Table 2 Summary of results for medical comorbidities included in the rapid review

Cardiovascular Complications (4 studies)

AN has attracted the most research focus given its increased risk of cardiac failure due to severe malnutrition, dehydration and electrolyte imbalances [67]. Mitral valve prolapse impacted in 25% of patients, sinus bradycardia was the most common arrhythmia, pericardial effusion prevalence rates ranged from 15 to 30% [68]. The risk of cardiac arrest, arrhythmias and heart failure was higher in males with AN than females with AN [69]

Cancer (1 study)

An area of limited research. One study noted a worse prognosis with higher mortality rates for individuals with EDs from melanoma, cancers of genital organs and cancers of unspecified sites. However, there was no statistically significant difference in cancer risk compared to the general population [70]

Gastrointestinal disorders (GI) (14 studies)

More than 90% of AN patients report fullness, early satiety, abdominal distention, pain and nausea [68]. The actual cause of the increased prevalence of GI disorders and their contribution to ED maintenance remain poorly understood

Bone health (16 studies)

The RR found evidence for bone loss/poor bone mineral density (BMD) and EDs, particularly in AN. The negative impacts of bone loss are more pronounced in individuals with early-onset AN when the skeleton is still developing [67] and among those who have very low BMI [71], with comorbidity rates as high as 46.9% [71]. However, lowered BMD was also observed among patients with BN [72]

Refeeding syndrome (RFS) (20 studies)

Identified studies focused on individuals admitted to an inpatient unit for restrictive EDs. Noted variable prevalence rates of RFS [73] ranging from 0 to 62% [74]. Some studies noted that the provision of higher caloric feeds led to faster recoveries and shorter admission duration; with no incidence of RFS [75,76,77]. However, more research is required to establish best practice in this space including high quality RCTs in inpatient samples, and controlling for feeding methods (i.e. NG vs oral feeding)

Metabolic syndrome (11 studies)

Most research regarding metabolic syndrome has been among patients with BN, BED and NES. Both BN and BED have increased risk for type 2 diabetes [78]. The results suggested importance of increased monitoring and treatment of type 2 diabetes in individuals with EDs, particularly BED and NES

Oral health (7 studies)

Despite ED patients reporting an increased concern for dental issues and engaging in more frequent oral hygiene, their oral health was worse [79]; with increased risk of dental erosion, periodontal disease, missing teeth and oral mucosal lesions [80, 81]

Vitamin deficiencies (6 studies)

The impact of prolonged malnutrition in early-onset EDs can also impair brain development, substantially reducing neurocognitive function in some younger patients even after weight restoration [82]

Cognitive functioning (1 study)

Some cognitive functions affected (attention, decision making, memory) by EDs recover following nutritional restoration [83]

Reproductive health (9 studies)

Infertility and higher rates of poor reproductive health are strongly associated with EDs, including miscarriages, induced abortions, obstetric complications, and poorer birth outcomes [84, 85]. Amenorrhea is a known consequence of AN, oligomenorrhea (irregular periods) was common among individuals with BN and BED [86]

Further, the RR found higher rates of Poly Cystic Ovarian Syndrome (PCOS), premenstrual syndrome (PMS) and premenstrual dysphoric disorder (PMDD) among the ED population compared to the general population