Systemic immune-inflammation index predicts first stroke and affects the efficacy of folic acid in stroke prevention.

Background: Systemic immune-inflammation index (SII) is a novel biomarker of growing interest in predicting stroke. The aim of this study was to investigate its predictive value and explore its effect modification on folic acid supplement for stroke primary prevention in a Chinese population with hypertension. Methods: A total of 10,013 participants from the China Stroke Primary Prevention Trial with available neutrophil, platelet and lymphocyte count were included, including 5,019 subjects in the enalapril group and 4,994 in the enalapril-folic acid group. SII was calculated as (platelet × neutrophil)/lymphocyte. The primary endpoint was first stroke. Cox proportional hazards models were used to evaluate the association between SII and first stroke. Results: A U-shape association between SII and first stroke risk was observed in enalapril group. Compared with the reference group (Quartile 2: 335.1 to <443.9 × 109 cell/L), the adjusted HRs were 1.68 (95 % CI: 1.06-2.66, P = 0.027) in Quartile 1 (<335.1 × 109 cell/L), 1.43 (95 % CI: 0.90-2.27, P = 0.126) in Quartile 3 (443.9 to <602.6 × 109 cell/L), and 1.61 (95 % CI: 1.03-2.51, P = 0.035) in Quartile 4 (≥602.6 × 109 cell/L). There was no significant association between SII and first stroke in the enalapril-folic acid group, with adjusted HR of 0.92 (95%CI: 0.54-1.56, P = 0.749) in Quartile 1(<334.7 × 109 cell/L), 1.36 (95%CI: 0.84-2.21, P = 0.208) in Quartile 3 (446.2 to <595.2 × 109 cell/L), and 1.41 (95%CI: 0.87-2.27, P = 0.163) in Quartile 4 (≥595.2 × 109 cell/L). A remarkable interaction between baseline SII and folic acid supplement for stroke prevention was observed, with particularly reduced risk by 44 % (HR: 0.56; 95 % CI: 0.34-0.90; P = 0.018) in the lowest SII group (P for interaction = 0.041). Conclusions: Among Chinese adults with hypertension, both low and high SII at baseline predicted increased first stroke risk. And compensatory folic acid particularly reduced first stroke risk in the lowest SII subgroup.

Association of folic acid dosage with circulating unmetabolized folic acid in Chinese adults with H-type hypertension: a multicenter, double-blind, randomized controlled trial.

Background: There is growing concern regarding elevated levels of circulating unmetabolized folic acid (UMFA) due to excessive intake of folic acid (FA). However, no randomized clinical trial has been conducted to examine the FA-UMFA dose-response relationship. Objective: This study aimed to investigate the FA-UMFA dose-response relationship in Chinese adults with hypertension and elevated homocysteine (H-type hypertension), a population with clear clinical indication for FA treatment. Methods: The data for this study were derived from a randomized, double-blind, multicenter clinical trial of 8 FA dosages on efficacy of homocysteine (Hcy) lowering. The parent trial had three 3 stages: screening period (2-10 days), run-in period (0-2 weeks, baseline visit), and double-blind treatment period (8 weeks) with follow-up visits at the end of the 2nd, 4th, 6th, and 8th weeks of treatment. Participants were randomly assigned to 8 treatment groups corresponding to FA dosages of 0, 0.4, 0.6, 0.8, 1.2, 1.6, 2.0 mg to 2.4 mg. Results: This study included 1,567 Chinese adults aged ≥45 years with H-type hypertension. There was a positive but non-linear association between FA supplementation and UMFA levels in the dosage range of 0 mg to 2.4 mg. In the regression analysis, the coefficients for the linear and quadratic terms of FA dosage were both statistically significant (P < 0.001). Notably, the slope for UMFA was greater for FA dosages >0.8 mg (ß = 11.21, 95% CI: 8.97, 13.45) compared to FA dosages ≤0.8 mg (ß = 2.94, 95% CI: 2.59, 3.29). Furthermore, FA dosages higher than 0.8 mg did not confer additional benefits in terms of increasing 5-methyl tetrahydrofolic acid (5-MTHF, active form of folate) or reducing homocysteine (Hcy). Conclusion: In Chinese adults with H-type hypertension, this study showed a positive, non-linear, dosage-response relationship between FA supplementation ranging from 0 to 2.4 mg and circulating UMFA levels. It revealed that 0.8 mg FA is an optimal dosage in terms of balancing efficacy (increasing 5-MTHF and lowering Hcy) while minimizing undesirable elevation of UMFA. Clinical trial registration: https://clinicaltrials.gov/ct2/show/NCT03472508?term=NCT03472508&draw=2&rank=1, identifier NCT03472508.

