Increased risk of hypertension in patients with bipolar disorder and patients with anxiety compared to background population and patients with schizophrenia

BackgroundThe relationship between depression and bipolar disorders and cardio-vascular diseases has been studied previously although the direction of the correlation is investigated less often. The present study examines the prevalence of hypertension among Danish psychiatric patients admitted with a diagnosis of bipolar affective disorder (BP) and controls.MethodsDemographic, medical and psychiatric data on 25,339 BP patients and 113,698 controls were extracted from The Danish Psychiatric Central Research Register, The Danish National Patient Registry — for somatic patients, The Danish Civil Registration System, and The Danish Causes of Death Registry. Similar information about patients with schizophrenia and anxiety was collected for comparison.ResultsHypertension was overrepresented in BP: IRR = 1.27, 95% confidence interval (1.16 to 1.39). This association was also found in anxiety patients: IRR = 1.96 (1.73 to 2.22), but not among patients with schizophrenia: IRR = 0.93 (0.77 to 1.14).LimitationsThe study uses nationwide data based on administrative health service registers. The data therefore are historical and heterogeneous samples.ConclusionsA significant increase in levels of hypertension in BP patients was observed which may explain some of the increased cardio-vascular morbidity/mortality in BP patients.