Physical Activity Is Associated With Decreased Cardiovascular Disease Risk Factors In Children With Type 1 Diabetes

Abstract

Type 1 diabetes is associated with increased cardiovascular disease risk factors, one third of patients dying from premature coronary heart disease. This increased risk profile is due to an accelerated atherosclerotic process resulting from increased blood pressure and blood lipids. These complications may develop during childhood, but their relationships with physical activity and fitness remain unknown. PURPOSE To measure ambulatory 24-hour blood pressure (BP), blood lipids and percentage of body fat in children and adolescents with type 1 diabetes, and to evaluate their relationships with physical activity and fitness. METHODS Cross-sectional study including 25 children with type 1 diabetes and 25 matched healthy controls (age 11.3 +/- 2.4 yr). None of the patients with diabetes had nephropathy or retinopathy. We measured 24-hour ambulatory systolic and diastolic BP and heart rate; fasting total-, LDL-, HDL-cholesterol, and triglycerides levels; body composition by DXA; maximal aerobic capacity (peak VO) by a treadmill test; past 12-month physical activity using the Modifiable Physical Activity Questionnaire for Adolescents; 7-day physical activity count by uniaxial accelerometer; diabetes control (HbA1c) and history. RESULTS Groups had similar gender, age, height, weight, BMI, percentage of body fat, and pubertal stage. There were no significant differences between groups for blood lipids levels, mean 24-hour heart rate, past 12-month physical activity, 7-day activity count or peak VO2. Children with diabetes had significantly higher day systolic and diastolic BP, and night-time systolic BP, compared to healthy controls. In patients with diabetes, physical activity in the past 12 months was negatively correlated with night-time diastolic BP (r = −0.42), and percentage of body fat (r = −0.53), and current activity count was negatively correlated with total (r = −0.46) and LDL-cholesterol (r = −0.44). Peak VO was also inversely related to the percentage of body fat (r = −0.64). Glycemic control was negatively correlated with triglycerides (r = −0.46) and duration of diabetes was positively correlated with diastolic BPs. CONCLUSIONS We confirmed that children and adolescents with type 1 diabetes have higher 24-hour blood pressure compared to non-diabetic controls. Blood pressure, blood lipids and percentage of body fat are associated with physical activity and fitness level, as well as control and duration of diabetes. We conclude that children with this condition should be encouraged to participate in physical activities, to prevent early development of cardiovascular disease risk factors.