Effect of improving dietary quality on carotid intima media thickness in subjects with type 1 and type 2 diabetes: a 12-mo randomized controlled trial.
BACKGROUND
People with diabetes are at a heightened risk of cardiovascular disease compared with the general population. To our knowledge, randomized controlled trials investigating the effect of improving dietary quality on carotid intima media thickness, a marker of subclinical atherosclerosis and predictor of cardiovascular disease, have not been conducted in populations with diabetes.


OBJECTIVE
We aimed to determine whether increasing fruit (+1 serving; 150 g/d), vegetable (+2 servings; 150 g/d), and dairy (+1 serving; 200-250 g/d) intakes slows 12-mo common carotid artery intima media thickness (CCA IMT) progression, compared with a control group continuing to consume their usual diet, in people with type 1 and type 2 diabetes.


METHODS
A 12-mo randomized controlled trial was conducted. The primary outcome was mean CCA IMT, measured at baseline and 12 mo, with B-mode ultrasound. Participants in the intervention group received counseling from a dietitian at baseline and 1, 3, 6, and 9 mo, and compliance was measured with a food-frequency questionnaire at baseline, 3 mo, and 12 mo. The control group continued consuming their usual diet.


RESULTS
In total, 118 participants completed the study. Vegetable (46 g/d; 95% CI: 14, 77 g/d; P < 0.001) and fruit (179 g/d; 95% CI: 119, 239 g/d; P < 0.001) intakes were increased at 3 mo in the intervention group compared with the control group. This increase was not maintained at 12 mo, but intake increased overall in the cohort (fruit, 48 g/d; vegetables, 14 g/d). An increase in dairy consumption was not achieved, but yogurt intake was higher in the intervention group at 3 mo (38 g; 95% CI: 12, 65 g; P < 0.001); this was not maintained at 12 mo. At 12 mo, CCA IMT regressed (mean ± SD: -0.01 ± 0.04 mm; P < 0.001), with a greater effect in the treatment group (mean ± SD: -0.02 ± 0.04 mm compared with -0.004 ± 0.04 mm; P = 0.009).


CONCLUSIONS
Improving dietary quality in people with well-controlled type 1 and type 2 diabetes may slow CCA IMT progression. This trial was registered at https://www.anzctr.org.au as ACTRN12613000251729.
School of Pharmacy and Medical Sciences & Sansom Institute for Health Research, University of South Australia, Adelaide, Australia.
Kristina S
KS
Petersen
School of Pharmacy and Medical Sciences & Sansom Institute for Health Research, University of South Australia, Adelaide, Australia.
Peter M
PM
Clifton
School of Pharmacy and Medical Sciences & Sansom Institute for Health Research, University of South Australia, Adelaide, Australia.
Natalie
N
Blanch
School of Pharmacy and Medical Sciences & Sansom Institute for Health Research, University of South Australia, Adelaide, Australia jennifer.keogh@unisa.edu.au.
Jennifer B
JB
Keogh
D000328:Adult; D000368:Aged; D001794:Blood Pressure; D017536:Carotid Artery, Common / Q000378:metabolism; D059168:Carotid Intima-Media Thickness; D003404:Creatinine / Q000652:urine; D003922:Diabetes Mellitus, Type 1 / Q000178:diet therapy*; D003924:Diabetes Mellitus, Type 2 / Q000178:diet therapy*; D004032:Diet; D018450:Disease Progression; D005260:Female; D005638:Fruit; D006801:Humans; D008019:Life Style; D008297:Male; D020783:Matrix Metalloproteinase 7 / Q000097:blood; D008875:Middle Aged; D010349:Patient Compliance; D011188:Potassium / Q000652:urine; D012964:Sodium / Q000652:urine; D011795:Surveys and Questionnaires; D014675:Vegetables
D012964:Sodium; D003404:Creatinine; C060932:MMP7 protein, human; D020783:Matrix Metalloproteinase 7; D011188:Potassium
carotid intima media thickness; dairy; diabetes; dietary quality; fruit; randomized controlled trial; vegetables