SUMMARYThe results of ambulatory 24 hour oesophageal pH monitoring in 20 patients with established gastro-oesophageal reflux disease were compared with those of 20 healthy individuals with normal endoscopy. Cut off limits of pH 3, 4, and 5 were superior to pH 2 with respect to the discrimination of patients from normal subjects, and for the detection of pathological reflux. Using pH 4 as a cut off limit, the ambulant and recumbent periods of pH monitoring were more discriminatory than the postprandial period. Furthermore, it was possible to get complete separation between patients and normal subjects using several combinations of two reflux variables.

Objectives The clinical significance of low‐level viraemia (LLV) during antiretroviral therapy (ART) is debated. We retrospectively investigated longitudinal levels of plasma markers associated with inflammation, altered coagulation and cardiovascular disease in Swedish HIV‐positive adults in relation to LLV or permanent virological suppression during long‐term ART. Methods Plasma levels of C‐reactive protein (CRP), D‐dimer, vascular cell adhesion molecule 1 (VCAM‐1), suppression of tumorigenicity 2 (ST2), growth differentiation factor 15 (GDF‐15), soluble CD14 (sCD14), soluble CD163 (sCD163), interferon‐γ‐induced protein 10 (IP‐10) and β‐2‐microglobulin were measured in 34 individuals with LLV (viral load 50–999 HIV‐1 RNA copies/mL) and in matched controls with persistent virological suppression. Biomarker levels were analysed in samples obtained during episodes of LLV and follow‐up samples obtained 1 year later (with similar timing for controls). All biomarkers were analysed using an independent sample t‐test and analysis of covariance (ANCOVA) after logarithmic transformation. Log‐rank analysis was applied for markers with concentration values out of range. Results Compared with controls, patients with LLV had significantly higher levels of GDF‐15 [geometric mean 3416 (95% confidence interval (CI) 804–14 516) pg/mL versus 2002 (95% CI 355–11 295) pg/mL in controls; P = 0.026] and D‐dimer [mean 1114 (95% CI 125–9917) ng/mL versus 756 (95% CI 157–3626) ng/mL; P = 0.038] after adjustment for age, CD4 count nadir and type of ART. In the unadjusted t‐test, only GDF‐15 was significantly higher and in the log‐rank test, both GDF‐15 and D‐dimer were significantly elevated. No significant differences were observed for the other biomarkers analysed. Conclusions Although levels of inflammation markers were similar in ART recipients with and without LLV, persons with LLV had significantly higher levels of GDF‐15 and D‐dimer. These findings suggest a potential link between LLV and cardiovascular outcomes.