Effect of Potassium Supplementation on Endothelial Function: A Systematic Review and Meta-Analysis of Intervention Studies.

(1) Background: Endothelial dysfunction is an early predictor of cardiovascular diseases. Although a large body of evidence shows an inverse association between potassium intake and cardiovascular risk, the studies on endothelial function provided contrasting results. Thus, we carried out a systematic review and a meta-analysis of the available intervention studies of the potassium supplementation on endothelial function. (2) Methods: A systematic search of the online databases available (up to December 2022) was conducted including the intervention trials that reported flow-mediated dilation (FMD) changes-a non-invasive method of assessing endothelial function-after two different potassium intake regimens. For each study, the mean difference (MD) and 95% confidence intervals were pooled using a random effect model. (3) Results: Five studies met the pre-defined inclusion criteria and provided eight cohorts with 332 participants. In the pooled analysis, potassium supplementation was associated with a significant increase in FMD (MD: 0.74%), with a higher effect for a urinary potassium excretion higher than 90 mmol/day. There was a moderate heterogeneity among studies (I2 = 59%), explained by the different amount of potassium supplementation. (4) Conclusions: The results of our meta-analysis indicate that dietary potassium supplement improves endothelial function. This effect is directly associated with the amount of potassium supplement. The findings support the campaigns in favour of an increase in dietary potassium intake to reduce cardiovascular risk.

Effect of dietary salt restriction on central blood pressure: A systematic review and meta-analysis of the intervention studies.

Central blood pressure (cBP) is highly associated with cardiovascular risk. Although reduction of salt intake leads to lower peripheral blood pressure (BP), the studies on cBP provided inconsistent results. Therefore, we performed a systematic review and a meta-analysis of the available intervention trials of salt reduction on cBP values to reach definitive conclusions. A systematic search of the online databases available (up to December 2018) was conducted including the intervention trials that reported non-invasively assessed cBP changes after two different salt intake regimens. For each study, the mean difference and 95% confidence intervals were pooled using a random-effect model. Sensitivity, heterogeneity, publication bias, subgroup, and meta-regression analyses were performed. Fourteen studies met the pre-defined inclusion criteria and provided 17 cohorts with 457 participants with 1-13 weeks of intervention time. In the pooled analysis, salt restriction was associated with a significant reduction in augmentation index (9.3%) as well as central systolic BP and central pulse pressure. There was a significant heterogeneity among studies (I2  = 70%), but no evidence of publication bias. Peripheral BP changes seemed to partially interfere on the relationship between salt restriction and cBP. The results of this meta-analysis indicate that dietary salt restriction reduces cBP. This effect seems to be, at least in part, independent of the changes in peripheral BP.

Coffee consumption and risk of hypertension: a dose-response meta-analysis of prospective studies.

PURPOSE: Recently, a large prospective study provided additional information concerning the debated possible association between habitual coffee consumption and risk of hypertension (HPT). Therefore, we updated the state of knowledge on this issue by carrying out a comprehensive new systematic review of the literature and a meta-analysis of the available relevant studies. METHODS: We performed a systematic search for prospective studies on general population, published without language restrictions (1966-August 2017). A random-effects dose-response meta-analysis was conducted to combine study specific relative risks (RRs) and 95% confidence intervals. Potential non-linear relation was investigated using restricted cubic splines. RESULTS: Four studies (196,256 participants, 41,184 diagnosis of HPT) met the inclusion criteria. Coffee intake was assessed by dietary questionnaire. Dose-response meta-analysis showed a non-linear relationship between coffee consumption and risk of HPT (p for non-linearity < 0.001). Whereas the habitual drinking of one or two cups of coffee per day, compared with non-drinking, was not associated with risk of HPT, a significantly protective effect of coffee consumption was found starting from the consumption of three cups of coffee per day (RR = 0.97, 95% CI = 0.94 to 0.99), and was confirmed for greater consumption. CONCLUSIONS: The results of this analysis indicate that habitual moderate coffee intake is not associated with higher risk of HPT in the general population and that in fact a non-linear inverse dose-response relationship occurs between coffee consumption and risk of HPT.

Effect of statin therapy on pulse wave velocity: A meta-analysis of randomized controlled trials.

