Refeeding syndrome among survivors of prolonged captivity in Sudan: a cross-sectional study and nutritional intervention, 2025

¹Faculty of Medicine, University of Khartoum, Khartoum, Sudan, ²Public Health, Federal Ministry of Health, Khartoum, Sudan, ³Department of Nutrition, Federal Ministry of Health, Khartoum, Sudan

^&Corresponding author
Salwa Eltigani, Faculty of Medicine, University of Khartoum, Khartoum, Sudan

Introduction    

Refeeding syndrome is an emergency situation due to prolonged starvation. It can be defined as the potentially fatal shifts in fluids and electrolytes that may occur in malnourished patients receiving artificial refeeding (whether enterally or parenterally) [1,2]. It is characterized by electrolyte and fluid shifts, particularly hypophosphatemia, hypokalemia, and hypomagnesaemia, which may lead to serious clinical complications if not promptly recognized and managed [3]. Survivors of prolonged captivity are at particularly high risk of refeeding syndrome due to sustained nutritional deprivation, weight loss, and micronutrient deficiencies [4,5]. In post-conflict and humanitarian settings, including Sudan, limited healthcare resources and delayed access to nutritional rehabilitation further increase this risk. Despite this, data on the burden of refeeding syndrome among survivors of prolonged captivity remain scarce [6-8].

Understanding the magnitude and metabolic characteristics of refeeding syndrome in this vulnerable population is essential to inform early screening and appropriate nutritional management strategies [9-12]. The body shifts from getting energy from carbohydrates found in food to using fat and muscle within your own body. The rate of metabolism slows significantly, and vital body functions are reduced. This kind of metabolism uses a limited amount of energy and requires no influx of vitamins, minerals, or electrolytes. It is the final, heroic effort of the human body to survive [7,13-15]. Refeeding syndrome can occur in anyone undergoing the process of nutritional rehabilitation, particularly in individuals with specific risk factors [16-19]. Mid-upper-arm-circumference (MUAC) is often used as a screening tool in emergency situation to monitor change in nutrition status [7].

Refeeding syndrome is considered a greater risk when a person has a body mass index (BMI) under 16. More than fifteen percent of a person´s body weight has been lost in the last three to six months. A person´s blood test confirms low levels of phosphate, potassium, and/or magnesium. Little to no food has been consumed by the patient in ten or more days [20]. Therefore, this study aimed to determine the prevalence of refeeding syndrome and identify associated factors among survivors of prolonged captivity in Sudan.

Research questions: 1) What is the prevalence of refeeding syndrome among survivors of prolonged captivity? 2) What factors are associated with the development of refeeding syndrome? 3) What is the effect of nutritional intervention on metabolic outcomes?

Methods     

Study design: this study was designed as a descriptive cross-sectional hospital-based investigation. It aimed to assess the prevalence, clinical characteristics, biochemical abnormalities, and outcomes of refeeding syndrome among adult survivors of prolonged captivity. The cross-sectional design was selected to provide a comprehensive overview of the condition at the time of hospital admission.

Study setting: the study was conducted in major teaching hospitals in Khartoum State, Sudan. These hospitals serve as referral centers for patients affected by conflict-related malnutrition and post-captivity conditions. Data collection was carried out during April 2025.

Participants: adult survivors of prolonged captivity who were admitted to the study hospitals and diagnosed with acute malnutrition were eligible for inclusion. Both severe and moderate acute malnutrition cases were considered. Participants were enrolled consecutively during the study period to ensure complete coverage of eligible cases.

Variables: the study variables included sociodemographic characteristics such as age and sex. Clinical variables comprised nutritional status at admission, presenting symptoms, therapeutic interventions, and clinical outcomes. Laboratory variables included electrolyte and micronutrient abnormalities associated with refeeding syndrome.

Data sources and measurement: data were collected using a predesigned structured questionnaire administered through direct interviews. Anthropometric measurements, including body mass index and mid-upper arm circumference, were recorded using standard techniques. Laboratory investigations were performed according to routine hospital protocols.

Bias: selection bias was minimized by including all eligible patients admitted during the study period. Information bias was reduced through the use of standardized data collection tools and trained healthcare personnel.

Study size: the study included a total of 476 participants. This number represented all eligible adult survivors admitted during the defined study period, and no formal sample size calculation was performed.

Quantitative variables: quantitative variables were summarized using frequencies and percentages. Continuous variables were categorized where appropriate to facilitate clinical interpretation and reporting.

Statistical analysis: data were entered and analyzed using the Statistical Package for the Social Sciences (SPSS) version 26. Descriptive statistical methods were applied to summarize study variables. Statistical significance was defined as a p-value of less than 0.05.

Ethical considerations: ethical approval for this study was obtained from the Institutional Review Board (IRB) of the University of Khartoum, Sudan. All participants were informed about the purpose of the study, and written informed consent was obtained prior to data collection. Due to the humanitarian and emergency context of the study, a formal reference number was not issued.

Results     

Characteristics of the study participants: a total of 476 adult survivors of prolonged captivity diagnosed with acute malnutrition were included in the analysis. All participants met the eligibility criteria and were assessed during their hospital admission. The majority of participants were aged between 20 and 40 years (53.96%), representing the most affected age group. Baseline demographic and clinical characteristics are summarized in Table 1.

Regarding nutritional status at admission, severe acute malnutrition (SAM) was observed in 369 participants (77.5%), whereas moderate acute malnutrition (MAM) was identified in 107 participants (22.5%) (Table 2). Overall, nutritional recovery was observed in 364 participants (76.5%), while a smaller proportion had incomplete recovery or persistent complications during follow-up. These outcomes are summarized in Table 3.

