Amelioration of Retinal Vessel Diameters through Behavioural Changes of Lifestyle in Obese Populations

Background: Previous studies affirm that obesity plays a role in developing endothelial and microvascular dysfunction. The incidence of obesity is associated with narrower arteriolar and wider venular calibres, which makes the retinal microcirculation a good predictor for cardiovascular diseases. This study investigates the effects of structured lifestyle intervention on different physiological parameters, such as the vascular retinal diameters, in obese people.
Methods: The variation and abnormalities in the retinal vasculature is determined through retinal photographic imaging. The digital pictures, taking by a non-invasive method, reveal information of the calibre. Two pictures are taken of each eye to ensure stable values. All obese participants are divided into either the intervention group, following a 20-week structured lifestyle intervention (BASEL-program), or in the control group, where information about lifestyle modification in individual consultations is provided. The objective is to analyse the retinal vessel diameter and to evaluate if the retinal vessel physiology is improved trough structured physical activity, nutritional counselling, and behavioural therapy.
Results: According to the analysis no significant treatment effect occurs on the retinal vessel parameters. The intervention group shows a widening of the retinal arteriolar calibre, but the control group presents even better amelioration of the retinal arteriolar diameters. With regards to the retinal venular diameters, a narrowing effect is detected in the intervention group, where the median venular diameters decrease during the treatment. The improvements in arteriolar and venular diameters do not result in a positive change in the arteriolar to venular diameter ratio, whose value remains constant during the intervention.
Conclusion: The study is a success in the sense that amelioration of the retinal vessels is achieved with the proposed intervention program, but it failed to produce better results than conventional counselling. Besides the retinal vascular physiology, the BASEL-Program proved to have a successful treatment effect on weight, fat content, BMI, and body composition.
Keywords: Obesity; structured lifestyle intervention; microcirculation (retinal vessel diameters)