Reference values of retinal microcirculation parameters derived from a population random sample

Retinal microcirculation reflects retinal perfusion abnormalities and retinal arterial structural changes at relatively early stages of various cardiovascular diseases. Our objective has been to establish reference values for major functional and structural parameters of retinal microcirculation in a randomly selected urban population sample. A total of 398 randomly selected individuals from an urban population aged 25 to 65 years, resident in Pilsen, Czech Republic, were screened for major cardiovascular risk factors. Retinal microcirculation was assessed using scanning laser Doppler flowmetry (SLDF), with data evaluable in 343 patients. Of this number, complete data were available for 256 individuals free from manifest cardiovascular disease, diabetes and drug treatment for hypertension and/or dyslipidemia, constituting the reference value population. Juxtapapillary retinal capillary blood flow has increased significantly with age whereas vessel and luminal diameters have decreased. No sex differences in retinal microcirculation parameters have been found. Therefore, reference values for retinal microcirculation parameters have been established by age groups. Unattended automated office systolic BP, after adjusting for age, correlated significantly with wall-to-lumen ratio (WLR) and wall thickness (WT). Moreover, after adjusting for age and mean BP, a positive relationship has been found between carotid femoral pulse wave velocity and WT, WLR and wall cross-sectional area, indicating the interaction between micro- and macro-vasculature. In conclusion, our study is the first to provide reference values of retinal microcirculation parameters in a random Caucasian population sample. Our results have shown that, at the population level, the first structural changes in retinal microcirculation are those in lumen diameters. Of note, a close relationship between BP and vascular remodeling of retinal arterioles and between aortic stiffness and WLR of retinal arterioles suggests an interaction between micro- and macro-vasculature.

Longitudinal trends in the prevalence of hyperuricaemia and chronic kidney disease in hypertensive and normotensive adults

The purpose: To evaluate longitudinal trends in the prevalence of hyperuricaemia and chronic kidney disease (CKD) in Czech adults with and without arterial hypertension (HT).Materials and methods: Two independent cross-sectional surveys were performed in 2006-2009 and 2015-2018, each screening involving 1% population random sample of the general population of nine districts of the Czech Republic aged 25-64 years, stratified by age and gender. Hyperuricaemia was defined as serum uric acid ≥ 420 μmol/l in men, and ≥ 360 μmol/l in women. CKD was defined as estimated glomerular filtration rate < 60 ml/min/1.73 m² and/or albumin/creatinine ratio ≥ 3 mg/mmol.Results: Final analyses included 3504 individuals examined in 2006-2009, and 2309 in 2015-2018. The overall prevalence of hyperuricaemia increased from 16.4% to 25.2% in men (p < 0.001), and from 7.6% to 10.9% in women (p < 0.001), whereas the overall prevalence of CKD declined from 6.8% to 3.6% in men (p = 0.001), and from 7.6% to 4.8% in women (p < 0.001). There was no interaction between HT and hyperuricaemia in either gender; the increase in hyperuricaemia prevalence was observed both in hypertensive and normotensive adults and was accompanied by the increased prevalence of abdominal obesity. Contrarily, there was an interaction between HT and CKD in both men (p < 0.001) and women (p = 0.011); the CKD prevalence declined only in hypertensive individuals, specifically in those using antihypertensive medication and was accompanied by the increased use of renin-angiotensin-aldosterone system (RAS) inhibitors and calcium channel blockers (CCBs).Conclusions: Over the period of 10 years, the overall prevalence of hyperuricaemia increased, while the prevalence of CKD decreased. An increase in the prevalence of hyperuricaemia was observed both in hypertensive and normotensive individuals and was accompanied by an increase in the prevalence of abdominal obesity. A decline in the prevalence of CKD was only observed in hypertensive individuals and was accompanied by the increased use of RAS inhibitors and CCBs.