DOI: https://doi.org/10.21203/rs.3.rs-1287563/v1
Spinal cord injury (SCI) leads to the permanent loss or reduction of the function of movement and sensation, and no effective clinical treatment has been reported. Animal studies have shown that intermittent fasting (IF) has a neuroprotective effect on SCI, but it has not been used in clinical treatment of SCI. Intermittent fasting from dawn to sunset is a form of fasting during human activity, which may improve the dysfunction of patients with SCI. Therefore, this study is the first to explore the safety of intermittent fasting from dawn to sunset in the treatment of SCI. Twenty-six SCI participants were randomly divided into a control group or an IF group. The IF group was fasted for more than 14 hours a day, and the control group had normal diet and water. Changes in blood routine, liver function, renal function, electrolytes, plasma glucose, weight, body mass index (BMI), American Spinal Injury Association (ASIA) score and occurrence of adverse events were monitored before enrollment and at the end of IF intervention. The IF group developed hypoglycemia, hunger, weight loss, and intestinal dysfunction (nausea, abdominal discomfort, diarrhea). There were no significant differences in blood routine, liver function, renal function, electrolytes and ASIA scores before and after IF intervention, or compared with the control group. Compared with the control group, there was no difference in body weight and BMI before IF intervention, and weight loss after IF intervention, but there was no significant change in BMI. Moreover, there were significant differences in body weight and BMI before and after IF intervention. The plasma glucose of the IF group began to decrease from the 14th day, and there were significant differences in plasma glucose before and after IF intervention. These findings suggested that IF was safe and feasible for SCI participants.
Spinal cord injury (SCI) is a common central nervous system injury that can lead to permanent loss or reduction of the function of movement and sensation below the injury site, causing a serious burden on patients, families and society 1. About 930,000 people suffering from SCI in the worldwide every year 2. Although the currently recommended methods, such as early surgical decompression, spinal fixation, and rehabilitation strategies have been proven to be beneficial 3,4, but no exact and effective treatment methods have been found 5. Intermittent fasting (IF) is becoming a promising treatment strategy to prevent SCI tissue damage and promote damaged tissue repair and functional recovery.
Intermittent fasting from dawn to sunset is a form of fasting during human activity. At present, the most prevalent way of fasting is the one-month Ramadan fasting in Islam every year. In addition to changes in the time of food and fluid intake, IF also cause significant changes in energy balance and diet composition 5. Therefore, it is important to study the changes in eating habits and the effects of these changes on the human body. Intermittent fasting can protect neurons against injury by enhancing endogenous cellular stress responses and energy metabolism, by dampening oxygen free radical formation and inflammation, and activating cell survival pathways, as well as by increasing growth factor expression and axonal plasticity 6–9. Animal studies have shown that IF therapy preserves the integrity of neurons, reduces the lesion volume by more than 50%, and increases the axon protruding buds of the corticospinal tract. Moreover, blood β-hydroxybutyrate, blood ketones and brain-derived neurotrophic factors increase, thereby promoting the recovery of motor function 10,11. This shows that IF is important to the treatment of SCI. Although animal studies have shown that IF can improve dysfunction after SCI, which has not yet been used in clinical treatment of patients with SCI. Therefore, this study is the first to explore the clinical safety of intermittent fasting from dawn to sunset in the treatment of SCI, so as to lay a foundation for the follow-up clinical efficacy study.
