Association between Physical Activity Advice Only or Structured Exercise Training with Blood Pressure Levels in Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis

Background Diabetes is associated with marked cardiovascular morbidity and mortality. However, the association between different types of exercise training and blood pressure (BP) changes is not fully clear in type 2 diabetes. Objective The aim of this systematic review and meta-analysis of randomized controlled clinical trials (RCTs) was to determine the effects of structured exercise training (aerobic [AER], resistance [RES], or combined [COMB]) and physical activity (PA) advice only on BP changes in patients with type 2 diabetes. Methods Searches in five electronic databases were conducted to retrieve studies published from 1980 to 2013. Eligible studies were RCTs consisting of structured exercise training or PA advice versus no intervention in patients with type 2 diabetes. We used random effect models to derive weighted mean differences (WMDs) of exercises on absolute changes in systolic BP (SBP) and diastolic BP (DBP). Results A total of 30 RCTs of structured training (2,217 patients) and 21 of PA advice (7,323 patients) were included. Data were extracted independently in duplicate. Structured exercise was associated with reductions in SBP (WMD -4.22 mmHg; 95 % confidence interval [CI] -5.89 to -2.56) and DBP (WMD -2.07 mmHg; 95 % CI -3.03 to -1.11) versus controls. In structured exercise interventions, AER and RES were associated with declines in BP, and COMB was not associated with BP changes. However, in sensitivity analysis, a high-intensity protocol within COMB was associated with declines in SBP (WMD -3.30 mmHg; 95 % CI -4.71 to -1.89). Structured exercise longer than 150 min/week was associated with greater BP reductions. PA advice only was associated with reduction in SBP (WMD -2.97 mmHg; 95 % CI -4.52 to -1.43) and DBP (WMD -1.41 mmHg; 95 % CI -1.94 to -0.88) versus controls. Conclusions AER, RES, and high-intensity combined training are associated with BP reduction in patients with type 2 diabetes, especially in exercise programs lasting more than 150 min/week. PA advice only is also associated with lower BP levels.