Introduction
Across the world, chronic kidney
disease (CKD) has been a debilitating progressive disease which affects elderly
people [1]. For adequate management of CKD, various interventions have been
presented such as lifestyle modification, applicable medication for type 2
diabetes (T2D) and hypertension (HTN). Main purpose is to delay the progress of
CKD in several stages. As to nutritional aspect, low-protein diet (LPD),
Mediterranean diet (Med), the alternate Mediterranean (aMed) diet, the
Alternative Healthy Eating index (AHEI) may slow the CKD progression. The
strategy of weight reduction has been also effective for suppressing the
exacerbation of CKD when the patient has been obesity problem [2]. For weight
control, low carbohydrate diet (LCD) has been one of the effective measures
with satisfactory result.
On the other hand, CKD has mutual
relationship with atherosclerotic cardiovascular disease (ASCVD) [3].
Arteriosclerotic diseases include T2D, HTN, dyslipidemia, CKD, CVD, cerebral
vascular accident (CVA), and metabolic syndrome (Met-S)-related diseases. These
diseases need adequate control of blood pressure (BP), blood glucose, LDL-C and
other factors. For clinical management of CKD, the Kidney Disease: Improving
Global Outcomes (KDIGO) guidelines have been recommended to be applied [4].
For improving the QOL in CKD patient,
the National Kidney Foundation's Kidney Disease Outcomes Quality Initiative
(KDOQI) established the guideline for make slowing the progression of renal
diseases [5]. Some study presented that low-protein diet (LPD) may be effective
for serum urea and uric acid in CKD patient [6]. However, compared with usual
diet, LPD did not show certain efficacy on serum creatinine value [7]. Other
nutritional options for CKD show aMed diet and Alternative Healthy Eating Index
(AHEI)-2010. These aMed and AHEI showed lower risk for progress in CKD [8].
When low-salt diet is continued, the doubling time of increasing Cre becomes
moderately longer. However, this clinical effect has not been clarified for proteinuria,
estimated glomerular filtration rate (eGFR), or all-cause mortality, where
further investigation will be required [9].
Authors and collaborators have
continued our clinical practice and related research on various fields. They
include T2D, CKD, hemodialysis (HD), ASCVD, CVD, CVA, meal tolerance test
(MTT), continuous glucose monitoring (CGM), and others [10-12]. Among them,
several cases were provided LCD as nutritional treatment. Currently, we have an
impressive male patient with CKD. He was obese, and then treated to continue
LCD. He had successively showed weight reduction, followed by the improvement
of renal function. These general situations and some perspectives are described
in the current article.
Presentation of the Case
Medical history
The patient is 66-year-old male with
CKD. When he was 20 years old, his body weight was 62kg. After that, his weight
had been gradually increased, and he had 87kg as the maximum level 2 years ago.
He was pointed out to have hypertension and dyslipidemia, and had been
prescribed amlodipine and rosuvastatin. He visited the internal medicine and
diabetes department of our hospital in May 2020. We had further evaluation of
his medical check-up in detail.
Physicals and laboratory exams
His physical examination in May 2020
showed the following status: consciousness and speech are normal during the
conversation in our out clinic, his vitals are in the normal ranges such as
pulse, BP, temperature, respiration and SpO2, unremarkable changes were found
in the heart, lung, abdomen and extremities, and neurological findings were
intact. His physique showed 171 cm in height and 87.0 kg in weight with BMI
29.7 kg/m2.
Table 1: Laboratory Results.