In summary, this study compares the normal diet group with the IF group from dawn to sunset for 4 weeks, and observes blood routine, liver function, kidney function, electrolytes, plasma glucose, weight, body mass index (BMI), and American Spinal Injury Association (ASIA) score between the two groups. This is the first time to explore the clinical safety of intermittent fasting from dawn to sunset in the treatment of SCI. The results showed that the IF group developed hypoglycemia, hunger, weight loss, and intestinal dysfunction (nausea, abdominal discomfort, diarrhea). There were no significant differences in blood routine, liver function, renal function, electrolytes and ASIA scores before and after IF intervention, or compared with the control group. Compared with the control group, there was no significant difference in body weight and BMI before IF intervention, and weight loss after IF intervention, but there was no significant change in BMI. At the same time, there were significant differences in body weight and BMI before and after IF intervention. The plasma glucose of the IF group began to decrease from the 14th day, and there were significant differences in plasma glucose before and after IF intervention. Overall, the results of this experimental study show that intermittent fasting from dawn to sunset is safe and feasible for patients with SCI.
2.1 Participants
In this study, we enrolled participants (n=26) aged 26-51who were hospitalized in rehabilitation medicine department of General Hospital of Western Theater Command and met the diagnostic criteria for SCI. All volunteers were provided with written informed consent. The present study was approved by the General Hospital of Western Theater Command thics committee (case Number: 2014 Research), and registered in the Chinese Clinical Trial Registry (Registration Website: www.chictr.org.cn, Registration Number: ChiCTR-ONC-16008267, First registration time:12/04/2016), which was completed from July 2017 to May 2019. All methods were performed in accordance with the Declaration of Helsinki guidelines and regulations.
2.2 Study design and Procedures
We performed a single-center randomized controlled study to evaluate the safety of intermittent fasting from dawn to sunset on treated SCI participants. Participants were screened according to the criteria of diagnosis, inclusion and exclusion of SCI. The researchers are separated from the data statistician, and the safety evaluation is carried out by the third party.
The diagnostic criteria were as follows: I. Have a history of trauma; II. Loss of sensation and movement of lower limbs, incontinence of urination and urination;III. There is significant muscle atrophy in the late stage, or bedsores occur; IV. CT and MRI examinations are helpful to understand spinal cord damage. Spinal Cord Injury Degree Grading: Refer to the International Spinal Cord Injury Functional Grading Standard ASIA grading standard. Inclusion criteria: I. 18 years ≤ age ≤ 60 years old; II. Meet the diagnostic criteria for SCI; III. Inpatients who have no serious heart, liver, or kidney diseases and can cooperate to complete the study; IV. The subject himself or his immediate family members know and sign the informed consent form. Exclusion criteria: I. Age > 60 years old, or < 18 years old; II. Does not meet the diagnostic criteria for SCI; Ⅲ. Currently suffering from or previously suffering from mental system diseases such as depression, anxiety, substance abuse, etc.; IV. Patients with serious primary diseases such as heart, liver, kidney and hematopoietic system, such as: unstable angina pectoris; V. There are serious complications, such as: respiratory failure, heart failure and other SCI patients that have a serious impact on the quality of life of the patient; VI. Women during pregnancy and lactation.
2.3 Dietary regimen
Twenty-six SCI participants were randomly divided into a control group (n=13) and an IF group from dawn to sunset (n=13). Participants in the control group can eat freely without special restrictions, and the IF group from dawn to sunset started fasting after breakfast before dawn. Strict fasting between dawn and sunset (dusk) for 4 consecutive weeks, with a daily fast for more than 14 hours. Participants in the IF group can eat freely after fasting diet is over. All participants are allowed to drink water freely.
2.4 Biochemical analysis
The venous blood of the participants was collected before and after IF intervention, and the blood routine, liver function, renal function and electrolytes were measured with Hitachi 7600 biochemical analyzer (Hitachi, Tokyo, Japan).The participants ' basic plasma glucose level was measured before IF intervention, and the plasma glucose was tested before dinner every day after IF intervention. Plasma glucose was measured by using a plasma glucose meter (Beijing Yicheng Bioelectronics Technology Co., Ltd.).
2.5 Weight measurement and Malnutrition diagnosis
Body weight was measured before and after IF intervention. According to the European Society for Clinical Nutrition and Metabolism (ESPEN) diagnostic criteria for malnutrition (EDC) 12, in this study, participants who lost > 5% of their body weight during or at the end of the IF intervention, or whose BMI < 18.5 Kg/m2, were considered unsafe.
