American diabetes association recommends lifestyle change as the first line treatment to address high cholesterol, obesity, and hypertension in youth with diabetes [
61]. A few randomized trials have looked at the effect of diet and exercise on CVD risk reduction in youth with T1DM. A 6-month prospective cohort trial aimed to promote Mediterranean style diet in 96 adolescents with T1DM using dietary intervention. The authors showed significant improvements with reduction of LDL cholesterol, non-HDL-cholesterol, and total cholesterol: HDL-cholesterol ratios in the intervention group (
P < 0.001) [
95]. Another study from the SEARCH study investigated the CVD effects of the DASH diet which encourages fruits, vegetables, low-fat milk products, whole grains, fish/poultry/nuts, lean red meats, and limited intake of sugar and sweets [
96]. Authors found that better DASH diet score was significantly associated with lower HbA1c levels in youth with type 1 diabetes (
β= − 0.20,
P = 0.0063) and improved blood pressure in youth with T2DM (
β= − 2.02,
P = 0.0406) [
96].
There have been some pediatric clinical trials looking at the effects of exercise on CVD health in youth with T1DM. In the large European database with 23,251 pediatric patients with T1DM, more exercise was associated with better cardiovascular risk profile, such as lower levels of LDL cholesterol (
P < 0.005) and triglycerides (
P < 0.00001) and higher levels of HDL cholesterol (
P < 0.00001) in girls with T1DM while in boys there were differences only for triglycerides (
P < 0.0005) and HDL cholesterol (
P < 0.00001). Also, the percentage of patients with elevated diastolic blood pressure was lower in the exercise group (
P < 0.005) and A1c was lower in the group of patients that exercised more (
P < 0.000001) [
62]. In an interventional trial, 15 children with T1DM received exercise training three times a week for 12 weeks [
97]. After the intervention, the authors found significant improvements in total cholesterol levels (179.9 ± 2.6 versus 164.4 ± 11.4 mg/dl,
P < 0.01) and in some parameters of the autonomic dysfunction (LF power and VLF power) [
97]. In another study, seven children with T1DM received 18 weeks exercise training program, and at the end of the study, authors found improvements in physical fitness (measured by peak oxygen uptake during running test
,
P = 0.039) and brachial artery endothelial dysfunction (measured by FMD,
P < 0.05) [
98]. In another trial, 16 subjects with T1DM were randomized to a twice per week combined aerobic and resistance training or regular physical activities for 20 weeks [
99]. Authors found that exercise seemed to lower daily insulin requirements (0.96 versus 0.90 IU/kg/day,
P < 0.05) and improved physical fitness (
P < 0.05) [
99]. A systematic review and meta-analysis of the exercise intervention trials in youth with T1DM analyzed data from 23 studies [
100]. Authors concluded that exercise intervention has beneficial effects on HbA1c, BMI, triglycerides, and the total cholesterol [
100]. The above studies indicate that exercise can be effective in improving CVD health in youth with T1DM.