Given the strong selective constraints stemming from low oxygen level in the blood, divers of the Indonesian naval uniquely adapted to their hypoxemic in terms of systemic vasculature. Vascular endothelial nitric oxide (NO) impairment can increase peripheral vascular resistance, leads to high blood pressure. In the previous study, the effectiveness of hyperbaric oxygen therapy (HBO2T) on selected divers suffering hypertension remains controversial. Hereby, the aim of this study was to assess the usefulness of HBO2T in the secondary prevention of hypertension among naval divers.Design and Method:
72 consecutive naval divers with hypertension (JNC 8 criteria) who met the inclusion criteria were entered in this randomized controlled clinical trial. The patients were randomized into two groups, as follows: 1) experimental: received 2.5 ATA hyperbaric chambers with 96% oxygen supply via oxygen hoods + standard treatment (Amlodipine 10 mg), 2) control: received only standard treatment (Amlodipine 10 mg). The systolic BP (SBP), diastolic BP (DBP), and heart rate (HR) were measured before each HBO2T session every 2 weeks until 1-year follow-up.Results:
Before the first treatment session with HBO2T, the average SBP, DBP, and HR were similar in both groups. The average HR was significantly lower in experimental groups after at least 2-months treatment duration (p-value = 0.01). The average SBP was significantly lower in experimental groups after at least 3-months treatment duration (p-value = 0.04). No significant difference of DBP were detected in both groups until 1-year follow up (p-value = 0.36).Conclusions:
Cold water and hydrostatic pressure from water immersion can increase blood pressure among naval divers, while HBO2T can reduce blood pressure significantly. This is a pilot study for effectiveness of HBO2T in hypertension; need to be caution in interpreted.