Compliance with dietary guidelines affects capillary recruitment in healthy middle-aged men and women

Abstract

PurposeHealthy microcirculation is important to maintain the health of tissues and organs, most notably the heart, kidney and retina. Single components of the diet such as salt, lipids and polyphenols may influence microcirculation, but the effects of dietary patterns that are consistent with current dietary guidelines are uncertain. It was hypothesized that compliance to UK dietary guidelines would have a favourable effect on skin capillary density/recruitment compared with a traditional British diet (control diet).MethodsA 12-week randomized controlled trial in men and women aged 40–70 years was used to test whether skin microcirculation, measured by skin video-capillaroscopy on the dorsum of the finger, influenced functional capillary density (number of capillaries perfused under basal conditions), structural capillary density (number of anatomical capillaries perfused during finger cuff inflation) and capillary recruitment (percentage difference between structural and functional capillary density).ResultsMicrovascular measures were available for 137 subjects out of the 165 participants randomized to treatment. There was evidence of compliance to the dietary intervention, and participants randomized to follow dietary guidelines showed significant falls in resting supine systolic, diastolic and mean arterial pressure of 3.5, 2.6 and 2.9 mmHg compared to the control diet. There was no evidence of differences in capillary density, but capillary recruitment was 3.5 % (95 % CI 0.2, 6.9) greater (P = 0.04) on dietary guidelines compared with control.ConclusionsAdherence to dietary guidelines may help maintain a healthy microcirculation in middle-aged men and women. This study is registered at www.isrctn.com as ISRCTN92382106.

Salt‐induced effects on microvascular function: A critical factor in hypertension mediated organ damage

“…Decreasing salt consumption in hypertensive patients, even if it is not too high, has beneficial effects on the microcirculation by improving both functional and structural capillary rarefactions . In a 12‐week randomized controlled trial, skin microcirculation, measured by skin video‐capillaroscopy on the dorsum of the finger, and capillary recruitment (percentage difference between structural and functional capillary density) were beneficially affected by a low‐sodium diet (<6 g/d) . Adherence to a healthy diet, including <5‐6 mg/d salt consumption, may help maintain a healthy microcirculation.…”

“…33 In a 12-week randomized controlled trial, skin microcirculation, measured by skin video-capillaroscopy on the dorsum of the finger, and capillary recruitment (percentage difference between structural and functional capillary density) were beneficially affected by a low-sodium diet (<6 g/d). 34 Adherence to a healthy diet, including <5-6 mg/d salt consumption, may help maintain a healthy microcirculation. Dietary sodium restriction confers a high degree of vascular protection, not only through its BPlowering effects, but also because it largely reverses microvascular endothelial dysfunction by enhancing NO, restoring tetrahydrobiopterin bioavailability and reducing oxidative stress.…”

Arterial Hypertension and the Hidden Disease of the Eye: Diagnostic Tools and Therapeutic Strategies

“…Indeed, the impact of diet on the microcirculation was documented by studies using capillaroscopy or ocular imaging techniques to assess the effect of such interventions at the level of the skin or the retina, two easily accessible sites for the study of microvessels. For instance, a randomized controlled trial of 137 men and women aged 40 to 70 years that compared compliance to UK dietary guidelines with a traditional British diet [ 106 ] found an increased capillary recruitment in the skin, as assessed by capillaroscopy, in individuals on a diet compared with the counterpart [ 106 ]. The intervention diet was characterized by a decreased amount of total and saturated fats, simple carbohydrates, and salt, and an increased content of greens, seeds, and oily fish.…”