Effect of weight loss on pulse wave velocity: systematic review and meta-analysis.

OBJECTIVE: To conduct a systematic review and meta-analysis of clinical trials involving adults, to determine the effect of weight loss induced by energy restriction with or without exercise, antiobesity drugs or bariatric surgery on pulse wave velocity (PWV) measured at all arterial segments. APPROACH AND RESULTS: A systematic search of Pubmed (1966 to 2014), EMBASE (1947 to 2014), MEDLINE (1946 to 2014), and the Cochrane Library (1951 to 2014) was conducted and the reference lists of identified articles were searched to find intervention trials (randomized/nonrandomized) that aimed to achieve weight loss and included PWV as an outcome. The search was restricted to human studies. Two independent researchers extracted the data. Data were analyzed using Comprehensive Meta Analysis version 2 using random effects analysis. A total of 22 studies were included in the qualitative synthesis and 20 studies (3 randomized controlled trials), involving 1259 participants, were included in the meta-analysis. The standardized mean difference for the overall effect of weight loss on PWV measured at all sites was -0.32 (95% confidence interval, -0.41, -0.24; P=0.0001). Carotid femoral pulse wave velocity (standardized mean difference, -0.35; 95% confidence interval, -0.44, -0.26; P=0.0001; 16 studies) and brachial ankle PWV (standardized mean difference, -0.48; 95% confidence interval, -0.78, -0.18; P=0.002; 5 studies) were improved with weight loss. Meta-regression showed that change in blood pressure was a predictor of change in PWV (P<0.01). CONCLUSION: Modest weight loss (mean 8% of initial body weight) achieved with diet and lifestyle measures improved PWV. The results of this meta-analysis suggest that weight loss may reduce PWV, although future research is required.

Weight Loss, Dietary Intake and Pulse Wave Velocity.

We have recently conducted a meta-analysis to determine the effect of weight loss achieved by an energy-restricted diet with or without exercise, anti-obesity drugs or bariatric surgery on pulse wave velocity (PWV) measured at all arterial segments. Twenty studies, including 1,259 participants, showed that modest weight loss (8% of the initial body weight) caused a reduction in PWV measured at all arterial segments. However, due to the poor methodological design of the included studies, the results of this meta-analysis can only be regarded as hypothesis generating and highlight the need for further research in this area. In the future, well-designed randomised controlled trials are required to determine the effect of diet-induced weight loss on PWV and the mechanisms involved. In addition, there is observational evidence that dietary components such as fruit, vegetables, dairy foods, sodium, potassium and fatty acids may be associated with PWV, although evidence from well-designed intervention trials is lacking. In the future, the effect of concurrently improving dietary quality and achieving weight loss should be assessed in randomised controlled trials.

Effect of sodium and potassium supplementation on vascular and endothelial function: a randomized controlled trial.

BACKGROUND: It is known that increased potassium and reduced sodium intakes can improve postprandial endothelial function. However, the effect of increasing potassium in the presence of high sodium in the postprandial state is not known. OBJECTIVE: We aimed to determine the effect of high potassium and high sodium on postprandial endothelial function as assessed by using flow-mediated dilatation (FMD) and arterial compliance as assessed by using pulse wave velocity (PWV) and central augmentation index (AIx). DESIGN: Thirty-nine healthy, normotensive volunteers [21 women and 18 men; mean ± SD age: 37 ± 15 y; BMI (in kg/m(2)): 23.0 ± 2.8] received a meal with 3 mmol K and 65 mmol Na (low-potassium, high-sodium meal (LKHN)], a meal with 38 mmol K and 65 mmol Na [high-potassium, high-sodium meal (HKHN)], and a control meal with 3 mmol K and 6 mmol Na (low-potassium, low-sodium meal) on 3 separate occasions in a randomized crossover trial. Brachial artery FMD, carotid-femoral PWV, central AIx, and blood pressure (BP) were measured while participants were fasting and at 30, 60, 90, and 120 min after meals. RESULTS: Compared with the LKHN, the addition of potassium (HKHN) significantly attenuated the postmeal decrease in FMD (P-meal by time interaction < 0.05). FMD was significantly lower after the LKHN than after the HKHN at 30 min (P < 0.01). AIx decreased after all meals (P < 0.05). There were no significant differences in AIx, PWV, or BP between treatments over time. CONCLUSION: The addition of potassium to a high-sodium meal attenuates the sodium-induced postmeal reduction in endothelial function as assessed by FMD. This trial was registered at http://www.anzctr.org.au/ as ACTRN12613000772741.

Effect of improving dietary quality on carotid intima media thickness in subjects with type 1 and type 2 diabetes: a 12-mo randomized controlled trial.

BACKGROUND: People with diabetes are at a heightened risk of cardiovascular disease compared with the general population. To our knowledge, randomized controlled trials investigating the effect of improving dietary quality on carotid intima media thickness, a marker of subclinical atherosclerosis and predictor of cardiovascular disease, have not been conducted in populations with diabetes. OBJECTIVE: We aimed to determine whether increasing fruit (+1 serving; 150 g/d), vegetable (+2 servings; 150 g/d), and dairy (+1 serving; 200-250 g/d) intakes slows 12-mo common carotid artery intima media thickness (CCA IMT) progression, compared with a control group continuing to consume their usual diet, in people with type 1 and type 2 diabetes. DESIGN: A 12-mo randomized controlled trial was conducted. The primary outcome was mean CCA IMT, measured at baseline and 12 mo, with B-mode ultrasound. Participants in the intervention group received counseling from a dietitian at baseline and 1, 3, 6, and 9 mo, and compliance was measured with a food-frequency questionnaire at baseline, 3 mo, and 12 mo. The control group continued consuming their usual diet. RESULTS: In total, 118 participants completed the study. Vegetable (46 g/d; 95% CI: 14, 77 g/d; P < 0.001) and fruit (179 g/d; 95% CI: 119, 239 g/d; P < 0.001) intakes were increased at 3 mo in the intervention group compared with the control group. This increase was not maintained at 12 mo, but intake increased overall in the cohort (fruit, 48 g/d; vegetables, 14 g/d). An increase in dairy consumption was not achieved, but yogurt intake was higher in the intervention group at 3 mo (38 g; 95% CI: 12, 65 g; P < 0.001); this was not maintained at 12 mo. At 12 mo, CCA IMT regressed (mean ± SD: -0.01 ± 0.04 mm; P < 0.001), with a greater effect in the treatment group (mean ± SD: -0.02 ± 0.04 mm compared with -0.004 ± 0.04 mm; P = 0.009). CONCLUSION: Improving dietary quality in people with well-controlled type 1 and type 2 diabetes may slow CCA IMT progression. This trial was registered at https://www.anzctr.org.au as ACTRN12613000251729.

Dietary quality in people with type 1 and type 2 diabetes compared to age, sex and BMI matched controls.

A case-control analysis involving 98 individuals with diabetes and 98 age, sex and BMI matched controls was conducted to determine dietary quality and adherence to dietary recommendations. Diet quality was comparable and intake of fat, saturated fat, fibre, fruit and vegetables did not meet recommendations in both groups.