Objectives: To evaluated the total body water (TBW) among patients with primary Sjögren's syndrome (pSS) and assess its correlation with the severity of oral and ocular sicca symptoms, and some objective sicca variables.
Methods: We included 85 patients and 85 controls matched by sex, age, and body mass index (BMI). We assessed the Schirmer-I test and the non-stimulated whole salivary flow (NSWSF). We evaluated ocular and oral symptoms during the past 15 days using a 0-10 visual analogue scale (VAS) (highest score=worst symptoms). We obtained the TBW by bioelectric impedance analysis.
Results: 80% were women (mean age 54.8 years and mean disease duration 11.5 years). TBW was similar in pSS and controls (46.8±4.6 vs. 46.9±4.5, p=0.88). TBW correlated with age (ρ=-0.25, p=0.02), disease duration (ρ=-0.30, p=0.005), BMI (ρ=-0.78, p=0.001) and ocular VAS scale (ρ=-0.28, p=0.01); but not with NSWSF, Schirmer test or oral VAS scale. When comparing patients in the lowest TBW percentile (≤25%) with the remaining patients, the former group was older, had longer disease duration, higher BMI, lower frequency of anti-Ro/SSA and antinuclear antibodies, and higher ocular VAS scores. In the multivariate analysis, the ocular VAS score (OR 1.88, 95% CI 1.08-3.2, p=0.02) and the BMI 1.92 (OR 1.4, 95% CI 1.4-2.66, p=0.0001) remained associated with a lower TBW percentage.
Conclusions: Patients with pSS had similar TBW percentages to control subjects. However, lower TBW percentages in the pSS were associated with higher BMI and also with the most severe ocular symptoms.