2.6 Assessment of functional recovery from spinal cord injury
According to the international classification standard of SCI 13, sensory function and motor function of participants were scored before and after intervention. Sensation function assessment: According to 28 key points in the distribution area of nerve roots of C2-S5, the acupuncture and light touch sensation at key points on both sides of the body were detected; score three levels: 0 point was missing, 1 point was disorder, 2 points was normal, full score 224 points. Motor function assessment: the strength of 20 key muscles on both sides of the body were tested, and score five levels: 0 point was complete paralysis; 1 point was palpable muscle contraction; 2 points was active joint movement, unable to resist gravity; 3 points was can actively move all joints against gravity; 4 points was active movement of all joints against moderate resistance; 5 points was completely normal; full score is 100 points.
2.7 Statistical analysis
The Kolmogorov-Smirnov test was used to evaluate the normal distribution of the data. Normally distributed data was described as the mean ± SD. Repeated measures analysis of variance was used to analyze plasma glucose data. The data between groups were compared by independent sample t test (two-tailed), and the data within groups were compared by paired t test (two-tailed). Differences were considered statistically significant at P < 0.05 and P < 0.01. All data were analyzed using SPSS 24.0 software (IBM Corp., Armonk, NY, USA).
3.1 Participants registration and Baseline characteristics
A total of 26 participants with SCI were enrolled for IF intervention, including 21 males and 5 females; 10 grade A, 7 grade B, 5 grade C, and 4 grade D; 8 cervical cord injury, 15 thoracic cord injury and 3 lumbar cord injury. The 13 participants in the IF group included 11 males and 2 females, and the 13 participants in the control group included 10 males and 3 females. Participants in the IF group failed to complete the test due to unbearable hunger, dizziness, and hypoglycemia, and 1 participants was discontinued due to failure to eat as required. Intestinal dysfunction (nausea, abdominal discomfort, and diarrhea) were IF found in 1 participant in the IF group and control group. In the IF group, 1 patient developed urinary system infection.
3.2 Baseline data comparison
In order to investigate whether there is a difference between the IF group and the control group, the baseline data, gender, age, course of disease, and basal plasma glucose of participants were tested. As shown in Table 1, the results showed that there were no significant differences in gender (P = 0.382), age (P = 0.136), disease course (P = 0.775), and blood sugar (P = 0.397) between the control group and the IF group. The results suggested that the two groups are comparable and the grouping is reasonable.
Table 1 Basic information of subjects
|
Parameter |
Control group (n=13) |
Intermittent fasting group (n=11) |
P |
|
Gender(man/female) |
13/3 |
11/1 |
0.382 |
|
Age(year) |
39.15±7.22 |
34.64±7.02 |
0.136 |
|
Course of disease (month) |
16.62±12.65 |
15.09±13.08 |
0.775 |
|
Plasma glucose(mmol/L) |
5.46± 0.40 |
5.59 ±0.32 |
0.397 |
Table 1 Basic information of subjects, including gender, age, course of disease, and baseline plasma glucose values.
3.3 Comparison of blood routine, liver and kidney function, electrolytes before and after intervention
In order to investigate the effects of IF on the physical function of the participants, the blood routine, liver function, kidney function, and electrolytes of participants were tested. As shown in Figure 1, compared with the control group, there were no significant differences in red blood cells (P = 0.693, 0.921, respectively), hemoglobin (P = 0.88, 0.909, respectively), alanine aminotransferase (P = 0.59, 0.402, respectively), aspartate aminotransferase (P = 0.16, 0.561, respectively), total protein (P = 0.492, 0.215, respectively), albumin (P = 0.211, 0.127, respectively), (P = 0.666, 0.992, respectively), creatinine (P = 0.611, 0.717, respectively), serum potassium (P = 0.613, 0.499, respectively), serum sodium (P = 0.119, 0.159, respectively), serum chlorine (P = 0.59, 0.144, respectively), serum calcium ( P = 0.919, 0.975, respectively) before and after IF intervention.
