In cats, onset of RHPT, defined by increased PTH concentration, has been documented even before the onset of azotemia . It has also been reported that PTH concentrations do not increase significantly in cats until end‐stage disease is present . The discrepancies in these results may be a reflection of different laboratory reference ranges among studies or a reflection of patient variability we have yet to understand.…”