Differences in phosphatemia and frequency of consumption of dietary sources of phosphorus in hemodialysis patients in southern and northern Brazil

Abstract Introduction: Hyperphosphatemia is associated with unfavorable outcomes, and the percentage of patients presenting with this condition in hemodialysis (HD) in kidney foundation units in the state of Santa Catarina (SC) is historically higher than that of patients in the state of Tocantins (TO). Objective: To assess the frequency of consumption of the main dietary sources of phosphorus and to compare them between the two states. Methodology: A cross-sectional study was carried out involving 123 patients, 66 of SC and 57 of TO: 52% were men, average age was 46.9 ± 15.7 years, and mean HD time 48 (57-71) months. A food frequency questionnaire (FFQ) with 33 items that are dietary sources of phosphorus was applied. A consumption score was calculated for sources of organic, inorganic, and total phosphorus, and the six-month average of phosphatemia was obtained. Results: The mean phosphatemia of SC patients was higher (6.2 ± 1.5 vs 4.7 ± 1.3 mg/dL, p <0001) than TO patients, as well as the prevalence of hyperphosphatemia (62% vs 28%; p <10001). In the total sample, the foods most frequently consumed were milk and beans. Comparing the frequency of consumption between the two states, a significant difference was found in 17 items. In TO, beef and beans were the foods most frequently consumed, and in SC, fourteen other items of the FFQ (pork, sausages, dairy products, etc.) were the most frequently consumed. Phosphatemia correlated with the frequency of consumption of inorganic phosphorus sources. Conclusion: the frequency of consumption of several items was different between the states, and this explains the differences in phosphatemia between the two regions.

摘要引言：高磷血症（hyperphosphatemia）与不良预后相关，圣卡塔琳娜州（Santa Catarina, SC）肾脏基金会诊疗中心的血液透析（hemodialysis, HD）患者中，高磷血症的检出率历来高于托坎廷斯州（Tocantins, TO）患者。研究目的：本研究旨在评估磷主要膳食来源的摄入频率，并比较两州之间的摄入差异。研究方法：本研究为横断面研究，共纳入123例血液透析患者，其中圣卡塔琳娜州66例，托坎廷斯州57例；受试者中男性占52%，平均年龄为46.9±15.7岁，平均血液透析时长为48（57-71）个月。研究采用包含33项磷膳食来源的食物频率问卷（food frequency questionnaire, FFQ）进行调查，分别计算有机磷（organic phosphorus）、无机磷（inorganic phosphorus）及总磷的摄入评分，并获取患者6个月的平均血磷（phosphatemia）水平。研究结果：圣卡塔琳娜州患者的平均血磷水平（6.2±1.5 mg/dL）高于托坎廷斯州患者（4.7±1.3 mg/dL，p<0.0001），高磷血症患病率同样更高（62% vs 28%；p<0.0001）。全样本中摄入频率最高的食物为牛奶与豆类。两州患者的食物摄入频率比较显示，17项食物条目存在显著差异。托坎廷斯州最常摄入的食物为牛肉和豆类，而圣卡塔琳娜州最常摄入的则为食物频率问卷中的其余14项（猪肉、香肠、乳制品等）。血磷水平与无机磷来源食物的摄入频率呈显著相关。研究结论：两州患者的多项食物摄入频率存在差异，该差异可解释两地区血磷水平的不同。