Retinal vascular caliber and the development of hypertension: a meta-analysis of individual participant data

Abstract

Objective: Microvascular dysfunction has been suggested to be a major pathogenic factor for the development of hypertension. We examined the association between retinal vascular caliber, a marker of systemic microvascular dysfunction, and incident hypertension on a meta-analysis of individual participant data.

Methods: We performed a systematic review with relevant studies identified through a search of electronic databases, a review of reference lists, and correspondence with experts. Studies were included if participants were selected from a general population, retinal vascular caliber was measured from photographs using computer-assisted methods at baseline, and individuals were followed up to ascertain the incidence of hypertension. Prespecified individual recorded data from six population-based prospective cohort studies were included. Discrete time proportional odds models were constructed for each study with adjustment for hypertension risk factors. Log odds ratios (ORs) per 20-μm difference were pooled using random-effects meta-analysis.

Results: Among 10 229 participants without prevalent hypertension, diabetes, or cardiovascular disease, 2599 developed new-onset hypertension during median follow-up periods ranging from 2.9 to 10 years. Both narrower retinal arterioles [pooled multivariate-adjusted OR per 20-μm difference 1.29, 95% confidence interval (CI) 1.20-1.39] and wider venules (OR per 20-μm difference 1.14, 95% CI 1.06-1.23) were associated with an increased risk of hypertension. Each 20 μm narrower arterioles at baseline were associated with a 1.12 mmHg (95% CI 0.25-1.99) greater increase in SBP over 5 years.

Conclusions: Retinal arteriolar narrowing and venular widening were independently associated with an increased risk of hypertension. These findings underscore the importance of microvascular remodeling in the pathogenesis of hypertension.

Figure 1

Multivariate-adjusted odds ratios (ORs) (model 3) for risk of incident hypertension per 20 μm decrease in CRAE (a), per 20 μm increase in CRVE (b). The size of the data markers is proportional to weight of the study in the random effect meta-analysis. The error bars indicate 95% CIs. Pooled using random effects and one-stage multilevel random-intercept models. CI, confidence interval; CRAE, central retinal arteriolar equivalent; CRVE, central retinal venular equivalent.