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

l Background: The 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. Methods: Demographic, 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. Results: Hypertension 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). Limitations: The study uses nationwide data based on administrative health service registers. The data therefore are historical and heterogeneous samples. Conclusions: A 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. (c) 2006 Elsevier B.V. All rights reserved.