Association of dietary minerals and phosphorus to protein ratio with quality of life in Iranian Hemodialysis patients: a cross-sectional study

Abstract

Hemodialysis patients often face significant challenges related to their quality of life, which can be influenced by various dietary factors. Among these, dietary minerals and the phosphorus to protein ratio may play important roles in maintaining overall quality of life and its subscales. Despite the critical nature of this topic, there remains a dearth of studies examining these associations. Therefore, we aimed to investigate the relationship between dietary intake of phosphorus, calcium, magnesium, and the phosphorus to protein ratio with quality of life and its subscales in hemodialysis patients. The present multi-center cross-sectional study was performed on 323 maintenance hemodialysis patients. Dietary intake was obtained through a validated 168-item semi-quantitative food frequency questionnaire. The Kidney Disease Quality of Life Short Form (KDQOL-SF) was used to assess quality of life and its subscales. Exclusion criteria were applied to individuals whose daily caloric intake exceeded 4200 kcal or fell below 800 kcal. Nutritionist IV software was used to calculate overall energy and nutrient intake and SPSS software version 20 was utilized for data analysis. The results showed that lower phosphorus intake increased the odds of symptoms (OR = 2.65, 95% CI: 1.07-6.59), sleep disturbances (OR = 2.82, 95% CI: 1.18-6.71), and low emotional well-being (OR = 2.63, 95% CI: 1.09-6.31) in fully adjusted model, adjusted for age, sex, BMI, energy intake, Kt-V, and URR. Low calcium intake was also associated with higher odds of low role-physical component (OR = 1.88, 95% CI: 1.13-3.15) in age and sex adjusted model. However, high dietary calcium decreased odds of low QoL in general health subscale in fully adjusted model (OR = 0.28, 95% CI: 0.09-0.88). Low magnesium intake increased odds of low QoL in work status subscale, and physical and mental composite in age and sex adjusted model, while improved symptom/problem subscale in fully adjusted model. High phosphorus to protein ratio associated with low patient satisfaction in fully adjusted model (p-value < 0.05). The study indicated a relationship between the intakes of certain minerals with low QoL in HD patients. Phosphorus, calcium, and magnesium intake were positively associated with increased overall QoL scores, while an increased phosphorus-to-protein ratio was associated with a decline in QoL. Larger sample sizes and the inclusion of healthy control groups should be pursued in future research on this topic.

Keywords: Calcium; Dietary phosphorus to protein ratio; Magnesium; Phosphorus; Quality of life; Renal Dialysis.