Clinical trials assessing the effects of salt substitutes on blood pressure (BP) have reported mixed results. A meta-analysis of randomized controlled trials was conducted to evaluate the effect of salt substitutes on BP, including systolic BP (SBP) and diastolic BP (DBP). Studies were identified via systematic searches of the PubMed, Embase, Cochrane Library, Wanfang Data, and the China National Knowledge Infrastructure databases through December 2013. Random-effects models were used to estimate pooled mean differences in SBP and DBP. Six cohorts from 5 articles (1 trial enrolled 2 cohorts for independent intervention) consisting of 1974 participants were included. Pooled results showed that salt substitutes had a significant effect on SBP (mean difference: -4.9 mm Hg; 95% CI: -7.3, -2.5 mm Hg; P < 0.001) and DBP (mean difference: -1.5 mm Hg; 95% CI: -2.7, -0.3 mm Hg; P = 0.013). Significant heterogeneity was found for both SBP (I(2) = 76.7%) and DBP (I(2) = 65.8%). The sensitivity analysis indicated that the pooled effects of salt substitutes on SBP and DBP were robust to systematically dropping each trial. Furthermore, no evidence of significant publication bias from funnel plots or Egger's tests (P = 0.17 and 0.22 for SBP and DBP, respectively) was found. This meta-analysis showed that salt-substitution strategies are effective at lowering SBP and DBP, which supports a nutritional approach to preventing hypertension.

Effective policies to control hypertension require an understanding of its distribution in the population and the barriers people face along the pathway from detection through to treatment and control. One key factor is household wealth, which may enable or limit a household’s ability to access health care services and adequately control such a chronic condition. This study aims to describe the scale and patterns of wealth-related inequalities in the awareness, treatment and control of hypertension in 21 countries using baseline data from the Prospective Urban and Rural Epidemiology study. A cross-section of 163,397 adults aged 35 to 70 years were recruited from 661 urban and rural communities in selected low-, middle- and high-income countries (complete data for this analysis from 151,619 participants). Using blood pressure measurements, self-reported health and household data, concentration indices adjusted for age, sex and urban-rural location, we estimate the magnitude of wealth-related inequalities in the levels of hypertension awareness, treatment, and control in each of the 21 country samples. Overall, the magnitude of wealth-related inequalities in hypertension awareness, treatment, and control was observed to be higher in poorer than in richer countries. In poorer countries, levels of hypertension awareness and treatment tended to be higher among wealthier households; while a similar pro-rich distribution was observed for hypertension control in countries at all levels of economic development. In some countries, hypertension awareness was greater among the poor (Sweden, Argentina, Poland), as was treatment (Sweden, Poland) and control (Sweden). Inequality in hypertension management outcomes decreased as countries became richer, but the considerable variation in patterns of wealth-related inequality - even among countries at similar levels of economic development - underscores the importance of health systems in improving hypertension management for all. These findings show that some, but not all, countries, including those with limited resources, have been able to achieve more equitable management of hypertension; and strategies must be tailored to national contexts to achieve optimal impact at population level.

24-h urinary sodium excretion is the gold standard for evaluating dietary sodium intake, but it is often not feasible in large epidemiological studies due to high participant burden and cost. Three methods—Kawasaki, INTERSALT, and Tanaka—have been proposed to estimate 24-h urinary sodium excretion from a spot urine sample, but these methods have not been validated in the general Chinese population. This aim of this study was to assess the validity of three methods for estimating 24-h urinary sodium excretion using spot urine samples against measured 24-h urinary sodium excretion in a Chinese sample population. Data are from a substudy of the Prospective Urban Rural Epidemiology (PURE) study that enrolled 120 participants aged 35 to 70 years and collected their morning fasting urine and 24-h urine specimens. Bias calculations (estimated values minus measured values) and Bland-Altman plots were used to assess the validity of the three estimation methods. 116 participants were included in the final analysis. Mean bias for the Kawasaki method was -740 mg/day (95% CI: -1219, 262 mg/day), and was the lowest among the three methods. Mean bias for the Tanaka method was -2305 mg/day (95% CI: -2735, 1875 mg/day). Mean bias for the INTERSALT method was -2797 mg/day (95% CI: -3245, 2349 mg/day), and was the highest of the three methods. Bland-Altman plots indicated that all three methods underestimated 24-h urinary sodium excretion. The Kawasaki, INTERSALT and Tanaka methods for estimation of 24-h urinary sodium excretion using spot urines all underestimated true 24-h urinary sodium excretion in this sample of Chinese adults. Among the three methods, the Kawasaki method was least biased, but was still relatively inaccurate. A more accurate method is needed to estimate the 24-h urinary sodium excretion from spot urine for assessment of dietary sodium intake in China.

Background: Total and differential white blood cell counts are important for the diagnostic evaluation of suspected diseases. To facilitate the interpretation of total and differential white blood cell counts in pediatric patients, the present study investigated age-dependent changes in total and differential white blood cell counts in healthy reference children. Methods: Data were obtained from the Pediatric Reference Intervals in China study (PRINCE), which aims to establish and verify pediatric reference intervals for Chinese children based on a nationwide multicenter cross-sectional study from January 2017 to December 2018. Quantile curves were calculated using the generalized additive models for location, shape, and scale method. The 2.5th, 50th, and 97.5th quantile curves were calculated for both total and differential white blood counts. Percents of stacked area charts were used to demonstrate the proportions of differential white blood cells. All statistical analyses were performed using R software. Results: Both 50th and 97.5th quantiles of total white blood cell count and monocyte count were highest at birth, then rapidly decreased in the first 6 months of life; relatively slow reduction continued until 2 years of age. The lymphocyte count was low during infancy and increased to its highest level at 6 months of age; it then exhibited moderate and continuous reduction until approximately 9 years of age. The pattern of neutrophil count changed with age in a manner opposite to that of lymphocyte count. Besides, there were two inter-sections of lymphocyte count and neutrophil count during infancy and at approximately 5 years of age, based on locally weighted regression (LOESS) analysis. There were no apparent age-related changes in eosinophil or basophil counts. Conclusion: These data regarding age-related changes in total and differential white blood cell counts can be used to assess the health of pediatric patients and guide clinical decisions.

To evaluate the effects of metformin on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in nondiabetic patients. In this meta-analysis, we systematically searched PubMed, Embase, and the Cochrane Library through March 2016, and randomized controlled trials assessing the effects of metformin treatment compared with placebo were included. Random-effects models were used to estimate pooled mean differences in SBP and DBP. Twenty-eight studies from 26 articles consisting of 4113 participants were included. Pooled results showed that metformin had a significant effect on SBP (mean difference −1.98 mmHg; 95% confidence interval −3.61, −0.35; P = 0.02), but not on DBP (mean difference −0.67 mmHg; 95% confidence interval −1.74, 0.41; P = 0.22). In subgroup analysis, we found that the effect of metformin on SBP was significant in patients with impaired glucose tolerance or obesity (BMI ≥30 kg/m2), with a mean reduction of 5.03 and 3.00 mmHg, respectively. Significant heterogeneity was found for both SBP (I2 = 60.0%) and DBP (I2 = 45.4%). A sensitivity analysis indicated that the pooled effects of metformin on SBP and DBP were robust to systematically dropping each trial. Furthermore, no evidence of significant publication bias from funnel plots or Egger's tests (P = 0.51 and 0.21 for SBP and DBP, respectively) was found. This meta-analysis suggested that metformin could effectively lower SBP in nondiabetic patients, especially in those with impaired glucose tolerance or obesity.