Inverse Association Between Baseline Plasma Selenium Concentrations and Risks of Renal Function Decline in Hypertensive Adults.

BACKGROUND: The kidney has the highest level of selenium (Se) in the body, but the role of plasma Se in chronic kidney disease is uncertain. OBJECTIVE: We aimed to investigate the longitudinal association between baseline plasma Se and renal function decline in adults with hypertension and to explore possible effect modifiers. METHODS: This was a post hoc analysis of 935 men and women with hypertension aged 40 to 75 years from a folic-acid intervention trial (the China Stroke Primary Prevention Trial) in China. The baseline plasma Se was analyzed both as a continuous variable and as tertiles. The primary outcome was a rapid decline in renal function, defined as a mean decline in the estimated glomerular filtration rate of ≥ 5 mL/(min × 1.73 m2) per year. RESULTS: The median follow-up duration from baseline to outcome was 4.4 years. After multivariate adjustment, there was an inverse association between plasma Se and a rapid decline in renal function (per 10-unit increment; OR: 0.85; 95% CI: 0.73, 0.99). When the baseline plasma Se was assessed as tertiles, compared to the lowest tertile (<74.5 µg/L), a lower trend of the primary outcome was found in the second tertile (74.5 to < 89.4 µg/L; OR: 0.60; 95% CI: 0.34, 1.07) and the highest tertile (89.4 to <150 µg/L; OR: 0.42; 95% CI: 0.22, 0.80; Ptrend = 0.006). Furthermore, the Se-renal association was more pronounced among participants with folic acid treatment or with a higher baseline folate concentration (both Pinteraction values < 0.05). CONCLUSIONS: In this sample of Chinese adults with hypertension, baseline plasma Se concentrations were inversely associated with the risk of renal function decline. The China Stroke Primary Prevention Trial was registered at clinicaltrials.gov as NCT00794885.

Plasma selenium and the risk of first stroke in adults with hypertension: a secondary analysis of the China Stroke Primary Prevention Trial.

BACKGROUND: Previous studies have indicated that selenium (Se) may play an important role in cardio-cerebrovascular disease. However, the relation between circulating selenium and risk of first stroke remains inconclusive. OBJECTIVES: We conducted a secondary analysis of the China Stroke Primary Prevention Trial (CSPPT), using a nested case-control design, and aimed to investigate the correlation between Se concentration and first stroke risk in adults with hypertension and examine the potential effect modifiers. METHODS: In the CSPPT, a total of 20,702 adults with hypertension were randomly assigned to a double-blind daily treatment with either 10 mg enalapril and 0.8 mg folic acid or 10 mg enalapril alone. A total of 618 first stroke cases and 618 controls matched for age, sex, treatment group, and study site were included in this study. RESULTS: During a median follow-up duration of 4.5 y (IQR: 4.2-4.6 y), there was a significant inverse association between plasma Se and the risk of first stroke (per SD increment; adjusted OR: 0.81; 95% CI: 0.68, 0.96) and ischemic stroke (per SD increment; adjusted OR: 0.76; 95% CI: 0.62, 0.93). Furthermore, a stronger inverse association between plasma Se and first stroke was observed in participants with higher folate concentrations at baseline [≥7.7 ng/mL (median), adjusted OR: 0.67; 95% CI: 0.54, 0.85, compared with <7.7 ng/mL, adjusted OR: 0.98; 95% CI: 0.80, 1.21; P-interaction = 0.008] and those with higher time-averaged systolic blood pressure (SBP) over the treatment period (≥140 mm Hg, adjusted OR: 0.71; 95% CI: 0.58, 0.86, compared with <140 mm Hg, adjusted OR: 0.96; 95% CI: 0.77, 1.20; P-interaction = 0.023). CONCLUSIONS: There was a significant inverse association between plasma Se and risk of first stroke in Chinese adults with hypertension, especially among those with higher baseline folate concentrations and those with higher time-averaged SBP over the treatment period. This trial was registered at clinicaltrials.gov as NCT00794885.

Sex difference in the association between plasma selenium and first stroke: a community-based nested case-control study.

