ORAL NUTRITION SUPPLEMENTATION
IN CKD
When nutrition counseling per se fails to meet the differ-
ence between the spontaneous dietary intake and the rec-
ommended nutrition requirements in CKD, the use of oral
nutrition supplements (ONSs) should be considered as the
immediate choice of nutrition support therapy to replen-
ish and prevent depletion of protein-energy stores. Specif-
ically, the KDOQI/AND guidelines advocate a trial of ONS
for at least 3 months to improve nutrition status if nutri-
tion counseling alone does not attain sufficient protein and
energy intake in both non–dialysis-dependent CKD and
maintenance dialysis patients.18 The ISRNM suggested a
list of indicators for commencing ONS.13 These include
(1) poor oral intake and/or poor appetite; (2) dietary
intake of energy and protein30 kcal/kg/d and1.2
g/kg/d, respectively; (3) serum concentrations of albumin
< 3.8 g/dL or prealbumin28 mg/ml (only for patients
undergoing maintenance dialysis lacking residual renal
function); (4) unintentional weight loss5% of estimated
dry weight or IBW over a 3-month period; (5) SGA compos-
ite nutrition score within the range for PEW; and (6) dete-
riorating nutrition status reflected by temporal changes in
various nutrition markers.
In general, ONSs provide a further 0.3–0.4 g/kg/d pro-
tein and 7–10 kcal/kg/d and demand the complement of
an oral intake of 0.4–0.8 g/kg/d protein and >20 kcal/kg/d
to achieve the recommended requirements for dietary pro-
tein and energy.11,13 Oral nutrition supplementation is an
effective nutrition support strategy in cases of mild to
moderate PEW because routine nutrition intake in many
patients with CKD usually surpasses the necessary mini-
mum level of spontaneous oral intake.46,54
Various research settings have explored the effective-
ness of ONSs. Metabolic studies demonstrated a positive
whole-body protein balance achievable with ONSs during
hemodialysis55,56 in addition to sustainable anabolic effects
in the postdialytic period.56 Clinical trials, comprising both
RCTs and non-RCTs, also supported the efficacy of ONSs in
sustaining and improving nutrition status in patients with
CKD. Table 3 summarizes a list of clinical trials with rele-
vant clinical and nutrition outcome measures.
Although the effect of ONSs has been evaluated in
patients undergoing hemodialysis,57–69 there is relatively
little attention on the use of ONSs among non–dialysis-
dependent CKD70 and peritoneal dialysis patients.66,71,72
The variety of ONSs depicted in the existing literature
comprised commercial58–72 and food-based57 supplements
taken during dialysis or at home, all of which consisted
of energy-based,65,70 protein-based,62–64,66,72 protein-
energy,57–61,67–69,71 and renal-specific59,60,68,69 formulas.
Although the lack of placebo controls in clinical trials
remains a significant limitation in the current literature,64
the majority of these studies incorporated a comparative
group in which patients with CKD were provided with
nutrition counseling only,57–59,62,65,66,69,70,72 ONS com-
bined with IDPN,61 or no supplementation.60,63,67,68,71
The duration of supplementation was variable, ranging
from 3 months to longer than a year. The use of an
energy-based supplement in patients with non–dialysis-
dependent CKD resulted in reduction of dietary protein
intake, improved compliance with a low-protein diet,
and decreased proteinuria.70 By contrast, in patients
undergoing maintenance dialysis, these supplements led
to improvements in dietary intake of energy59,60,62,65,72
and protein59,61–63,66,72; biomarkers such as serum con-
centrations of albumin,58,61–63,66–69,72 prealbumin,61
and total protein63; anthropometric markers including
BW,62,63,65,69,71 BMI,61 fat mass,60,62,65,69,71,72 and mus-
cle mass62,65,71,72; and composite nutrition score such
as SGA score.57,59,72 The improvements were appre-
ciated as early as 1 month62,65 and were found to be
sustainable.58,61,62,65,67,72 Notably, there were improve-
ments in inflammation,63,64 physical functioning,64 and
quality of life.57,59,68 Although mortality and hospitaliza-
tion were frequently described in clinical trials,58,61,66 the
majority of studies had inadequate statistical power to
sufficiently address the clinical effectiveness of ONSs. Nev-
ertheless, large-scale observational studies had depicted
lower mortality73 and hospitalization67 rates among
patients on maintenance dialysis who consumed ONSs.
To optimize the beneficial effects of oral nutrition sup-
plementation, particular attention should be paid to the
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