Dehydration and electrolyte imbalance: a common presenting manifestation of cystic fibrosis in Cyprus

Abstract

Background: In Western Europe and North America, dehydration and electrolyte imbalance are uncommon presenting manifestations in cystic fibrosis (CF) patients.

Aims and Objectives: Our aim was to determine the prevalence of dehydration and/or electrolyte imbalance episodes leading to CF diagnosis in a country with temperate dry-summer climate, and describe other related features of the disease.

Methods: The national CF patients’ registry in Cyprus was searched for all cases whose initial clinical presentation included dehydration and/or electrolyte imbalance, and patients’ core data (demographics, diagnosis, genotype) were retrieved.

Results: In a total of 50 CF cases, 17 (34%) presented at diagnosis with dehydration and/or electrolyte imbalance, which ranked third amongst the most common presenting manifestations: acute or persistent respiratory symptoms (46%) and failure to thrive or malnutrition (42%). Dehydration and/or electrolyte imbalance as presenting symptom was associated with younger age at diagnosis (r=-0.36, p=0.02), and was manifested for the vast majority (82.4%) during the warm period of the year, i.e. May-September (chi-squared test 5.9, p=0.015). Mean±SD sweat test in those patients did not differ significantly from the rest of CF cases (87.1±24.1 mmol/L vs. 80.2±29.9 mmol/L, p=0.43). Among the 17 cases, p.Phe508del was the commonest mutation (32.4%), followed by p.Leu346Pro (10.8%), a mutation detected solely in individuals of Cypriot descent.

Conclusions: In countries with warmer climates, clinical practitioners should be aware that dehydration or electrolyte imbalance is a major initial presenting manifestation of CF, especially during the summer period.