Prevalence of refeeding syndrome and biochemical abnormalities: biochemical abnormalities consistent with refeeding syndrome were highly prevalent; hypokalemia was detected in 452 participants (95%), hypophosphatemia in 357 participants (75%), and hypomagnesaemia in 414 participants (87%). Additionally, hyponatremia was observed in 452 participants (95%) during the refeeding period (Table 4).

Nutritional management and clinical outcomes: during nutritional rehabilitation, 262 participants (55%) received F-75 during the stabilization phase due to complications, while the same proportion transitioned to F-100 during the rehabilitation phase. Ready-to-use-therapeutic-food (RUTF) was administered to 214 participants (45%) without complications. Thiamine supplementation was provided to 414 participants (87%) (Table 5).

Summary of key findings: refeeding-related electrolyte disturbances were common among survivors of prolonged captivity, particularly hypokalemia, hypophosphatemia, and hypomagnesemia. Most participants presented with severe acute malnutrition, and nutritional intervention, including therapeutic feeding and micronutrient supplementation, resulted in recovery in more than three-quarters of the study population.

Discussion     

This study demonstrates a high prevalence of refeeding-related metabolic abnormalities among survivors of prolonged captivity in Sudan, the majority of whom presented with severe acute malnutrition at admission. These findings confirm that this population represents a high-risk group for refeeding syndrome and requires careful metabolic monitoring during nutritional rehabilitation.

The predominance of severe acute malnutrition observed in this study is consistent with the prolonged nutritional deprivation experienced during captivity. Similar findings have been reported in humanitarian and post-conflict settings, where prolonged starvation is a major risk factor for refeeding syndrome. In our study, hypokalemia, hypophosphatemia, and hypomagnesemia were highly prevalent, reflecting the characteristic biochemical profile of refeeding syndrome and supporting existing evidence from malnourished populations.

Hypophosphatemia, identified in three-quarters of participants, is a key biochemical marker of refeeding syndrome and has been associated with adverse clinical outcomes in previous studies. The concurrent high prevalence of hypokalemia and hypomagnesemia further emphasizes the importance of early electrolyte assessment and correction during the refeeding process, particularly in severely malnourished individuals. The nutritional management approach applied in this study was aligned with international recommendations for the treatment of acute malnutrition. The use of F-75 during the stabilization phase, followed by F-100 during rehabilitation, and the provision of ready-to-use therapeutic food for uncomplicated cases contributed to favorable outcomes. More than three-quarters of participants achieved nutritional recovery, indicating that structured nutritional intervention can be effective even in resource-limited and high-risk settings when appropriately implemented.

From a public health perspective, these findings highlight the need to integrate refeeding syndrome screening and prevention into post-release and post-conflict healthcare services. Survivors of prolonged captivity should be systematically assessed for malnutrition and electrolyte abnormalities, and healthcare providers in similar settings should be trained to recognize and manage refeeding syndrome early to reduce preventable complications. This study has some limitations. The cross-sectional design limits the ability to establish causal relationships, and the lack of a control group restricts comparison with non-captive populations. In addition, incomplete biochemical data for some participants may have influenced the observed prevalence of metabolic abnormalities. Despite these limitations, the study provides valuable data on an underreported population and addresses an important gap in the literature. In conclusion, refeeding-related electrolyte disturbances were common among survivors of prolonged captivity in Sudan, particularly among those with severe acute malnutrition. Early identification and structured nutritional management were associated with substantial recovery. These findings support the need for context-specific guidelines and strengthened nutritional rehabilitation strategies in humanitarian and post-conflict settings.

Recent consensus recommendations emphasize systematic risk assessment, regular electrolyte monitoring, and thiamine and multivitamin supplementation for patients at risk of refeeding syndrome. These recommendations support the clinical approach used in the present study and reinforce the importance of structured nutritional rehabilitation in high-risk patients [21]. The 2025 Australasian consensus further recommends multidisciplinary management, regular electrolyte monitoring, micronutrient supplementation, and replacement of low electrolyte levels according to local guidelines [21].

Highlights: 1) high burden of refeeding syndrome among survivors of captivity; 2) severe electrolyte and vitamin deficiencies were common; 3) structured WHO-based refeeding improved recovery and survival.

Conclusion     

Refeeding-related metabolic abnormalities were highly prevalent among survivors of prolonged captivity in Sudan, particularly among individuals with severe acute malnutrition. Early identification of at-risk patients, close biochemical monitoring, and structured nutritional rehabilitation were associated with favorable outcomes. These findings highlight the need to integrate refeeding syndrome screening and management into post-conflict and humanitarian health services to reduce preventable morbidity and improve nutritional recovery in vulnerable populations.

Competing interests     

The authors declare no competing interests.

Authors' contributions     

All the authors read and approved the final version of this manuscript.

Tables     

Table 1: sociodemographic characteristics (age distribution) of survivors with refeeding syndrome admitted to teaching hospitals in Khartoum State, Sudan, April 2025 (N=476)

Table 2: nutritional status of adult survivors diagnosed with acute malnutrition at admission in Khartoum State, Sudan, April 2025 (N=476)

Table 3: clinical outcome of survivors with refeeding syndrome during follow-up in teaching hospitals, Khartoum State, Sudan, April 2025 (N=476)

Table 4: electrolyte and micronutrient disturbances among patients with refeeding syndrome admitted to teaching hospitals in Khartoum State, Sudan, April 2025 (N=476)

Table 5: therapeutic feeding regimens and associated vitamin deficiencies among patients with refeeding syndrome in Khartoum State, Sudan, April 2025 (N=476)

References