Association of history of fracture with prehypertension and hypertension: a retrospective case–control study

BACKGROUND Hypertension is one of the most common encountered medical comorbidities after hip fracture. Whether fracture is a potential risk factor for hypertension remains poorly understood. The aim of our study was to examine the risk of prehypertension and hypertension in the participants with and without a history of fracture. METHODS We conducted a retrospective case-control study of 3,515 men and women aged between 20 and 85 years old from the National Health and Nutrition Examination Survey 2005-2006. History of fracture was collected via structured questionnaire. Multiple blood pressure readings (up to 4 times) were performed at interview, and an average of blood pressure readings were used to define prehypertension and hypertension. RESULTS Among 3,515 participants, 30% (n = 1074), 1.4% (n = 48) and 10% (n = 347) of them had a history of any, hip and wrist fracture, respectively. The positive association between history of any, hip and wrist fracture and prehypertension was similar to the association between history of any, hip and wrist fracture and hypertension in both unadjusted and adjusted model. In the unadjusted model, history of any, hip and wrist fracture was each associated with increased overall risk of prehypertension and hypertension (odds ratio [OR] = 1.61, 95% confidence interval [CI] = 1.38-1.89 for any fracture; OR = 3.57, 95% CI = 1.60-8.00 for hip fracture; and OR = 1.82, 95% CI = 1.41-2.36 for wrist fracture). However, in multivariable adjusted model, only the positive association between history of wrist fracture and overall risk of prehypertension and hypertension remained significant (OR = 1.48, 95% CI = 1.10-1.99). CONCLUSIONS There was no overall independent association between history of fracture, and risk of prehypertension and hypertension. Although history of fracture overall may not directly cause hypertension, people with a history of wrist fracture can be potentially benefitted from hypertension control at the early stage.