Previous research has shown that dysphagia and gastrointestinal problems occur frequently in carriers of the m.3243A>G mutation; however, the exact frequency and severity have not been determined. We hypothesise that adult carriers have an increased risk for malnutrition.
In this observational study we evaluated the presence of gastrointestinal problems and dysphagia in 92 carriers of the m.3243A>G mutation. The severity of the general disease involvement was classified using the Newcastle Mitochondrial Disease Adult Scale (NMDAS). Gastrointestinal involvement, dysphagia and the risk for malnutrition were scored using the Gastrointestinal Symptoms Questionnaire and the Malnutrition Universal Screening Tool. Gastrointestinal symptoms and anthropometrics were compared with healthy controls.
Our results show that the height, weight and body mass index (BMI) of these carriers were lower than the national average (p < 0.05). Seventy-nine carriers (86%) suffered from at least one gastrointestinal symptom, mainly flatulence or hard stools. Both frequency and severity of symptoms were significantly increased compared with reference data of healthy Dutch adults. Of the carriers, 45% reported (mostly mild) dysphagia. Solid foods cause more problems than liquids. A negative correlation between BMI and heteroplasmy levels in urinary epithelial cells (UEC) was present (Spearman correlation coefficient = - 0.319, p = 0.003).
Dysphagia and gastrointestinal problems, especially constipation, are common symptoms in the total m.3243A>G carriers cohort and are not related to heteroplasmy levels in UEC or disease severity. The severity of gastrointestinal problems as well as overall disease severity is associated with an increased risk for malnutrition.