As shown in Figure 2, there were no significant differences in red blood cells (P = 0.115), hemoglobin (P = 0.123), alanine aminotransferase (P = 0.071), aspartate aminotransferase (P = 0.064), total protein (P = 0.089), albumin (P = 0.098), urea (P = 0.058), creatinine (P = 0.127), serum potassium (P = 0.135), serum sodium (P = 0.173), serum chlorine (P = 0.116), serum calcium (P = 0.185) before and after IF. The results suggested that IF is safe and feasible to participants with SCI.
3.4 Comparison of plasma glucose before and after intervention
In order to investigate the effect of IF on the plasma glucose of participants, the plasma glucose before dinner were tested every day. As shown in Figure 3, Repeated measures ANOVA revealed a significant main effect of group [F(1,22) = 226.734, P < 0.001], a main effect of day [F (27,594) = 1.648, P = 0.022], and a significant interaction between group and time [F(27,594) = 1.750, P = 0.012]. Due to the interaction effect, the t-test is used to analyze the daily blood glucose situation. The results showed that, compared with the control group, the plasma glucose of the IF group was significantly reduced from the 14th day (all P < 0.040), and the plasma glucose after the IF intervention was significantly lower than before (P = 0.038). The results suggested that IF can reduce plasma glucose in participants with SCI.
3.5 Comparison of body weight and BMI before and after intervention
In order to investigate the effect of IF on the weight and BMI of participants, which was tested. As shown in Figure 4, compared with the control group, there was no significant differences in body weight (P = 0.099) and BMI (P = 0.501) before IF intervention, and weight loss after intervention (P=0.043), but there was no significant difference in BMI index (P = 0.898). Moreover, there was significant differences in body weight and BMI before and after IF intervention (all P <0.001). The results suggested that IF can reduce the weight in participants with SCI.
3.6 Comparison of ASIA scores before and after intervention
In order to investigate whether IF can promote the recovery of dysfunction in participants with SCI, the participants’ ASIA scores was tested. As shown in Figure 4, compared with the control group, there was no significant difference in sensory function (P = 0.515, 0.469, respectively) and motor function (P = 0.892, 0.772, respectively) in the IF group before and after intervention, and the comparison before and after IF was also meaningless (P = 0.053, 0.054, respectively). The results suggested that IF didn’t promote the recovery of dysfunction in participants with SCI.
This study found that IF from dawn to sunset for four consecutive weeks is a feasible and well-tolerated diet strategy for SCI patients. During the IF intervention, there is no serious adverse events occurred, although some adverse reactions experienced, such as hypoglycemia, hunger, weight loss, urinary tract infection, and intestinal dysfunction (nausea, abdominal discomfort, and diarrhea). Moreover, there were no significant differences in blood routine, liver function, kidney function, and electrolytes. Although weight and BMI in participant decreased, they were both within the normal range. The results suggested that IF from dawn to sunset is safe for patients with SCI. Overall, these findings create a key platform for larger, longer-term IF clinical trials to improve dysfunction in patients with SCI.
