High prevalence of ascorbate deficiency in an Australian peritoneal dialysis population

Varying association of nutrient intakes with quality of life in patients receiving different modes of dialysis

Background

Nutrients are crucial for dialysis patients, especially elderly patients. Nutrition-related complications in dialysis patients are often closely related to cardiovascular aging. However, we know little about the effect of different nutrients on the commonly used outcome predictor, health-related quality of life (HRQOL). Therefore, this study investigated the associations between different nutrients and HRQOL among dialysis patients.

Methods

A cross-sectional study was conducted on 123 dialysis adults at multiple dialysis centers. The Short Form-36 Health Survey (SF-36) assesses HRQOL. Modified quantitative subjective global assessment (MQSGA) evaluates nutritional status. A 3-day dietary record evaluated nutrient intakes.

Results

Among the 123 participants, 79 received hemodialysis (HD), and 44 were on peritoneal dialysis (PD). Patients with PD had a higher SF-36 score than HD (525 ± 136 vs. 375 ± 179, P < 0.001). A negative association between nutrition status and HRQOL was observed in HD (regression coefficient β = -17.4, P < 0.001) but not in PD (β = -12.3, P = 0.07). For HD patients, the nutrition status was negatively correlated with intakes of carbohydrates, fiber, selenium, copper, and Manganese (β = -0.02, P = 0.032; β = -0.3, P = 0.031; β = -0.1, P = 0.006; β = -2.3, P = 0.025; β = -1.3, P = 0.003, respectively). Their HRQOL was positively associated with calories, fat, niacin, and vitamin E (β = 2.19, P = 0.035; β = 2.4, P = 0.043; β = 8.5, P = 0.044; β = 6.9, P = 0.017, respectively). Conversely, for patients with PD, only vitamin B2 was found to be adversely correlated with their nutritional status (β = -5.2, P = 0.037), and increased intakes of vitamin A, vitamin C and fiber (β = 0.1, P = 0.031; β = 0.8, P = 0.028; β = 15.8, P = 0.045, respectively) were associated with a better HRQOL.

Conclusions

The nutritional intake of PD patients and HD patients affects their quality of life differently. Macronutrients significantly impact HRQOL in HD patients, while vitamins have a more substantial impact on PD patients.

Uremic leontiasis ossea due to secondary hyperparathyroidism complicated by vitamin C deficiency in a non-adherent chronic hemodialysis patient: A case report

Non-adherence to medical therapy in patients with end-stage kidney disease (ESKD) can lead to severe metabolic derangements rarely seen in the current medical era. Such complications may take the form of secondary hyperparathyroidism (HPT) leading to rare manifestations of bone mineral disease, and profound vitamin C deficiency from poor nutrition combined with removal of water-soluble vitamins during dialysis. Secondary HPT causes renal osteodystrophy which can lead to diffuse enlargement of the facial skeleton and morphological changes suggestive of leontiasis ossea. We report a 36-year-old, non-adherent woman on chronic dialysis for over 10 years who developed progressive, diffuse facial bone enlargement in the context of years of extreme HPT and newly diagnosed severe vitamin C deficiency. Imaging revealed diffuse hypertrophy of the maxillary and mandibular bones. Histopathology showed extensive fibro-osseous proliferation without evidence of Brown tumor, suggestive of uremic leontiasis ossea. In this report, we discuss the orofacial manifestations of secondary HPT and the possible potentiating role of vitamin C deficiency on the development of renal osteodystrophy through altered vitamin D metabolism. Non-adherent patients on chronic dialysis should be evaluated for vitamin C deficiency, and the development of uremic leontiasis ossea should be considered when such patients present with distortion of facial features in the context of severe secondary HPT.

An Unexpected Case of Scurvy in a Peritoneal Dialysis Patient

This case describes an obese adult male peritoneal dialysis patient who presented with a pruritic follicular rash. Nutrient deficiency was not suspected initially in this case because there was no history of protein-calorie malnutrition, but the patient reported a diet devoid of fruits and vegetables and had not been taking his dialysis vitamin as prescribed. Skin biopsy showed follicular hyperkeratosis with fragmented hair shafts and corkscrew hairs consistent with scurvy. After supplementation with ascorbic acid 500 mg twice daily for 2 weeks, the rash resolved completely. Dialysis patients are at increased risk for vitamin C deficiency due to indiscriminant clearance of the nutrient with dialysis, but scurvy is rarely seen.

Water-soluble vitamins in people with low glomerular filtration rate or on dialysis: a review

People with low glomerular filtration rate and people on dialysis are spontaneously at risk for vitamin deficiency because of the potential for problems with decreased appetite and decreased sense of smell and taste, leading to decreased intake, and because decreased energy or decreased cognitive ability results in difficulties in shopping and cooking. Imposed dietary restrictions because of their renal dysfunction and because of comorbidities such as hypertension and diabetes exacerbate this problem. Finally, particularly for water-soluble vitamins, loss may occur into the dialysate. We did not identify any randomized trials of administering daily doses close to the recommended daily allowances of these vitamins. In people who are eating at all, deficiencies of B5 and B7 seem unlikely. It is unclear whether supplements of B2 and B3 are necessary. Because of dialyzability and documented evidence of insufficiency in dialysis patients, B1 supplementation is likely to be helpful. B6, B9, and B12 are implicated in the hyperhomocysteinemia observed in patients on dialysis. These vitamins have been studied in combinations, in high doses, with the hope of reducing cardiovascular outcomes. No reductions in patient-important outcomes were seen in adequately powered randomized trials. Because of their involvement in the homocysteine pathway, however, supplementation with lower doses, close to the recommended daily allowances, may be helpful. Vitamin C deficiency is common in patients on dialysis who are not taking supplements: low-dose supplements are warranted. Vitamins for dialysis patients contain most or all of the B vitamins and low-dose vitamin C. We are not aware of any medical reasons to choose one over another.

