Diving and long-term cardiovascular health

Background Short-term cardiovascular effects from ambient pressure exposure are known. However, long-term cardiovascular effects from diving in humans have been less studied. Aims To examine possible long-term cardiovascular health effects from occupational diving. Methods We compared the prevalence of cardiovascular disease in former divers to non-divers. We obtained data on male former divers with a certificate valid for professional diving after 1980, from the Norwegian Diver 2011 project, and matched data on the general male population from the HUNT3 Survey. We also compared former divers with high and low grades of diving exposure. Results Data were available on 768 former divers. The prevalence of self-reported high blood pressure in former divers who often omitted a dive-free day after 3 days of strenuous diving was 28% compared with 18% in those who rarely violated these regulations [relative risk (RR) 1.47, confidence interval (CI) 1.01-2.15]. Also, the prevalence of myocardial infarction/angina pectoris was 11% in divers with > 150 professional dives/year compared with 4% in divers with <= 50 professional dives/year [RR adj. 2.91 (CI 1.23-6.87)] and 16% in divers with > 2000 air dives in total relative to 3% in divers with <= 2000 dives [RR adj. 3.05 (CI 1.47-6.34)]. Conclusions The prevalence of some cardiovascular symptoms and diseases may be higher in male former divers than in the general population. Diving might have adverse long-term cardiovascular effects. Whether this is associated with diving per se or strenuous physical activity requires further studies.