In the current research on IF, hunger is one of the common adverse reactions of participants 14. The hunger of the participants in this study mostly occurred during the lunch period and lasted for varying lengths. It was alleviated by strengthening patient education, communicating between doctors and patients, psychological cues and diversions when they were hungry. Another common adverse reaction is weight loss 15,16. Compared with before IF, the body weight was lower after IF, but the BMI of all participants were higher than the lower limit of normal value, which is basically consistent with the results of a foreign study 15. Moreover, most studies suggest IF interventions produce significant reductions in body fat without significant loss of lean tissue in middle-age and younger individuals 17. Since body composition was not measured in this study, it is not clear whether the observed weight loss is due to a decrease in fat mass, muscle mass, or both. SCI can cause neurogenic bladder, and urinary tract infection is a common complication of SCI 18, which may be related to the failure to strictly implement clean intermittent catheterization. Patients are advised to drink more water, anti-infective treatment, and symptoms disappear after strict implementation of clean intermittent catheterization. In addition, two case of intestinal dysfunction (nausea, abdominal discomfort, diarrhea) occurred in two groups, and the symptoms disappeared after symptomatic treatment with montmorillonite powder, which may be related to neurogenic gastrointestinal dysfunction after SCI. Studies have shown that some participants with SCI have mild to severe intestinal dysfunction, manifested as constipation, fecal incontinence, diarrhea and other intestinal complications 19–22.
Biochemical analysis showed that, compared with before IF, there was no significant in blood routine, liver function, kidney function, and electrolytes after IF intervention. The patient's vital signs were stable before and after IF intervention, which indicated that IF did not lead to malnutrition. Studies have found that 25% calorie restriction to healthy non-obese adults for a period of 2 years is safe and well tolerated, but it is necessary to pay attention to anemia and bone loss 23. The participants did not develop anemia after IF intervention, which may be related to the shorter intervention period. The follow-up trials can extend the intervention time for further observation. Long-term insufficient dietary intake can lead to malnutrition and the decrease of total protein, albumin and creatinine. The total protein, albumin and creatinine of the participants did not significantly decrease, and no limb edema was observed. Although the participants had obvious hunger during the experiment, the results showed that the energy intake of the participants during the free eating period can meet the needs of their bodies. The Chinese Dietary Guidelines recommend an adult daily intake of 1875–5625 mg potassium and no more than 6 g of salt 24, and an adult is recommended that a daily calcium intake of between 700 and 1200 mg should be advised 25. This study did not observe a significant decrease in serum potassium, serum sodium, serum chloride, and serum calcium, which indicated that IF does not cause electrolyte disorders in participants with SCI. Although lack of lunch intake in IF group, the patient consumed sufficient calories and trace elements during the free eating period. There was no significance difference in blood routine, liver function, kidney function, and electrolyte indicators after IF intervention. The follow-up further research can increase the intervention time and observe the effect of this diet on the basic vital signs of patients.
IF is associated with the decrease of plasma glucose 26. Due to the control group ate lunch normally, the plasma glucose of which was usually higher than IF group. The average plasma glucose of IF group began to decrease significantly from the 14th day, and the difference became more significant as the intervention time was extended. The results showed that there is a time-cumulative effect of IF and the reduction of plasma glucose, but the cumulative effect of longer time is worthy of further discussion.
Although not statistically significant, the movement and sensory score increased slightly after IF intervention. We speculate that the effect of IF on promoting nerve regeneration and inducing axon remodeling has not been shown related to the short period of this trial. The future trials can further evaluate the feasibility of longer treatment time.
The findings of this study suggest that IF from dawn to sunset is a safe and feasible eating pattern for SCI Patients. At the same time, the decrease of weight and plasma glucose after IF, which providing a possibility for diet intervention for obese and diabetic patients. The findings should be interpreted very cautiously as the present study has a number of limitations. Future studies should examine the effects of this eating pattern using larger samples of SCI patients over longer time periods.
Acknowledgments
The authors would like to express their appreciation to the participants and research associates who made it possible to complete this research project.
Author Contributions
WX conceived and designed the study, recruited participants, collected and analyzed the full data set, wrote the initial draft of the manuscript and revised the manuscript. JYW analyzed data and interpreted the results. BJJ conceived and designed the study, supervised the study, and revised the manuscript. All authors have read and agreed to the published version of the manuscript.
Funding
This research received no external funding.
Data availability
All data generated or analysed during this study are included in this published article.
Competing interests
The authors declare no competing interests.