|
Lab |
May 2020 |
May 2021 |
unit |
|
|
Glucose |
HbA1c |
6.1 |
5.3 |
% |
|
Liver |
AST |
57 |
15 |
U/L |
|
ALT |
117 |
19 |
U/L |
|
|
GGT |
71 |
28 |
U/L |
|
|
Lipids |
LDL |
178 |
128 |
mg/dL |
|
HDL |
39 |
50 |
mg/dL |
|
|
TG |
214 |
213 |
mg/dL |
|
|
Renal |
BUN |
26 |
28 |
mg/dL |
|
UA |
7.1 |
5.3 |
mg/dL |
|
|
Cre |
1.53 |
1.24 |
mg/dL |
|
|
eGFR |
36.8 |
46.1 |
mL/min/1.73m*2 |
|
|
Na |
149 |
144 |
mEq/L |
|
|
K |
102 |
102 |
mEq/L |
|
|
Cl |
4.6 |
4.4 |
mEq/L |
|
|
CBC |
WBC |
70 |
9300 |
10*2/?L |
|
RBC |
537 |
545 |
10*4/?L |
|
|
Hb |
16.9 |
16.9 |
g/dL |
|
|
Ht |
50.6 |
50.8 |
% |
|
|
MCV |
94.1 |
93.3 |
FL |
|
|
MCH |
31.5 |
31 |
PG |
|
|
MCHC |
33.4 |
33.2 |
g/dL |
|
|
Plt |
24.1 |
23.4 |
10*4/?L |
Biochemical examination was
conducted, and their data are shown in Table 1. Among them, positive results
were in the following: Cre 1.53 mg/dL, eGFR 36.8 mL/min/1.73m2, LDL-C 163
mg/dL, AST 57 U/L, ALT 117 U/L. Urinalysis showed protein (-), glucose (-),
urobilinogen (+/-), pH 6.0, ketone bodies (-), occult blood (-), urinary
microalbumin 6.9 mg/g?cre (0-26.9). Chest X-ray revealed no remarkable
changes. Electrocardiogram (ECG) showed ordinary sinus rhythm, pulse 64/min,
normal axis deviation, no ST-T changes. He had the exam of arteriosclerosis for
mechanocardiogram and sphygmogram (Figure 1). The result showed that ankle
brachial index?ABI?was 0.88/0.98 for right/left respectively, and that
cardio-ankle vascular index (CAVI) was 6.0/5.8 for right/left, respectively. As
its detail analysis, upstroke time (UT) and % mean arterial pressure (%MAP)
showed unremarkable results.
Clinical course
His medical problems were summarized
as follows: #1 hypertension, #2 dyslipidemia, #3 obesity, #4 CKD, #5 T2D due to
increased HbA1c and #6 fatty liver from elevated AST/ALT. After clarifying the diagnosis at that time,
he was ordered to start super-LCD method in order to decrease his body weight.
Super LCD includes 12% of carbohydrate in calorie ratio, in which bread, rice,
noodles and other carbo food are restricted. His diet therapy was successfully
continued for 1 year (Figure 2). His general data were improved as 87kg to 78
kg in weight, 6.1% to 5.3% in HbA1c, 1.53 mg/dL to 1.24 mg/dL in creatinine and
36.8 to 46.1 mL/min/1.73m2 in eGFR. In Jan 2023, he showed weight
76kg, HbA1c 5.2%, Cr 1.18 mg/dL and eGFR 48.4 mL/min/1.73m2,
associated satisfactory improvement.
Figure 1: The results of mechanocardiogram and sphygmogram.
Figure 2: Clinical progress about changes in Creatinine and eGFR.
Ethical standards
This male case has been complied with
the ethic guideline for previous Declaration of Helsinki. In addition, some
comment was along with the standard protection regulation concerning the
personal information. This principle was also based on usual ethical rules for
clinical practice and related research for human. Several guidelines were
conducted from the proposal of Japanese Ministry. They are on the Ministry of
Health, Labor and Welfare, Japan and the Ministry of Education, Culture,
Sports, Science Technology, Japan. The authors in current article have
established our ethical committee as to this research that was in Sakamoto
Hospital in Kagawa prefecture, Japan. It included professional medical and also
legal persons that has hospital president, physicians, pharmacist, surgeon,
nurse, registered nutritionist and legal professionals. Those members have
discussed satisfactory about this case, and agreed the current protocol about
this research.
Discussion
The current case was 66-year-old
male, who had medical problems of hypertension, dyslipidemia, obesity, CKD,
T2D, and fatty liver in May 2020. These diseases have mutual complex
relationships and influences [13]. He has successfully continued LCD for about
2 years. Consequently, several biomarkers were improved as follows; weight 87kg
to 76kg, Cr 1.53 mg/dL to 1.18 mg/dL, eGFR 36.8 to 48.4 mL/min/1.73m2,
HbA1c 6.1% to 5.2%, and ALT 117 to 23 U/L. In this case, three aspects of
discussion can be supposed, which will be described in this order.
Firstly, this case had clinical
efficacy by LCD. Concerning LCD, authors’ research group have continued LCD
development for years through Japan LCD promotion association (JLCDPA) [14]. As
practical LCD meal method, we have recommended three types of LCD. They are
super-LCD, standard-LCD and petite-LCD, which include carbohydrate ratio as
12%, 26% and 40%, respectively [15]. When applying super-LCD, T2D patient had
shown significant improvement of glucose variability associated with remarkable
weight reduction [16]. LCD is expected to be more recognized as useful
nutritional method for weight reduction.