Low levels of vitamin C in dialysis patients is associated with decreased prealbumin and increased C-reactive protein

BACKGROUND

Subclinical inflammation is a common phenomenon in patients on either continuous ambulatory peritoneal dialysis (CAPD) or maintenance hemodialysis (MHD). We hypothesized that vitamin C had anti-inflammation effect because of its electron offering ability. The current study was designed to test the relationship of plasma vitamin C level and some inflammatory markers.

METHODS

In this cross-sectional study, 284 dialysis patients were recruited, including 117 MHD and 167 CAPD patients. The demographics were recorded. Plasma vitamin C was measured by high-performance liquid chromatography. And we also measured body mass index (BMI, calculated as weight/height(2)), Kt/V, serum albumin, serum prealbumin, high-sensitivity C-reactive protein (hsCRP), ferritin, hemoglobin. The relationships between vitamin C and albumin, pre-albumin and hsCRP levels were tested by Spearman correlation analysis and multiple regression analysis. Patients were classified into three subgroups by vitamin C level according to previous recommendation 12 in MHD and CAPD patients respectively: group A: < 2 ug/ml (< 11.4 umol/l, deficiency), group B: 2-4 ug/ml (11.4-22.8 umol/l, insufficiency) and group C: > 4 ug/ml (> 22.8 umol/l, normal and above).

RESULTS

Patients showed a widely distribution of plasma vitamin C levels in the total 284 dialysis patients. Vitamin C deficiency (< 2 ug/ml) was present in 95(33.45%) and insufficiency (2-4 ug/ml) in 88(30.99%). 73(25.70%) patients had plasma vitamin C levels within normal range (4-14 ug/ml) and 28(9.86%) at higher than normal levels (> 14 ug/ml). The similar proportion of different vitamin C levels was found in both MHD and CAPD groups. Plasma vitamin C level was inversely associated with hsCRP concentration (Spearman r = -0.201, P = 0.001) and positively associated with prealbumin (Spearman r = 0.268, P < 0.001), albumin levels (Spearman r = 0.161, P = 0.007). In multiple linear regression analysis, plasma vitamin C level was inversely associated with log(10)hsCRP (P = 0.048) and positively with prealbumin levels (P = 0.002) adjusted for gender, age, diabetes, modality of dialysis and some other confounding effects.

CONCLUSIONS

The investigation indicates that vitamin C deficiency is common in both MHD patients and CAPD patients. Plasma vitamin C level is positively associated with serum prealbumin level and negatively associated with hsCRP level in both groups. Vitamin C deficiency may play an important role in the increased inflammatory status in dialysis patients. Further studies are needed to determine whether inflammatory status in dialysis patients can be improved by using vitamin C supplements.

Hemoglobin and plasma vitamin C levels in patients on peritoneal dialysis

OBJECTIVE

To determine the contribution of vitamin C (Vit C) status in relation to hemoglobin (Hb) levels in patients on long-term peritoneal dialysis (PD).

METHODS

56 stable PD patients were evaluated in a cross-sectional survey. Plasma samples were collected for Vit C (analyzed by HPLC with electrochemical detection) and high-sensitivity C-reactive protein (hs-CRP) determinations. Clinical records were reviewed for Hb, transferrin saturation (TSAT), ferritin, erythropoietin (EPO) dose, and other clinical parameters. Dietary Vit C intake was evaluated by patient survey and from patient records. Total Vit C removed during PD treatment was measured in 24-hour dialysate collections.

RESULTS

Patients showed a highly skewed distribution of plasma Vit C levels, with 40% of patients below normal plasma Vit C levels (<30 μmol/L) and 9% at higher than normal levels (>80 μmol/L). Higher plasma Vit C levels were associated with higher Hb levels (Pearson r = 0.33, p < 0.004). No direct connection between Vit C levels and reported dietary intake could be established. In stepwise multiple regression, plasma Vit C remained significantly associated with Hb (p = 0.017) but there was no significant association with other variables (dialysis vintage, age, ferritin, TSAT, hs-CRP, residual renal function, and EPO dose). In 9 patients that were evaluated for Vit C in dialysate, plasma Vit C was positively associated (Spearman r = 0.85, p = 0.01) with the amount of Vit C removed during dialysis treatment.

CONCLUSIONS

These data indicate that plasma Vit C is positively associated with higher Hb level. Vit C status could play a major role in helping PD patients to utilize iron for erythropoiesis and achieve a better Hb response during anemia management.