BACKGROUND AND OBJECTIVE: Arterial stiffness (AS) is an independent cardiovascular risk factor. A number of studies have reported a beneficial role of statins on AS albeit with controversial results, in addition to their effects on lipid profile. Therefore, we carried out a meta-analysis of the available randomized controlled trials assessing the effects of statin therapy on AS, in the attempt to reach more definitive conclusions. METHODS: A systematic search of the on-line databases available up to March 2017 was conducted, including intervention studies reporting AS expressed by carotid-femoral pulse wave velocity (PWV), as difference between the effects of treatment with or without statins. For each study, mean difference (MD) and 95% confidence intervals (CI) were pooled using a random effect model. RESULTS: Eleven studies met the pre-defined inclusion criteria, for a total of 573 participants and 2-144 weeks' intervention time. In the pooled analysis, statin therapy was associated with a -6.8% (95% C.I.: -11.7 to -1.8) reduction in PWV. There was significant heterogeneity among studies (I2 = 96%); none of the study characteristics seems to have influenced the effect of statin use on PWV. CONCLUSIONS: The results of this meta-analysis suggest that statin therapy reduces AS. This effect appears to be at least in part independent of the changes in blood pressure and lipid profile.

Effect of dietary sodium restriction on arterial stiffness: systematic review and meta-analysis of the randomized controlled trials.

OBJECTIVE: Arterial stiffness is an independent cardiovascular risk factor and sodium intake could be a determinant of arterial stiffness. Nevertheless, the studies that investigated the effect of reducing dietary sodium intake on arterial stiffness in humans provided inconsistent results. Therefore, we performed a systematic review and a meta-analysis of the available randomized controlled trials of salt restriction and arterial stiffness to try and achieve more definitive conclusions. METHODS: A systematic search of the online databases available (from 1996 through July 2017) was conducted including randomized controlled trials that reported arterial stiffness, expressed by carotid-femoral pulse wave velocity (PWV), as difference between the effects of two different sodium intake regimens. For each study, the mean difference and 95% confidence intervals were pooled using a random effect model. Sensitivity, heterogeneity, publication bias, subgroup and meta-regression analyses were performed. RESULTS: Eleven studies met the predefined inclusion criteria and provided 14 cohorts with 431 participants and 1-6 weeks intervention time. In the pooled analysis, an average reduction in sodium intake of 89.3 mmol/day was associated with a 2.84% (95% CI: 0.51-5.08) reduction in PWV. There was no significant heterogeneity among studies and no evidence of publication bias was detected. No single feature of the studies analyzed seemed to impact on the effect of salt restriction on PWV. CONCLUSION: The results of this meta-analysis indicate that restriction of dietary sodium intake reduces arterial stiffness. This effect seems be at least in part independent of the changes in blood pressure.

Preventing Venous Thromboembolism in Ambulatory Cancer Patients: The ONKOTEV Study.

BACKGROUND: The efficacy of risk model scores to predict venous thromboembolism (VTE) in ambulatory cancer patients is under investigation, aiming to stratify on an individual risk basis the subset of the cancer population that could mostly benefit from primary thromboprophylaxis. MATERIALS AND METHODS: We prospectively assessed 843 patients with active cancers, collecting clinical and laboratory data. We screened all the patients with a duplex ultrasound (B-mode imaging and Doppler waveform analysis) of the upper and lower limbs to evaluate the right incidence of VTE (both asymptomatic and symptomatic). The efficacy of the existing Khorana risk model in preventing VTE was also explored in our population. Several risk factors associated with VTE were analyzed, leading to the construction of a risk model. The Fine and Gray model was used to account for death as a competing risk in the derivation of the new model. RESULTS: The risk factors significantly associated with VTE at univariate analysis and further confirmed in the multivariate analysis, after bootstrap validation, were the presence of metastatic disease, the compression of vascular/lymphatic structures by tumor, a history of previous VTE, and a Khorana score >2. Time-dependent receiving operating characteristic (ROC) curve analysis showed a significant improvement in the area under the curve of the new score over the Khorana model at 3 months (71.9% vs. 57.9%, p = .001), 6 months (75.4% vs. 58.6%, p < .001), and 12 months (69.8% vs. 58.3%, p = .014). CONCLUSION: ONKOTEV score steps into history of cancer-related-VTE as a promising tool to drive the decision about primary prophylaxis in cancer outpatients. The validation represents the goal of the prospective ONKOTEV-2 study, endorsed and approved by the European Organization for Research and Treatment of Cancer Young Investigators Program. The Oncologist 2017;22:601-608 IMPLICATIONS FOR PRACTICE: Preventing venous thromboembolism in cancer outpatients with a risk model score will drive physicians' decision of starting thromboprophylaxis in high-risk patients.