Secondly, the relationship between
LCD and diabetic nephropathy (DN) was investigated. The protocol showed two
groups of with and without DN. Furthermore, 147 items of biochemical and
anthropometric measures were analyzed [17]. From these data, LCD score was calculated.
Thus, LCD score and odd ratio for developing to DN were compared. As a result,
LCD scores were not significantly related with DN (OR=0.39). However, by the
highest quartile of LCD score showed 71% lower risk of DN (OR =0.29). For
significant trend, urinary albumin was decreased associated with elevation of
LCD score (p=0.005). In conclusion, LCD showed inverse association with DN
risk. Future detail investigation will be required for confirming these
results. Concerning the efficacy of LCD on renal function in T2D, meta-analysis
was performed [18]. The method included 12 controlled trials with 942 cases
were analyzed. As a result, significant differences were not found for eGFR,
Ccr, urinary albumin and serum creatinine. Consequently, clinical efficacy was
not observed for renal function by the comparison of LCD and control diet for
T2D.
Concerning the progress of DN, the
influence of daily meal was investigated. The protocol included 210 female T2D
with and without DN (2 groups of 105 and 105) [19]. The meal was used for the
Dietary Approaches to Stop Hypertension (DASH) diet, and detail questionnaire
of food intake with 147 items. By conducting the control of potential
confounders, the highest DASH adherence showed 84% lower add ratio of DN. It was
compared to those of the lowest, which showed odd ratio of 0.16 (p< 0.001).
Recently, LCD has been known for its clinical efficacy for T2D. In the case of
T2D with nephropathy, LCD may elevate usual protein intake. Dietary protein
amount can influence renal function, and then various debate has been observed.
From the cohort study, clinical efficacy of LCD for renal function was
investigated for 143 cases [20]. As a result, LCD contributed the improvement
of renal and cardiovascular risk factors for T2D. In the comparative cohort
study with mild CKD and normal renal function for 30 months, serum creatinine
level was improved significantly. For the detail data, serum creatinine showed
the improvement from 80.0 to 74.5 ?mol/L (p <0.001), and eGFR showed the improvement
from 85.5 to 88.0 mL/min/1.73m2 (p=0.003).
Thirdly, a recent report was found as
to CKD and obesity [21]. Totally 140 CKD patients were included and analyzed,
in which average data were age 69, body weight 99kg, BMI 36 kg/m2,
eGFR 17 mL/min/1.73m2 (12-20),
HbA1c 7.0%?(5.9-8.1), and albumin to creatinine ratio 61 mg/g?Cr
(18.3-220.1). For further detail data, etiology of CKD showed diabetes 56%,
hypertension 39%, renovascular disease 4%, and obesity-related comorbidity
showed diabetes 66%, hypertension 70%, dyslipidemia 16%, cardiovascular disease
26%. Related nephrologists showed the agreement that obesity would affect
negatively health of CKD cases. Both of T2DM and obesity may lead to CKD and
DKD associated with acceleration of renal function impairment. Adequate diet
can bring the suppression of DKD, CKD or progression by reducing blood pressure
and body weight [22]. It can contribute more by reducing inflammatory
phenomenon and renal hyperfiltration. By continuing LCD, T2D case will have
successful improved glycemic control and weight reduction. However, it may
bring some concerning of DKD/CKD from relatively higher intake of protein.
The relationship of CKD and weight
reduction was in focus, and comprehensive reviews were reported with impressive
content [23,24]. From these results, cases with remarkable weight reduction
have showed stable or improved GFR and proteinuria excretion by observational
and interventional investigations [25,26]. These reports showed the involvement
of lifestyle analysis, pharmacological treatment, and surgical interventions.
In addition, weight reduction and CKD biomarkers in these circumstances showed
better results than surgical interventions.
Some limitation may exist in this
report. This case showed the improvement of renal function. The reason would be
from weight reduction by LCD. However, other factors may be involved in the
clinical progress, such as blood pressure, blood glucose, lipids, and
arteriosclerosis. Further follow up will be required in this case.
In summary, the case of 66-year-old
male with CKD was presented and some perspectives as to CKD, LCD and weight
reduction were described. Some impressive points will become a useful reference
for future practice and research of CKD.
Conflict of Interest
The authors declare no conflict of
interest.
Funding
There was no funding received for
this paper.
References