# Retinal Microvascular Calibres and Body Fat Indices in Young Adults

## TL;DR

This study shows that body fat in young adults is linked to changes in retinal blood vessels, which could help detect early signs of cardiovascular disease.

## Contribution

It is the first to show that upper body fat is associated with retinal arteriolar narrowing and total body fat with venular widening in young adults.

## Key findings

- Neck circumference was negatively associated with central retinal arteriolar equivalent (CRAE).
- Body fat percentage was positively associated with central retinal venular equivalent (CRVE).

## Abstract

Public health relevance—How does this work relate to a public health issue?
This study links a major modifiable risk factor to an indicator of systemic vascular health by investigating the relationship between excess body fat and changes in retinal microvascular calibres.Retinal microvascular calibres are useful for detecting early cardio-metabolic risk associated with excess adiposity by providing a non-invasive window to systemic microvascular health.

This study links a major modifiable risk factor to an indicator of systemic vascular health by investigating the relationship between excess body fat and changes in retinal microvascular calibres.

Retinal microvascular calibres are useful for detecting early cardio-metabolic risk associated with excess adiposity by providing a non-invasive window to systemic microvascular health.

Public health significance—Why is this work of significance to public health?
Associating body fat to changes in retinal microvascular calibres can help to identify individuals at a higher risk of developing cardiovascular diseases before clinical signs can manifest.This research is crucial for developing preventative strategies aimed at young adults as early changes in the retinal microvascular structure may precede the development of hypertension, diabetes and cardiovascular diseases.

Associating body fat to changes in retinal microvascular calibres can help to identify individuals at a higher risk of developing cardiovascular diseases before clinical signs can manifest.

This research is crucial for developing preventative strategies aimed at young adults as early changes in the retinal microvascular structure may precede the development of hypertension, diabetes and cardiovascular diseases.

Public health implications—What are the key implications or messages for practitioners, policy makers and/or researchers in public health?
The use of simple measures of body fat with retinal imaging could be employed by healthcare professionals to enhance early risk identification in primary care.These results could be used by policy makers to advocate for early-life obesity focused interventions to reduce cardiovascular diseases burden in the future.

The use of simple measures of body fat with retinal imaging could be employed by healthcare professionals to enhance early risk identification in primary care.

These results could be used by policy makers to advocate for early-life obesity focused interventions to reduce cardiovascular diseases burden in the future.

Adverse microvascular complications are early markers of cardiovascular risk and precede the development of cardiovascular diseases. An increase in adiposity has been associated with changes in retinal microvascular calibre in a specific age group. However, this association is scarce in young adults. Therefore, this study aimed to investigate the relationship between neck circumference and body fat with retinal microvascular calibres in young adults. In our cross-sectional study, 330 students aged (18–30 years) participated. Anthropometric measurements were taken according to standard procedures. Retinal photographs were obtained with an Optomed retinal camera and analyzed with MONA-REVA vessel analysis software to obtain microvascular calibres such as central retinal arteriolar equivalent (CRAE), central venular equivalent (CRVE) and artery-to-venous ratio (AVR). In the stepwise multiple regression analysis, neck circumference (NC) was negatively associated with CRAE [adjusted R2 = 0.050; β = −0.122 (95% CI = −0.963; −0.067), p = 0.024], and body fat percentage was positively associated with CRVE [adjusted R2 = 0.060; β = 0.157 (95% CI = 0.072; 0.364), p = 0.004] adjusted for age, gender, body mass index, smoking, alcohol and mean arterial pressure. For the first time in young adults, an increase in upper body fat was associated with retinal arteriolar narrowing, while an increase in total body fat was associated with retinal venular widening.