The aim of this study was to assess the effect of the level of adherence to the DASH diet on hypertension risk by conducting a systematic review and meta-analysis. A systematic literature search was performed. Two independent investigators performed the study selection, data abstraction, and assessment of the included studies. The meta-analysis was performed separately with the adjusted hazard (HR) or incident rate ratios (IRR) and the odds ratios (OR) of the highest compared to the lowest DASH diet adherence scores using a random effects model. A total of 12 studies were included in the qualitative and quantitative synthesis. When cohort studies reporting HR were pooled together, high adherence to the DASH diet was associated with a lower risk of hypertension (HR: 0.81, 95% CI 0.73–0.90, I² = 69%, PI 0.61–1.08) compared to the low adherence. When cross-sectional studies reporting OR were combined, high adherence to the DASH diet was also related to a lower risk of hypertension (OR: 0.80, 95% CI 0.70–0.91, I² = 81%, PI 0.46–1.39). The findings suggest that high adherence to the DASH diet has a positive effect on reducing hypertension risk compared to low adherence. These data strengthen and are in line with all hypertension guidelines, indicating that lifestyle changes should start early even in populations with normal blood pressure.

This study examined in vivo (1) skeletal muscle oxygenation and microvascular function, at rest and during handgrip exercise, and (2) their association with macrovascular function and exercise blood pressure (BP), in newly diagnosed, never-treated patients with hypertension and normotensive individuals. Ninety-one individuals (51 hypertensives and 40 normotensives) underwent office and 24-hour ambulatory BP, arterial stiffness, and central aortic BP assessment, followed by a 5-minute arterial occlusion and a 3-minute submaximal handgrip exercise. Changes in muscle oxygenated and deoxygenated hemoglobin and tissue oxygen saturation were continuously monitored by near-infrared spectroscopy and beat-by-beat BP by Finapres. Hypertensives had higher ( P <0.001) central aortic BP and pulse wave velocity versus normotensives and exhibited (1) a blunted tissue oxygen saturation response during occlusion, with slower ( P =0.006) deoxygenation rate, suggesting reduced muscle oxidative capacity, and (2) a slower reoxygenation rate and blunted hyperemic response ( P <0.05), showing reduced microvascular reactivity. Muscle oxygenation responses were correlated with aortic systolic and pulse pressure and augmentation index ( P <0.05; age and body mass index (BMI) adjusted). When exercising at the same submaximal intensity, hypertensives required a significantly greater ( P <0.001) increase in BP for achieving similar muscle oxygenation levels as normotensives. This response was correlated with the magnitude of microvascular hyperemia and aortic BP. In conclusion, nontreated patients with hypertension exhibit prominent reductions in in vivo indices of skeletal muscle oxidative capacity, suggestive of mitochondrial dysfunction, and blunted muscle microvascular reactivity. These dysfunctions were associated with higher aortic systolic BP and arterial stiffness. Dysregulations in muscle oxygen delivery/utilization and microvascular stiffness, in hypertensive patients, partially contribute to their exaggerated BP during exercise.

Although impairment of the micro- and macrocirculation is considered inherent to sustained hypertension, there is a substantial lack of studies investigating whether an association exists between micro- and macrovascular damage, especially in early-stage hypertension. We studied a meticulously selected population, free of diabetes and cardiovascular disease, of 223 individuals: 137 never-treated, newly diagnosed patients with recent onset of hypertension and 86 normotensive individuals. Nonmydriatic retinal photography was used to assess retinal microvascular diameters, including central retinal arteriolar (CRAE) and venular equivalent and arteriovenous ratio (AVR). Arterial stiffness was evaluated by measurement of pulse wave velocity (PWV) and aortic augmentation index (AIx). Compared with normotensive subjects, hypertensive patients exhibited significantly increased PWV (8.1 vs. 7.1 m/sec; P < 0.001) and AIx (23.86% vs. 18.8%; P = 0.01) and decreased CRAE (86.47 vs. 91.44 μm; P = 0.001) and AVR (0.74 vs. 0.78; P = 0.007). A significant inverse association was demonstrated between PWV and CRAE (r = -0.205; P = 0.002), which remained significant after multivariable analysis. Likewise, CRAE (P = 0.04) and AVR (P = 0.02) were independent predictors of AIx. This study shows for the first time an association between quantitatively assessed retinal abnormalities and increased arterial stiffness in a sample of early-stage hypertensive and normotensive individuals, suggesting that micro- and macrocirculation impairment in hypertension is a dynamic, mutual, interdependent process present from its very early stages. Given the predictive value of both retinal arteriolar narrowing and arterial stiffness in terms of cardiovascular mortality and morbidity, identification of combined micro- and macrovascular damage might be helpful in cardiovascular risk stratification of hypertensive patients.