BACKGROUND: To date, there is no clearly defined association between plasma selenium levels and first stroke. We aimed to investigate the association between baseline plasma selenium and first stroke risk in a community-based Chinese population. METHODS: Using a nested case-control study design, a total of 1255 first stroke cases and 1255 matched controls were analyzed. Participant plasma selenium concentrations were measured by inductively coupled plasma mass spectrometry (ICP-MS), and the association of plasma selenium with first stroke risk was estimated by conditional logistic regression models. RESULTS: Overall, a non-linear negative association between plasma selenium and first total stroke and first ischemic stroke risks was found in males but not in females. Compared with participants with lower selenium levels (tertile 1-2, < 94.1 ng/mL), participants with higher selenium levels (tertile 3, ≥ 94.1 ng/mL) had significantly lower risks of first total stroke (OR 0.63; 95% CI 0.48, 0.83) and first ischemic stroke (OR 0.61; 95% CI 0.45, 0.83) in males but not in females with first total stroke (OR 0.92; 95% CI 0.69, 1.22) and first ischemic stroke (OR 0.89; 95% CI 0.65, 1.22). Furthermore, a stronger association between plasma selenium and first total stroke was found in males with higher vitamin E levels (≥ 13.5 µg/mL vs. < 13.5 µg/mL P-interaction = 0.007). No significant association was observed between plasma selenium and first hemorrhagic stroke risk in either males or females. CONCLUSION: Our study indicated a significant, non-linear, negative association between plasma selenium and first stroke in males but not in females. TRIAL REGISTRATION: ChiCTR1800017274 .

Plasma selenium levels and risk of new-onset diabetes in hypertensive adults.

OBJECTIVE: The association between plasma selenium and new-onset diabetes in hypertensive adults is still unclear. We aimed to evaluate the relationship of baseline plasma selenium with new-onset diabetes and examine possible effect modifiers in a post-hoc analysis of the China Stroke Primary Prevention Trial (CSPPT). METHODS: A total of 2367 hypertensive, non-diabetic patients with plasma selenium measurements at baseline were included. The primary outcome was new-onset diabetes, defined as physician-diagnosed diabetes or use of glucose-lowering drugs during the follow-up period, or fasting glucose (FG) ≥126.0 mg/dL at the exit visit. RESULTS: At baseline, higher FG levels were found among participants with plasma selenium in quartile 4 (≥94.8 µg/L) (ß, 1.64 mg/dL; 95%CI: 0.54, 2.73) compared to those in quartiles 1-3. During a median follow-up duration of 4.5 years, new-onset diabetes occurred in 270 (11.4%) participants. Graphic plot showed a positive association between baseline selenium levels and risk of new-onset diabetes. This was further confirmed by adjusted regression analyses; the odds ratios (OR) for new-onset diabetes comparing quartile 4 (≥94.8 µg/L) to quartiles 1-3 was 1.36 (95%CI: 1.01, 1.83). No clear trend was evident across quartiles 1-3. CONCLUSIONS: Our data suggest that high plasma selenium (≥94.8 µg/L) was associated with increased risk of new-onset diabetes in hypertensive patients.

Platelet Count Affects Efficacy of Folic Acid in Preventing First Stroke.

BACKGROUND: The role of platelets and important effect modifiers on the risk of first stroke is unknown. OBJECTIVES: This study examined whether low platelet count (PLT) and elevated total homocysteine (tHcy) levels jointly increase the risk of first stroke, and, if so, whether folic acid treatment is particularly effective in stroke prevention in such a setting. METHODS: A total of 10,789 Chinese hypertensive adults (mean age 59.5 years; 38% male, with no history of stroke and myocardial infarction) were analyzed from the China Stroke Primary Prevention Trial, where participants were randomly assigned to daily treatments of 10 mg enalapril and 0.8 mg folic acid (n = 5,408) or 10 mg enalapril alone (n = 5,381). The primary endpoint was first stroke. RESULTS: During 4.2 years of follow-up, a total of 371 first strokes occurred. In the enalapril-alone group, the lowest rate of first stroke (3.3%) was found in patients with high PLT (quartiles 2 to 4) and low tHcy (<15 µmol/l); and the highest rate (5.6%) was in patients with low PLT (quartile 1) and high tHcy (≥15 µmol/l) levels. Following folic acid treatment, the high-risk group had a 73% reduction in stroke (hazard ratio: 0.27; 95% confidence interval: 0.11 to 0.64; p = 0.003), whereas there was no significant effect among the low-risk group. CONCLUSIONS: Among Chinese hypertensive adults, the subgroup with low PLT and high tHcy had the highest risk of first stroke, and this risk was reduced by 73% with folic acid treatment. If confirmed, PLT and tHcy could serve as biomarkers to identify high-risk individuals who would particularly benefit from folic acid treatment. (China Stroke Primary Prevention Trial [CSPPT]; NCT00794885).