Usefulness of Exercise for Home Blood Pressure Control in People with Diabetes: A Study Protocol for a Crossover Randomized Controlled Trial

BACKGROUND: The coexistence of hypertension and diabetes mellitus significantly increases the risk of macrovascular complications in patients with diabetes. Home blood pressure is important because it is more strongly associated with target organ damage and total mortality than clinic blood pressure measurements. Regular moderate aerobic exercise has antihypertensive effects. This study aims to examine the effect of aerobic exercise therapy on blood pressure at home in patients with diabetes. PATIENTS AND METHODS: In this crossover randomized controlled trial, 110 patients with type 2 diabetes will be randomly assigned to two groups: an exercise preceding group and an exercise lagging group. During the exercise period, patients will be instructed to walk either 30 minutes twice each day or 60 minutes once each day for at least 3 days per week. During the non-exercise period, patients will be permitted to perform physical activity associated with activities of daily life. Patients will be followed up for 56 days. The primary outcome will be the mean nocturnal blood pressure from day 24 to 28 during the exercise period compared to that during the non-exercise period. The secondary outcome will include variation in nocturnal blood pressure, mean blood pressure values and variation of morning and evening blood pressure from day 24 to 28 in the exercise period compared to the non-exercise period, body weight, body mass index and bioelectrical impedance analysis. Biochemical tests such as hemoglobin A1c level, blood glucose level, serum lipid profile, renal function, uric acid levels and liver function tests will also be measured. DISCUSSION: This randomized controlled trial will provide critical information regarding the effectiveness of moderate exercise on nocturnal blood pressure reduction. If successful, the results of this randomized controlled trial may increase exercise motivation in people with diabetes and may lead to improvement or prevention of target organ damage and overall mortality. TRIAL REGISTRATION: Trial registration: University Hospital Medical Information Network, UMIN 000035973. Protocol version number: R000040969. Registration date: February 22, 2019. Recruitment began: June 19, 2019. The date of completion of recruitment: July 3, 2020. URL: http://www.umin.ac.jp.